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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-09-11 04:34:46 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-09-11 04:34:46 -0300
commit863981e96738983919de841ec669e157e6bdaeb0 (patch)
treed6d89a12e7eb8017837c057935a2271290907f76 /drivers/firmware/efi/runtime-wrappers.c
parent8dec7c70575785729a6a9e6719a955e9c545bcab (diff)
Linux-libre 4.7.1-gnupck-4.7.1-gnu
Diffstat (limited to 'drivers/firmware/efi/runtime-wrappers.c')
-rw-r--r--drivers/firmware/efi/runtime-wrappers.c60
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