linux-stable.git/drivers/ufs, branch linux-6.8.y

scsi: ufs: core: mcq: Fix ufshcd_mcq_sqe_search()

2024-05-30T07:49:15+00:00

[ Upstream commit 3c5d0dce8ce0a2781ac306b9ad1492b005ecbab5 ]

Fix the calculation of the utrd pointer. This patch addresses the following
Coverity complaint:

CID 1538170: (#1 of 1): Extra sizeof expression (SIZEOF_MISMATCH)
suspicious_pointer_arithmetic: Adding sq_head_slot * 32UL /* sizeof (struct
utp_transfer_req_desc) */ to pointer hwq->sqe_base_addr of type struct
utp_transfer_req_desc * is suspicious because adding an integral value to
this pointer automatically scales that value by the size, 32 bytes, of the
pointed-to type, struct utp_transfer_req_desc. Most likely, the
multiplication by sizeof (struct utp_transfer_req_desc) in this expression
is extraneous and should be eliminated.

Cc: Bao D. Nguyen 
Cc: Stanley Chu 
Cc: Can Guo 
Fixes: 8d7290348992 ("scsi: ufs: mcq: Add supporting functions for MCQ abort")
Signed-off-by: Bart Van Assche 
Link: https://lore.kernel.org/r/20240410000751.1047758-1-bvanassche@acm.org
Signed-off-by: Martin K. Petersen 
Signed-off-by: Sasha Levin

scsi: ufs: core: Perform read back after disabling UIC_COMMAND_COMPL

2024-05-30T07:49:10+00:00

[ Upstream commit 4bf3855497b60765ca03b983d064b25e99b97657 ]

Currently, the UIC_COMMAND_COMPL interrupt is disabled and a wmb() is used
to complete the register write before any following writes.

wmb() ensures the writes complete in that order, but completion doesn't
mean that it isn't stored in a buffer somewhere. The recommendation for
ensuring this bit has taken effect on the device is to perform a read back
to force it to make it all the way to the device. This is documented in
device-io.rst and a talk by Will Deacon on this can be seen over here:

    https://youtu.be/i6DayghhA8Q?si=MiyxB5cKJXSaoc01&t=1678

Let's do that to ensure the bit hits the device. Because the wmb()'s
purpose wasn't to add extra ordering (on top of the ordering guaranteed by
writel()/readl()), it can safely be removed.

Fixes: d75f7fe495cf ("scsi: ufs: reduce the interrupts for power mode change requests")
Reviewed-by: Bart Van Assche 
Reviewed-by: Can Guo 
Reviewed-by: Manivannan Sadhasivam 
Signed-off-by: Andrew Halaney 
Link: https://lore.kernel.org/r/20240329-ufs-reset-ensure-effect-before-delay-v5-9-181252004586@redhat.com
Signed-off-by: Martin K. Petersen 
Signed-off-by: Sasha Levin

scsi: ufs: core: Perform read back after disabling interrupts

2024-05-30T07:49:09+00:00

[ Upstream commit e4a628877119bd40164a651d20321247b6f94a8b ]

Currently, interrupts are cleared and disabled prior to registering the
interrupt. An mb() is used to complete the clear/disable writes before the
interrupt is registered.

mb() ensures that the write completes, but completion doesn't mean that it
isn't stored in a buffer somewhere. The recommendation for ensuring these
bits have taken effect on the device is to perform a read back to force it
to make it all the way to the device. This is documented in device-io.rst
and a talk by Will Deacon on this can be seen over here:

    https://youtu.be/i6DayghhA8Q?si=MiyxB5cKJXSaoc01&t=1678

Let's do that to ensure these bits hit the device. Because the mb()'s
purpose wasn't to add extra ordering (on top of the ordering guaranteed by
writel()/readl()), it can safely be removed.

Fixes: 199ef13cac7d ("scsi: ufs: avoid spurious UFS host controller interrupts")
Reviewed-by: Manivannan Sadhasivam 
Reviewed-by: Bart Van Assche 
Reviewed-by: Can Guo 
Signed-off-by: Andrew Halaney 
Link: https://lore.kernel.org/r/20240329-ufs-reset-ensure-effect-before-delay-v5-8-181252004586@redhat.com
Signed-off-by: Martin K. Petersen 
Signed-off-by: Sasha Levin

scsi: ufs: core: Perform read back after writing UTP_TASK_REQ_LIST_BASE_H

2024-05-30T07:49:09+00:00

[ Upstream commit 408e28086f1c7a6423efc79926a43d7001902fae ]

Currently, the UTP_TASK_REQ_LIST_BASE_L/UTP_TASK_REQ_LIST_BASE_H regs are
written to and then completed with an mb().

mb() ensures that the write completes, but completion doesn't mean that it
isn't stored in a buffer somewhere. The recommendation for ensuring these
bits have taken effect on the device is to perform a read back to force it
to make it all the way to the device. This is documented in device-io.rst
and a talk by Will Deacon on this can be seen over here:

    https://youtu.be/i6DayghhA8Q?si=MiyxB5cKJXSaoc01&t=1678

Let's do that to ensure the bits hit the device. Because the mb()'s purpose
wasn't to add extra ordering (on top of the ordering guaranteed by
writel()/readl()), it can safely be removed.

Fixes: 88441a8d355d ("scsi: ufs: core: Add hibernation callbacks")
Reviewed-by: Manivannan Sadhasivam 
Reviewed-by: Bart Van Assche 
Reviewed-by: Can Guo 
Signed-off-by: Andrew Halaney 
Link: https://lore.kernel.org/r/20240329-ufs-reset-ensure-effect-before-delay-v5-7-181252004586@redhat.com
Signed-off-by: Martin K. Petersen 
Signed-off-by: Sasha Levin

scsi: ufs: cdns-pltfrm: Perform read back after writing HCLKDIV

2024-05-30T07:49:09+00:00

[ Upstream commit b715c55daf598aac8fa339048e4ca8a0916b332e ]

Currently, HCLKDIV is written to and then completed with an mb().

mb() ensures that the write completes, but completion doesn't mean that it
isn't stored in a buffer somewhere. The recommendation for ensuring this
bit has taken effect on the device is to perform a read back to force it to
make it all the way to the device. This is documented in device-io.rst and
a talk by Will Deacon on this can be seen over here:

    https://youtu.be/i6DayghhA8Q?si=MiyxB5cKJXSaoc01&t=1678

Let's do that to ensure the bit hits the device. Because the mb()'s purpose
wasn't to add extra ordering (on top of the ordering guaranteed by
writel()/readl()), it can safely be removed.

Fixes: d90996dae8e4 ("scsi: ufs: Add UFS platform driver for Cadence UFS")
Reviewed-by: Manivannan Sadhasivam 
Signed-off-by: Andrew Halaney 
Link: https://lore.kernel.org/r/20240329-ufs-reset-ensure-effect-before-delay-v5-6-181252004586@redhat.com
Reviewed-by: Bart Van Assche 
Signed-off-by: Martin K. Petersen 
Signed-off-by: Sasha Levin

scsi: ufs: qcom: Perform read back after writing CGC enable

2024-05-30T07:49:09+00:00

[ Upstream commit d9488511b3ac7eb48a91bc5eded7027525525e03 ]

Currently, the CGC enable bit is written and then an mb() is used to ensure
that completes before continuing.

mb() ensures that the write completes, but completion doesn't mean that it
isn't stored in a buffer somewhere. The recommendation for ensuring this
bit has taken effect on the device is to perform a read back to force it to
make it all the way to the device. This is documented in device-io.rst and
a talk by Will Deacon on this can be seen over here:

    https://youtu.be/i6DayghhA8Q?si=MiyxB5cKJXSaoc01&t=1678

Let's do that to ensure the bit hits the device. Because the mb()'s purpose
wasn't to add extra ordering (on top of the ordering guaranteed by
writel()/readl()), it can safely be removed.

Reviewed-by: Manivannan Sadhasivam 
Reviewed-by: Can Guo 
Fixes: 81c0fc51b7a7 ("ufs-qcom: add support for Qualcomm Technologies Inc platforms")
Signed-off-by: Andrew Halaney 
Link: https://lore.kernel.org/r/20240329-ufs-reset-ensure-effect-before-delay-v5-5-181252004586@redhat.com
Signed-off-by: Martin K. Petersen 
Signed-off-by: Sasha Levin

scsi: ufs: qcom: Perform read back after writing unipro mode

2024-05-30T07:49:09+00:00

[ Upstream commit 823150ecf04f958213cf3bf162187cd1a91c885c ]

Currently, the QUNIPRO_SEL bit is written to and then an mb() is used to
ensure that completes before continuing.

mb() ensures that the write completes, but completion doesn't mean that it
isn't stored in a buffer somewhere. The recommendation for ensuring this
bit has taken effect on the device is to perform a read back to force it to
make it all the way to the device. This is documented in device-io.rst and
a talk by Will Deacon on this can be seen over here:

    https://youtu.be/i6DayghhA8Q?si=MiyxB5cKJXSaoc01&t=1678

But, there's really no reason to even ensure completion before
continuing. The only requirement here is that this write is ordered to this
endpoint (which readl()/writel() guarantees already). For that reason the
mb() can be dropped altogether without anything forcing completion.

Fixes: f06fcc7155dc ("scsi: ufs-qcom: add QUniPro hardware support and power optimizations")
Signed-off-by: Andrew Halaney 
Link: https://lore.kernel.org/r/20240329-ufs-reset-ensure-effect-before-delay-v5-4-181252004586@redhat.com
Reviewed-by: Manivannan Sadhasivam 
Signed-off-by: Martin K. Petersen 
Signed-off-by: Sasha Levin

scsi: ufs: qcom: Perform read back after writing REG_UFS_SYS1CLK_1US

2024-05-30T07:49:09+00:00

[ Upstream commit a862fafa263aea0f427d51aca6ff7fd9eeaaa8bd ]

Currently after writing to REG_UFS_SYS1CLK_1US a mb() is used to ensure
that write has gone through to the device.

mb() ensures that the write completes, but completion doesn't mean that it
isn't stored in a buffer somewhere. The recommendation for ensuring this
bit has taken effect on the device is to perform a read back to force it to
make it all the way to the device. This is documented in device-io.rst and
a talk by Will Deacon on this can be seen over here:

    https://youtu.be/i6DayghhA8Q?si=MiyxB5cKJXSaoc01&t=1678

Let's do that to ensure the bit hits the device. Because the mb()'s purpose
wasn't to add extra ordering (on top of the ordering guaranteed by
writel()/readl()), it can safely be removed.

Fixes: f06fcc7155dc ("scsi: ufs-qcom: add QUniPro hardware support and power optimizations")
Reviewed-by: Can Guo 
Signed-off-by: Andrew Halaney 
Link: https://lore.kernel.org/r/20240329-ufs-reset-ensure-effect-before-delay-v5-2-181252004586@redhat.com
Reviewed-by: Manivannan Sadhasivam 
Signed-off-by: Martin K. Petersen 
Signed-off-by: Sasha Levin

scsi: ufs: qcom: Perform read back after writing reset bit

2024-05-30T07:49:09+00:00

[ Upstream commit c4d28e06b0c94636f6e35d003fa9ebac0a94e1ae ]

Currently, the reset bit for the UFS provided reset controller (used by its
phy) is written to, and then a mb() happens to try and ensure that hit the
device. Immediately afterwards a usleep_range() occurs.

mb() ensures that the write completes, but completion doesn't mean that it
isn't stored in a buffer somewhere. The recommendation for ensuring this
bit has taken effect on the device is to perform a read back to force it to
make it all the way to the device. This is documented in device-io.rst and
a talk by Will Deacon on this can be seen over here:

    https://youtu.be/i6DayghhA8Q?si=MiyxB5cKJXSaoc01&t=1678

Let's do that to ensure the bit hits the device. By doing so and
guaranteeing the ordering against the immediately following usleep_range(),
the mb() can safely be removed.

Fixes: 81c0fc51b7a7 ("ufs-qcom: add support for Qualcomm Technologies Inc platforms")
Reviewed-by: Manivannan Sadhasivam 
Reviewed-by: Can Guo 
Signed-off-by: Andrew Halaney 
Link: https://lore.kernel.org/r/20240329-ufs-reset-ensure-effect-before-delay-v5-1-181252004586@redhat.com
Signed-off-by: Martin K. Petersen 
Signed-off-by: Sasha Levin

scsi: ufs: core: Fix MCQ mode dev command timeout

2024-05-17T10:14:40+00:00

[ Upstream commit 2a26a11e9c258b14be6fd98f8a85f20ac1fff66e ]

When a dev command times out in MCQ mode, a successfully cleared command
should cause a retry. However, because we currently return 0, the caller
considers the command a success which causes the following error to be
logged: "Invalid offset 0x0 in descriptor IDN 0x9, length 0x0".

Retry if clearing the command was successful.

Signed-off-by: Peter Wang 
Link: https://lore.kernel.org/r/20240328111244.3599-1-peter.wang@mediatek.com
Reviewed-by: Bart Van Assche 
Signed-off-by: Martin K. Petersen 
Signed-off-by: Sasha Levin