Commit cc10eee9 authored by Vishal Verma's avatar Vishal Verma Committed by Dan Williams
Browse files

PCI/ACPI: add a helper for retrieving _OSC Control DWORDs 



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: default avatarDavidlohr Bueso <dave@stgolabs.net>
Acked-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: default avatarDavidlohr Bueso <dave@stgolabs.net>
Reviewed by: Adam Manzanares <a.manzanares@samsung.com>
Signed-off-by: default avatarVishal Verma <vishal.l.verma@intel.com>
Link: https://lore.kernel.org/r/20220413073618.291335-2-vishal.l.verma@intel.com


Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 35e01667

drivers/acpi/bus.c

+1 −1
Original line number Diff line number Diff line
@@ -425,7 +425,7 @@ static void acpi_bus_osc_negotiate_usb_control(void) 
	}



	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",

drivers/acpi/pci_root.c

+1 −1
Original line number Diff line number Diff line
@@ -183,7 +183,7 @@ static acpi_status acpi_pci_run_osc(acpi_handle handle, 


	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;

include/linux/acpi.h

+13 −0
Original line number Diff line number Diff line
@@ -608,6 +608,13 @@ 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
@@ -1004,6 +1011,12 @@ static inline int acpi_register_wakeup_handler(int wake_irq, 
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