linux-stable.git/kernel/dma, branch v6.12.52

dma-debug: fix physical address calculation for struct dma_debug_entry

2025-09-19T14:35:42+00:00

[ Upstream commit aef7ee7649e02f7fc0d2e5e532f352496976dcb1 ]

Offset into the page should also be considered while calculating a physical
address for struct dma_debug_entry. page_to_phys() just shifts the value
PAGE_SHIFT bits to the left so offset part is zero-filled.

An example (wrong) debug assertion failure with CONFIG_DMA_API_DEBUG
enabled which is observed during systemd boot process after recent
dma-debug changes:

DMA-API: e1000 0000:00:03.0: cacheline tracking EEXIST, overlapping mappings aren't supported
WARNING: CPU: 4 PID: 941 at kernel/dma/debug.c:596 add_dma_entry
CPU: 4 UID: 0 PID: 941 Comm: ip Not tainted 6.12.0+ #288
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:add_dma_entry kernel/dma/debug.c:596
Call Trace:
 
debug_dma_map_page kernel/dma/debug.c:1236
dma_map_page_attrs kernel/dma/mapping.c:179
e1000_alloc_rx_buffers drivers/net/ethernet/intel/e1000/e1000_main.c:4616
...

Found by Linux Verification Center (linuxtesting.org).

Fixes: 9d4f645a1fd4 ("dma-debug: store a phys_addr_t in struct dma_debug_entry")
Signed-off-by: Fedor Pchelkin 
[hch: added a little helper to clean up the code]
Signed-off-by: Christoph Hellwig 
Signed-off-by: Sasha Levin

dma-mapping: fix swapped dir/flags arguments to trace_dma_alloc_sgt_err

2025-09-19T14:35:42+00:00

[ Upstream commit d5bbfbad58ec0ccd187282f0e171bc763efa6828 ]

trace_dma_alloc_sgt_err was called with the dir and flags arguments
swapped. Fix this.

Fixes: 68b6dbf1f441 ("dma-mapping: trace more error paths")
Signed-off-by: Sean Anderson 
Reported-by: kernel test robot 
Closes: https://lore.kernel.org/oe-kbuild-all/202410302243.1wnTlPk3-lkp@intel.com/
Signed-off-by: Christoph Hellwig 
Signed-off-by: Sasha Levin

dma-debug: don't enforce dma mapping check on noncoherent allocations

2025-09-19T14:35:42+00:00

[ Upstream commit 7e2368a21741e2db542330b32aa6fdd8908e7cff ]

As discussed in [1], there is no need to enforce dma mapping check on
noncoherent allocations, a simple test on the returned CPU address is
good enough.

Add a new pair of debug helpers and use them for noncoherent alloc/free
to fix this issue.

Fixes: efa70f2fdc84 ("dma-mapping: add a new dma_alloc_pages API")
Link: https://lore.kernel.org/all/ff6c1fe6-820f-4e58-8395-df06aa91706c@oss.qualcomm.com # 1
Signed-off-by: Baochen Qiang 
Signed-off-by: Marek Szyprowski 
Link: https://lore.kernel.org/r/20250828-dma-debug-fix-noncoherent-dma-check-v1-1-76e9be0dd7fc@oss.qualcomm.com
Signed-off-by: Sasha Levin

dma-mapping: trace more error paths

2025-09-19T14:35:42+00:00

[ Upstream commit 68b6dbf1f441c4eba3b8511728a41cf9b01dca35 ]

It can be surprising to the user if DMA functions are only traced on
success. On failure, it can be unclear what the source of the problem
is. Fix this by tracing all functions even when they fail. Cases where
we BUG/WARN are skipped, since those should be sufficiently noisy
already.

Signed-off-by: Sean Anderson 
Reviewed-by: Steven Rostedt (Google) 
Signed-off-by: Christoph Hellwig 
Stable-dep-of: 7e2368a21741 ("dma-debug: don't enforce dma mapping check on noncoherent allocations")
Signed-off-by: Sasha Levin

dma-mapping: use trace_dma_alloc for dma_alloc* instead of using trace_dma_map

2025-09-19T14:35:42+00:00

[ Upstream commit c4484ab86ee00f2d9236e2851621ea02c105f4cc ]

In some cases, we use trace_dma_map to trace dma_alloc* functions. This
generally follows dma_debug. However, this does not record all of the
relevant information for allocations, such as GFP flags. Create new
dma_alloc tracepoints for these functions. Note that while
dma_alloc_noncontiguous may allocate discontiguous pages (from the CPU's
point of view), the device will only see one contiguous mapping.
Therefore, we just need to trace dma_addr and size.

Signed-off-by: Sean Anderson 
Reviewed-by: Steven Rostedt (Google) 
Signed-off-by: Christoph Hellwig 
Stable-dep-of: 7e2368a21741 ("dma-debug: don't enforce dma mapping check on noncoherent allocations")
Signed-off-by: Sasha Levin

dma-mapping: trace dma_alloc/free direction

2025-09-19T14:35:41+00:00

[ Upstream commit 3afff779a725cba914e6caba360b696ae6f90249 ]

In preparation for using these tracepoints in a few more places, trace
the DMA direction as well. For coherent allocations this is always
bidirectional.

Signed-off-by: Sean Anderson 
Reviewed-by: Steven Rostedt (Google) 
Signed-off-by: Christoph Hellwig 
Stable-dep-of: 7e2368a21741 ("dma-debug: don't enforce dma mapping check on noncoherent allocations")
Signed-off-by: Sasha Levin

dma-debug: store a phys_addr_t in struct dma_debug_entry

2025-09-19T14:35:41+00:00

[ Upstream commit 9d4f645a1fd49eea70a21e8671d358ebe1c08d02 ]

dma-debug goes to great length to split incoming physical addresses into
a PFN and offset to store them in struct dma_debug_entry, just to
recombine those for all meaningful uses.  Just store a phys_addr_t
instead.

Signed-off-by: Christoph Hellwig 
Stable-dep-of: 7e2368a21741 ("dma-debug: don't enforce dma mapping check on noncoherent allocations")
Signed-off-by: Sasha Levin

dma/pool: Ensure DMA_DIRECT_REMAP allocations are decrypted

2025-09-04T13:31:54+00:00

commit 89a2d212bdb4bc29bed8e7077abe054b801137ea upstream.

When CONFIG_DMA_DIRECT_REMAP is enabled, atomic pool pages are
remapped via dma_common_contiguous_remap() using the supplied
pgprot. Currently, the mapping uses
pgprot_dmacoherent(PAGE_KERNEL), which leaves the memory encrypted
on systems with memory encryption enabled (e.g., ARM CCA Realms).

This can cause the DMA layer to fail or crash when accessing the
memory, as the underlying physical pages are not configured as
expected.

Fix this by requesting a decrypted mapping in the vmap() call:
pgprot_decrypted(pgprot_dmacoherent(PAGE_KERNEL))

This ensures that atomic pool memory is consistently mapped
unencrypted.

Cc: stable@vger.kernel.org
Signed-off-by: Shanker Donthineni 
Reviewed-by: Catalin Marinas 
Signed-off-by: Marek Szyprowski 
Link: https://lore.kernel.org/r/20250811181759.998805-1-sdonthineni@nvidia.com
Signed-off-by: Greg Kroah-Hartman

of: reserved_mem: Restructure call site for dma_contiguous_early_fixup()

2025-09-04T13:31:45+00:00

[ Upstream commit 2c223f7239f376a90d71903ec474ba887cf21d94 ]

Restructure the call site for dma_contiguous_early_fixup() to
where the reserved_mem nodes are being parsed from the DT so that
dma_mmu_remap[] is populated before dma_contiguous_remap() is called.

Fixes: 8a6e02d0c00e ("of: reserved_mem: Restructure how the reserved memory regions are processed")
Signed-off-by: Oreoluwa Babatunde 
Tested-by: William Zhang 
Signed-off-by: Marek Szyprowski 
Link: https://lore.kernel.org/r/20250806172421.2748302-1-oreoluwa.babatunde@oss.qualcomm.com
Signed-off-by: Sasha Levin

dma-mapping: Fix warning reported for missing prototype

2025-05-29T09:01:59+00:00

[ Upstream commit cae5572ec9261f752af834cdaaf5a0ba0afcf256 ]

lkp reported a warning about missing prototype for a recent patch.

The kernel-doc style comments are out of sync, move them to the right
function.

Cc: Marek Szyprowski 
Cc: Christoph Hellwig 

Reported-by: kernel test robot 
Closes: https://lore.kernel.org/oe-kbuild-all/202504190615.g9fANxHw-lkp@intel.com/

Signed-off-by: Balbir Singh 
[mszyprow: reformatted subject]
Signed-off-by: Marek Szyprowski 
Link: https://lore.kernel.org/r/20250422114034.3535515-1-balbirs@nvidia.com
Signed-off-by: Sasha Levin