From: Vishal Verma <vishal.l.verma@intel.com>
Date: Wed, 13 Apr 2022 01:36:16 -0600
Subject: PCI/ACPI: add a helper for retrieving _OSC Control DWORDs
Patch-mainline: v5.19-rc1
Git-commit: cc10eee95204579fcd66fd5965073fdcbf629676
References: jsc#PED-1408
During _OSC negotiation, when the 'Control' DWORD is needed from the
result buffer after running _OSC, a couple of places performed manual
pointer arithmetic to offset into the right spot in the raw buffer.
Add a acpi_osc_ctx_get_pci_control() helper to use the #define'd
DWORD offsets to fetch the DWORDs needed from @acpi_osc_context, and
replace the above instances of the open-coded arithmetic.
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Suggested-by: Davidlohr Bueso <dave@stgolabs.net>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed by: Adam Manzanares <a.manzanares@samsung.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Link: https://lore.kernel.org/r/20220413073618.291335-2-vishal.l.verma@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Lee, Chun-Yi <jlee@suse.com>
---
drivers/acpi/bus.c | 2 +-
drivers/acpi/pci_root.c | 2 +-
include/linux/acpi.h | 13 +++++++++++++
3 files changed, 15 insertions(+), 2 deletions(-)
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -443,7 +443,7 @@ static void acpi_bus_osc_negotiate_usb_c
}
osc_sb_native_usb4_control =
- control & ((u32 *)context.ret.pointer)[OSC_CONTROL_DWORD];
+ control & acpi_osc_ctx_get_pci_control(&context);
acpi_bus_decode_usb_osc("USB4 _OSC: OS supports", control);
acpi_bus_decode_usb_osc("USB4 _OSC: OS controls",
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -183,7 +183,7 @@ static acpi_status acpi_pci_run_osc(acpi
status = acpi_run_osc(handle, &context);
if (ACPI_SUCCESS(status)) {
- *retval = *((u32 *)(context.ret.pointer + 8));
+ *retval = acpi_osc_ctx_get_pci_control(&context);
kfree(context.ret.pointer);
}
return status;
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -610,6 +610,13 @@ extern u32 osc_sb_native_usb4_control;
#define OSC_PCI_EXPRESS_LTR_CONTROL 0x00000020
#define OSC_PCI_EXPRESS_DPC_CONTROL 0x00000080
+static inline u32 acpi_osc_ctx_get_pci_control(struct acpi_osc_context *context)
+{
+ u32 *ret = context->ret.pointer;
+
+ return ret[OSC_CONTROL_DWORD];
+}
+
#define ACPI_GSB_ACCESS_ATTRIB_QUICK 0x00000002
#define ACPI_GSB_ACCESS_ATTRIB_SEND_RCV 0x00000004
#define ACPI_GSB_ACCESS_ATTRIB_BYTE 0x00000006
@@ -1006,6 +1013,12 @@ static inline int acpi_register_wakeup_h
static inline void acpi_unregister_wakeup_handler(
bool (*wakeup)(void *context), void *context) { }
+struct acpi_osc_context;
+static inline u32 acpi_osc_ctx_get_pci_control(struct acpi_osc_context *context)
+{
+ return 0;
+}
+
#endif /* !CONFIG_ACPI */
#ifdef CONFIG_ACPI_HOTPLUG_IOAPIC