linux-stable.git/drivers/dma/ptdma, branch linux-6.2.y

dmaengine: ptdma: check for null desc before calling pt_cmd_callback

2023-03-10T08:28:57+00:00

[ Upstream commit 928469986171a6f763b34b039427f5667ba3fd50 ]

Resolves a panic that can occur on AMD systems, typically during host
shutdown, after the PTDMA driver had been exercised. The issue was
the pt_issue_pending() function is mistakenly assuming that there will
be at least one descriptor in the Submitted queue when the function
is called. However, it is possible that both the Submitted and Issued
queues could be empty, which could result in pt_cmd_callback() being
mistakenly called with a NULL pointer.
Ref: Bugzilla Bug 216856.

Fixes: 6fa7e0e836e2 ("dmaengine: ptdma: fix concurrency issue with multiple dma transfer")
Signed-off-by: Eric Pilmore 
Link: https://lore.kernel.org/r/20230210075142.58253-1-epilmore@gigaio.com
Signed-off-by: Vinod Koul 
Signed-off-by: Sasha Levin

ptdma: pt_core_execute_cmd() should use spinlock

2023-01-19T13:29:34+00:00

The interrupt handler (pt_core_irq_handler()) of the ptdma
driver can be called from interrupt context. The code flow
in this function can lead down to pt_core_execute_cmd() which
will attempt to grab a mutex, which is not appropriate in
interrupt context and ultimately leads to a kernel panic.
The fix here changes this mutex to a spinlock, which has
been verified to resolve the issue.

Fixes: fa5d823b16a9 ("dmaengine: ptdma: Initial driver for the AMD PTDMA")
Signed-off-by: Eric Pilmore 
Link: https://lore.kernel.org/r/20230119033907.35071-1-epilmore@gigaio.com
Signed-off-by: Vinod Koul

dmaengine: ptdma: statify pt_tx_status

2022-04-22T05:59:13+00:00

LKP bot reports a new warning:
Warning:
drivers/dma/ptdma/ptdma-dmaengine.c:262:1: warning: no previous prototype for 'pt_tx_status' [-Wmissing-prototypes]

pt_tx_status() should be static, so declare as such.

Reported-by: kernel test robot 
Fixes: d965068259d1 ("dmaengine: PTDMA: support polled mode")
Link: https://lore.kernel.org/r/20220421052407.745637-1-vkoul@kernel.org
Signed-off-by: Vinod Koul

dmaengine: PTDMA: support polled mode

2022-04-20T11:08:19+00:00

If the DMA_PREP_INTERRUPT flag is not provided, run in polled mode,
which significantly improves IOPS: more than twice on chunks < 4K.

Signed-off-by: Ilya Novikov 
Link: https://lore.kernel.org/r/20220413113733.59041-1-i.m.novikov@yadro.com
Signed-off-by: Vinod Koul

Merge tag 'dmaengine-fix-5.17' into next

2022-03-10T04:42:25+00:00

This merges dmaengine/dmaengine-fix-5.17 tag into next as that is
already merged mainline and resolves depencency in patches

dmaengine: ptdma: handle the cases based on DMA is complete

2022-02-15T05:24:54+00:00

There is a need to segregate the cases when DMA is complete or not.
In case if DMA is already complete there is no need to handle it
again and gracefully exit from the function.

Signed-off-by: Sanjay R Mehta 
Link: https://lore.kernel.org/r/1643814880-3882-3-git-send-email-Sanju.Mehta@amd.com
Signed-off-by: Vinod Koul

dmaengine: ptdma: fix concurrency issue with multiple dma transfer

2022-02-15T05:24:54+00:00

The command should be submitted only if the engine is idle,
for this, the next available descriptor is checked and set the flag
to false in case the descriptor is non-empty.

Signed-off-by: Sanjay R Mehta 
Link: https://lore.kernel.org/r/1643814880-3882-2-git-send-email-Sanju.Mehta@amd.com
Signed-off-by: Vinod Koul

dmaengine: ptdma: Fix the error handling path in pt_core_init()

2022-02-15T05:17:36+00:00

In order to free resources correctly in the error handling path of
pt_core_init(), 2 goto's have to be switched. Otherwise, some resources
will leak and we will try to release things that have not been allocated
yet.

Also move a dev_err() to a place where it is more meaningful.

Fixes: fa5d823b16a9 ("dmaengine: ptdma: Initial driver for the AMD PTDMA")
Signed-off-by: Christophe JAILLET 
Acked-by: Sanjay R Mehta 
Reviewed-by: Dan Carpenter 
Link: https://lore.kernel.org/r/41a963a35173f89c874f5c44df5530dc09fea8da.1644044244.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Vinod Koul

dmaengine: ptdma: remove PT_OFFSET to avoid redefnition

2021-08-29T13:44:21+00:00

Building on ARCH=um causes a "redefined" warning, so remove this
PT_OFFSET macro to avoid the warning.

drivers/dma/ptdma/ptdma.h:34: warning: "PT_OFFSET" redefined
34 | #define PT_OFFSET   0x0
|
In file included from ./arch/um/include/asm/thread_info.h:17,
from ./include/linux/thread_info.h:60,
from ./include/asm-generic/preempt.h:5,
from ./arch/um/include/generated/asm/preempt.h:1,
from ./include/linux/preempt.h:78,
from ./include/linux/spinlock.h:55,
from ./include/linux/wait.h:9,
from ./include/linux/wait_bit.h:8,
from ./include/linux/fs.h:6,
from ./include/linux/debugfs.h:15,
from drivers/dma/ptdma/ptdma-debugfs.c:12:
./arch/x86/um/shared/sysdep/ptrace_user.h:4: note: this is the location of the previous definition
4 | #define PT_OFFSET(r) ((r) * sizeof(long))

Reported-by: kernel test robot 
Fixes: 2a99524459ce ("dmaengine: ptdma: Initial driver for the AMD PTDMA")
Signed-off-by: Sanjay R Mehta 
Link: https://lore.kernel.org/r/1630178908-54973-1-git-send-email-Sanju.Mehta@amd.com
Signed-off-by: Vinod Koul

dmaengine: ptdma: Add debugfs entries for PTDMA

2021-08-29T13:44:20+00:00

Expose data about the configuration and operation of the
PTDMA through debugfs entries: device name, capabilities,
configuration, statistics.

Signed-off-by: Sanjay R Mehta 
Link: https://lore.kernel.org/r/1629208559-51964-4-git-send-email-Sanju.Mehta@amd.com
Signed-off-by: Vinod Koul