From: Herve Codina herve.codina@bootlin.com
[ Upstream commit 8fc5133d6d4da65cad6b73152fc714ad3d7f91c1 ]
On some arch (ie aarch64 iMX8MM) unaligned PCIe accesses are not allowed and lead to a kernel Oops. [ 1911.668835] Unable to handle kernel paging request at virtual address ffff80001bc00a8c [ 1911.668841] Mem abort info: [ 1911.668844] ESR = 0x96000061 [ 1911.668847] EC = 0x25: DABT (current EL), IL = 32 bits [ 1911.668850] SET = 0, FnV = 0 [ 1911.668852] EA = 0, S1PTW = 0 [ 1911.668853] Data abort info: [ 1911.668855] ISV = 0, ISS = 0x00000061 [ 1911.668857] CM = 0, WnR = 1 [ 1911.668861] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000040ff4000 [ 1911.668864] [ffff80001bc00a8c] pgd=00000000bffff003, pud=00000000bfffe003, pmd=0068000018400705 [ 1911.668872] Internal error: Oops: 96000061 [#1] PREEMPT SMP ...
The llp register present in the channel group registers is not aligned on 64bit.
Fix unaligned 64bit access using two 32bit accesses
Fixes: 04e0a39fc10f ("dmaengine: dw-edma: Add writeq() and readq() for 64 bits architectures") Signed-off-by: Herve Codina herve.codina@bootlin.com Link: https://lore.kernel.org/r/20220225120252.309404-1-herve.codina@bootlin.com Signed-off-by: Vinod Koul vkoul@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/dma/dw-edma/dw-edma-v0-core.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/dma/dw-edma/dw-edma-v0-core.c b/drivers/dma/dw-edma/dw-edma-v0-core.c index 329fc2e57b70..b5b8f8181e77 100644 --- a/drivers/dma/dw-edma/dw-edma-v0-core.c +++ b/drivers/dma/dw-edma/dw-edma-v0-core.c @@ -415,8 +415,11 @@ void dw_edma_v0_core_start(struct dw_edma_chunk *chunk, bool first) (DW_EDMA_V0_CCS | DW_EDMA_V0_LLE)); /* Linked list */ #ifdef CONFIG_64BIT - SET_CH_64(dw, chan->dir, chan->id, llp.reg, - chunk->ll_region.paddr); + /* llp is not aligned on 64bit -> keep 32bit accesses */ + SET_CH_32(dw, chan->dir, chan->id, llp.lsb, + lower_32_bits(chunk->ll_region.paddr)); + SET_CH_32(dw, chan->dir, chan->id, llp.msb, + upper_32_bits(chunk->ll_region.paddr)); #else /* CONFIG_64BIT */ SET_CH_32(dw, chan->dir, chan->id, llp.lsb, lower_32_bits(chunk->ll_region.paddr));