diff options
Diffstat (limited to 'drivers/firmware/efi/runtime-wrappers.c')
| -rw-r--r-- | drivers/firmware/efi/runtime-wrappers.c | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/drivers/firmware/efi/runtime-wrappers.c b/drivers/firmware/efi/runtime-wrappers.c index de6953039..23bef6bb7 100644 --- a/drivers/firmware/efi/runtime-wrappers.c +++ b/drivers/firmware/efi/runtime-wrappers.c @@ -16,10 +16,70 @@ #include <linux/bug.h> #include <linux/efi.h> +#include <linux/irqflags.h> #include <linux/mutex.h> #include <linux/spinlock.h> +#include <linux/stringify.h> #include <asm/efi.h> +static void efi_call_virt_check_flags(unsigned long flags, const char *call) +{ + unsigned long cur_flags, mismatch; + + local_save_flags(cur_flags); + + mismatch = flags ^ cur_flags; + if (!WARN_ON_ONCE(mismatch & ARCH_EFI_IRQ_FLAGS_MASK)) + return; + + add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_NOW_UNRELIABLE); + pr_err_ratelimited(FW_BUG "IRQ flags corrupted (0x%08lx=>0x%08lx) by EFI %s\n", + flags, cur_flags, call); + local_irq_restore(flags); +} + +/* + * Arch code can implement the following three template macros, avoiding + * reptition for the void/non-void return cases of {__,}efi_call_virt: + * + * * arch_efi_call_virt_setup + * + * Sets up the environment for the call (e.g. switching page tables, + * allowing kernel-mode use of floating point, if required). + * + * * arch_efi_call_virt + * + * Performs the call. The last expression in the macro must be the call + * itself, allowing the logic to be shared by the void and non-void + * cases. + * + * * arch_efi_call_virt_teardown + * + * Restores the usual kernel environment once the call has returned. + */ + +#define efi_call_virt(f, args...) \ +({ \ + efi_status_t __s; \ + unsigned long flags; \ + arch_efi_call_virt_setup(); \ + local_save_flags(flags); \ + __s = arch_efi_call_virt(f, args); \ + efi_call_virt_check_flags(flags, __stringify(f)); \ + arch_efi_call_virt_teardown(); \ + __s; \ +}) + +#define __efi_call_virt(f, args...) \ +({ \ + unsigned long flags; \ + arch_efi_call_virt_setup(); \ + local_save_flags(flags); \ + arch_efi_call_virt(f, args); \ + efi_call_virt_check_flags(flags, __stringify(f)); \ + arch_efi_call_virt_teardown(); \ +}) + /* * According to section 7.1 of the UEFI spec, Runtime Services are not fully * reentrant, and there are particular combinations of calls that need to be |