PCI: switchtec: Fix an error handling path in switchtec_pci_probe()

The commit in Fixes changed the logic on how resources are released and
introduced a new switchtec_exit_pci() that need to be call

PCI: switchtec: Fix an error handling path in switchtec_pci_probe()

The commit in Fixes changed the logic on how resources are released and
introduced a new switchtec_exit_pci() that need to be called explicitly in
order to undo a corresponding switchtec_init_pci().

This was done in the remove function, but not in the probe.

Fix the probe now.

Fixes: df25461119d9 ("PCI: switchtec: Fix stdev_release() crash after surprise hot remove")
Link: https://lore.kernel.org/r/01446d2ccb91a578239915812f2b7dfbeb2882af.1703428183.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

show more ...

PCI: switchtec: Fix stdev_release() crash after surprise hot remove

A PCI device hot removal may occur while stdev->cdev is held open. The call
to stdev_release() then happens during close or exit,

PCI: switchtec: Fix stdev_release() crash after surprise hot remove

A PCI device hot removal may occur while stdev->cdev is held open. The call
to stdev_release() then happens during close or exit, at a point way past
switchtec_pci_remove(). Otherwise the last ref would vanish with the
trailing put_device(), just before return.

At that later point in time, the devm cleanup has already removed the
stdev->mmio_mrpc mapping. Also, the stdev->pdev reference was not a counted
one. Therefore, in DMA mode, the iowrite32() in stdev_release() will cause
a fatal page fault, and the subsequent dma_free_coherent(), if reached,
would pass a stale &stdev->pdev->dev pointer.

Fix by moving MRPC DMA shutdown into switchtec_pci_remove(), after
stdev_kill(). Counting the stdev->pdev ref is now optional, but may prevent
future accidents.

Reproducible via the script at
https://lore.kernel.org/r/20231113212150.96410-1-dns@arista.com

Link: https://lore.kernel.org/r/20231122042316.91208-2-dns@arista.com
Signed-off-by: Daniel Stodden <dns@arista.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Dmitry Safonov <dima@arista.com>

show more ...

PCI: switchtec: Add support for PCIe Gen5 devices

Advertise support of Gen5 devices in the driver's device ID table and
add the same IDs for the switchtec quirks. Also update driver code to
accommod

PCI: switchtec: Add support for PCIe Gen5 devices

Advertise support of Gen5 devices in the driver's device ID table and
add the same IDs for the switchtec quirks. Also update driver code to
accommodate them.

Link: https://lore.kernel.org/r/20230624000003.2315364-3-kelvin.cao@microchip.com
Signed-off-by: Kelvin Cao <kelvin.cao@microchip.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>

show more ...

PCI: switchtec: Use normal comment style

Use normal comment style '/* */' for device ID description.

Link: https://lore.kernel.org/r/20230624000003.2315364-2-kelvin.cao@microchip.com
Signed-off-by:

PCI: switchtec: Use normal comment style

Use normal comment style '/* */' for device ID description.

Link: https://lore.kernel.org/r/20230624000003.2315364-2-kelvin.cao@microchip.com
Signed-off-by: Kelvin Cao <kelvin.cao@microchip.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>

show more ...

driver core: class: remove module * from class_create()

The module pointer in class_create() never actually did anything, and it
shouldn't have been requred to be set as a parameter even if it did
s

driver core: class: remove module * from class_create()

The module pointer in class_create() never actually did anything, and it
shouldn't have been requred to be set as a parameter even if it did
something. So just remove it and fix up all callers of the function in
the kernel tree at the same time.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Link: https://lore.kernel.org/r/20230313181843.1207845-4-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

PCI: switchtec: Return -EFAULT for copy_to_user() errors

switchtec_dev_read() didn't handle copy_to_user() errors correctly: it
assigned "rc = -EFAULT", but actually returned either "size", -ENXIO,

PCI: switchtec: Return -EFAULT for copy_to_user() errors

switchtec_dev_read() didn't handle copy_to_user() errors correctly: it
assigned "rc = -EFAULT", but actually returned either "size", -ENXIO, or
-EBADMSG instead.

Update the failure cases to unlock mrpc_mutex and return -EFAULT directly.

Link: https://lore.kernel.org/r/20221216162126.207863-3-helgaas@kernel.org
Fixes: 080b47def5e5 ("MicroSemi Switchtec management interface driver")
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>

show more ...

PCI: switchtec: Simplify switchtec_dma_mrpc_isr()

The "ret" variable in switchtec_dma_mrpc_isr() is superfluous. Remove it
and just return the value. No functional change intended.

Link: https://

PCI: switchtec: Simplify switchtec_dma_mrpc_isr()

The "ret" variable in switchtec_dma_mrpc_isr() is superfluous. Remove it
and just return the value. No functional change intended.

Link: https://lore.kernel.org/r/20221216162126.207863-2-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>

show more ...

PCI: switchtec: Prefer ida_alloc()/free() over ida_simple_get()/remove()

Use ida_alloc() and ida_free() instead of deprecated ida_simple_get() and
ida_simple_remove().

Link: https://lore.kernel.org

PCI: switchtec: Prefer ida_alloc()/free() over ida_simple_get()/remove()

Use ida_alloc() and ida_free() instead of deprecated ida_simple_get() and
ida_simple_remove().

Link: https://lore.kernel.org/r/20220602071115.3833935-1-liuke94@huawei.com
Signed-off-by: Ke Liu <liuke94@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Logan Gunthorpe <logang@deltatee.com>

show more ...

PCI/switchtec: Declare local state_names[] as static

The local state_names[] array is constant and need not be allocated and
populated each time we enter stuser_set_state(). Declare it as static.

PCI/switchtec: Declare local state_names[] as static

The local state_names[] array is constant and need not be allocated and
populated each time we enter stuser_set_state(). Declare it as static.

See the link below for the discussion.

https://lore.kernel.org/r/20211014141859.11444-1-kelvin.cao@microchip.com/

[bhelgaas: simplify commit log]
Suggested-by: Krzysztof Wilczyński <kw@linux.com>
Link: https://lore.kernel.org/r/20211119003803.2333-3-kelvin.cao@microchip.com
Signed-off-by: Kelvin Cao <kelvin.cao@microchip.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>

show more ...

PCI/switchtec: Add Gen4 automotive device IDs

Advertise support of the Gen4 automotive variants in module's device ID
table and add the same IDs to the list of switchtec quirks.

Link: https://lore.

PCI/switchtec: Add Gen4 automotive device IDs

Advertise support of the Gen4 automotive variants in module's device ID
table and add the same IDs to the list of switchtec quirks.

Link: https://lore.kernel.org/r/20211119003803.2333-2-kelvin.cao@microchip.com
Signed-off-by: Kelvin Cao <kelvin.cao@microchip.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>

show more ...

PCI/switchtec: Add check of event support

Not all events are supported by every gen/variant of the Switchtec
firmware. To solve this, since Gen4, a new bit in each event header
is introduced to indi

PCI/switchtec: Add check of event support

Not all events are supported by every gen/variant of the Switchtec
firmware. To solve this, since Gen4, a new bit in each event header
is introduced to indicate if an event is supported by the firmware.

Link: https://lore.kernel.org/r/20211014141859.11444-6-kelvin.cao@microchip.com
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Kelvin Cao <kelvin.cao@microchip.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

show more ...

PCI/switchtec: Replace ENOTSUPP with EOPNOTSUPP

ENOTSUPP is not a SUSV4 error code, and the following checkpatch.pl
warning will be given for new patches which still use ENOTSUPP.

WARNING: ENOT

PCI/switchtec: Replace ENOTSUPP with EOPNOTSUPP

ENOTSUPP is not a SUSV4 error code, and the following checkpatch.pl
warning will be given for new patches which still use ENOTSUPP.

WARNING: ENOTSUPP is not a SUSV4 error code, prefer EOPNOTSUPP

See the link below for the discussion.

https://lore.kernel.org/netdev/20200511165319.2251678-1-kuba@kernel.org/

Replace ENOTSUPP with EOPNOTSUPP to align with future patches which will
be using EOPNOTSUPP.

Link: https://lore.kernel.org/r/20211014141859.11444-5-kelvin.cao@microchip.com
Signed-off-by: Kelvin Cao <kelvin.cao@microchip.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

show more ...

PCI/switchtec: Update the way of getting management VEP instance ID

Gen4 firmware adds DMA VEP and NVMe VEP support in VEP (virtual EP)
instance ID register in addtion to management EP, update the w

PCI/switchtec: Update the way of getting management VEP instance ID

Gen4 firmware adds DMA VEP and NVMe VEP support in VEP (virtual EP)
instance ID register in addtion to management EP, update the way of
getting management VEP instance ID.

Link: https://lore.kernel.org/r/20211014141859.11444-4-kelvin.cao@microchip.com
Signed-off-by: Kelvin Cao <kelvin.cao@microchip.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

show more ...

PCI/switchtec: Fix a MRPC error status handling issue

If an error is encountered when executing a MRPC command, the firmware
will set the status register to SWITCHTEC_MRPC_STATUS_ERROR and return
th

PCI/switchtec: Fix a MRPC error status handling issue

If an error is encountered when executing a MRPC command, the firmware
will set the status register to SWITCHTEC_MRPC_STATUS_ERROR and return
the error code in the return value register.

Add handling of SWITCHTEC_MRPC_STATUS_ERROR on status register when
completing a MRPC command.

Link: https://lore.kernel.org/r/20211014141859.11444-3-kelvin.cao@microchip.com
Signed-off-by: Kelvin Cao <kelvin.cao@microchip.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

show more ...

PCI/switchtec: Error out MRPC execution when MMIO reads fail

A firmware hard reset may be initiated by various mechanisms including a
UART interface, TWI sideband interface from BMC, MRPC command fr

PCI/switchtec: Error out MRPC execution when MMIO reads fail

A firmware hard reset may be initiated by various mechanisms including a
UART interface, TWI sideband interface from BMC, MRPC command from
userspace, etc. The switchtec management driver is unaware of these
resets.

The reset clears PCI state including the BARs and Memory Space Enable
bits, so the device no longer responds to the MMIO accesses the driver
uses to operate it.

MMIO reads to the device will fail with a PCIe error. When the root
complex handles that error, it typically fabricates ~0 data to complete
the CPU read.

Check for this sort of error by reading the device ID from MMIO space.
This ID can never be ~0, so if we see that value, it probably means the
PCIe Memory Read failed and we should return an error indication to the
application using the switchtec driver.

Link: https://lore.kernel.org/r/20211014141859.11444-2-kelvin.cao@microchip.com
Signed-off-by: Kelvin Cao <kelvin.cao@microchip.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

show more ...

PCI/sysfs: Use sysfs_emit() and sysfs_emit_at() in "show" functions

The sysfs_emit() and sysfs_emit_at() functions were introduced to make
it less ambiguous which function is preferred when writing

PCI/sysfs: Use sysfs_emit() and sysfs_emit_at() in "show" functions

The sysfs_emit() and sysfs_emit_at() functions were introduced to make
it less ambiguous which function is preferred when writing to the output
buffer in a device attribute's "show" callback [1].

Convert the PCI sysfs object "show" functions from sprintf(), snprintf()
and scnprintf() to sysfs_emit() and sysfs_emit_at() accordingly, as the
latter is aware of the PAGE_SIZE buffer and correctly returns the number
of bytes written into the buffer.

No functional change intended.

[1] Documentation/filesystems/sysfs.rst

Related commit: ad025f8e46f3 ("PCI/sysfs: Use sysfs_emit() and
sysfs_emit_at() in "show" functions").

Link: https://lore.kernel.org/r/20210603000112.703037-2-kw@linux.com
Signed-off-by: Krzysztof Wilczyński <kw@linux.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>

show more ...

PCI: switchtec: Add missing __iomem tag to fix sparse warnings

Fix a missing __iomem tag in the init_pfn() function. This fixes a sparse
warning of the form:

$ make C=2 drivers/pci/switch/
driv

PCI: switchtec: Add missing __iomem tag to fix sparse warnings

Fix a missing __iomem tag in the init_pfn() function. This fixes a sparse
warning of the form:

$ make C=2 drivers/pci/switch/
drivers/pci/switch/switchtec.c:... incorrect type assignment(different address spaces)

Fixes: 080b47def5e5 ("MicroSemi Switchtec management interface driver")
Link: https://lore.kernel.org/r/20200728192434.18993-2-logang@deltatee.com
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

show more ...

PCI: switchtec: Add missing __iomem and __user tags to fix sparse warnings

Fix a number of missing __iomem and __user tags in the ioctl functions of
the switchtec driver. This fixes a number of spar

PCI: switchtec: Add missing __iomem and __user tags to fix sparse warnings

Fix a number of missing __iomem and __user tags in the ioctl functions of
the switchtec driver. This fixes a number of sparse warnings of the form:

$ make C=2 drivers/pci/switch/
drivers/pci/switch/switchtec.c:... incorrect type in ... (different address spaces)

Fixes: 52eabba5bcdb ("switchtec: Add IOCTLs to the Switchtec driver")
Link: https://lore.kernel.org/r/20200728192434.18993-1-logang@deltatee.com
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

show more ...

PCI/switchtec: Correct bool variable type assignment

Use "true" instead of 1 to initialize "bool use_dma_mrpc". This resolves
the following Coccinelle warning:

drivers/pci/switch/switchtec.c:28:

PCI/switchtec: Correct bool variable type assignment

Use "true" instead of 1 to initialize "bool use_dma_mrpc". This resolves
the following Coccinelle warning:

drivers/pci/switch/switchtec.c:28:12-24: WARNING: Assignment of 0/1 to bool variable

Link: https://lore.kernel.org/r/20200521200439.1076672-1-kw@linux.com
Signed-off-by: Krzysztof Wilczynski <kw@linux.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>

show more ...

pci/switchtec: Replace completion wait queue usage for poll

The poll callback is using the completion wait queue and sticks it into
poll_wait() to wake up pollers after a command has completed.

Thi

pci/switchtec: Replace completion wait queue usage for poll

The poll callback is using the completion wait queue and sticks it into
poll_wait() to wake up pollers after a command has completed.

This works to some extent, but cannot provide EPOLLEXCLUSIVE support
because the waker side uses complete_all() which unconditionally wakes up
all waiters. complete_all() is required because completions internally use
exclusive wait and complete() only wakes up one waiter by default.

This mixes conceptually different mechanisms and relies on internal
implementation details of completions, which in turn puts contraints on
changing the internal implementation of completions.

Replace it with a regular wait queue and store the state in struct
switchtec_user.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200321113240.936097534@linutronix.de

show more ...

PCI/switchtec: Fix init_completion race condition with poll_wait()

The call to init_completion() in mrpc_queue_cmd() can theoretically
race with the call to poll_wait() in switchtec_dev_poll().

p

PCI/switchtec: Fix init_completion race condition with poll_wait()

The call to init_completion() in mrpc_queue_cmd() can theoretically
race with the call to poll_wait() in switchtec_dev_poll().

poll() write()
switchtec_dev_poll() switchtec_dev_write()
poll_wait(&s->comp.wait); mrpc_queue_cmd()
init_completion(&s->comp)
init_waitqueue_head(&s->comp.wait)

To my knowledge, no one has hit this bug.

Fix this by using reinit_completion() instead of init_completion() in
mrpc_queue_cmd().

Fixes: 080b47def5e5 ("MicroSemi Switchtec management interface driver")

Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lkml.kernel.org/r/20200313183608.2646-1-logang@deltatee.com

show more ...

PCI/switchtec: Add Gen4 device IDs

Now that Gen4 is properly supported, advertise support in the module's
device ID table and add the same IDs to the list of switchtec quirks.

[logang@deltatee.com:

PCI/switchtec: Add Gen4 device IDs

Now that Gen4 is properly supported, advertise support in the module's
device ID table and add the same IDs to the list of switchtec quirks.

[logang@deltatee.com: add commit message and quirk IDs]
Link: https://lore.kernel.org/r/20200115035648.2578-8-logang@deltatee.com
Signed-off-by: Kelvin Cao <kelvin.cao@microchip.com>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

show more ...

PCI/switchtec: Add Gen4 MRPC GAS access permission check

Gen4 hardware provides new MRPC commands to read and write directly from
any address in the PCI BAR (which Microsemi refers to as GAS). Since

PCI/switchtec: Add Gen4 MRPC GAS access permission check

Gen4 hardware provides new MRPC commands to read and write directly from
any address in the PCI BAR (which Microsemi refers to as GAS). Since
accessing BARs can be dangerous and break the driver, we don't want
unprivileged users to have this ability.

Therefore, require CAP_SYS_ADMIN for the local and remote GAS access MRPC
commands. Privileged processes will already have access to the BAR through
the sysfs resource file so this doesn't give userspace any capabilities it
didn't already have.

[logang@deltatee.com: rework commit message]
Link: https://lore.kernel.org/r/20200106190337.2428-11-logang@deltatee.com
Signed-off-by: Kelvin Cao <kelvin.cao@microchip.com>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

show more ...

PCI/switchtec: Add Gen4 flash information interface support

Add the new flash_info registers struct and the implementation of
ioctl_flash_part_info() for the new Gen4 hardware.

[logang@deltatee.com

PCI/switchtec: Add Gen4 flash information interface support

Add the new flash_info registers struct and the implementation of
ioctl_flash_part_info() for the new Gen4 hardware.

[logang@deltatee.com: rewrote commit message]
Link: https://lore.kernel.org/r/20200115035648.2578-7-logang@deltatee.com
Signed-off-by: Kelvin Cao <kelvin.cao@microchip.com>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

show more ...

PCI/switchtec: Add Gen4 system info register support

Add the Gen4-specific system info registers and ensure their usage is
guarded by a check on the device's generation.

Link: https://lore.kernel.o

PCI/switchtec: Add Gen4 system info register support

Add the Gen4-specific system info registers and ensure their usage is
guarded by a check on the device's generation.

Link: https://lore.kernel.org/r/20200115035648.2578-6-logang@deltatee.com
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

show more ...