From d3cac1f83c631b9fe5edaebcba49f6989bfff089 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Mon, 1 Feb 2016 22:06:57 +0000 Subject: 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: Ard Biesheuvel Signed-off-by: Matt Fleming Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner 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: Ingo Molnar --- drivers/firmware/efi/runtime-wrappers.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efi/runtime-wrappers.c b/drivers/firmware/efi/runtime-wrappers.c index 228bbf910461..e9f2867f0d91 100644 --- a/drivers/firmware/efi/runtime-wrappers.c +++ b/drivers/firmware/efi/runtime-wrappers.c @@ -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; } -- cgit v1.2.3