linux-toradex.git/drivers/dma/dma-axi-dmac.c, branch v7.2-rc5 Linux kernel for Apalis and Colibri modules dmaengine: dma-axi-dmac: use DMA pool to manange DMA descriptor 2026-06-08T12:07:06+00:00 Nuno Sá nuno.sa@analog.com 2026-04-24T17:40:17+00:00 9e942c8579130e62734c14338e9f451780669164 For architectures like Microblaze or arm64 (where this IP is used), DMA_DIRECT_REMAP is set which means that dma_alloc_coherent() might remap (and hence vmalloc()) some memory. This became visible in a design where dma_direct_use_pool() is not possible. With the above, when calling dma_free_coherent(), vunmap() would be called from softirq context and thus leading to a BUG(). To fix it, use a dma pool that is allocated in .device_alloc_chan_resources() and allocate blocks from it. The key point is that now dma_pool_free() is used in axi_dmac_free_desc() to free the blocks and that just frees the blocks from the pool in the sense they can be used again. In other words, no actual call to dma_free_coherent() happens. That only happens when destroying the pool in axi_dmac_free_chan_resources() which does not happen in any interrupt context. Fixes: 3f8fd25936ee ("dmaengine: axi-dmac: Allocate hardware descriptors") Signed-off-by: Nuno Sá <nuno.sa@analog.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260424-dma-dmac-handle-vunmap-v4-4-90f43412fdc0@analog.com Signed-off-by: Vinod Koul <vkoul@kernel.org> 
For architectures like Microblaze or arm64 (where this IP is used),
DMA_DIRECT_REMAP is set which means that dma_alloc_coherent() might
remap (and hence vmalloc()) some memory. This became visible in a design
where dma_direct_use_pool() is not possible.

With the above, when calling dma_free_coherent(), vunmap() would be
called from softirq context and thus leading to a BUG().

To fix it, use a dma pool that is allocated in
.device_alloc_chan_resources() and allocate blocks from it. The key
point is that now dma_pool_free() is used in axi_dmac_free_desc() to
free the blocks and that just frees the blocks from the pool in the
sense they can be used again. In other words, no actual call to
dma_free_coherent() happens. That only happens when destroying the pool
in axi_dmac_free_chan_resources() which does not happen in any interrupt
context.

Fixes: 3f8fd25936ee ("dmaengine: axi-dmac: Allocate hardware descriptors")
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260424-dma-dmac-handle-vunmap-v4-4-90f43412fdc0@analog.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
dmaengine: dma-axi-dmac: Drop struct clk from main struct 2026-06-08T12:07:06+00:00 Nuno Sá nuno.sa@analog.com 2026-04-24T17:40:16+00:00 a725ac2055271fe8123fa854bfeff6e349f7cf0e There's no reason to keep struct clk in struct axi_dmac. Hence, use a local clk variable in .probe() and drop it from struct axi_dmac. Signed-off-by: Nuno Sá <nuno.sa@analog.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260424-dma-dmac-handle-vunmap-v4-3-90f43412fdc0@analog.com Signed-off-by: Vinod Koul <vkoul@kernel.org> 
There's no reason to keep struct clk in struct axi_dmac. Hence, use a
local clk variable in .probe() and drop it from struct axi_dmac.

Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260424-dma-dmac-handle-vunmap-v4-3-90f43412fdc0@analog.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
dmaengine: dma-axi-dmac: Properly free struct axi_dmac_desc 2026-06-08T12:07:06+00:00 Nuno Sá nuno.sa@analog.com 2026-04-24T17:40:15+00:00 4910ce1b3b35687bb2a5e742c4bfbea3c647c980 Use axi_dmac_free_desc() to free fully the descriptor at fail path when call axi_dmac_alloc_desc() in axi_dmac_prep_peripheral_dma_vec(). Fixes: 74609e568670 ("dmaengine: dma-axi-dmac: Implement device_prep_peripheral_dma_vec") Signed-off-by: Nuno Sá <nuno.sa@analog.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260424-dma-dmac-handle-vunmap-v4-2-90f43412fdc0@analog.com Signed-off-by: Vinod Koul <vkoul@kernel.org> 
Use axi_dmac_free_desc() to free fully the descriptor at fail path when
call axi_dmac_alloc_desc() in axi_dmac_prep_peripheral_dma_vec().

Fixes: 74609e568670 ("dmaengine: dma-axi-dmac: Implement device_prep_peripheral_dma_vec")
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260424-dma-dmac-handle-vunmap-v4-2-90f43412fdc0@analog.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
dmaengine: dma-axi-dmac: Gracefully terminate HW cyclic transfers 2026-03-09T07:28:21+00:00 Nuno Sá nuno.sa@analog.com 2026-03-03T10:25:04+00:00 f1d201e7e4e7646e55ce4946f0adec4b035ffb4b Add support for gracefully terminating hardware cyclic DMA transfers when a new transfer is queued and is flagged with DMA_PREP_LOAD_EOT. Without this, cyclic transfers would continue indefinitely until we brute force it with .device_terminate_all(). When a new descriptor is queued while a cyclic transfer is active, mark the cyclic transfer for termination. For hardware with scatter-gather support, modify the last segment flags to trigger end-of-transfer. For non-SG hardware, clear the CYCLIC flag to allow natural completion. Older IP core versions (pre-4.6.a) can prefetch data when clearing the CYCLIC flag, causing corruption in the next transfer. Work around this by disabling and re-enabling the core to flush prefetched data. The cyclic_eot flag tracks transfers marked for termination, preventing new transfers from starting until the cyclic one completes. Non-EOT transfers submitted after cyclic transfers are discarded with a warning. Also note that for hardware cyclic transfers not using SG, we need to make sure that chan->next_desc is also set to NULL (so we can look at possible EOT transfers) and we also need to move the queue check to after axi_dmac_get_next_desc() because with hardware based cyclic transfers we might get the queue marked as full and hence we would not be able to check for cyclic termination. Signed-off-by: Nuno Sá <nuno.sa@analog.com> Link: https://patch.msgid.link/20260303-axi-dac-cyclic-support-v2-5-0db27b4be95a@analog.com Signed-off-by: Vinod Koul <vkoul@kernel.org> 
Add support for gracefully terminating hardware cyclic DMA transfers when
a new transfer is queued and is flagged with DMA_PREP_LOAD_EOT. Without
this, cyclic transfers would continue indefinitely until we brute force
it with .device_terminate_all().

When a new descriptor is queued while a cyclic transfer is active, mark
the cyclic transfer for termination. For hardware with scatter-gather
support, modify the last segment flags to trigger end-of-transfer. For
non-SG hardware, clear the CYCLIC flag to allow natural completion.

Older IP core versions (pre-4.6.a) can prefetch data when clearing the
CYCLIC flag, causing corruption in the next transfer. Work around this
by disabling and re-enabling the core to flush prefetched data.

The cyclic_eot flag tracks transfers marked for termination, preventing
new transfers from starting until the cyclic one completes. Non-EOT
transfers submitted after cyclic transfers are discarded with a warning.

Also note that for hardware cyclic transfers not using SG, we need to
make sure that chan->next_desc is also set to NULL (so we can look at
possible EOT transfers) and we also need to move the queue check to
after axi_dmac_get_next_desc() because with hardware based cyclic
transfers we might get the queue marked as full and hence we would not
be able to check for cyclic termination.

Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Link: https://patch.msgid.link/20260303-axi-dac-cyclic-support-v2-5-0db27b4be95a@analog.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
dmaengine: dma-axi-dmac: Gracefully terminate SW cyclic transfers 2026-03-09T07:28:21+00:00 Nuno Sá nuno.sa@analog.com 2026-03-03T10:25:03+00:00 ca3bf200dea50fada92ec371e9e294b18a589676 As of now, to terminate a cyclic transfer, one pretty much needs to use brute force and terminate all transfers with .device_terminate_all(). With this change, when a cyclic transfer terminates (and generates an EOT interrupt), look at any new pending transfer with the DMA_PREP_LOAD_EOT flag set. If there is one, the current cyclic transfer is terminated and the next one is enqueued. If the flag is not set, that transfer is ignored. Signed-off-by: Nuno Sá <nuno.sa@analog.com> Link: https://patch.msgid.link/20260303-axi-dac-cyclic-support-v2-4-0db27b4be95a@analog.com Signed-off-by: Vinod Koul <vkoul@kernel.org> 
As of now, to terminate a cyclic transfer, one pretty much needs to use
brute force and terminate all transfers with .device_terminate_all().
With this change, when a cyclic transfer terminates (and generates an
EOT interrupt), look at any new pending transfer with the DMA_PREP_LOAD_EOT
flag set. If there is one, the current cyclic transfer is terminated and
the next one is enqueued. If the flag is not set, that transfer is ignored.

Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Link: https://patch.msgid.link/20260303-axi-dac-cyclic-support-v2-4-0db27b4be95a@analog.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
dmaengine: dma-axi-dmac: Add helper for getting next desc 2026-03-09T07:28:21+00:00 Nuno Sá nuno.sa@analog.com 2026-03-03T10:25:02+00:00 c60990ba1fb2a6c1ff2789e610aa130f3047a2ff Add a new helper for getting the next valid struct axi_dmac_desc. This will be extended in follow up patches to support to gracefully terminate cyclic transfers. Reviewed-by: Frank Li <Frank.Li@nxp.com> Signed-off-by: Nuno Sá <nuno.sa@analog.com> Link: https://patch.msgid.link/20260303-axi-dac-cyclic-support-v2-3-0db27b4be95a@analog.com Signed-off-by: Vinod Koul <vkoul@kernel.org> 
Add a new helper for getting the next valid struct axi_dmac_desc. This
will be extended in follow up patches to support to gracefully terminate
cyclic transfers.

Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Link: https://patch.msgid.link/20260303-axi-dac-cyclic-support-v2-3-0db27b4be95a@analog.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
dmaengine: dma-axi-dmac: Add cyclic transfers in .device_prep_peripheral_dma_vec() 2026-03-09T07:28:21+00:00 Nuno Sá nuno.sa@analog.com 2026-03-03T10:25:01+00:00 ac85913ab71e0de9827b7f8f7fccb9f20943c02f Add support for cyclic transfers by checking the DMA_PREP_REPEAT flag. If the flag is set, close the loop and clear the flag for the last segment (the same done for .device_prep_dma_cyclic(). Reviewed-by: Frank Li <Frank.Li@nxp.com> Signed-off-by: Nuno Sá <nuno.sa@analog.com> Link: https://patch.msgid.link/20260303-axi-dac-cyclic-support-v2-2-0db27b4be95a@analog.com Signed-off-by: Vinod Koul <vkoul@kernel.org> 
Add support for cyclic transfers by checking the DMA_PREP_REPEAT
flag. If the flag is set, close the loop and clear the flag for the last
segment (the same done for .device_prep_dma_cyclic().

Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Link: https://patch.msgid.link/20260303-axi-dac-cyclic-support-v2-2-0db27b4be95a@analog.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
treewide: Replace kmalloc with kmalloc_obj for non-scalar types 2026-02-21T09:02:28+00:00 Kees Cook kees@kernel.org 2026-02-21T07:49:23+00:00 69050f8d6d075dc01af7a5f2f550a8067510366f 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> 
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>
dmaengine: axi-dmac: use sg_nents_for_dma() helper 2026-01-09T03:06:00+00:00 Andy Shevchenko andriy.shevchenko@linux.intel.com 2026-01-08T10:50:14+00:00 024ae9d3092c425f3ea6eae92086a2001ca2e0c7 Instead of open coded variant let's use recently introduced helper. Reviewed-by: Bjorn Andersson <andersson@kernel.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Nuno Sá <nuno.sa@analog.com> Link: https://patch.msgid.link/20260108105619.3513561-4-andriy.shevchenko@linux.intel.com Signed-off-by: Vinod Koul <vkoul@kernel.org> 
Instead of open coded variant let's use recently introduced helper.

Reviewed-by: Bjorn Andersson <andersson@kernel.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Link: https://patch.msgid.link/20260108105619.3513561-4-andriy.shevchenko@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
dma: dma-axi-dmac: simplify axi_dmac_parse_dt() 2025-12-23T11:13:15+00:00 Nuno Sá nuno.sa@analog.com 2025-11-04T16:22:28+00:00 c23918bedc74a7809e6fa2fd1d09b860625a90b8 Simplify axi_dmac_parse_dt() by using the cleanup device_node class for automatically releasing the of_node reference when going out of scope. Signed-off-by: Nuno Sá <nuno.sa@analog.com> base-commit: 398035178503bf662281bbffb4bebce1460a4bc5 change-id: 20251104-axi-dmac-fixes-and-improvs-e3ad512a329c Acked-by: Michael Hennerich <michael.hennerich@analog.com> Link: https://patch.msgid.link/20251104-axi-dmac-fixes-and-improvs-v1-4-3e6fd9328f72@analog.com Signed-off-by: Vinod Koul <vkoul@kernel.org> 
Simplify axi_dmac_parse_dt() by using the cleanup device_node class for
automatically releasing the of_node reference when going out of scope.

Signed-off-by: Nuno Sá <nuno.sa@analog.com>
base-commit: 398035178503bf662281bbffb4bebce1460a4bc5
change-id: 20251104-axi-dmac-fixes-and-improvs-e3ad512a329c
Acked-by: Michael Hennerich <michael.hennerich@analog.com>
Link: https://patch.msgid.link/20251104-axi-dmac-fixes-and-improvs-v1-4-3e6fd9328f72@analog.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>