| Message ID | 167571664152.587790.608196538260467034.stgit@djiang5-mobl3.local (mailing list archive) |
|---|---|
| State | Handled Elsewhere |
| Headers | show |
| Series | cxl: Add support for QTG ID retrieval for CXL subsystem | expand |
On Mon, 06 Feb 2023 13:50:42 -0700 Dave Jiang <dave.jiang@intel.com> wrote: > Provide a helper to find the ACPI0017 device in order to issue the _DSM. > The helper will take the 'struct device' from a cxl_port and iterate until > the root device is reached. The ACPI handle will be returned from the root > device. > > Signed-off-by: Dave Jiang <dave.jiang@intel.com> > --- > drivers/cxl/core/acpi.c | 30 ++++++++++++++++++++++++++++++ > drivers/cxl/cxl.h | 1 + > 2 files changed, 31 insertions(+) > > diff --git a/drivers/cxl/core/acpi.c b/drivers/cxl/core/acpi.c > index 86dc6c9c1f24..05fcd4751619 100644 > --- a/drivers/cxl/core/acpi.c > +++ b/drivers/cxl/core/acpi.c > @@ -5,6 +5,7 @@ > #include <linux/kernel.h> > #include <linux/acpi.h> > #include <linux/pci.h> > +#include <linux/platform_device.h> > #include <asm/div64.h> > #include "cxlpci.h" > #include "cxl.h" > @@ -13,6 +14,35 @@ const guid_t acpi_cxl_qtg_id_guid = > GUID_INIT(0xF365F9A6, 0xA7DE, 0x4071, > 0xA6, 0x6A, 0xB4, 0x0C, 0x0B, 0x4F, 0x8E, 0x52); > > +/** > + * cxl_acpi_get_root_acpi_handle - get the ACPI handle of the CXL root device > + * @dev: 'struct device' to start searching from. Should be from cxl_port->dev. > + * Looks for the ACPI0017 device and return the ACPI handle > + **/ Inconsistent comment style. > +acpi_handle cxl_acpi_get_rootdev_handle(struct device *dev) > +{ > + struct device *itr = dev, *root_dev; Not nice for readability to have an assignment in a list of definitions all on the same line. > + acpi_handle handle; > + > + if (!dev) > + return ERR_PTR(-EINVAL); > + > + while (itr->parent) { > + root_dev = itr; > + itr = itr->parent; > + } > + > + if (!dev_is_platform(root_dev)) > + return ERR_PTR(-ENODEV); > + > + handle = ACPI_HANDLE(root_dev); > + if (!handle) > + return ERR_PTR(-ENODEV); > + > + return handle; > +} > +EXPORT_SYMBOL_NS_GPL(cxl_acpi_get_rootdev_handle, CXL); > + > /** > * cxl_acpi_evaluate_qtg_dsm - Retrieve QTG ids via ACPI _DSM > * @handle: ACPI handle > diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h > index e70df07f9b4b..ac6ea550ab0a 100644 > --- a/drivers/cxl/cxl.h > +++ b/drivers/cxl/cxl.h > @@ -733,6 +733,7 @@ struct qtg_dsm_output { > > struct qtg_dsm_output *cxl_acpi_evaluate_qtg_dsm(acpi_handle handle, > struct qtg_dsm_input *input); > +acpi_handle cxl_acpi_get_rootdev_handle(struct device *dev); > > /* > * Unit test builds overrides this to __weak, find the 'strong' version > >
On 2/9/23 7:10 AM, Jonathan Cameron wrote: > On Mon, 06 Feb 2023 13:50:42 -0700 > Dave Jiang <dave.jiang@intel.com> wrote: > >> Provide a helper to find the ACPI0017 device in order to issue the _DSM. >> The helper will take the 'struct device' from a cxl_port and iterate until >> the root device is reached. The ACPI handle will be returned from the root >> device. >> >> Signed-off-by: Dave Jiang <dave.jiang@intel.com> >> --- >> drivers/cxl/core/acpi.c | 30 ++++++++++++++++++++++++++++++ >> drivers/cxl/cxl.h | 1 + >> 2 files changed, 31 insertions(+) >> >> diff --git a/drivers/cxl/core/acpi.c b/drivers/cxl/core/acpi.c >> index 86dc6c9c1f24..05fcd4751619 100644 >> --- a/drivers/cxl/core/acpi.c >> +++ b/drivers/cxl/core/acpi.c >> @@ -5,6 +5,7 @@ >> #include <linux/kernel.h> >> #include <linux/acpi.h> >> #include <linux/pci.h> >> +#include <linux/platform_device.h> >> #include <asm/div64.h> >> #include "cxlpci.h" >> #include "cxl.h" >> @@ -13,6 +14,35 @@ const guid_t acpi_cxl_qtg_id_guid = >> GUID_INIT(0xF365F9A6, 0xA7DE, 0x4071, >> 0xA6, 0x6A, 0xB4, 0x0C, 0x0B, 0x4F, 0x8E, 0x52); >> >> +/** >> + * cxl_acpi_get_root_acpi_handle - get the ACPI handle of the CXL root device >> + * @dev: 'struct device' to start searching from. Should be from cxl_port->dev. >> + * Looks for the ACPI0017 device and return the ACPI handle >> + **/ > > Inconsistent comment style. ok > >> +acpi_handle cxl_acpi_get_rootdev_handle(struct device *dev) >> +{ >> + struct device *itr = dev, *root_dev; > > Not nice for readability to have an assignment in a list of definitions > all on the same line. ok > >> + acpi_handle handle; >> + >> + if (!dev) >> + return ERR_PTR(-EINVAL); >> + >> + while (itr->parent) { >> + root_dev = itr; >> + itr = itr->parent; >> + } >> + >> + if (!dev_is_platform(root_dev)) >> + return ERR_PTR(-ENODEV); >> + >> + handle = ACPI_HANDLE(root_dev); >> + if (!handle) >> + return ERR_PTR(-ENODEV); >> + >> + return handle; >> +} >> +EXPORT_SYMBOL_NS_GPL(cxl_acpi_get_rootdev_handle, CXL); >> + >> /** >> * cxl_acpi_evaluate_qtg_dsm - Retrieve QTG ids via ACPI _DSM >> * @handle: ACPI handle >> diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h >> index e70df07f9b4b..ac6ea550ab0a 100644 >> --- a/drivers/cxl/cxl.h >> +++ b/drivers/cxl/cxl.h >> @@ -733,6 +733,7 @@ struct qtg_dsm_output { >> >> struct qtg_dsm_output *cxl_acpi_evaluate_qtg_dsm(acpi_handle handle, >> struct qtg_dsm_input *input); >> +acpi_handle cxl_acpi_get_rootdev_handle(struct device *dev); >> >> /* >> * Unit test builds overrides this to __weak, find the 'strong' version >> >> >
diff --git a/drivers/cxl/core/acpi.c b/drivers/cxl/core/acpi.c index 86dc6c9c1f24..05fcd4751619 100644 --- a/drivers/cxl/core/acpi.c +++ b/drivers/cxl/core/acpi.c @@ -5,6 +5,7 @@ #include <linux/kernel.h> #include <linux/acpi.h> #include <linux/pci.h> +#include <linux/platform_device.h> #include <asm/div64.h> #include "cxlpci.h" #include "cxl.h" @@ -13,6 +14,35 @@ const guid_t acpi_cxl_qtg_id_guid = GUID_INIT(0xF365F9A6, 0xA7DE, 0x4071, 0xA6, 0x6A, 0xB4, 0x0C, 0x0B, 0x4F, 0x8E, 0x52); +/** + * cxl_acpi_get_root_acpi_handle - get the ACPI handle of the CXL root device + * @dev: 'struct device' to start searching from. Should be from cxl_port->dev. + * Looks for the ACPI0017 device and return the ACPI handle + **/ +acpi_handle cxl_acpi_get_rootdev_handle(struct device *dev) +{ + struct device *itr = dev, *root_dev; + acpi_handle handle; + + if (!dev) + return ERR_PTR(-EINVAL); + + while (itr->parent) { + root_dev = itr; + itr = itr->parent; + } + + if (!dev_is_platform(root_dev)) + return ERR_PTR(-ENODEV); + + handle = ACPI_HANDLE(root_dev); + if (!handle) + return ERR_PTR(-ENODEV); + + return handle; +} +EXPORT_SYMBOL_NS_GPL(cxl_acpi_get_rootdev_handle, CXL); + /** * cxl_acpi_evaluate_qtg_dsm - Retrieve QTG ids via ACPI _DSM * @handle: ACPI handle diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index e70df07f9b4b..ac6ea550ab0a 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -733,6 +733,7 @@ struct qtg_dsm_output { struct qtg_dsm_output *cxl_acpi_evaluate_qtg_dsm(acpi_handle handle, struct qtg_dsm_input *input); +acpi_handle cxl_acpi_get_rootdev_handle(struct device *dev); /* * Unit test builds overrides this to __weak, find the 'strong' version
Provide a helper to find the ACPI0017 device in order to issue the _DSM. The helper will take the 'struct device' from a cxl_port and iterate until the root device is reached. The ACPI handle will be returned from the root device. Signed-off-by: Dave Jiang <dave.jiang@intel.com> --- drivers/cxl/core/acpi.c | 30 ++++++++++++++++++++++++++++++ drivers/cxl/cxl.h | 1 + 2 files changed, 31 insertions(+)