A single AXIDMA controller can have one or two channels. When it has two
channels, the reset for both are tied together: resetting one channel
resets the other as well. This creates a problem where resetting one
channel will reset the registers for both channels, including clearing
interrupt enable bits for the other channel, which can then lead to
timeouts as the driver is waiting for an interrupt which never comes.
The driver currently has a probe-time work around for this: when a
channel is created, the driver also resets and enables the
interrupts. With two channels the reset for the second channel will
clear the interrupt enables for the first one. The work around in the
driver is just to manually enable the interrupts again in
xilinx_dma_alloc_chan_resources().
This workaround only addresses the probe-time issue. When channels are
reset at runtime (e.g., in xilinx_dma_terminate_all() or during error
recovery), there's no corresponding mechanism to restore the other
channel's interrupt enables. This leads to one channel having its
interrupts disabled while the driver expects them to work, causing
timeouts and DMA failures.
A proper fix is a complicated matter, as we should not reset the other
channel when it's operating normally. So, perhaps, there should be some
kind of synchronization for a common reset, which is not trivial to
implement. To add to the complexity, the driver also supports other DMA
types, like VDMA, CDMA and MCDMA, which don't have a shared reset.
However, when the two-channel AXIDMA is used in the (assumably) normal
use case, providing DMA for a single memory-to-memory device, the common
reset is a bit smaller issue: when something bad happens on one channel,
or when one channel is terminated, the assumption is that we also want
to terminate the other channel. And thus resetting both at the same time
is "ok".
With that line of thinking we can implement a bit better work around
than just the current probe time work around: let's enable the
AXIDMA interrupts at xilinx_dma_start_transfer() instead.
This ensures interrupts are enabled whenever a transfer starts,
regardless of any prior resets that may have cleared them.
This approach is also more logical: enable interrupts only when needed
for a transfer, rather than at resource allocation time, and, I think,
all the other DMA types should also use this model, but I'm reluctant to
do such changes as I cannot test them.
The reset function still enables interrupts even though it's not needed
for AXIDMA anymore, but it's common code for all DMA types (VDMA, CDMA,
MCDMA), so leave it unchanged to avoid affecting other variants.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Fixes: c0bba3a99f ("dmaengine: vdma: Add Support for Xilinx AXI Direct Memory Access Engine")
Link: https://patch.msgid.link/20260311-xilinx-dma-fix-v2-1-a725abb66e3c@ideasonboard.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The segment .control and .status fields both contain top bits which are
not part of the buffer size, the buffer size is located only in the bottom
max_buffer_len bits. To avoid interference from those top bits, mask out
the size using max_buffer_len first, and only then subtract the values.
Fixes: a575d0b4e6 ("dmaengine: xilinx_dma: Introduce xilinx_dma_get_residue")
Signed-off-by: Marek Vasut <marex@nabladev.com>
Link: https://patch.msgid.link/20260316222530.163815-1-marex@nabladev.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The cyclic DMA calculation is currently entirely broken and reports
residue only for the first segment. The problem is twofold.
First, when the first descriptor finishes, it is moved from active_list
to done_list, but it is never returned back into the active_list. The
xilinx_dma_tx_status() expects the descriptor to be in the active_list
to report any meaningful residue information, which never happens after
the first descriptor finishes. Fix this up in xilinx_dma_start_transfer()
and if the descriptor is cyclic, lift it from done_list and place it back
into active_list list.
Second, the segment .status fields of the descriptor remain dirty. Once
the DMA did one pass on the descriptor, the .status fields are populated
with data by the DMA, but the .status fields are not cleared before reuse
during the next cyclic DMA round. The xilinx_dma_get_residue() recognizes
that as if the descriptor was complete and had 0 residue, which is bogus.
Reinitialize the status field before placing the descriptor back into the
active_list.
Fixes: c0bba3a99f ("dmaengine: vdma: Add Support for Xilinx AXI Direct Memory Access Engine")
Signed-off-by: Marek Vasut <marex@nabladev.com>
Link: https://patch.msgid.link/20260316221943.160375-1-marex@nabladev.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Two members of struct xdma_desc_block are not descibed leading to
warnings, document them.
Warning: drivers/dma/xilinx/xdma.c:75 struct member 'last_interrupt' not described in 'xdma_chan'
Warning: drivers/dma/xilinx/xdma.c:75 struct member 'stop_requested' not described in 'xdma_chan'
Link: https://patch.msgid.link/20260227022905.233721-1-vkoul@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This converts some of the visually simpler cases that have been split
over multiple lines. I only did the ones that are easy to verify the
resulting diff by having just that final GFP_KERNEL argument on the next
line.
Somebody should probably do a proper coccinelle script for this, but for
me the trivial script actually resulted in an assertion failure in the
middle of the script. I probably had made it a bit _too_ trivial.
So after fighting that far a while I decided to just do some of the
syntactically simpler cases with variations of the previous 'sed'
scripts.
The more syntactically complex multi-line cases would mostly really want
whitespace cleanup anyway.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
Pull dmaengine updates from Vinod Koul:
"Core:
- Add Frank Li as susbstem reviewer to help with reviews
New Support:
- Mediatek support for Dimensity 6300 and 9200 controller
- Qualcomm Kaanapali and Glymur GPI DMA engine
- Synopsis DW AXI Agilex5
- Renesas RZ/V2N SoC
- Atmel microchip lan9691-dma
- Tegra ADMA tegra264
Updates:
- sg_nents_for_dma() helper use in subsystem
- pm_runtime_mark_last_busy() redundant call update for subsystem
- Residue support for xilinx AXIDMA driver
- Intel Max SGL Size Support and capabilities for DSA3.0
- AXI dma larger than 32bits address support"
* tag 'dmaengine-7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/dmaengine: (64 commits)
dmaengine: add Frank Li as reviewer
dt-bindings: dma: qcom,gpi: Update max interrupts lines to 16
dmaengine: fsl-edma: don't explicitly disable clocks in .remove()
dmaengine: xilinx: xdma: use sg_nents_for_dma() helper
dmaengine: sh: use sg_nents_for_dma() helper
dmaengine: sa11x0: use sg_nents_for_dma() helper
dmaengine: qcom: bam_dma: use sg_nents_for_dma() helper
dmaengine: qcom: adm: use sg_nents_for_dma() helper
dmaengine: pxa-dma: use sg_nents_for_dma() helper
dmaengine: lgm: use sg_nents_for_dma() helper
dmaengine: k3dma: use sg_nents_for_dma() helper
dmaengine: dw-axi-dmac: use sg_nents_for_dma() helper
dmaengine: bcm2835-dma: use sg_nents_for_dma() helper
dmaengine: axi-dmac: use sg_nents_for_dma() helper
dmaengine: altera-msgdma: use sg_nents_for_dma() helper
scatterlist: introduce sg_nents_for_dma() helper
dmaengine: idxd: Add Max SGL Size Support for DSA3.0
dmaengine: idxd: Expose DSA3.0 capabilities through sysfs
dmaengine: sh: rz-dmac: Make channel irq local
dmaengine: pl08x: Fix comment stating the difference between PL080 and PL081
...
The max_register field is assigned the size of the register memory
region instead of the offset of the last register.
The result is that reading from the regmap via debugfs can cause
a segmentation fault:
tail /sys/kernel/debug/regmap/xdma.1.auto/registers
Unable to handle kernel paging request at virtual address ffff800082f70000
Mem abort info:
ESR = 0x0000000096000007
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x07: level 3 translation fault
[...]
Call trace:
regmap_mmio_read32le+0x10/0x30
_regmap_bus_reg_read+0x74/0xc0
_regmap_read+0x68/0x198
regmap_read+0x54/0x88
regmap_read_debugfs+0x140/0x380
regmap_map_read_file+0x30/0x48
full_proxy_read+0x68/0xc8
vfs_read+0xcc/0x310
ksys_read+0x7c/0x120
__arm64_sys_read+0x24/0x40
invoke_syscall.constprop.0+0x64/0x108
do_el0_svc+0xb0/0xd8
el0_svc+0x38/0x130
el0t_64_sync_handler+0x120/0x138
el0t_64_sync+0x194/0x198
Code: aa1e03e9 d503201f f9400000 8b214000 (b9400000)
---[ end trace 0000000000000000 ]---
note: tail[1217] exited with irqs disabled
note: tail[1217] exited with preempt_count 1
Segmentation fault
Fixes: 17ce252266 ("dmaengine: xilinx: xdma: Add xilinx xdma driver")
Reviewed-by: Lizhi Hou <lizhi.hou@amd.com>
Reviewed-by: Radhey Shyam Pandey <radhey.shyam.pandey@amd.com>
Reviewed-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: Anthony Brandon <anthony@amarulasolutions.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The DMAEngine provides an interface for obtaining DMA transaction
descriptors from an array of scatter gather buffers represented by
struct dma_vec. This interface is used in the DMABUF API of the IIO
framework [1][2].
To enable DMABUF support through the IIO framework for the Xilinx DMA,
implement callback .device_prep_peripheral_dma_vec() of struct
dma_device in the driver.
[1]: 7a86d46998 ("iio: buffer-dmaengine: Support new DMABUF based userspace API")
[2]: 5878853fc9 ("dmaengine: Add API function dmaengine_prep_peripheral_dma_vec()")
Signed-off-by: Folker Schwesinger <dev@folker-schwesinger.de>
Reviewed-by: Suraj Gupta <suraj.gupta2@amd.com>
Reviewed-by: Radhey Shyam Pandey <radhey.shyam.pandey@amd.com>
Link: https://lore.kernel.org/r/DCCKQLKOZC06.2H6LJ8RJQJNV2@folker-schwesinger.de
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Add shutdown callback to ensure that DMA operations are properly stopped
and resources are released during system shutdown or kexec operations.
Fix incorrect PM state handling in the remove function that was causing
clock disable warnings during the shutdown operations, which was not
implemented earlier. The original logic used pm_runtime_enabled() check
after calling the pm_runtime_disable(), would always evaluate to true
after the disable call, which leads to unconditionally calling the
runtime_suspend regardless of the device's actual power state.
During shutdown, the device may already be suspended with clock disabled
from the autosuspend timer, causing the clock framework to warn about
the double-disable attempt. The pm_runtime_active() function checks the
actual device power state rather than the PM subsystem's enabled/disabled
status. ensuring the runtime_suspend is only called when the device is in
active power state. This prevents clock warnings during shutdown while
maintaining proper cleanup during normal remove operations.
Signed-off-by: Abin Joseph <abin.joseph@amd.com>
Reviewed-by: Radhey Shyam Pandey <radhey.shyam.pandey@amd.com>
Link: https://lore.kernel.org/r/20250722070255.28944-1-abin.joseph@amd.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Replace ternary (condition ? "enable" : "disable") syntax with helpers
from string_choices.h because:
1. Simple function call with one argument is easier to read. Ternary
operator has three arguments and with wrapping might lead to quite
long code.
2. Is slightly shorter thus also easier to read.
3. It brings uniformity in the text - same string.
4. Allows deduping by the linker, which results in a smaller binary
file.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> #dw-edma
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://lore.kernel.org/r/20250114191021.854080-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Uwe Kleine-König (The Capable Hub)
Linus Torvalds
Tomi Valkeinen
Marek Vasut
Vinod Koul
Krzysztof Kozlowski
Alexander Stein
Kees Cook
Andy Shevchenko
Sakari Ailus
Suraj Gupta
Anthony Brandon
Folker Schwesinger
Abin Joseph
Thomas Gessler
Krzysztof Kozlowski
Marek Vasut
Colin Ian King