linux.git/kernel/dma/coherent.c, branch v6.12.80

dma-mapping: save base/size instead of pointer to shared DMA pool

2025-02-08T08:58:17+00:00

commit 22293c33738c14bb84b9d3e771bc37150e7cf8e7 upstream.

On RZ/Five, which is non-coherent, and uses CONFIG_DMA_GLOBAL_POOL=y:

    Oops - store (or AMO) access fault [#1]
    CPU: 0 UID: 0 PID: 1 Comm: swapper Not tainted 6.12.0-rc1-00015-g8a6e02d0c00e #201
    Hardware name: Renesas SMARC EVK based on r9a07g043f01 (DT)
    epc : __memset+0x60/0x100
     ra : __dma_alloc_from_coherent+0x150/0x17a
    epc : ffffffff8062d2bc ra : ffffffff80053a94 sp : ffffffc60000ba20
     gp : ffffffff812e9938 tp : ffffffd601920000 t0 : ffffffc6000d0000
     t1 : 0000000000000000 t2 : ffffffffe9600000 s0 : ffffffc60000baa0
     s1 : ffffffc6000d0000 a0 : ffffffc6000d0000 a1 : 0000000000000000
     a2 : 0000000000001000 a3 : ffffffc6000d1000 a4 : 0000000000000000
     a5 : 0000000000000000 a6 : ffffffd601adacc0 a7 : ffffffd601a841a8
     s2 : ffffffd6018573c0 s3 : 0000000000001000 s4 : ffffffd6019541e0
     s5 : 0000000200000022 s6 : ffffffd6018f8410 s7 : ffffffd6018573e8
     s8 : 0000000000000001 s9 : 0000000000000001 s10: 0000000000000010
     s11: 0000000000000000 t3 : 0000000000000000 t4 : ffffffffdefe62d1
     t5 : 000000001cd6a3a9 t6 : ffffffd601b2aad6
    status: 0000000200000120 badaddr: ffffffc6000d0000 cause: 0000000000000007
    [] __memset+0x60/0x100
    [] dma_alloc_from_global_coherent+0x1c/0x28
    [] dma_direct_alloc+0x98/0x112
    [] dma_alloc_attrs+0x78/0x86
    [] rz_dmac_probe+0x3f6/0x50a
    [] platform_probe+0x4c/0x8a

If CONFIG_DMA_GLOBAL_POOL=y, the reserved_mem structure passed to
rmem_dma_setup() is saved for later use, by saving the passed pointer.
However, when dma_init_reserved_memory() is called later, the pointer
has become stale, causing a crash.

E.g. in the RZ/Five case, the referenced memory now contains the
reserved_mem structure for the "mmode_resv0@30000" node (with base
0x30000 and size 0x10000), instead of the correct "pma_resv0@58000000"
node (with base 0x58000000 and size 0x8000000).

Fix this by saving the needed reserved_mem structure's contents instead.

Fixes: 8a6e02d0c00e7b62 ("of: reserved_mem: Restructure how the reserved memory regions are processed")
Signed-off-by: Geert Uytterhoeven 
Reviewed-by: Oreoluwa Babatunde 
Tested-by: Lad Prabhakar 
Signed-off-by: Christoph Hellwig 
Signed-off-by: Greg Kroah-Hartman

dma-mapping: clear dev->dma_mem to NULL after freeing it

2023-12-15T11:32:45+00:00

Reproduced with below sequence:
dma_declare_coherent_memory()->dma_release_coherent_memory()
->dma_declare_coherent_memory()->"return -EBUSY" error

It will return -EBUSY from the dma_assign_coherent_memory()
in dma_declare_coherent_memory(), the reason is that dev->dma_mem
pointer has not been set to NULL after it's freed.

Fixes: cf65a0f6f6ff ("dma-mapping: move all DMA mapping code to kernel/dma")
Signed-off-by: Joakim Zhang 
Signed-off-by: Christoph Hellwig

dma-mapping: Add dma_release_coherent_memory to DMA API

2022-06-24T15:30:54+00:00

Add dma_release_coherent_memory to DMA API to allow dma
user call it to release dev->dma_mem when the device is
removed.

Signed-off-by: Mark-PK Tsai 
Acked-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20220422062436.14384-2-mark-pk.tsai@mediatek.com
Signed-off-by: Mathieu Poirier

dma-mapping: use 'bitmap_zalloc()' when applicable

2021-10-27T06:20:09+00:00

'dma_mem->bitmap' is a bitmap. So use 'bitmap_zalloc()' to simplify code,
improve the semantic and avoid some open-coded arithmetic in allocator
arguments.

Also change the corresponding 'kfree()' into 'bitmap_free()' to keep
consistency.

Signed-off-by: Christophe JAILLET 
Signed-off-by: Christoph Hellwig

dma-mapping: make the global coherent pool conditional

2021-08-19T07:02:39+00:00

Only build the code to support the global coherent pool if support for
it is enabled.

Signed-off-by: Christoph Hellwig 
Tested-by: Dillon Min

dma-mapping: add a dma_init_global_coherent helper

2021-08-18T14:24:11+00:00

Add a new helper to initialize the global coherent pool.  This both
cleans up the existing initialization which indirects through the
reserved_mem_ops that are normally only used for struct device, and
also allows using the global pool for non-devicetree architectures.

Signed-off-by: Christoph Hellwig 
Tested-by: Dillon Min

dma-mapping: simplify dma_init_coherent_memory

2021-08-18T14:24:10+00:00

Return the allocated dma_coherent_mem structure, set the
use_dma_pfn_offset and print the failure warning inside of
dma_init_coherent_memory instead of leaving that to the callers.

Signed-off-by: Christoph Hellwig 
Tested-by: Dillon Min

dma-mapping: allow using the global coherent pool for !ARM

2021-08-18T14:24:10+00:00

Switch an ifdef so that the global coherent pool is initialized for
any architecture that selects the DMA_GLOBAL_POOL symbol insted of
hardcoding ARM.

Signed-off-by: Christoph Hellwig 
Tested-by: Dillon Min

dma-mapping: remove a trailing space

2021-06-22T06:15:46+00:00

Signed-off-by: Zhen Lei 
Signed-off-by: Christoph Hellwig

dma-mapping: split

2020-10-06T05:07:03+00:00

Split out all the bits that are purely for dma_map_ops implementations
and related code into a new  header so that they
don't get pulled into all the drivers.  That also means the architecture
specific  is not pulled in by 
any more, which leads to a missing includes that were pulled in by the
x86 or arm versions in a few not overly portable drivers.

Signed-off-by: Christoph Hellwig