linux-stable.git/drivers/vfio/platform, branch linux-4.9.y

vfio: platform: Do not pass return buffer to ACPI _RST method

2023-01-07T11:07:24+00:00

[ Upstream commit e67e070632a665c932d534b8b800477bb3111449 ]

The ACPI _RST method has no return value, there's no need to pass a return
buffer to acpi_evaluate_object().

Fixes: d30daa33ec1d ("vfio: platform: call _RST method when using ACPI")
Signed-off-by: Rafael Mendonca 
Reviewed-by: Eric Auger 
Link: https://lore.kernel.org/r/20221018152825.891032-1-rafaelmendsr@gmail.com
Signed-off-by: Alex Williamson 
Signed-off-by: Sasha Levin

vfio/platform: fix module_put call in error flow

2021-06-10T10:42:35+00:00

[ Upstream commit dc51ff91cf2d1e9a2d941da483602f71d4a51472 ]

The ->parent_module is the one that use in try_module_get. It should
also be the one the we use in module_put during vfio_platform_open().

Fixes: 32a2d71c4e80 ("vfio: platform: introduce vfio-platform-base module")
Signed-off-by: Max Gurtovoy 
Message-Id: <20210518192133.59195-1-mgurtovoy@nvidia.com>
Signed-off-by: Alex Williamson 
Signed-off-by: Sasha Levin

vfio: platform: Fix reset module leak in error path

2018-08-03T05:55:13+00:00

[ Upstream commit 28a68387888997e8a7fa57940ea5d55f2e16b594 ]

If the IOMMU group setup fails, the reset module is not released.

Fixes: b5add544d677d363 ("vfio, platform: make reset driver a requirement by default")
Signed-off-by: Geert Uytterhoeven 
Reviewed-by: Eric Auger 
Reviewed-by: Simon Horman 
Acked-by: Eric Auger 
Signed-off-by: Alex Williamson 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

vfio: platform: mark symbols static where possible

2016-09-13T22:11:37+00:00

We get a few warnings when building kernel with W=1:
drivers/vfio/platform/vfio_platform_common.c:76:5: warning: no previous prototype for 'vfio_platform_acpi_call_reset' [-Wmissing-prototypes]
drivers/vfio/platform/vfio_platform_common.c:98:6: warning: no previous prototype for 'vfio_platform_acpi_has_reset' [-Wmissing-prototypes]
drivers/vfio/platform/vfio_platform_common.c:640:5: warning: no previous prototype for 'vfio_platform_of_probe' [-Wmissing-prototypes]
drivers/vfio/platform/reset/vfio_platform_amdxgbe.c:59:5: warning: no previous prototype for 'vfio_platform_amdxgbe_reset' [-Wmissing-prototypes]
drivers/vfio/platform/reset/vfio_platform_calxedaxgmac.c:60:5: warning: no previous prototype for 'vfio_platform_calxedaxgmac_reset' [-Wmissing-prototypes]
....

In fact, these functions are only used in the file in which they are
declared and don't need a declaration, but can be made static.
so this patch marks these functions with 'static'.

Signed-off-by: Baoyou Xie 
Acked-by: Arnd Bergmann 
Reviewed-by: Eric Auger 
Reviewed-by: Baptiste Reynal 
Signed-off-by: Alex Williamson

vfio: platform: check reset call return code during release

2016-07-19T16:54:45+00:00

Release call is ignoring the return code from reset call and can
potentially continue even though reset call failed.

If reset_required module parameter is set, this patch is going
to validate the return code and will cause stack dump with
WARN_ON and warn the user of failure.

Signed-off-by: Sinan Kaya 
Reviewed-by: Eric Auger 
Reviewed-by: Baptiste Reynal 
Signed-off-by: Alex Williamson

vfio: platform: check reset call return code during open

2016-07-19T16:54:45+00:00

Open call is ignoring the return code from reset call and can
potentially continue even though reset call failed.

If reset_required module parameter is set, this patch is going
to validate the return code and will abort open if reset fails.

Signed-off-by: Sinan Kaya 
Reviewed-by: Baptiste Reynal 
Reviewed-by: Eric Auger 
Signed-off-by: Alex Williamson

vfio, platform: make reset driver a requirement by default

2016-07-19T16:26:46+00:00

The code was allowing platform devices to be used without a supporting
VFIO reset driver. The hardware can be left in some inconsistent state
after a guest machine abort.

The reset driver will put the hardware back to safe state and disable
interrupts before returning the control back to the host machine.

Adding a new reset_required kernel module option to platform VFIO drivers.
The default value is true for the DT and ACPI based drivers.
The reset requirement value for AMBA drivers is set to false and is
unchangeable to maintain the existing functionality.

New requirements are:
1. A reset function needs to be implemented by the corresponding driver
via DT/ACPI.
2. The reset function needs to be discovered via DT/ACPI.

The probe of the driver will fail if any of the above conditions are
not satisfied.

Signed-off-by: Sinan Kaya 
Signed-off-by: Alex Williamson

vfio: platform: call _RST method when using ACPI

2016-07-19T16:26:44+00:00

The device tree code checks for the presence of a reset driver and calls
the of_reset function pointer by looking up the reset driver as a module.

ACPI defines _RST method to perform device level reset. After the _RST
method is executed, the OS can resume using the device. _RST method is
expected to stop DMA transfers and IRQs.

This patch introduces two functions as vfio_platform_acpi_has_reset and
vfio_platform_acpi_call_reset. The has reset method is used to declare
reset capability via the ioctl flag VFIO_DEVICE_FLAGS_RESET. The call
reset function is used to execute the _RST ACPI method.

Signed-off-by: Sinan Kaya 
Signed-off-by: Alex Williamson

vfio: platform: add extra debug info argument to call reset

2016-07-19T16:26:43+00:00

Getting ready to bring out extra debug information to the caller
so that more verbose information can be printed when an error is
observed.

Signed-off-by: Sinan Kaya 
Reviewed-by: Baptiste Reynal 
Signed-off-by: Alex Williamson

vfio: platform: add support for ACPI probe

2016-07-19T16:26:41+00:00

The code is using the compatible DT string to associate a reset driver
with the actual device itself. The compatible string does not exist on
ACPI based systems. HID is the unique identifier for a device driver
instead.

Signed-off-by: Sinan Kaya 
Signed-off-by: Alex Williamson