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Merge tag 'pci-v3.16-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci into next
Pull PCI changes from Bjorn Helgaas:
"Enumeration
- Notify driver before and after device reset (Keith Busch)
- Use reset notification in NVMe (Keith Busch)
NUMA
- Warn if we have to guess host bridge node information (Myron Stowe)
- Work around AMD Fam15h BIOSes that fail to provide _PXM (Suravee
Suthikulpanit)
- Clean up and mark early_root_info_init() as deprecated (Suravee
Suthikulpanit)
Driver binding
- Add "driver_override" for force specific binding (Alex Williamson)
- Fail "new_id" addition for devices we already know about (Bandan
Das)
Resource management
- Support BAR sizes up to 8GB (Nikhil Rao, Alan Cox)
- Don't move IORESOURCE_PCI_FIXED resources (Bjorn Helgaas)
- Mark SBx00 HPET BAR as IORESOURCE_PCI_FIXED (Bjorn Helgaas)
- Fail safely if we can't handle BARs larger than 4GB (Bjorn Helgaas)
- Reject BAR above 4GB if dma_addr_t is too small (Bjorn Helgaas)
- Don't convert BAR address to resource if dma_addr_t is too small
(Bjorn Helgaas)
- Don't set BAR to zero if dma_addr_t is too small (Bjorn Helgaas)
- Don't print anything while decoding is disabled (Bjorn Helgaas)
- Don't add disabled subtractive decode bus resources (Bjorn Helgaas)
- Add resource allocation comments (Bjorn Helgaas)
- Restrict 64-bit prefetchable bridge windows to 64-bit resources
(Yinghai Lu)
- Assign i82875p_edac PCI resources before adding device (Yinghai Lu)
PCI device hotplug
- Remove unnecessary "dev->bus" test (Bjorn Helgaas)
- Use PCI_EXP_SLTCAP_PSN define (Bjorn Helgaas)
- Fix rphahp endianess issues (Laurent Dufour)
- Acknowledge spurious "cmd completed" event (Rajat Jain)
- Allow hotplug service drivers to operate in polling mode (Rajat Jain)
- Fix cpqphp possible NULL dereference (Rickard Strandqvist)
MSI
- Replace pci_enable_msi_block() by pci_enable_msi_exact()
(Alexander Gordeev)
- Replace pci_enable_msix() by pci_enable_msix_exact() (Alexander Gordeev)
- Simplify populate_msi_sysfs() (Jan Beulich)
Virtualization
- Add Intel Patsburg (X79) root port ACS quirk (Alex Williamson)
- Mark RTL8110SC INTx masking as broken (Alex Williamson)
Generic host bridge driver
- Add generic PCI host controller driver (Will Deacon)
Freescale i.MX6
- Use new clock names (Lucas Stach)
- Drop old IRQ mapping (Lucas Stach)
- Remove optional (and unused) IRQs (Lucas Stach)
- Add support for MSI (Lucas Stach)
- Fix imx6_add_pcie_port() section mismatch warning (Sachin Kamat)
Renesas R-Car
- Add gen2 device tree support (Ben Dooks)
- Use new OF interrupt mapping when possible (Lucas Stach)
- Add PCIe driver (Phil Edworthy)
- Add PCIe MSI support (Phil Edworthy)
- Add PCIe device tree bindings (Phil Edworthy)
Samsung Exynos
- Remove unnecessary OOM messages (Jingoo Han)
- Fix add_pcie_port() section mismatch warning (Sachin Kamat)
Synopsys DesignWare
- Make MSI ISR shared IRQ aware (Lucas Stach)
Miscellaneous
- Check for broken config space aliasing (Alex Williamson)
- Update email address (Ben Hutchings)
- Fix Broadcom CNB20LE unintended sign extension (Bjorn Helgaas)
- Fix incorrect vgaarb conditional in WARN_ON() (Bjorn Helgaas)
- Remove unnecessary __ref annotations (Bjorn Helgaas)
- Add arch/x86/kernel/quirks.c to MAINTAINERS PCI file patterns
(Bjorn Helgaas)
- Fix use of uninitialized MPS value (Bjorn Helgaas)
- Tidy x86/gart messages (Bjorn Helgaas)
- Fix return value from pci_user_{read,write}_config_*() (Gavin Shan)
- Turn pcibios_penalize_isa_irq() into a weak function (Hanjun Guo)
- Remove unused serial device IDs (Jean Delvare)
- Use designated initialization in PCI_VDEVICE (Mark Rustad)
- Fix powerpc NULL dereference in pci_root_buses traversal (Mike Qiu)
- Configure MPS on ARM (Murali Karicheri)
- Remove unnecessary includes of <linux/init.h> (Paul Gortmaker)
- Move Open Firmware devspec attribute to PCI common code (Sebastian Ott)
- Use pdev->dev.groups for attribute creation on s390 (Sebastian Ott)
- Remove pcibios_add_platform_entries() (Sebastian Ott)
- Add new ID for Intel GPU "spurious interrupt" quirk (Thomas Jarosch)
- Rename pci_is_bridge() to pci_has_subordinate() (Yijing Wang)
- Add and use new pci_is_bridge() interface (Yijing Wang)
- Make pci_bus_add_device() void (Yijing Wang)
DMA API
- Clarify physical/bus address distinction in docs (Bjorn Helgaas)
- Fix typos in docs (Emilio López)
- Update dma_pool_create ()and dma_pool_alloc() descriptions (Gioh Kim)
- Change dma_declare_coherent_memory() CPU address to phys_addr_t
(Bjorn Helgaas)
- Pass GAPSPCI_DMA_BASE CPU & bus address to dma_declare_coherent_memory()
(Bjorn Helgaas)"
* tag 'pci-v3.16-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (92 commits)
MAINTAINERS: Add generic PCI host controller driver
PCI: generic: Add generic PCI host controller driver
PCI: imx6: Add support for MSI
PCI: designware: Make MSI ISR shared IRQ aware
PCI: imx6: Remove optional (and unused) IRQs
PCI: imx6: Drop old IRQ mapping
PCI: imx6: Use new clock names
i82875p_edac: Assign PCI resources before adding device
ARM/PCI: Call pcie_bus_configure_settings() to set MPS
PCI: imx6: Fix imx6_add_pcie_port() section mismatch warning
PCI: Make pci_bus_add_device() void
PCI: exynos: Fix add_pcie_port() section mismatch warning
PCI: Introduce new device binding path using pci_dev.driver_override
PCI: rcar: Add gen2 device tree support
PCI: cpqphp: Fix possible null pointer dereference
PCI: rcar: Add R-Car PCIe device tree bindings
PCI: rcar: Add MSI support for PCIe
PCI: rcar: Add Renesas R-Car PCIe driver
PCI: Fix return value from pci_user_{read,write}_config_*()
PCI: exynos: Remove unnecessary OOM messages
...
This commit is contained in:
@@ -250,3 +250,24 @@ Description:
|
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valid. For example, writing a 2 to this file when sriov_numvfs
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is not 0 and not 2 already will return an error. Writing a 10
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when the value of sriov_totalvfs is 8 will return an error.
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What: /sys/bus/pci/devices/.../driver_override
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Date: April 2014
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Contact: Alex Williamson <alex.williamson@redhat.com>
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Description:
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This file allows the driver for a device to be specified which
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will override standard static and dynamic ID matching. When
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specified, only a driver with a name matching the value written
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to driver_override will have an opportunity to bind to the
|
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device. The override is specified by writing a string to the
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driver_override file (echo pci-stub > driver_override) and
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may be cleared with an empty string (echo > driver_override).
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This returns the device to standard matching rules binding.
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Writing to driver_override does not automatically unbind the
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device from its current driver or make any attempt to
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automatically load the specified driver. If no driver with a
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matching name is currently loaded in the kernel, the device
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will not bind to any driver. This also allows devices to
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opt-out of driver binding using a driver_override name such as
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"none". Only a single driver may be specified in the override,
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there is no support for parsing delimiters.
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+132
-78
@@ -9,16 +9,76 @@ This is a guide to device driver writers on how to use the DMA API
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with example pseudo-code. For a concise description of the API, see
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DMA-API.txt.
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Most of the 64bit platforms have special hardware that translates bus
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addresses (DMA addresses) into physical addresses. This is similar to
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how page tables and/or a TLB translates virtual addresses to physical
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addresses on a CPU. This is needed so that e.g. PCI devices can
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access with a Single Address Cycle (32bit DMA address) any page in the
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64bit physical address space. Previously in Linux those 64bit
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platforms had to set artificial limits on the maximum RAM size in the
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system, so that the virt_to_bus() static scheme works (the DMA address
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translation tables were simply filled on bootup to map each bus
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address to the physical page __pa(bus_to_virt())).
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CPU and DMA addresses
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There are several kinds of addresses involved in the DMA API, and it's
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important to understand the differences.
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The kernel normally uses virtual addresses. Any address returned by
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kmalloc(), vmalloc(), and similar interfaces is a virtual address and can
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be stored in a "void *".
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The virtual memory system (TLB, page tables, etc.) translates virtual
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addresses to CPU physical addresses, which are stored as "phys_addr_t" or
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"resource_size_t". The kernel manages device resources like registers as
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physical addresses. These are the addresses in /proc/iomem. The physical
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address is not directly useful to a driver; it must use ioremap() to map
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the space and produce a virtual address.
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I/O devices use a third kind of address: a "bus address" or "DMA address".
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If a device has registers at an MMIO address, or if it performs DMA to read
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or write system memory, the addresses used by the device are bus addresses.
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In some systems, bus addresses are identical to CPU physical addresses, but
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in general they are not. IOMMUs and host bridges can produce arbitrary
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mappings between physical and bus addresses.
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Here's a picture and some examples:
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CPU CPU Bus
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Virtual Physical Address
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Address Address Space
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Space Space
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+-------+ +------+ +------+
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| | |MMIO | Offset | |
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| | Virtual |Space | applied | |
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C +-------+ --------> B +------+ ----------> +------+ A
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| | mapping | | by host | |
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+-----+ | | | | bridge | | +--------+
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| | | | +------+ | | | |
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| CPU | | | | RAM | | | | Device |
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| | | | | | | | | |
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+-----+ +-------+ +------+ +------+ +--------+
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| | Virtual |Buffer| Mapping | |
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X +-------+ --------> Y +------+ <---------- +------+ Z
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| | mapping | RAM | by IOMMU
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| | | |
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| | | |
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+-------+ +------+
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During the enumeration process, the kernel learns about I/O devices and
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their MMIO space and the host bridges that connect them to the system. For
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example, if a PCI device has a BAR, the kernel reads the bus address (A)
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from the BAR and converts it to a CPU physical address (B). The address B
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is stored in a struct resource and usually exposed via /proc/iomem. When a
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driver claims a device, it typically uses ioremap() to map physical address
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B at a virtual address (C). It can then use, e.g., ioread32(C), to access
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the device registers at bus address A.
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If the device supports DMA, the driver sets up a buffer using kmalloc() or
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a similar interface, which returns a virtual address (X). The virtual
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memory system maps X to a physical address (Y) in system RAM. The driver
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can use virtual address X to access the buffer, but the device itself
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cannot because DMA doesn't go through the CPU virtual memory system.
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In some simple systems, the device can do DMA directly to physical address
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Y. But in many others, there is IOMMU hardware that translates bus
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addresses to physical addresses, e.g., it translates Z to Y. This is part
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of the reason for the DMA API: the driver can give a virtual address X to
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an interface like dma_map_single(), which sets up any required IOMMU
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mapping and returns the bus address Z. The driver then tells the device to
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do DMA to Z, and the IOMMU maps it to the buffer at address Y in system
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RAM.
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So that Linux can use the dynamic DMA mapping, it needs some help from the
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drivers, namely it has to take into account that DMA addresses should be
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@@ -29,17 +89,17 @@ The following API will work of course even on platforms where no such
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hardware exists.
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Note that the DMA API works with any bus independent of the underlying
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microprocessor architecture. You should use the DMA API rather than
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the bus specific DMA API (e.g. pci_dma_*).
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microprocessor architecture. You should use the DMA API rather than the
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bus-specific DMA API, i.e., use the dma_map_*() interfaces rather than the
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pci_map_*() interfaces.
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First of all, you should make sure
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#include <linux/dma-mapping.h>
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is in your driver. This file will obtain for you the definition of the
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dma_addr_t (which can hold any valid DMA address for the platform)
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type which should be used everywhere you hold a DMA (bus) address
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returned from the DMA mapping functions.
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is in your driver, which provides the definition of dma_addr_t. This type
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can hold any valid DMA or bus address for the platform and should be used
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everywhere you hold a DMA address returned from the DMA mapping functions.
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What memory is DMA'able?
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@@ -123,9 +183,9 @@ Here, dev is a pointer to the device struct of your device, and mask
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is a bit mask describing which bits of an address your device
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supports. It returns zero if your card can perform DMA properly on
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the machine given the address mask you provided. In general, the
|
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device struct of your device is embedded in the bus specific device
|
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struct of your device. For example, a pointer to the device struct of
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your PCI device is pdev->dev (pdev is a pointer to the PCI device
|
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device struct of your device is embedded in the bus-specific device
|
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struct of your device. For example, &pdev->dev is a pointer to the
|
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device struct of a PCI device (pdev is a pointer to the PCI device
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struct of your device).
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If it returns non-zero, your device cannot perform DMA properly on
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@@ -147,8 +207,7 @@ exactly why.
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The standard 32-bit addressing device would do something like this:
|
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if (dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32))) {
|
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printk(KERN_WARNING
|
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"mydev: No suitable DMA available.\n");
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dev_warn(dev, "mydev: No suitable DMA available\n");
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goto ignore_this_device;
|
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}
|
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|
||||
@@ -170,8 +229,7 @@ all 64-bits when accessing streaming DMA:
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} else if (!dma_set_mask(dev, DMA_BIT_MASK(32))) {
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using_dac = 0;
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} else {
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printk(KERN_WARNING
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"mydev: No suitable DMA available.\n");
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dev_warn(dev, "mydev: No suitable DMA available\n");
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goto ignore_this_device;
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}
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@@ -187,22 +245,20 @@ the case would look like this:
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using_dac = 0;
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consistent_using_dac = 0;
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} else {
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printk(KERN_WARNING
|
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"mydev: No suitable DMA available.\n");
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dev_warn(dev, "mydev: No suitable DMA available\n");
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goto ignore_this_device;
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}
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|
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The coherent coherent mask will always be able to set the same or a
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smaller mask as the streaming mask. However for the rare case that a
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device driver only uses consistent allocations, one would have to
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check the return value from dma_set_coherent_mask().
|
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The coherent mask will always be able to set the same or a smaller mask as
|
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the streaming mask. However for the rare case that a device driver only
|
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uses consistent allocations, one would have to check the return value from
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dma_set_coherent_mask().
|
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|
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Finally, if your device can only drive the low 24-bits of
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address you might do something like:
|
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if (dma_set_mask(dev, DMA_BIT_MASK(24))) {
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printk(KERN_WARNING
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"mydev: 24-bit DMA addressing not available.\n");
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dev_warn(dev, "mydev: 24-bit DMA addressing not available\n");
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goto ignore_this_device;
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}
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@@ -232,14 +288,14 @@ Here is pseudo-code showing how this might be done:
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card->playback_enabled = 1;
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} else {
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card->playback_enabled = 0;
|
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printk(KERN_WARNING "%s: Playback disabled due to DMA limitations.\n",
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dev_warn(dev, "%s: Playback disabled due to DMA limitations\n",
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card->name);
|
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}
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if (!dma_set_mask(dev, RECORD_ADDRESS_BITS)) {
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card->record_enabled = 1;
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} else {
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card->record_enabled = 0;
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printk(KERN_WARNING "%s: Record disabled due to DMA limitations.\n",
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dev_warn(dev, "%s: Record disabled due to DMA limitations\n",
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card->name);
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}
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@@ -331,7 +387,7 @@ context with the GFP_ATOMIC flag.
|
||||
Size is the length of the region you want to allocate, in bytes.
|
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|
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This routine will allocate RAM for that region, so it acts similarly to
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||||
__get_free_pages (but takes size instead of a page order). If your
|
||||
__get_free_pages() (but takes size instead of a page order). If your
|
||||
driver needs regions sized smaller than a page, you may prefer using
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the dma_pool interface, described below.
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@@ -343,11 +399,11 @@ the consistent DMA mask has been explicitly changed via
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dma_set_coherent_mask(). This is true of the dma_pool interface as
|
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well.
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|
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dma_alloc_coherent returns two values: the virtual address which you
|
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dma_alloc_coherent() returns two values: the virtual address which you
|
||||
can use to access it from the CPU and dma_handle which you pass to the
|
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card.
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||||
|
||||
The cpu return address and the DMA bus master address are both
|
||||
The CPU virtual address and the DMA bus address are both
|
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guaranteed to be aligned to the smallest PAGE_SIZE order which
|
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is greater than or equal to the requested size. This invariant
|
||||
exists (for example) to guarantee that if you allocate a chunk
|
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@@ -359,13 +415,13 @@ To unmap and free such a DMA region, you call:
|
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dma_free_coherent(dev, size, cpu_addr, dma_handle);
|
||||
|
||||
where dev, size are the same as in the above call and cpu_addr and
|
||||
dma_handle are the values dma_alloc_coherent returned to you.
|
||||
dma_handle are the values dma_alloc_coherent() returned to you.
|
||||
This function may not be called in interrupt context.
|
||||
|
||||
If your driver needs lots of smaller memory regions, you can write
|
||||
custom code to subdivide pages returned by dma_alloc_coherent,
|
||||
custom code to subdivide pages returned by dma_alloc_coherent(),
|
||||
or you can use the dma_pool API to do that. A dma_pool is like
|
||||
a kmem_cache, but it uses dma_alloc_coherent not __get_free_pages.
|
||||
a kmem_cache, but it uses dma_alloc_coherent(), not __get_free_pages().
|
||||
Also, it understands common hardware constraints for alignment,
|
||||
like queue heads needing to be aligned on N byte boundaries.
|
||||
|
||||
@@ -373,37 +429,37 @@ Create a dma_pool like this:
|
||||
|
||||
struct dma_pool *pool;
|
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|
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pool = dma_pool_create(name, dev, size, align, alloc);
|
||||
pool = dma_pool_create(name, dev, size, align, boundary);
|
||||
|
||||
The "name" is for diagnostics (like a kmem_cache name); dev and size
|
||||
are as above. The device's hardware alignment requirement for this
|
||||
type of data is "align" (which is expressed in bytes, and must be a
|
||||
power of two). If your device has no boundary crossing restrictions,
|
||||
pass 0 for alloc; passing 4096 says memory allocated from this pool
|
||||
pass 0 for boundary; passing 4096 says memory allocated from this pool
|
||||
must not cross 4KByte boundaries (but at that time it may be better to
|
||||
go for dma_alloc_coherent directly instead).
|
||||
use dma_alloc_coherent() directly instead).
|
||||
|
||||
Allocate memory from a dma pool like this:
|
||||
Allocate memory from a DMA pool like this:
|
||||
|
||||
cpu_addr = dma_pool_alloc(pool, flags, &dma_handle);
|
||||
|
||||
flags are SLAB_KERNEL if blocking is permitted (not in_interrupt nor
|
||||
holding SMP locks), SLAB_ATOMIC otherwise. Like dma_alloc_coherent,
|
||||
flags are GFP_KERNEL if blocking is permitted (not in_interrupt nor
|
||||
holding SMP locks), GFP_ATOMIC otherwise. Like dma_alloc_coherent(),
|
||||
this returns two values, cpu_addr and dma_handle.
|
||||
|
||||
Free memory that was allocated from a dma_pool like this:
|
||||
|
||||
dma_pool_free(pool, cpu_addr, dma_handle);
|
||||
|
||||
where pool is what you passed to dma_pool_alloc, and cpu_addr and
|
||||
dma_handle are the values dma_pool_alloc returned. This function
|
||||
where pool is what you passed to dma_pool_alloc(), and cpu_addr and
|
||||
dma_handle are the values dma_pool_alloc() returned. This function
|
||||
may be called in interrupt context.
|
||||
|
||||
Destroy a dma_pool by calling:
|
||||
|
||||
dma_pool_destroy(pool);
|
||||
|
||||
Make sure you've called dma_pool_free for all memory allocated
|
||||
Make sure you've called dma_pool_free() for all memory allocated
|
||||
from a pool before you destroy the pool. This function may not
|
||||
be called in interrupt context.
|
||||
|
||||
@@ -418,7 +474,7 @@ one of the following values:
|
||||
DMA_FROM_DEVICE
|
||||
DMA_NONE
|
||||
|
||||
One should provide the exact DMA direction if you know it.
|
||||
You should provide the exact DMA direction if you know it.
|
||||
|
||||
DMA_TO_DEVICE means "from main memory to the device"
|
||||
DMA_FROM_DEVICE means "from the device to main memory"
|
||||
@@ -489,14 +545,14 @@ and to unmap it:
|
||||
dma_unmap_single(dev, dma_handle, size, direction);
|
||||
|
||||
You should call dma_mapping_error() as dma_map_single() could fail and return
|
||||
error. Not all dma implementations support dma_mapping_error() interface.
|
||||
error. Not all DMA implementations support the dma_mapping_error() interface.
|
||||
However, it is a good practice to call dma_mapping_error() interface, which
|
||||
will invoke the generic mapping error check interface. Doing so will ensure
|
||||
that the mapping code will work correctly on all dma implementations without
|
||||
that the mapping code will work correctly on all DMA implementations without
|
||||
any dependency on the specifics of the underlying implementation. Using the
|
||||
returned address without checking for errors could result in failures ranging
|
||||
from panics to silent data corruption. A couple of examples of incorrect ways
|
||||
to check for errors that make assumptions about the underlying dma
|
||||
to check for errors that make assumptions about the underlying DMA
|
||||
implementation are as follows and these are applicable to dma_map_page() as
|
||||
well.
|
||||
|
||||
@@ -516,13 +572,13 @@ Incorrect example 2:
|
||||
goto map_error;
|
||||
}
|
||||
|
||||
You should call dma_unmap_single when the DMA activity is finished, e.g.
|
||||
You should call dma_unmap_single() when the DMA activity is finished, e.g.,
|
||||
from the interrupt which told you that the DMA transfer is done.
|
||||
|
||||
Using cpu pointers like this for single mappings has a disadvantage,
|
||||
Using CPU pointers like this for single mappings has a disadvantage:
|
||||
you cannot reference HIGHMEM memory in this way. Thus, there is a
|
||||
map/unmap interface pair akin to dma_{map,unmap}_single. These
|
||||
interfaces deal with page/offset pairs instead of cpu pointers.
|
||||
map/unmap interface pair akin to dma_{map,unmap}_single(). These
|
||||
interfaces deal with page/offset pairs instead of CPU pointers.
|
||||
Specifically:
|
||||
|
||||
struct device *dev = &my_dev->dev;
|
||||
@@ -550,7 +606,7 @@ Here, "offset" means byte offset within the given page.
|
||||
You should call dma_mapping_error() as dma_map_page() could fail and return
|
||||
error as outlined under the dma_map_single() discussion.
|
||||
|
||||
You should call dma_unmap_page when the DMA activity is finished, e.g.
|
||||
You should call dma_unmap_page() when the DMA activity is finished, e.g.,
|
||||
from the interrupt which told you that the DMA transfer is done.
|
||||
|
||||
With scatterlists, you map a region gathered from several regions by:
|
||||
@@ -588,18 +644,16 @@ PLEASE NOTE: The 'nents' argument to the dma_unmap_sg call must be
|
||||
it should _NOT_ be the 'count' value _returned_ from the
|
||||
dma_map_sg call.
|
||||
|
||||
Every dma_map_{single,sg} call should have its dma_unmap_{single,sg}
|
||||
counterpart, because the bus address space is a shared resource (although
|
||||
in some ports the mapping is per each BUS so less devices contend for the
|
||||
same bus address space) and you could render the machine unusable by eating
|
||||
all bus addresses.
|
||||
Every dma_map_{single,sg}() call should have its dma_unmap_{single,sg}()
|
||||
counterpart, because the bus address space is a shared resource and
|
||||
you could render the machine unusable by consuming all bus addresses.
|
||||
|
||||
If you need to use the same streaming DMA region multiple times and touch
|
||||
the data in between the DMA transfers, the buffer needs to be synced
|
||||
properly in order for the cpu and device to see the most uptodate and
|
||||
properly in order for the CPU and device to see the most up-to-date and
|
||||
correct copy of the DMA buffer.
|
||||
|
||||
So, firstly, just map it with dma_map_{single,sg}, and after each DMA
|
||||
So, firstly, just map it with dma_map_{single,sg}(), and after each DMA
|
||||
transfer call either:
|
||||
|
||||
dma_sync_single_for_cpu(dev, dma_handle, size, direction);
|
||||
@@ -611,7 +665,7 @@ or:
|
||||
as appropriate.
|
||||
|
||||
Then, if you wish to let the device get at the DMA area again,
|
||||
finish accessing the data with the cpu, and then before actually
|
||||
finish accessing the data with the CPU, and then before actually
|
||||
giving the buffer to the hardware call either:
|
||||
|
||||
dma_sync_single_for_device(dev, dma_handle, size, direction);
|
||||
@@ -623,9 +677,9 @@ or:
|
||||
as appropriate.
|
||||
|
||||
After the last DMA transfer call one of the DMA unmap routines
|
||||
dma_unmap_{single,sg}. If you don't touch the data from the first dma_map_*
|
||||
call till dma_unmap_*, then you don't have to call the dma_sync_*
|
||||
routines at all.
|
||||
dma_unmap_{single,sg}(). If you don't touch the data from the first
|
||||
dma_map_*() call till dma_unmap_*(), then you don't have to call the
|
||||
dma_sync_*() routines at all.
|
||||
|
||||
Here is pseudo code which shows a situation in which you would need
|
||||
to use the dma_sync_*() interfaces.
|
||||
@@ -690,12 +744,12 @@ to use the dma_sync_*() interfaces.
|
||||
}
|
||||
}
|
||||
|
||||
Drivers converted fully to this interface should not use virt_to_bus any
|
||||
longer, nor should they use bus_to_virt. Some drivers have to be changed a
|
||||
little bit, because there is no longer an equivalent to bus_to_virt in the
|
||||
Drivers converted fully to this interface should not use virt_to_bus() any
|
||||
longer, nor should they use bus_to_virt(). Some drivers have to be changed a
|
||||
little bit, because there is no longer an equivalent to bus_to_virt() in the
|
||||
dynamic DMA mapping scheme - you have to always store the DMA addresses
|
||||
returned by the dma_alloc_coherent, dma_pool_alloc, and dma_map_single
|
||||
calls (dma_map_sg stores them in the scatterlist itself if the platform
|
||||
returned by the dma_alloc_coherent(), dma_pool_alloc(), and dma_map_single()
|
||||
calls (dma_map_sg() stores them in the scatterlist itself if the platform
|
||||
supports dynamic DMA mapping in hardware) in your driver structures and/or
|
||||
in the card registers.
|
||||
|
||||
@@ -709,9 +763,9 @@ as it is impossible to correctly support them.
|
||||
DMA address space is limited on some architectures and an allocation
|
||||
failure can be determined by:
|
||||
|
||||
- checking if dma_alloc_coherent returns NULL or dma_map_sg returns 0
|
||||
- checking if dma_alloc_coherent() returns NULL or dma_map_sg returns 0
|
||||
|
||||
- checking the returned dma_addr_t of dma_map_single and dma_map_page
|
||||
- checking the dma_addr_t returned from dma_map_single() and dma_map_page()
|
||||
by using dma_mapping_error():
|
||||
|
||||
dma_addr_t dma_handle;
|
||||
@@ -794,7 +848,7 @@ Example 2: (if buffers are allocated in a loop, unmap all mapped buffers when
|
||||
dma_unmap_single(array[i].dma_addr);
|
||||
}
|
||||
|
||||
Networking drivers must call dev_kfree_skb to free the socket buffer
|
||||
Networking drivers must call dev_kfree_skb() to free the socket buffer
|
||||
and return NETDEV_TX_OK if the DMA mapping fails on the transmit hook
|
||||
(ndo_start_xmit). This means that the socket buffer is just dropped in
|
||||
the failure case.
|
||||
@@ -831,7 +885,7 @@ transform some example code.
|
||||
DEFINE_DMA_UNMAP_LEN(len);
|
||||
};
|
||||
|
||||
2) Use dma_unmap_{addr,len}_set to set these values.
|
||||
2) Use dma_unmap_{addr,len}_set() to set these values.
|
||||
Example, before:
|
||||
|
||||
ringp->mapping = FOO;
|
||||
@@ -842,7 +896,7 @@ transform some example code.
|
||||
dma_unmap_addr_set(ringp, mapping, FOO);
|
||||
dma_unmap_len_set(ringp, len, BAR);
|
||||
|
||||
3) Use dma_unmap_{addr,len} to access these values.
|
||||
3) Use dma_unmap_{addr,len}() to access these values.
|
||||
Example, before:
|
||||
|
||||
dma_unmap_single(dev, ringp->mapping, ringp->len,
|
||||
|
||||
+76
-72
@@ -4,22 +4,26 @@
|
||||
James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
|
||||
|
||||
This document describes the DMA API. For a more gentle introduction
|
||||
of the API (and actual examples) see
|
||||
Documentation/DMA-API-HOWTO.txt.
|
||||
of the API (and actual examples), see Documentation/DMA-API-HOWTO.txt.
|
||||
|
||||
This API is split into two pieces. Part I describes the API. Part II
|
||||
describes the extensions to the API for supporting non-consistent
|
||||
memory machines. Unless you know that your driver absolutely has to
|
||||
support non-consistent platforms (this is usually only legacy
|
||||
platforms) you should only use the API described in part I.
|
||||
This API is split into two pieces. Part I describes the basic API.
|
||||
Part II describes extensions for supporting non-consistent memory
|
||||
machines. Unless you know that your driver absolutely has to support
|
||||
non-consistent platforms (this is usually only legacy platforms) you
|
||||
should only use the API described in part I.
|
||||
|
||||
Part I - dma_ API
|
||||
-------------------------------------
|
||||
|
||||
To get the dma_ API, you must #include <linux/dma-mapping.h>
|
||||
To get the dma_ API, you must #include <linux/dma-mapping.h>. This
|
||||
provides dma_addr_t and the interfaces described below.
|
||||
|
||||
A dma_addr_t can hold any valid DMA or bus address for the platform. It
|
||||
can be given to a device to use as a DMA source or target. A CPU cannot
|
||||
reference a dma_addr_t directly because there may be translation between
|
||||
its physical address space and the bus address space.
|
||||
|
||||
Part Ia - Using large dma-coherent buffers
|
||||
Part Ia - Using large DMA-coherent buffers
|
||||
------------------------------------------
|
||||
|
||||
void *
|
||||
@@ -33,20 +37,21 @@ to make sure to flush the processor's write buffers before telling
|
||||
devices to read that memory.)
|
||||
|
||||
This routine allocates a region of <size> bytes of consistent memory.
|
||||
It also returns a <dma_handle> which may be cast to an unsigned
|
||||
integer the same width as the bus and used as the physical address
|
||||
base of the region.
|
||||
|
||||
Returns: a pointer to the allocated region (in the processor's virtual
|
||||
It returns a pointer to the allocated region (in the processor's virtual
|
||||
address space) or NULL if the allocation failed.
|
||||
|
||||
It also returns a <dma_handle> which may be cast to an unsigned integer the
|
||||
same width as the bus and given to the device as the bus address base of
|
||||
the region.
|
||||
|
||||
Note: consistent memory can be expensive on some platforms, and the
|
||||
minimum allocation length may be as big as a page, so you should
|
||||
consolidate your requests for consistent memory as much as possible.
|
||||
The simplest way to do that is to use the dma_pool calls (see below).
|
||||
|
||||
The flag parameter (dma_alloc_coherent only) allows the caller to
|
||||
specify the GFP_ flags (see kmalloc) for the allocation (the
|
||||
The flag parameter (dma_alloc_coherent() only) allows the caller to
|
||||
specify the GFP_ flags (see kmalloc()) for the allocation (the
|
||||
implementation may choose to ignore flags that affect the location of
|
||||
the returned memory, like GFP_DMA).
|
||||
|
||||
@@ -61,24 +66,24 @@ void
|
||||
dma_free_coherent(struct device *dev, size_t size, void *cpu_addr,
|
||||
dma_addr_t dma_handle)
|
||||
|
||||
Free the region of consistent memory you previously allocated. dev,
|
||||
size and dma_handle must all be the same as those passed into the
|
||||
consistent allocate. cpu_addr must be the virtual address returned by
|
||||
the consistent allocate.
|
||||
Free a region of consistent memory you previously allocated. dev,
|
||||
size and dma_handle must all be the same as those passed into
|
||||
dma_alloc_coherent(). cpu_addr must be the virtual address returned by
|
||||
the dma_alloc_coherent().
|
||||
|
||||
Note that unlike their sibling allocation calls, these routines
|
||||
may only be called with IRQs enabled.
|
||||
|
||||
|
||||
Part Ib - Using small dma-coherent buffers
|
||||
Part Ib - Using small DMA-coherent buffers
|
||||
------------------------------------------
|
||||
|
||||
To get this part of the dma_ API, you must #include <linux/dmapool.h>
|
||||
|
||||
Many drivers need lots of small dma-coherent memory regions for DMA
|
||||
Many drivers need lots of small DMA-coherent memory regions for DMA
|
||||
descriptors or I/O buffers. Rather than allocating in units of a page
|
||||
or more using dma_alloc_coherent(), you can use DMA pools. These work
|
||||
much like a struct kmem_cache, except that they use the dma-coherent allocator,
|
||||
much like a struct kmem_cache, except that they use the DMA-coherent allocator,
|
||||
not __get_free_pages(). Also, they understand common hardware constraints
|
||||
for alignment, like queue heads needing to be aligned on N-byte boundaries.
|
||||
|
||||
@@ -87,7 +92,7 @@ for alignment, like queue heads needing to be aligned on N-byte boundaries.
|
||||
dma_pool_create(const char *name, struct device *dev,
|
||||
size_t size, size_t align, size_t alloc);
|
||||
|
||||
The pool create() routines initialize a pool of dma-coherent buffers
|
||||
dma_pool_create() initializes a pool of DMA-coherent buffers
|
||||
for use with a given device. It must be called in a context which
|
||||
can sleep.
|
||||
|
||||
@@ -102,25 +107,26 @@ from this pool must not cross 4KByte boundaries.
|
||||
void *dma_pool_alloc(struct dma_pool *pool, gfp_t gfp_flags,
|
||||
dma_addr_t *dma_handle);
|
||||
|
||||
This allocates memory from the pool; the returned memory will meet the size
|
||||
and alignment requirements specified at creation time. Pass GFP_ATOMIC to
|
||||
prevent blocking, or if it's permitted (not in_interrupt, not holding SMP locks),
|
||||
pass GFP_KERNEL to allow blocking. Like dma_alloc_coherent(), this returns
|
||||
two values: an address usable by the cpu, and the dma address usable by the
|
||||
pool's device.
|
||||
This allocates memory from the pool; the returned memory will meet the
|
||||
size and alignment requirements specified at creation time. Pass
|
||||
GFP_ATOMIC to prevent blocking, or if it's permitted (not
|
||||
in_interrupt, not holding SMP locks), pass GFP_KERNEL to allow
|
||||
blocking. Like dma_alloc_coherent(), this returns two values: an
|
||||
address usable by the CPU, and the DMA address usable by the pool's
|
||||
device.
|
||||
|
||||
|
||||
void dma_pool_free(struct dma_pool *pool, void *vaddr,
|
||||
dma_addr_t addr);
|
||||
|
||||
This puts memory back into the pool. The pool is what was passed to
|
||||
the pool allocation routine; the cpu (vaddr) and dma addresses are what
|
||||
dma_pool_alloc(); the CPU (vaddr) and DMA addresses are what
|
||||
were returned when that routine allocated the memory being freed.
|
||||
|
||||
|
||||
void dma_pool_destroy(struct dma_pool *pool);
|
||||
|
||||
The pool destroy() routines free the resources of the pool. They must be
|
||||
dma_pool_destroy() frees the resources of the pool. It must be
|
||||
called in a context which can sleep. Make sure you've freed all allocated
|
||||
memory back to the pool before you destroy it.
|
||||
|
||||
@@ -187,9 +193,9 @@ dma_map_single(struct device *dev, void *cpu_addr, size_t size,
|
||||
enum dma_data_direction direction)
|
||||
|
||||
Maps a piece of processor virtual memory so it can be accessed by the
|
||||
device and returns the physical handle of the memory.
|
||||
device and returns the bus address of the memory.
|
||||
|
||||
The direction for both api's may be converted freely by casting.
|
||||
The direction for both APIs may be converted freely by casting.
|
||||
However the dma_ API uses a strongly typed enumerator for its
|
||||
direction:
|
||||
|
||||
@@ -198,31 +204,30 @@ DMA_TO_DEVICE data is going from the memory to the device
|
||||
DMA_FROM_DEVICE data is coming from the device to the memory
|
||||
DMA_BIDIRECTIONAL direction isn't known
|
||||
|
||||
Notes: Not all memory regions in a machine can be mapped by this
|
||||
API. Further, regions that appear to be physically contiguous in
|
||||
kernel virtual space may not be contiguous as physical memory. Since
|
||||
this API does not provide any scatter/gather capability, it will fail
|
||||
if the user tries to map a non-physically contiguous piece of memory.
|
||||
For this reason, it is recommended that memory mapped by this API be
|
||||
obtained only from sources which guarantee it to be physically contiguous
|
||||
(like kmalloc).
|
||||
Notes: Not all memory regions in a machine can be mapped by this API.
|
||||
Further, contiguous kernel virtual space may not be contiguous as
|
||||
physical memory. Since this API does not provide any scatter/gather
|
||||
capability, it will fail if the user tries to map a non-physically
|
||||
contiguous piece of memory. For this reason, memory to be mapped by
|
||||
this API should be obtained from sources which guarantee it to be
|
||||
physically contiguous (like kmalloc).
|
||||
|
||||
Further, the physical address of the memory must be within the
|
||||
dma_mask of the device (the dma_mask represents a bit mask of the
|
||||
addressable region for the device. I.e., if the physical address of
|
||||
the memory anded with the dma_mask is still equal to the physical
|
||||
address, then the device can perform DMA to the memory). In order to
|
||||
Further, the bus address of the memory must be within the
|
||||
dma_mask of the device (the dma_mask is a bit mask of the
|
||||
addressable region for the device, i.e., if the bus address of
|
||||
the memory ANDed with the dma_mask is still equal to the bus
|
||||
address, then the device can perform DMA to the memory). To
|
||||
ensure that the memory allocated by kmalloc is within the dma_mask,
|
||||
the driver may specify various platform-dependent flags to restrict
|
||||
the physical memory range of the allocation (e.g. on x86, GFP_DMA
|
||||
guarantees to be within the first 16Mb of available physical memory,
|
||||
the bus address range of the allocation (e.g., on x86, GFP_DMA
|
||||
guarantees to be within the first 16MB of available bus addresses,
|
||||
as required by ISA devices).
|
||||
|
||||
Note also that the above constraints on physical contiguity and
|
||||
dma_mask may not apply if the platform has an IOMMU (a device which
|
||||
supplies a physical to virtual mapping between the I/O memory bus and
|
||||
the device). However, to be portable, device driver writers may *not*
|
||||
assume that such an IOMMU exists.
|
||||
maps an I/O bus address to a physical memory address). However, to be
|
||||
portable, device driver writers may *not* assume that such an IOMMU
|
||||
exists.
|
||||
|
||||
Warnings: Memory coherency operates at a granularity called the cache
|
||||
line width. In order for memory mapped by this API to operate
|
||||
@@ -281,9 +286,9 @@ cache width is.
|
||||
int
|
||||
dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
|
||||
|
||||
In some circumstances dma_map_single and dma_map_page will fail to create
|
||||
In some circumstances dma_map_single() and dma_map_page() will fail to create
|
||||
a mapping. A driver can check for these errors by testing the returned
|
||||
dma address with dma_mapping_error(). A non-zero return value means the mapping
|
||||
DMA address with dma_mapping_error(). A non-zero return value means the mapping
|
||||
could not be created and the driver should take appropriate action (e.g.
|
||||
reduce current DMA mapping usage or delay and try again later).
|
||||
|
||||
@@ -291,7 +296,7 @@ reduce current DMA mapping usage or delay and try again later).
|
||||
dma_map_sg(struct device *dev, struct scatterlist *sg,
|
||||
int nents, enum dma_data_direction direction)
|
||||
|
||||
Returns: the number of physical segments mapped (this may be shorter
|
||||
Returns: the number of bus address segments mapped (this may be shorter
|
||||
than <nents> passed in if some elements of the scatter/gather list are
|
||||
physically or virtually adjacent and an IOMMU maps them with a single
|
||||
entry).
|
||||
@@ -299,7 +304,7 @@ entry).
|
||||
Please note that the sg cannot be mapped again if it has been mapped once.
|
||||
The mapping process is allowed to destroy information in the sg.
|
||||
|
||||
As with the other mapping interfaces, dma_map_sg can fail. When it
|
||||
As with the other mapping interfaces, dma_map_sg() can fail. When it
|
||||
does, 0 is returned and a driver must take appropriate action. It is
|
||||
critical that the driver do something, in the case of a block driver
|
||||
aborting the request or even oopsing is better than doing nothing and
|
||||
@@ -335,7 +340,7 @@ must be the same as those and passed in to the scatter/gather mapping
|
||||
API.
|
||||
|
||||
Note: <nents> must be the number you passed in, *not* the number of
|
||||
physical entries returned.
|
||||
bus address entries returned.
|
||||
|
||||
void
|
||||
dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle, size_t size,
|
||||
@@ -350,7 +355,7 @@ void
|
||||
dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nelems,
|
||||
enum dma_data_direction direction)
|
||||
|
||||
Synchronise a single contiguous or scatter/gather mapping for the cpu
|
||||
Synchronise a single contiguous or scatter/gather mapping for the CPU
|
||||
and device. With the sync_sg API, all the parameters must be the same
|
||||
as those passed into the single mapping API. With the sync_single API,
|
||||
you can use dma_handle and size parameters that aren't identical to
|
||||
@@ -391,10 +396,10 @@ The four functions above are just like the counterpart functions
|
||||
without the _attrs suffixes, except that they pass an optional
|
||||
struct dma_attrs*.
|
||||
|
||||
struct dma_attrs encapsulates a set of "dma attributes". For the
|
||||
struct dma_attrs encapsulates a set of "DMA attributes". For the
|
||||
definition of struct dma_attrs see linux/dma-attrs.h.
|
||||
|
||||
The interpretation of dma attributes is architecture-specific, and
|
||||
The interpretation of DMA attributes is architecture-specific, and
|
||||
each attribute should be documented in Documentation/DMA-attributes.txt.
|
||||
|
||||
If struct dma_attrs* is NULL, the semantics of each of these
|
||||
@@ -458,7 +463,7 @@ Note: where the platform can return consistent memory, it will
|
||||
guarantee that the sync points become nops.
|
||||
|
||||
Warning: Handling non-consistent memory is a real pain. You should
|
||||
only ever use this API if you positively know your driver will be
|
||||
only use this API if you positively know your driver will be
|
||||
required to work on one of the rare (usually non-PCI) architectures
|
||||
that simply cannot make consistent memory.
|
||||
|
||||
@@ -492,30 +497,29 @@ continuing on for size. Again, you *must* observe the cache line
|
||||
boundaries when doing this.
|
||||
|
||||
int
|
||||
dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
|
||||
dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
|
||||
dma_addr_t device_addr, size_t size, int
|
||||
flags)
|
||||
|
||||
Declare region of memory to be handed out by dma_alloc_coherent when
|
||||
Declare region of memory to be handed out by dma_alloc_coherent() when
|
||||
it's asked for coherent memory for this device.
|
||||
|
||||
bus_addr is the physical address to which the memory is currently
|
||||
assigned in the bus responding region (this will be used by the
|
||||
platform to perform the mapping).
|
||||
phys_addr is the CPU physical address to which the memory is currently
|
||||
assigned (this will be ioremapped so the CPU can access the region).
|
||||
|
||||
device_addr is the physical address the device needs to be programmed
|
||||
with actually to address this memory (this will be handed out as the
|
||||
device_addr is the bus address the device needs to be programmed
|
||||
with to actually address this memory (this will be handed out as the
|
||||
dma_addr_t in dma_alloc_coherent()).
|
||||
|
||||
size is the size of the area (must be multiples of PAGE_SIZE).
|
||||
|
||||
flags can be or'd together and are:
|
||||
flags can be ORed together and are:
|
||||
|
||||
DMA_MEMORY_MAP - request that the memory returned from
|
||||
dma_alloc_coherent() be directly writable.
|
||||
|
||||
DMA_MEMORY_IO - request that the memory returned from
|
||||
dma_alloc_coherent() be addressable using read/write/memcpy_toio etc.
|
||||
dma_alloc_coherent() be addressable using read()/write()/memcpy_toio() etc.
|
||||
|
||||
One or both of these flags must be present.
|
||||
|
||||
@@ -572,7 +576,7 @@ region is occupied.
|
||||
Part III - Debug drivers use of the DMA-API
|
||||
-------------------------------------------
|
||||
|
||||
The DMA-API as described above as some constraints. DMA addresses must be
|
||||
The DMA-API as described above has some constraints. DMA addresses must be
|
||||
released with the corresponding function with the same size for example. With
|
||||
the advent of hardware IOMMUs it becomes more and more important that drivers
|
||||
do not violate those constraints. In the worst case such a violation can
|
||||
@@ -690,11 +694,11 @@ architectural default.
|
||||
void debug_dmap_mapping_error(struct device *dev, dma_addr_t dma_addr);
|
||||
|
||||
dma-debug interface debug_dma_mapping_error() to debug drivers that fail
|
||||
to check dma mapping errors on addresses returned by dma_map_single() and
|
||||
to check DMA mapping errors on addresses returned by dma_map_single() and
|
||||
dma_map_page() interfaces. This interface clears a flag set by
|
||||
debug_dma_map_page() to indicate that dma_mapping_error() has been called by
|
||||
the driver. When driver does unmap, debug_dma_unmap() checks the flag and if
|
||||
this flag is still set, prints warning message that includes call trace that
|
||||
leads up to the unmap. This interface can be called from dma_mapping_error()
|
||||
routines to enable dma mapping error check debugging.
|
||||
routines to enable DMA mapping error check debugging.
|
||||
|
||||
|
||||
@@ -16,7 +16,7 @@ To do ISA style DMA you need to include two headers:
|
||||
#include <asm/dma.h>
|
||||
|
||||
The first is the generic DMA API used to convert virtual addresses to
|
||||
physical addresses (see Documentation/DMA-API.txt for details).
|
||||
bus addresses (see Documentation/DMA-API.txt for details).
|
||||
|
||||
The second contains the routines specific to ISA DMA transfers. Since
|
||||
this is not present on all platforms make sure you construct your
|
||||
@@ -50,7 +50,7 @@ early as possible and not release it until the driver is unloaded.)
|
||||
Part III - Address translation
|
||||
------------------------------
|
||||
|
||||
To translate the virtual address to a physical use the normal DMA
|
||||
To translate the virtual address to a bus address, use the normal DMA
|
||||
API. Do _not_ use isa_virt_to_phys() even though it does the same
|
||||
thing. The reason for this is that the function isa_virt_to_phys()
|
||||
will require a Kconfig dependency to ISA, not just ISA_DMA_API which
|
||||
|
||||
@@ -0,0 +1,100 @@
|
||||
* Generic PCI host controller
|
||||
|
||||
Firmware-initialised PCI host controllers and PCI emulations, such as the
|
||||
virtio-pci implementations found in kvmtool and other para-virtualised
|
||||
systems, do not require driver support for complexities such as regulator
|
||||
and clock management. In fact, the controller may not even require the
|
||||
configuration of a control interface by the operating system, instead
|
||||
presenting a set of fixed windows describing a subset of IO, Memory and
|
||||
Configuration Spaces.
|
||||
|
||||
Such a controller can be described purely in terms of the standardized device
|
||||
tree bindings communicated in pci.txt:
|
||||
|
||||
|
||||
Properties of the host controller node:
|
||||
|
||||
- compatible : Must be "pci-host-cam-generic" or "pci-host-ecam-generic"
|
||||
depending on the layout of configuration space (CAM vs
|
||||
ECAM respectively).
|
||||
|
||||
- device_type : Must be "pci".
|
||||
|
||||
- ranges : As described in IEEE Std 1275-1994, but must provide
|
||||
at least a definition of non-prefetchable memory. One
|
||||
or both of prefetchable Memory and IO Space may also
|
||||
be provided.
|
||||
|
||||
- bus-range : Optional property (also described in IEEE Std 1275-1994)
|
||||
to indicate the range of bus numbers for this controller.
|
||||
If absent, defaults to <0 255> (i.e. all buses).
|
||||
|
||||
- #address-cells : Must be 3.
|
||||
|
||||
- #size-cells : Must be 2.
|
||||
|
||||
- reg : The Configuration Space base address and size, as accessed
|
||||
from the parent bus.
|
||||
|
||||
|
||||
Properties of the /chosen node:
|
||||
|
||||
- linux,pci-probe-only
|
||||
: Optional property which takes a single-cell argument.
|
||||
If '0', then Linux will assign devices in its usual manner,
|
||||
otherwise it will not try to assign devices and instead use
|
||||
them as they are configured already.
|
||||
|
||||
Configuration Space is assumed to be memory-mapped (as opposed to being
|
||||
accessed via an ioport) and laid out with a direct correspondence to the
|
||||
geography of a PCI bus address by concatenating the various components to
|
||||
form an offset.
|
||||
|
||||
For CAM, this 24-bit offset is:
|
||||
|
||||
cfg_offset(bus, device, function, register) =
|
||||
bus << 16 | device << 11 | function << 8 | register
|
||||
|
||||
Whilst ECAM extends this by 4 bits to accomodate 4k of function space:
|
||||
|
||||
cfg_offset(bus, device, function, register) =
|
||||
bus << 20 | device << 15 | function << 12 | register
|
||||
|
||||
Interrupt mapping is exactly as described in `Open Firmware Recommended
|
||||
Practice: Interrupt Mapping' and requires the following properties:
|
||||
|
||||
- #interrupt-cells : Must be 1
|
||||
|
||||
- interrupt-map : <see aforementioned specification>
|
||||
|
||||
- interrupt-map-mask : <see aforementioned specification>
|
||||
|
||||
|
||||
Example:
|
||||
|
||||
pci {
|
||||
compatible = "pci-host-cam-generic"
|
||||
device_type = "pci";
|
||||
#address-cells = <3>;
|
||||
#size-cells = <2>;
|
||||
bus-range = <0x0 0x1>;
|
||||
|
||||
// CPU_PHYSICAL(2) SIZE(2)
|
||||
reg = <0x0 0x40000000 0x0 0x1000000>;
|
||||
|
||||
// BUS_ADDRESS(3) CPU_PHYSICAL(2) SIZE(2)
|
||||
ranges = <0x01000000 0x0 0x01000000 0x0 0x01000000 0x0 0x00010000>,
|
||||
<0x02000000 0x0 0x41000000 0x0 0x41000000 0x0 0x3f000000>;
|
||||
|
||||
|
||||
#interrupt-cells = <0x1>;
|
||||
|
||||
// PCI_DEVICE(3) INT#(1) CONTROLLER(PHANDLE) CONTROLLER_DATA(3)
|
||||
interrupt-map = < 0x0 0x0 0x0 0x1 &gic 0x0 0x4 0x1
|
||||
0x800 0x0 0x0 0x1 &gic 0x0 0x5 0x1
|
||||
0x1000 0x0 0x0 0x1 &gic 0x0 0x6 0x1
|
||||
0x1800 0x0 0x0 0x1 &gic 0x0 0x7 0x1>;
|
||||
|
||||
// PCI_DEVICE(3) INT#(1)
|
||||
interrupt-map-mask = <0xf800 0x0 0x0 0x7>;
|
||||
}
|
||||
@@ -0,0 +1,66 @@
|
||||
Renesas AHB to PCI bridge
|
||||
-------------------------
|
||||
|
||||
This is the bridge used internally to connect the USB controllers to the
|
||||
AHB. There is one bridge instance per USB port connected to the internal
|
||||
OHCI and EHCI controllers.
|
||||
|
||||
Required properties:
|
||||
- compatible: "renesas,pci-r8a7790" for the R8A7790 SoC;
|
||||
"renesas,pci-r8a7791" for the R8A7791 SoC.
|
||||
- reg: A list of physical regions to access the device: the first is
|
||||
the operational registers for the OHCI/EHCI controllers and the
|
||||
second is for the bridge configuration and control registers.
|
||||
- interrupts: interrupt for the device.
|
||||
- clocks: The reference to the device clock.
|
||||
- bus-range: The PCI bus number range; as this is a single bus, the range
|
||||
should be specified as the same value twice.
|
||||
- #address-cells: must be 3.
|
||||
- #size-cells: must be 2.
|
||||
- #interrupt-cells: must be 1.
|
||||
- interrupt-map: standard property used to define the mapping of the PCI
|
||||
interrupts to the GIC interrupts.
|
||||
- interrupt-map-mask: standard property that helps to define the interrupt
|
||||
mapping.
|
||||
|
||||
Example SoC configuration:
|
||||
|
||||
pci0: pci@ee090000 {
|
||||
compatible = "renesas,pci-r8a7790";
|
||||
clocks = <&mstp7_clks R8A7790_CLK_EHCI>;
|
||||
reg = <0x0 0xee090000 0x0 0xc00>,
|
||||
<0x0 0xee080000 0x0 0x1100>;
|
||||
interrupts = <0 108 IRQ_TYPE_LEVEL_HIGH>;
|
||||
status = "disabled";
|
||||
|
||||
bus-range = <0 0>;
|
||||
#address-cells = <3>;
|
||||
#size-cells = <2>;
|
||||
#interrupt-cells = <1>;
|
||||
interrupt-map-mask = <0xff00 0 0 0x7>;
|
||||
interrupt-map = <0x0000 0 0 1 &gic 0 108 IRQ_TYPE_LEVEL_HIGH
|
||||
0x0800 0 0 1 &gic 0 108 IRQ_TYPE_LEVEL_HIGH
|
||||
0x1000 0 0 2 &gic 0 108 IRQ_TYPE_LEVEL_HIGH>;
|
||||
|
||||
pci@0,1 {
|
||||
reg = <0x800 0 0 0 0>;
|
||||
device_type = "pci";
|
||||
phys = <&usbphy 0 0>;
|
||||
phy-names = "usb";
|
||||
};
|
||||
|
||||
pci@0,2 {
|
||||
reg = <0x1000 0 0 0 0>;
|
||||
device_type = "pci";
|
||||
phys = <&usbphy 0 0>;
|
||||
phy-names = "usb";
|
||||
};
|
||||
};
|
||||
|
||||
Example board setup:
|
||||
|
||||
&pci0 {
|
||||
status = "okay";
|
||||
pinctrl-0 = <&usb0_pins>;
|
||||
pinctrl-names = "default";
|
||||
};
|
||||
@@ -0,0 +1,47 @@
|
||||
* Renesas RCar PCIe interface
|
||||
|
||||
Required properties:
|
||||
- compatible: should contain one of the following
|
||||
"renesas,pcie-r8a7779", "renesas,pcie-r8a7790", "renesas,pcie-r8a7791"
|
||||
- reg: base address and length of the pcie controller registers.
|
||||
- #address-cells: set to <3>
|
||||
- #size-cells: set to <2>
|
||||
- bus-range: PCI bus numbers covered
|
||||
- device_type: set to "pci"
|
||||
- ranges: ranges for the PCI memory and I/O regions.
|
||||
- dma-ranges: ranges for the inbound memory regions.
|
||||
- interrupts: two interrupt sources for MSI interrupts, followed by interrupt
|
||||
source for hardware related interrupts (e.g. link speed change).
|
||||
- #interrupt-cells: set to <1>
|
||||
- interrupt-map-mask and interrupt-map: standard PCI properties
|
||||
to define the mapping of the PCIe interface to interrupt
|
||||
numbers.
|
||||
- clocks: from common clock binding: clock specifiers for the PCIe controller
|
||||
and PCIe bus clocks.
|
||||
- clock-names: from common clock binding: should be "pcie" and "pcie_bus".
|
||||
|
||||
Example:
|
||||
|
||||
SoC specific DT Entry:
|
||||
|
||||
pcie: pcie@fe000000 {
|
||||
compatible = "renesas,pcie-r8a7791";
|
||||
reg = <0 0xfe000000 0 0x80000>;
|
||||
#address-cells = <3>;
|
||||
#size-cells = <2>;
|
||||
bus-range = <0x00 0xff>;
|
||||
device_type = "pci";
|
||||
ranges = <0x01000000 0 0x00000000 0 0xfe100000 0 0x00100000
|
||||
0x02000000 0 0xfe200000 0 0xfe200000 0 0x00200000
|
||||
0x02000000 0 0x30000000 0 0x30000000 0 0x08000000
|
||||
0x42000000 0 0x38000000 0 0x38000000 0 0x08000000>;
|
||||
dma-ranges = <0x42000000 0 0x40000000 0 0x40000000 0 0x40000000
|
||||
0x42000000 2 0x00000000 2 0x00000000 0 0x40000000>;
|
||||
interrupts = <0 116 4>, <0 117 4>, <0 118 4>;
|
||||
#interrupt-cells = <1>;
|
||||
interrupt-map-mask = <0 0 0 0>;
|
||||
interrupt-map = <0 0 0 0 &gic 0 116 4>;
|
||||
clocks = <&mstp3_clks R8A7791_CLK_PCIE>, <&pcie_bus_clk>;
|
||||
clock-names = "pcie", "pcie_bus";
|
||||
status = "disabled";
|
||||
};
|
||||
@@ -6710,6 +6710,7 @@ F: Documentation/PCI/
|
||||
F: drivers/pci/
|
||||
F: include/linux/pci*
|
||||
F: arch/x86/pci/
|
||||
F: arch/x86/kernel/quirks.c
|
||||
|
||||
PCI DRIVER FOR IMX6
|
||||
M: Richard Zhu <r65037@freescale.com>
|
||||
@@ -6757,6 +6758,14 @@ L: linux-pci@vger.kernel.org
|
||||
S: Maintained
|
||||
F: drivers/pci/host/*designware*
|
||||
|
||||
PCI DRIVER FOR GENERIC OF HOSTS
|
||||
M: Will Deacon <will.deacon@arm.com>
|
||||
L: linux-pci@vger.kernel.org
|
||||
L: linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
|
||||
S: Maintained
|
||||
F: Documentation/devicetree/bindings/pci/host-generic-pci.txt
|
||||
F: drivers/pci/host/pci-host-generic.c
|
||||
|
||||
PCMCIA SUBSYSTEM
|
||||
P: Linux PCMCIA Team
|
||||
L: linux-pcmcia@lists.infradead.org
|
||||
|
||||
@@ -59,11 +59,6 @@ struct pci_controller {
|
||||
|
||||
extern void pcibios_set_master(struct pci_dev *dev);
|
||||
|
||||
extern inline void pcibios_penalize_isa_irq(int irq, int active)
|
||||
{
|
||||
/* We don't do dynamic PCI IRQ allocation */
|
||||
}
|
||||
|
||||
/* IOMMU controls. */
|
||||
|
||||
/* The PCI address space does not equal the physical memory address space.
|
||||
|
||||
@@ -31,11 +31,6 @@ static inline int pci_proc_domain(struct pci_bus *bus)
|
||||
}
|
||||
#endif /* CONFIG_PCI_DOMAINS */
|
||||
|
||||
static inline void pcibios_penalize_isa_irq(int irq, int active)
|
||||
{
|
||||
/* We don't do dynamic PCI IRQ allocation */
|
||||
}
|
||||
|
||||
/*
|
||||
* The PCI address space does equal the physical memory address space.
|
||||
* The networking and block device layers use this boolean for bounce
|
||||
|
||||
@@ -545,6 +545,18 @@ void pci_common_init_dev(struct device *parent, struct hw_pci *hw)
|
||||
*/
|
||||
pci_bus_add_devices(bus);
|
||||
}
|
||||
|
||||
list_for_each_entry(sys, &head, node) {
|
||||
struct pci_bus *bus = sys->bus;
|
||||
|
||||
/* Configure PCI Express settings */
|
||||
if (bus && !pci_has_flag(PCI_PROBE_ONLY)) {
|
||||
struct pci_bus *child;
|
||||
|
||||
list_for_each_entry(child, &bus->children, node)
|
||||
pcie_bus_configure_settings(child);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
#ifndef CONFIG_PCI_HOST_ITE8152
|
||||
|
||||
@@ -10,9 +10,4 @@
|
||||
#define PCIBIOS_MIN_IO 0x00001000
|
||||
#define PCIBIOS_MIN_MEM 0x10000000
|
||||
|
||||
static inline void pcibios_penalize_isa_irq(int irq)
|
||||
{
|
||||
/* We don't do dynamic PCI IRQ allocation */
|
||||
}
|
||||
|
||||
#endif /* _ASM_BFIN_PCI_H */
|
||||
|
||||
@@ -20,7 +20,6 @@ void pcibios_config_init(void);
|
||||
struct pci_bus * pcibios_scan_root(int bus);
|
||||
|
||||
void pcibios_set_master(struct pci_dev *dev);
|
||||
void pcibios_penalize_isa_irq(int irq);
|
||||
struct irq_routing_table *pcibios_get_irq_routing_table(void);
|
||||
int pcibios_set_irq_routing(struct pci_dev *dev, int pin, int irq);
|
||||
|
||||
|
||||
@@ -24,8 +24,6 @@ struct pci_dev;
|
||||
|
||||
extern void pcibios_set_master(struct pci_dev *dev);
|
||||
|
||||
extern void pcibios_penalize_isa_irq(int irq);
|
||||
|
||||
#ifdef CONFIG_MMU
|
||||
extern void *consistent_alloc(gfp_t gfp, size_t size, dma_addr_t *dma_handle);
|
||||
extern void consistent_free(void *vaddr);
|
||||
|
||||
@@ -55,10 +55,6 @@ void __init pcibios_fixup_irqs(void)
|
||||
}
|
||||
}
|
||||
|
||||
void __init pcibios_penalize_isa_irq(int irq)
|
||||
{
|
||||
}
|
||||
|
||||
void pcibios_enable_irq(struct pci_dev *dev)
|
||||
{
|
||||
pci_write_config_byte(dev, PCI_INTERRUPT_LINE, dev->irq);
|
||||
|
||||
@@ -50,12 +50,6 @@ struct pci_dev;
|
||||
extern unsigned long ia64_max_iommu_merge_mask;
|
||||
#define PCI_DMA_BUS_IS_PHYS (ia64_max_iommu_merge_mask == ~0UL)
|
||||
|
||||
static inline void
|
||||
pcibios_penalize_isa_irq (int irq, int active)
|
||||
{
|
||||
/* We don't do dynamic PCI IRQ allocation */
|
||||
}
|
||||
|
||||
#include <asm-generic/pci-dma-compat.h>
|
||||
|
||||
#ifdef CONFIG_PCI
|
||||
|
||||
@@ -49,9 +49,7 @@ static void pci_fixup_video(struct pci_dev *pdev)
|
||||
* type BRIDGE, or CARDBUS. Host to PCI controllers use
|
||||
* PCI header type NORMAL.
|
||||
*/
|
||||
if (bridge
|
||||
&&((bridge->hdr_type == PCI_HEADER_TYPE_BRIDGE)
|
||||
||(bridge->hdr_type == PCI_HEADER_TYPE_CARDBUS))) {
|
||||
if (bridge && (pci_is_bridge(bridge))) {
|
||||
pci_read_config_word(bridge, PCI_BRIDGE_CONTROL,
|
||||
&config);
|
||||
if (!(config & PCI_BRIDGE_CTL_VGA))
|
||||
|
||||
@@ -44,11 +44,6 @@ struct pci_dev;
|
||||
*/
|
||||
#define pcibios_assign_all_busses() 0
|
||||
|
||||
static inline void pcibios_penalize_isa_irq(int irq, int active)
|
||||
{
|
||||
/* We don't do dynamic PCI IRQ allocation */
|
||||
}
|
||||
|
||||
#ifdef CONFIG_PCI
|
||||
extern void set_pci_dma_ops(struct dma_map_ops *dma_ops);
|
||||
extern struct dma_map_ops *get_pci_dma_ops(void);
|
||||
|
||||
@@ -168,26 +168,6 @@ struct pci_controller *pci_find_hose_for_OF_device(struct device_node *node)
|
||||
return NULL;
|
||||
}
|
||||
|
||||
static ssize_t pci_show_devspec(struct device *dev,
|
||||
struct device_attribute *attr, char *buf)
|
||||
{
|
||||
struct pci_dev *pdev;
|
||||
struct device_node *np;
|
||||
|
||||
pdev = to_pci_dev(dev);
|
||||
np = pci_device_to_OF_node(pdev);
|
||||
if (np == NULL || np->full_name == NULL)
|
||||
return 0;
|
||||
return sprintf(buf, "%s", np->full_name);
|
||||
}
|
||||
static DEVICE_ATTR(devspec, S_IRUGO, pci_show_devspec, NULL);
|
||||
|
||||
/* Add sysfs properties */
|
||||
int pcibios_add_platform_entries(struct pci_dev *pdev)
|
||||
{
|
||||
return device_create_file(&pdev->dev, &dev_attr_devspec);
|
||||
}
|
||||
|
||||
void pcibios_set_master(struct pci_dev *dev)
|
||||
{
|
||||
/* No special bus mastering setup handling */
|
||||
|
||||
@@ -73,11 +73,6 @@ extern unsigned long PCIBIOS_MIN_MEM;
|
||||
|
||||
extern void pcibios_set_master(struct pci_dev *dev);
|
||||
|
||||
static inline void pcibios_penalize_isa_irq(int irq, int active)
|
||||
{
|
||||
/* We don't do dynamic PCI IRQ allocation */
|
||||
}
|
||||
|
||||
#define HAVE_PCI_MMAP
|
||||
|
||||
extern int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
|
||||
|
||||
Some files were not shown because too many files have changed in this diff Show More
Reference in New Issue
Block a user