| Message ID | 1468461995-32676-7-git-send-email-okaya@codeaurora.org (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On Wed, 13 Jul 2016 22:06:32 -0400 Sinan Kaya <okaya@codeaurora.org> wrote: > 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 <okaya@codeaurora.org> > --- > drivers/vfio/platform/vfio_platform_common.c | 52 +++++++++++++++++++++++++++- > 1 file changed, 51 insertions(+), 1 deletion(-) > > diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c > index 03483c2..2d9c905 100644 > --- a/drivers/vfio/platform/vfio_platform_common.c > +++ b/drivers/vfio/platform/vfio_platform_common.c > @@ -28,6 +28,8 @@ > #define DRIVER_AUTHOR "Antonios Motakis <a.motakis@virtualopensystems.com>" > #define DRIVER_DESC "VFIO platform base module" > > +#define VFIO_PLATFORM_IS_ACPI(vdev) ((vdev)->acpihid != NULL) > + > static LIST_HEAD(reset_list); > static DEFINE_MUTEX(driver_lock); > > @@ -77,13 +79,55 @@ static int vfio_platform_acpi_probe(struct vfio_platform_device *vdev, > #endif > } > > +static inline > +int vfio_platform_acpi_call_reset(struct vfio_platform_device *vdev, > + const char **extra_dbg) > +{ > +#ifdef CONFIG_ACPI > + struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; > + struct device *dev = vdev->device; > + acpi_handle handle = ACPI_HANDLE(dev); > + acpi_status acpi_ret; > + > + acpi_ret = acpi_evaluate_object(handle, "_RST", NULL, &buffer); > + if (ACPI_FAILURE(acpi_ret)) { > + if (extra_dbg) > + *extra_dbg = acpi_format_exception(acpi_ret); > + return -EINVAL; > + } > + > + return 0; > +#else > + return -ENOENT; > +#endif > +} > + > +static inline > +bool vfio_platform_acpi_has_reset(struct vfio_platform_device *vdev) > +{ > +#ifdef CONFIG_ACPI > + struct device *dev = vdev->device; > + acpi_handle handle = ACPI_HANDLE(dev); > + > + return acpi_has_method(handle, "_RST"); > +#else > + return false; > +#endif > +} What exactly is the rationale for making these inline? Clearly reset is not a performance relevant path. Thanks, Alex > + > static bool vfio_platform_has_reset(struct vfio_platform_device *vdev) > { > + if (VFIO_PLATFORM_IS_ACPI(vdev)) > + return vfio_platform_acpi_has_reset(vdev); > + > return vdev->of_reset ? true : false; > } > > static void vfio_platform_get_reset(struct vfio_platform_device *vdev) > { > + if (VFIO_PLATFORM_IS_ACPI(vdev)) > + return; > + > vdev->of_reset = vfio_platform_lookup_reset(vdev->compat, > &vdev->reset_module); > if (!vdev->of_reset) { > @@ -95,6 +139,9 @@ static void vfio_platform_get_reset(struct vfio_platform_device *vdev) > > static void vfio_platform_put_reset(struct vfio_platform_device *vdev) > { > + if (VFIO_PLATFORM_IS_ACPI(vdev)) > + return; > + > if (vdev->of_reset) > module_put(vdev->reset_module); > } > @@ -170,7 +217,10 @@ static void vfio_platform_regions_cleanup(struct vfio_platform_device *vdev) > static int vfio_platform_call_reset(struct vfio_platform_device *vdev, > const char **extra_dbg) > { > - if (vdev->of_reset) { > + if (VFIO_PLATFORM_IS_ACPI(vdev)) { > + dev_info(vdev->device, "reset\n"); > + return vfio_platform_acpi_call_reset(vdev, extra_dbg); > + } else if (vdev->of_reset) { > dev_info(vdev->device, "reset\n"); > return vdev->of_reset(vdev); > } -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 7/14/2016 6:04 PM, Alex Williamson wrote: >> +static inline >> > +bool vfio_platform_acpi_has_reset(struct vfio_platform_device *vdev) >> > +{ >> > +#ifdef CONFIG_ACPI >> > + struct device *dev = vdev->device; >> > + acpi_handle handle = ACPI_HANDLE(dev); >> > + >> > + return acpi_has_method(handle, "_RST"); >> > +#else >> > + return false; >> > +#endif >> > +} > What exactly is the rationale for making these inline? Clearly reset > is not a performance relevant path. Thanks, > > Alex > It is remaining from the previous stub functions which were inline. I'll get rid of the inlines.
diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c index 03483c2..2d9c905 100644 --- a/drivers/vfio/platform/vfio_platform_common.c +++ b/drivers/vfio/platform/vfio_platform_common.c @@ -28,6 +28,8 @@ #define DRIVER_AUTHOR "Antonios Motakis <a.motakis@virtualopensystems.com>" #define DRIVER_DESC "VFIO platform base module" +#define VFIO_PLATFORM_IS_ACPI(vdev) ((vdev)->acpihid != NULL) + static LIST_HEAD(reset_list); static DEFINE_MUTEX(driver_lock); @@ -77,13 +79,55 @@ static int vfio_platform_acpi_probe(struct vfio_platform_device *vdev, #endif } +static inline +int vfio_platform_acpi_call_reset(struct vfio_platform_device *vdev, + const char **extra_dbg) +{ +#ifdef CONFIG_ACPI + struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; + struct device *dev = vdev->device; + acpi_handle handle = ACPI_HANDLE(dev); + acpi_status acpi_ret; + + acpi_ret = acpi_evaluate_object(handle, "_RST", NULL, &buffer); + if (ACPI_FAILURE(acpi_ret)) { + if (extra_dbg) + *extra_dbg = acpi_format_exception(acpi_ret); + return -EINVAL; + } + + return 0; +#else + return -ENOENT; +#endif +} + +static inline +bool vfio_platform_acpi_has_reset(struct vfio_platform_device *vdev) +{ +#ifdef CONFIG_ACPI + struct device *dev = vdev->device; + acpi_handle handle = ACPI_HANDLE(dev); + + return acpi_has_method(handle, "_RST"); +#else + return false; +#endif +} + static bool vfio_platform_has_reset(struct vfio_platform_device *vdev) { + if (VFIO_PLATFORM_IS_ACPI(vdev)) + return vfio_platform_acpi_has_reset(vdev); + return vdev->of_reset ? true : false; } static void vfio_platform_get_reset(struct vfio_platform_device *vdev) { + if (VFIO_PLATFORM_IS_ACPI(vdev)) + return; + vdev->of_reset = vfio_platform_lookup_reset(vdev->compat, &vdev->reset_module); if (!vdev->of_reset) { @@ -95,6 +139,9 @@ static void vfio_platform_get_reset(struct vfio_platform_device *vdev) static void vfio_platform_put_reset(struct vfio_platform_device *vdev) { + if (VFIO_PLATFORM_IS_ACPI(vdev)) + return; + if (vdev->of_reset) module_put(vdev->reset_module); } @@ -170,7 +217,10 @@ static void vfio_platform_regions_cleanup(struct vfio_platform_device *vdev) static int vfio_platform_call_reset(struct vfio_platform_device *vdev, const char **extra_dbg) { - if (vdev->of_reset) { + if (VFIO_PLATFORM_IS_ACPI(vdev)) { + dev_info(vdev->device, "reset\n"); + return vfio_platform_acpi_call_reset(vdev, extra_dbg); + } else if (vdev->of_reset) { dev_info(vdev->device, "reset\n"); return vdev->of_reset(vdev); }
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 <okaya@codeaurora.org> --- drivers/vfio/platform/vfio_platform_common.c | 52 +++++++++++++++++++++++++++- 1 file changed, 51 insertions(+), 1 deletion(-)