efi: Convert efi_call_virt() to efi_call_virt_pointer()

This commit makes a few slight modifications to the efi_call_virt() macro
to get it to work with function pointers that are stored in locations
other than efi.systab->runtime, and renames the macro to
efi_call_virt_pointer().  The majority of the changes here are to pull
these macros up into header files so that they can be accessed from
outside of drivers/firmware/efi/runtime-wrappers.c.

The most significant change not directly related to the code move is to
add an extra "p" argument into the appropriate efi_call macros, and use
that new argument in place of the, formerly hard-coded,
efi.systab->runtime pointer.

The last piece of the puzzle was to add an efi_call_virt() macro back into
drivers/firmware/efi/runtime-wrappers.c to wrap around the new
efi_call_virt_pointer() macro - this was mainly to keep the code from
looking too cluttered by adding a bunch of extra references to
efi.systab->runtime everywhere.

Note that I also broke up the code in the efi_call_virt_pointer() macro a
bit in the process of moving it.

Signed-off-by: Alex Thorlton <athorlton@sgi.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dimitri Sivanich <sivanich@sgi.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roy Franz <roy.franz@linaro.org>
Cc: Russ Anderson <rja@sgi.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1466839230-12781-5-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>

drivers/firmware/efi/runtime-wrappers.c

@@ -22,7 +22,16 @@
 #include <linux/stringify.h>
 #include <asm/efi.h>
 
-static void efi_call_virt_check_flags(unsigned long flags, const char *call)
+/*
+ * Wrap around the new efi_call_virt_generic() macros so that the
+ * code doesn't get too cluttered:
+ */
+#define efi_call_virt(f, args...)   \
+	efi_call_virt_pointer(efi.systab->runtime, f, args)
+#define __efi_call_virt(f, args...) \
+	__efi_call_virt_pointer(efi.systab->runtime, f, args)
+
+void efi_call_virt_check_flags(unsigned long flags, const char *call)
 {
 	unsigned long cur_flags, mismatch;
 
@@ -38,48 +47,6 @@ static void efi_call_virt_check_flags(unsigned long flags, const char *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