diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2021-09-08 16:33:21 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-09-08 16:33:21 -0700 |
commit | 9c566611ac5cc7b45af943632f7a9b1b6a642991 (patch) | |
tree | 5317ae932fad42578cb75518cc1e94d8eb82aeb5 /drivers/pci/pci-acpi.c | |
parent | 0f4b9289bad354b606190a4cd54d5222b4e41d98 (diff) | |
parent | e543b10cd9d75309c820d2175200d09b2a62f249 (diff) | |
download | linux-9c566611ac5cc7b45af943632f7a9b1b6a642991.tar.bz2 |
Merge tag 'acpi-5.15-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull more ACPI updates from Rafael Wysocki:
"These add ACPI support to the PCI VMD driver, improve suspend-to-idle
support for AMD platforms and update documentation.
Specifics:
- Add ACPI support to the PCI VMD driver (Rafael Wysocki)
- Rearrange suspend-to-idle support code to reflect the platform
firmware expectations on some AMD platforms (Mario Limonciello)
- Make SSDT overlays documentation follow the code documented by it
more closely (Andy Shevchenko)"
* tag 'acpi-5.15-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
ACPI: PM: s2idle: Run both AMD and Microsoft methods if both are supported
Documentation: ACPI: Align the SSDT overlays file with the code
PCI: VMD: ACPI: Make ACPI companion lookup work for VMD bus
Diffstat (limited to 'drivers/pci/pci-acpi.c')
-rw-r--r-- | drivers/pci/pci-acpi.c | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c index fe286c861187..a1b1e2a01632 100644 --- a/drivers/pci/pci-acpi.c +++ b/drivers/pci/pci-acpi.c @@ -17,6 +17,7 @@ #include <linux/pci-acpi.h> #include <linux/pm_runtime.h> #include <linux/pm_qos.h> +#include <linux/rwsem.h> #include "pci.h" /* @@ -1178,6 +1179,69 @@ void acpi_pci_remove_bus(struct pci_bus *bus) } /* ACPI bus type */ + + +static DECLARE_RWSEM(pci_acpi_companion_lookup_sem); +static struct acpi_device *(*pci_acpi_find_companion_hook)(struct pci_dev *); + +/** + * pci_acpi_set_companion_lookup_hook - Set ACPI companion lookup callback. + * @func: ACPI companion lookup callback pointer or NULL. + * + * Set a special ACPI companion lookup callback for PCI devices whose companion + * objects in the ACPI namespace have _ADR with non-standard bus-device-function + * encodings. + * + * Return 0 on success or a negative error code on failure (in which case no + * changes are made). + * + * The caller is responsible for the appropriate ordering of the invocations of + * this function with respect to the enumeration of the PCI devices needing the + * callback installed by it. + */ +int pci_acpi_set_companion_lookup_hook(struct acpi_device *(*func)(struct pci_dev *)) +{ + int ret; + + if (!func) + return -EINVAL; + + down_write(&pci_acpi_companion_lookup_sem); + + if (pci_acpi_find_companion_hook) { + ret = -EBUSY; + } else { + pci_acpi_find_companion_hook = func; + ret = 0; + } + + up_write(&pci_acpi_companion_lookup_sem); + + return ret; +} +EXPORT_SYMBOL_GPL(pci_acpi_set_companion_lookup_hook); + +/** + * pci_acpi_clear_companion_lookup_hook - Clear ACPI companion lookup callback. + * + * Clear the special ACPI companion lookup callback previously set by + * pci_acpi_set_companion_lookup_hook(). Block until the last running instance + * of the callback returns before clearing it. + * + * The caller is responsible for the appropriate ordering of the invocations of + * this function with respect to the enumeration of the PCI devices needing the + * callback cleared by it. + */ +void pci_acpi_clear_companion_lookup_hook(void) +{ + down_write(&pci_acpi_companion_lookup_sem); + + pci_acpi_find_companion_hook = NULL; + + up_write(&pci_acpi_companion_lookup_sem); +} +EXPORT_SYMBOL_GPL(pci_acpi_clear_companion_lookup_hook); + static struct acpi_device *acpi_pci_find_companion(struct device *dev) { struct pci_dev *pci_dev = to_pci_dev(dev); @@ -1185,6 +1249,16 @@ static struct acpi_device *acpi_pci_find_companion(struct device *dev) bool check_children; u64 addr; + down_read(&pci_acpi_companion_lookup_sem); + + adev = pci_acpi_find_companion_hook ? + pci_acpi_find_companion_hook(pci_dev) : NULL; + + up_read(&pci_acpi_companion_lookup_sem); + + if (adev) + return adev; + check_children = pci_is_bridge(pci_dev); /* Please ref to ACPI spec for the syntax of _ADR */ addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn); |