On 6/23/2016 2:59 PM, Alex Williamson wrote: > On Mon, 13 Jun 2016 00:26:38 -0400 > Sinan Kaya <[email protected]> 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 <[email protected]> >> Reviewed-by: Eric Auger <[email protected]> >> --- >> drivers/vfio/platform/vfio_platform_common.c | 51 >> ++++++++++++++++++++++++++++ >> 1 file changed, 51 insertions(+) >> >> diff --git a/drivers/vfio/platform/vfio_platform_common.c >> b/drivers/vfio/platform/vfio_platform_common.c >> index e7ce2c2..0ea8c26 100644 >> --- a/drivers/vfio/platform/vfio_platform_common.c >> +++ b/drivers/vfio/platform/vfio_platform_common.c >> @@ -73,21 +73,66 @@ static int vfio_platform_acpi_probe(struct >> vfio_platform_device *vdev, >> } >> return 0; >> } >> + >> +static int vfio_platform_acpi_call_reset(struct vfio_platform_device *vdev, >> + const char **extra_dbg) >> +{ >> + struct device *dev = vdev->device; >> + acpi_handle handle = ACPI_HANDLE(dev); >> + acpi_status acpi_ret; >> + unsigned long long val; >> + >> + acpi_ret = acpi_evaluate_integer(handle, "_RST", NULL, &val); >> + if (ACPI_FAILURE(acpi_ret)) { >> + if (extra_dbg) >> + *extra_dbg = acpi_format_exception(acpi_ret); >> + return -EINVAL; >> + } >> + >> + return 0; >> +} >> + >> +static bool vfio_platform_acpi_has_reset(struct vfio_platform_device *vdev) >> +{ >> + struct device *dev = vdev->device; >> + acpi_handle handle = ACPI_HANDLE(dev); >> + >> + return acpi_has_method(handle, "_RST"); >> +} >> #else >> static inline int vfio_platform_acpi_probe(struct vfio_platform_device >> *vdev, >> struct device *dev) >> { >> return -ENOENT; >> } >> + >> +static inline >> +int vfio_platform_acpi_call_reset(struct vfio_platform_device *vdev, >> + const char **extra_dbg) >> +{ >> + return -ENOENT; >> +} >> + >> +static inline >> +bool vfio_platform_acpi_has_reset(struct vfio_platform_device *vdev) >> +{ >> + return false; >> +} >> #endif >> >> static bool vfio_platform_has_reset(struct vfio_platform_device *vdev) >> { >> + if (vdev->acpihid) >> + 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 (vdev->acpihid) >> + return; >> + >> vdev->of_reset = vfio_platform_lookup_reset(vdev->compat, >> &vdev->reset_module); >> if (!vdev->of_reset) { >> @@ -99,6 +144,9 @@ static void vfio_platform_get_reset(struct >> vfio_platform_device *vdev) >> >> static void vfio_platform_put_reset(struct vfio_platform_device *vdev) >> { >> + if (vdev->acpihid) >> + return; >> + >> if (vdev->of_reset) >> module_put(vdev->reset_module); >> } >> @@ -177,6 +225,9 @@ static int vfio_platform_call_reset(struct >> vfio_platform_device *vdev, >> if (vdev->of_reset) { >> dev_info(vdev->device, "reset\n"); >> return vdev->of_reset(vdev); >> + } else if (vdev->acpihid) { >> + dev_info(vdev->device, "reset\n"); >> + return vfio_platform_acpi_call_reset(vdev, extra_dbg); > > > nit, all the cases until this one prioritize ACPI over DT, here we have > the opposite.
I'll reorder to be consistent. > Granted we should never have of_reset set when acpihid > is set. A macro like > > #define vfio_platform_is_acpi(vdev) (vdev->acpihid != NULL) > > might be useful. I like your idea. If you don't mind, I like capitals in macros. > > >> } >> >> dev_warn(vdev->device, "no reset function found!\n"); > -- Sinan Kaya Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.
