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Commit d3cac1f8 authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Ingo Molnar
Browse files

efi/runtime-wrappers: Add a nonblocking version of QueryVariableInfo() 



This introduces a new runtime wrapper for the
QueryVariableInfo() UEFI Runtime Service, which gives up
immediately rather than spins on failure to grab the efi_runtime
spinlock.

This is required in the non-blocking path of the efi-pstore
code.

Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: default avatarMatt Fleming <matt@codeblueprint.co.uk>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1454364428-494-4-git-send-email-matt@codeblueprint.co.uk


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 70d2a3cf

drivers/firmware/efi/runtime-wrappers.c

+22 −0
Original line number Diff line number Diff line
@@ -230,6 +230,27 @@ static efi_status_t virt_efi_query_variable_info(u32 attr, 
	return status;

}



static efi_status_t

virt_efi_query_variable_info_nonblocking(u32 attr,

					 u64 *storage_space,

					 u64 *remaining_space,

					 u64 *max_variable_size)

{

	unsigned long flags;

	efi_status_t status;



	if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)

		return EFI_UNSUPPORTED;



	if (!spin_trylock_irqsave(&efi_runtime_lock, flags))

		return EFI_NOT_READY;



	status = efi_call_virt(query_variable_info, attr, storage_space,

			       remaining_space, max_variable_size);

	spin_unlock_irqrestore(&efi_runtime_lock, flags);

	return status;

}



static efi_status_t virt_efi_get_next_high_mono_count(u32 *count)

{

	unsigned long flags;
@@ -300,6 +321,7 @@ void efi_native_runtime_setup(void) 
	efi.get_next_high_mono_count = virt_efi_get_next_high_mono_count;

	efi.reset_system = virt_efi_reset_system;

	efi.query_variable_info = virt_efi_query_variable_info;

	efi.query_variable_info_nonblocking = virt_efi_query_variable_info_nonblocking;

	efi.update_capsule = virt_efi_update_capsule;

	efi.query_capsule_caps = virt_efi_query_capsule_caps;

}

include/linux/efi.h

+1 −0
Original line number Diff line number Diff line
@@ -849,6 +849,7 @@ extern struct efi { 
	efi_set_variable_t *set_variable;

	efi_set_variable_t *set_variable_nonblocking;

	efi_query_variable_info_t *query_variable_info;

	efi_query_variable_info_t *query_variable_info_nonblocking;

	efi_update_capsule_t *update_capsule;

	efi_query_capsule_caps_t *query_capsule_caps;

	efi_get_next_high_mono_count_t *get_next_high_mono_count;