[PATCH 1/3] Convert efi_call_virt to efi_call_virt_pointer

From: Alex Thorlton
Date: Wed Jun 15 2016 - 15:04:34 EST


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@xxxxxxx>
Cc: Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx>
Cc: Russ Anderson <rja@xxxxxxx>
Cc: Dimitri Sivanich <sivanich@xxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Roy Franz <roy.franz@xxxxxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-efi@xxxxxxxxxxxxxxx
Cc: x86@xxxxxxxxxx
---
arch/arm/include/asm/efi.h | 4 +--
arch/arm64/include/asm/efi.h | 4 +--
arch/x86/include/asm/efi.h | 9 +++---
drivers/firmware/efi/runtime-wrappers.c | 53 +++++++--------------------------
include/linux/efi.h | 51 +++++++++++++++++++++++++++++++
5 files changed, 69 insertions(+), 52 deletions(-)

diff --git a/arch/arm/include/asm/efi.h b/arch/arm/include/asm/efi.h
index a708fa1..766bf9b 100644
--- a/arch/arm/include/asm/efi.h
+++ b/arch/arm/include/asm/efi.h
@@ -28,10 +28,10 @@ int efi_set_mapping_permissions(struct mm_struct *mm, efi_memory_desc_t *md);
#define arch_efi_call_virt_setup() efi_virtmap_load()
#define arch_efi_call_virt_teardown() efi_virtmap_unload()

-#define arch_efi_call_virt(f, args...) \
+#define arch_efi_call_virt(p, f, args...) \
({ \
efi_##f##_t *__f; \
- __f = efi.systab->runtime->f; \
+ __f = p->f; \
__f(args); \
})

diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h
index 622db3c..bd88766 100644
--- a/arch/arm64/include/asm/efi.h
+++ b/arch/arm64/include/asm/efi.h
@@ -23,10 +23,10 @@ int efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md);
efi_virtmap_load(); \
})

-#define arch_efi_call_virt(f, args...) \
+#define arch_efi_call_virt(p, f, args...) \
({ \
efi_##f##_t *__f; \
- __f = efi.systab->runtime->f; \
+ __f = p->f; \
__f(args); \
})

diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h
index 78d1e74..55b4596 100644
--- a/arch/x86/include/asm/efi.h
+++ b/arch/x86/include/asm/efi.h
@@ -41,10 +41,9 @@ extern unsigned long asmlinkage efi_call_phys(void *, ...);
/*
* Wrap all the virtual calls in a way that forces the parameters on the stack.
*/
-#define arch_efi_call_virt(f, args...) \
+#define arch_efi_call_virt(p, f, args...) \
({ \
- ((efi_##f##_t __attribute__((regparm(0)))*) \
- efi.systab->runtime->f)(args); \
+ ((efi_##f##_t __attribute__((regparm(0)))*) p->f)(args); \
})

#define efi_ioremap(addr, size, type, attr) ioremap_cache(addr, size)
@@ -81,8 +80,8 @@ struct efi_scratch {
} \
})

-#define arch_efi_call_virt(f, args...) \
- efi_call((void *)efi.systab->runtime->f, args) \
+#define arch_efi_call_virt(p, f, args...) \
+ efi_call((void *)p->f, args) \

#define arch_efi_call_virt_teardown() \
({ \
diff --git a/drivers/firmware/efi/runtime-wrappers.c b/drivers/firmware/efi/runtime-wrappers.c
index 23bef6b..6a364f5 100644
--- a/drivers/firmware/efi/runtime-wrappers.c
+++ b/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;

@@ -39,48 +48,6 @@ static void efi_call_virt_check_flags(unsigned long flags, const char *call)
}

/*
- * 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
* serialized. (source: UEFI Specification v2.4A)
diff --git a/include/linux/efi.h b/include/linux/efi.h
index f196dd0..3cf6afb 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -1465,4 +1465,55 @@ efi_status_t efi_setup_gop(efi_system_table_t *sys_table_arg,
unsigned long size);

bool efi_runtime_disabled(void);
+extern void efi_call_virt_check_flags(unsigned long flags, const char *call);
+
+/*
+ * 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_pointer(p, f, args...) \
+({ \
+ efi_status_t __s; \
+ unsigned long flags; \
+ \
+ arch_efi_call_virt_setup(); \
+ \
+ local_save_flags(flags); \
+ __s = arch_efi_call_virt(p, f, args); \
+ efi_call_virt_check_flags(flags, __stringify(f)); \
+ \
+ arch_efi_call_virt_teardown(); \
+ \
+ __s; \
+})
+
+#define __efi_call_virt_pointer(p, f, args...) \
+({ \
+ unsigned long flags; \
+ \
+ arch_efi_call_virt_setup(); \
+ \
+ local_save_flags(flags); \
+ arch_efi_call_virt(p, f, args); \
+ efi_call_virt_check_flags(flags, __stringify(f)); \
+ \
+ arch_efi_call_virt_teardown(); \
+})
+
#endif /* _LINUX_EFI_H */
--
1.8.5.6