With the msi_list and the msi_domain properties now being at the
generic device level, it is starting to be relatively easy to offer
a generic way of providing non-PCI MSIs.
The two major hurdles with this idea are:
- Lack of global ID that identifies a device: this is worked around by
having a global ID allocator for each device that gets enrolled in
the platform MSI subsystem
- Lack of standard way to write the message in the generating device.
This is solved by mandating driver code to provide a write_msg
callback, so that everyone can have their own square wheel
Apart from that, the API is fairly straightforward:
- platform_msi_create_irq_domain creates an MSI domain that gets
tagged with DOMAIN_BUS_PLATFORM_MSI
- platform_msi_domain_alloc_irqs allocate MSIs for a given device,
populating the msi_list
- platform_msi_domain_free_irqs does what is written on the tin
[ tglx: Created a seperate struct platform_msi_desc and added
kerneldoc entries ]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: Yijing Wang <wangyijing@huawei.com>
Cc: Ma Jun <majun258@huawei.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Duc Dang <dhdang@apm.com>
Cc: Hanjun Guo <hanjun.guo@linaro.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Link: http://lkml.kernel.org/r/1438091186-10244-10-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
mask/unmask_msi_irq and __mask_msi/msix_irq are PCI/MSI specific
functions and should be named accordingly. This is a preparatory patch
to support MSI on non PCI devices.
Rename mask/unmask_msi_irq to pci_msi_mask/unmask_irq and document the
functions. Provide conversion helpers.
Rename __mask_msi/msix_irq to __pci_msi/msix_desc_mask so its clear
that they operated on msi_desc. Fixup the only user outside of
pci/msi.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Yijing Wang <wangyijing@huawei.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
"msi_chip" isn't very descriptive, so rename it to "msi_controller". That
tells a little more about what it does and is already used in device tree
bindings.
No functional change.
[bhelgaas: changelog, change *only* the struct name so it's reviewable]
Suggested-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Now only s390/MSI use default_msi_mask_irq() and default_msix_mask_irq(),
replace them with the common MSI mask IRQ functions __msi_mask_irq() and
__msix_mask_irq(). Remove default_msi_mask_irq() and
default_msix_mask_irq().
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
CC: linux-s390@vger.kernel.org
The problem fixed by 0e4ccb1505 ("PCI: Add x86_msi.msi_mask_irq() and
msix_mask_irq()") has been fixed in a simpler way by a previous commit
("PCI/MSI: Add pci_msi_ignore_mask to prevent writes to MSI/MSI-X Mask
Bits").
The msi_mask_irq() and msix_mask_irq() x86_msi_ops added by 0e4ccb1505
are no longer needed, so revert the commit.
default_msi_mask_irq() and default_msix_mask_irq() were added by
0e4ccb1505 and are still used by s390, so keep them for now.
[bhelgaas: changelog]
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: David Vrabel <david.vrabel@citrix.com>
CC: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
CC: xen-devel@lists.xenproject.org
MSI-X vector Mask Bits are in MSI-X Tables in PCI memory space. Xen PV
guests can't write to those tables. MSI vector Mask Bits are in PCI
configuration space. Xen PV guests can write to config space, but those
writes are ignored.
Commit 0e4ccb1505 ("PCI: Add x86_msi.msi_mask_irq() and
msix_mask_irq()") added a way to override default_mask_msi_irqs() and
default_mask_msix_irqs() so they can be no-ops in Xen guests, but this is
more complicated than necessary.
Add "pci_msi_ignore_mask" in the core PCI MSI code. If set,
default_mask_msi_irqs() and default_mask_msix_irqs() return without doing
anything. This is less flexible, but much simpler.
[bhelgaas: changelog]
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
CC: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
CC: xen-devel@lists.xenproject.org
"msi_attrib.pos" is only used for MSI (not MSI-X), and we already cache the
MSI capability offset in "dev->msi_cap".
Remove "pos" from the struct msi_attrib and use "dev->msi_cap" directly.
[bhelgaas: changelog, fix whitespace]
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
After commit 1c51b50c29 ("PCI/MSI: Export MSI mode using attributes, not
kobjects"), the kobject in struct msi_desc is unused.
Remove the unused struct kobject from struct msi_desc.
[bhelgaas: changelog]
Fixes: 1c51b50c29 ("PCI/MSI: Export MSI mode using attributes, not kobjects")
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
No architectures implement arch_msi_check_device() or the struct msi_chip
.check_device() method, so remove them.
Remove the "type" parameter to pci_msi_check_device() because it was only
used to call arch_msi_check_device() and is no longer needed.
[bhelgaas: changelog, split to separate patch]
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
The Multiple Message Capable field in the MSI Message Control register
indicates how many vectors the device supports. This field is read-only,
so cache it in msi_desc to avoid reading it repeatedly.
Since we cache the extracted field (not the entire Message Control
register), we can use msi_mask() instead of msi_capable_mask(), which is
then unused, so remove it.
[bhelgaas: fix whitespace, changelog]
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
