[PATCHv2 0/3] x86/UV, x86/efi: Re-factor efi_call_virt for general use

[PATCHv2 0/3] x86/UV, x86/efi: Re-factor efi_call_virt for general use

[Alex Thorlton]

Hey guys,

This patchset creates a general purpose version of the efi_call_virt
macro that does not assume that the function pointer being passed in is
inside of efi.systab->runtime.  It also fixes up uv_bios_call to use the
new functionality, and does a bit of cleanup in the efi_thunk macro.

Quick breakdown of the patches:

Patch 1) Move necessary macros to locations where we can access them.
	 Remove hard-coded efi.systab reference from efi_call_virt.
	 Rename/create new macros as needed.
Patch 2) Simple change to allow UV code to utilize the new
	 functionality.  Included a detailed explanation of how we got
	 here.
Patch 3) Replace a few bits of the efi_thunk macro with the
	 arch_efi_call_setup/teardown macros.

The first two have been tested on simulators and hardware, but the third
has only been compile-tested.  I don't have any hardware to test that
on.

Updates for v2:

- Fix up arm and arm64 versions of arch_efi_call_virt.  I missed these
  on my first pass 
- Add some more detail to the commit message for the uv_bios_call fix.
- Change the third patch to use the arch_efi_call_setup/teardown macros
  inside of the efi_thunk macro, instead of replacing efi_thunk entirely
  for the CONFIG_EFI_MIXED case.

Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Russ Anderson <rja@sgi.com>
Cc: Dimitri Sivanich <sivanich@sgi.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Roy Franz <roy.franz@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-efi@vger.kernel.org
Cc: x86@kernel.org

Alex Thorlton (3):
  Convert efi_call_virt to efi_call_virt_pointer
  Update uv_bios_call to use efi_call_virt_pointer
  Update efi_thunk to use the the arch_efi_call_virt* macros

 arch/arm/include/asm/efi.h              |  4 +--
 arch/arm64/include/asm/efi.h            |  4 +--
 arch/x86/include/asm/efi.h              |  9 +++---
 arch/x86/platform/efi/efi_64.c          | 11 ++-----
 arch/x86/platform/uv/bios_uv.c          |  3 +-
 drivers/firmware/efi/runtime-wrappers.c | 53 +++++++--------------------------
 include/linux/efi.h                     | 51 +++++++++++++++++++++++++++++++
 7 files changed, 73 insertions(+), 62 deletions(-)

-- 
1.8.5.6

[PATCHv2 0/3] x86/UV, x86/efi: Re-factor efi_call_virt for general use

[Alex Thorlton]

Hey guys,

This patchset creates a general purpose version of the efi_call_virt
macro that does not assume that the function pointer being passed in is
inside of efi.systab->runtime.  It also fixes up uv_bios_call to use the
new functionality, and does a bit of cleanup in the efi_thunk macro.

Quick breakdown of the patches:

Patch 1) Move necessary macros to locations where we can access them.
	 Remove hard-coded efi.systab reference from efi_call_virt.
	 Rename/create new macros as needed.
Patch 2) Simple change to allow UV code to utilize the new
	 functionality.  Included a detailed explanation of how we got
	 here.
Patch 3) Replace a few bits of the efi_thunk macro with the
	 arch_efi_call_setup/teardown macros.

The first two have been tested on simulators and hardware, but the third
has only been compile-tested.  I don't have any hardware to test that
on.

Updates for v2:

- Fix up arm and arm64 versions of arch_efi_call_virt.  I missed these
  on my first pass 
- Add some more detail to the commit message for the uv_bios_call fix.
- Change the third patch to use the arch_efi_call_setup/teardown macros
  inside of the efi_thunk macro, instead of replacing efi_thunk entirely
  for the CONFIG_EFI_MIXED case.

Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Russ Anderson <rja@sgi.com>
Cc: Dimitri Sivanich <sivanich@sgi.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Roy Franz <roy.franz@linaro.org>
Cc: linux-arm-kernel at lists.infradead.org
Cc: linux-efi at vger.kernel.org
Cc: x86 at kernel.org

Alex Thorlton (3):
  Convert efi_call_virt to efi_call_virt_pointer
  Update uv_bios_call to use efi_call_virt_pointer
  Update efi_thunk to use the the arch_efi_call_virt* macros

 arch/arm/include/asm/efi.h              |  4 +--
 arch/arm64/include/asm/efi.h            |  4 +--
 arch/x86/include/asm/efi.h              |  9 +++---
 arch/x86/platform/efi/efi_64.c          | 11 ++-----
 arch/x86/platform/uv/bios_uv.c          |  3 +-
 drivers/firmware/efi/runtime-wrappers.c | 53 +++++++--------------------------
 include/linux/efi.h                     | 51 +++++++++++++++++++++++++++++++
 7 files changed, 73 insertions(+), 62 deletions(-)

-- 
1.8.5.6

[PATCH 1/3] Convert efi_call_virt to efi_call_virt_pointer

[Alex Thorlton]

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>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Russ Anderson <rja@sgi.com>
Cc: Dimitri Sivanich <sivanich@sgi.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Roy Franz <roy.franz@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-efi@vger.kernel.org
Cc: x86@kernel.org
---
 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

[PATCH 1/3] Convert efi_call_virt to efi_call_virt_pointer

[Alex Thorlton]

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>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Russ Anderson <rja@sgi.com>
Cc: Dimitri Sivanich <sivanich@sgi.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Roy Franz <roy.franz@linaro.org>
Cc: linux-arm-kernel at lists.infradead.org
Cc: linux-efi at vger.kernel.org
Cc: x86 at kernel.org
---
 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

[PATCH 2/3] Update uv_bios_call to use efi_call_virt_pointer

[Alex Thorlton]

Now that the efi_call_virt macro has been generalized to be able to
use EFI system tables besides efi.systab, we are able to convert our
uv_bios_call wrapper to use this standard EFI callback mechanism.

This simple change is part of a much larger effort to recover from some
issues with the way we were mapping in some of our MMRs, and the way
that we were doing our BIOS callbacks, which were uncovered by commit
67a9108ed431 ("x86/efi: Build our own page table structures").

The first issue that this uncovered was that we were relying on the EFI
memory mapping mechanism to map in our MMR space for us, which, while
reliable, was technically a bug, as it relied on "undefined" behavior in
the mapping code.

The reason we were able to piggyback on the EFI memory mapping code to
map in our MMRs was because, previously, EFI code used the
trampoline_pgd, which shares a few entries with the main kernel pgd.  It
just so happened, that the memory range containing our MMRs was inside
one of those shared regions, which kept our code working without issue
for quite a while.

Anyways, once we discovered this problem, we brought back our original
code to map in the MMRs with commit 08914f436bdd ("x86/platform/UV:
Bring back the call to map_low_mmrs in uv_system_init").  This got our
systems a little further along, but we were still running into trouble
with our EFI callbacks, which prevented us from booting all the way up.

Our first step towards fixing the BIOS callbacks was to get our
uv_bios_call wrapper updated to use efi_call_virt instead of the plain
efi_call.  The previous patch took care of the effort needed to make
that possible.  Along the way, we hit a major issue with some confusion
about how to properly pull arguments higher than number 6 off the stack
in the efi_call code, which resulted in Linus's commit 683ad8092cd2
("x86/efi: Fix 7-parameter efi_call()s").

Now that all of those issues are out of the way, we're able to make this
simple change to use the new efi_call_virt_pointer in uv_bios_call which
gets our machines booting, running properly, and able to execute our
callbacks with 6+ arguments.

Note that, since we are now using the EFI page table when we make our
function call, we are no longer able to make the call using the __va()
of our function pointer, since the memory range containing that address
isn't mapped into the EFI page table.  For now, we will use the physical
address of the function directly, since that is mapped into the EFI page
table.  In the near future, we're going to get some code added in to
properly update our function pointer to its virtual address during
SetVirtualAddressMap.

Signed-off-by: Alex Thorlton <athorlton@sgi.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Russ Anderson <rja@sgi.com>
Cc: Dimitri Sivanich <sivanich@sgi.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Roy Franz <roy.franz@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-efi@vger.kernel.org
Cc: x86@kernel.org
---
 arch/x86/platform/uv/bios_uv.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/x86/platform/uv/bios_uv.c b/arch/x86/platform/uv/bios_uv.c
index 815fec6..66b2166 100644
--- a/arch/x86/platform/uv/bios_uv.c
+++ b/arch/x86/platform/uv/bios_uv.c
@@ -40,8 +40,7 @@ s64 uv_bios_call(enum uv_bios_cmd which, u64 a1, u64 a2, u64 a3, u64 a4, u64 a5)
 		 */
 		return BIOS_STATUS_UNIMPLEMENTED;
 
-	ret = efi_call((void *)__va(tab->function), (u64)which,
-			a1, a2, a3, a4, a5);
+	ret = efi_call_virt_pointer(tab, function, (u64)which, a1, a2, a3, a4, a5);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(uv_bios_call);
-- 
1.8.5.6

[PATCH 2/3] Update uv_bios_call to use efi_call_virt_pointer

[Alex Thorlton]

Now that the efi_call_virt macro has been generalized to be able to
use EFI system tables besides efi.systab, we are able to convert our
uv_bios_call wrapper to use this standard EFI callback mechanism.

This simple change is part of a much larger effort to recover from some
issues with the way we were mapping in some of our MMRs, and the way
that we were doing our BIOS callbacks, which were uncovered by commit
67a9108ed431 ("x86/efi: Build our own page table structures").

The first issue that this uncovered was that we were relying on the EFI
memory mapping mechanism to map in our MMR space for us, which, while
reliable, was technically a bug, as it relied on "undefined" behavior in
the mapping code.

The reason we were able to piggyback on the EFI memory mapping code to
map in our MMRs was because, previously, EFI code used the
trampoline_pgd, which shares a few entries with the main kernel pgd.  It
just so happened, that the memory range containing our MMRs was inside
one of those shared regions, which kept our code working without issue
for quite a while.

Anyways, once we discovered this problem, we brought back our original
code to map in the MMRs with commit 08914f436bdd ("x86/platform/UV:
Bring back the call to map_low_mmrs in uv_system_init").  This got our
systems a little further along, but we were still running into trouble
with our EFI callbacks, which prevented us from booting all the way up.

Our first step towards fixing the BIOS callbacks was to get our
uv_bios_call wrapper updated to use efi_call_virt instead of the plain
efi_call.  The previous patch took care of the effort needed to make
that possible.  Along the way, we hit a major issue with some confusion
about how to properly pull arguments higher than number 6 off the stack
in the efi_call code, which resulted in Linus's commit 683ad8092cd2
("x86/efi: Fix 7-parameter efi_call()s").

Now that all of those issues are out of the way, we're able to make this
simple change to use the new efi_call_virt_pointer in uv_bios_call which
gets our machines booting, running properly, and able to execute our
callbacks with 6+ arguments.

Note that, since we are now using the EFI page table when we make our
function call, we are no longer able to make the call using the __va()
of our function pointer, since the memory range containing that address
isn't mapped into the EFI page table.  For now, we will use the physical
address of the function directly, since that is mapped into the EFI page
table.  In the near future, we're going to get some code added in to
properly update our function pointer to its virtual address during
SetVirtualAddressMap.

Signed-off-by: Alex Thorlton <athorlton@sgi.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Russ Anderson <rja@sgi.com>
Cc: Dimitri Sivanich <sivanich@sgi.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Roy Franz <roy.franz@linaro.org>
Cc: linux-arm-kernel at lists.infradead.org
Cc: linux-efi at vger.kernel.org
Cc: x86 at kernel.org
---
 arch/x86/platform/uv/bios_uv.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/x86/platform/uv/bios_uv.c b/arch/x86/platform/uv/bios_uv.c
index 815fec6..66b2166 100644
--- a/arch/x86/platform/uv/bios_uv.c
+++ b/arch/x86/platform/uv/bios_uv.c
@@ -40,8 +40,7 @@ s64 uv_bios_call(enum uv_bios_cmd which, u64 a1, u64 a2, u64 a3, u64 a4, u64 a5)
 		 */
 		return BIOS_STATUS_UNIMPLEMENTED;
 
-	ret = efi_call((void *)__va(tab->function), (u64)which,
-			a1, a2, a3, a4, a5);
+	ret = efi_call_virt_pointer(tab, function, (u64)which, a1, a2, a3, a4, a5);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(uv_bios_call);
-- 
1.8.5.6

[PATCH 3/3] Update efi_thunk to use the the arch_efi_call_virt* macros

[Alex Thorlton]

Currently, the efi_thunk macro has some semi-duplicated code in it that
can be replaced with the arch_efi_call_virt_setup/teardown macros. This
commit simply replaces the duplicated code with those macros.

Signed-off-by: Alex Thorlton <athorlton@sgi.com>
Suggested-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Russ Anderson <rja@sgi.com>
Cc: Dimitri Sivanich <sivanich@sgi.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Roy Franz <roy.franz@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-efi@vger.kernel.org
Cc: x86@kernel.org
---
 arch/x86/platform/efi/efi_64.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
index 6e7242b..4cc2b96 100644
--- a/arch/x86/platform/efi/efi_64.c
+++ b/arch/x86/platform/efi/efi_64.c
@@ -469,18 +469,13 @@ extern efi_status_t efi64_thunk(u32, ...);
 	unsigned long flags;						\
 	u32 func;							\
 									\
-	efi_sync_low_kernel_mappings();					\
 	local_irq_save(flags);						\
-									\
-	efi_scratch.prev_cr3 = read_cr3();				\
-	write_cr3((unsigned long)efi_scratch.efi_pgt);			\
-	__flush_tlb_all();						\
+	arch_efi_call_virt_setup();					\
 									\
 	func = runtime_service32(f);					\
-	__s = efi64_thunk(func, __VA_ARGS__);			\
+	__s = efi64_thunk(func, __VA_ARGS__);				\
 									\
-	write_cr3(efi_scratch.prev_cr3);				\
-	__flush_tlb_all();						\
+	arch_efi_call_virt_teardown();					\
 	local_irq_restore(flags);					\
 									\
 	__s;								\
-- 
1.8.5.6

[PATCH 3/3] Update efi_thunk to use the the arch_efi_call_virt* macros

[Alex Thorlton]

Currently, the efi_thunk macro has some semi-duplicated code in it that
can be replaced with the arch_efi_call_virt_setup/teardown macros. This
commit simply replaces the duplicated code with those macros.

Signed-off-by: Alex Thorlton <athorlton-sJ/iWh9BUns@public.gmane.org>
Suggested-by: Matt Fleming <matt-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org>
Cc: Russ Anderson <rja-sJ/iWh9BUns@public.gmane.org>
Cc: Dimitri Sivanich <sivanich-sJ/iWh9BUns@public.gmane.org>
Cc: Russell King <linux-I+IVW8TIWO2tmTQ+vhA3Yw@public.gmane.org>
Cc: Catalin Marinas <catalin.marinas-5wv7dgnIgG8@public.gmane.org>
Cc: Will Deacon <will.deacon-5wv7dgnIgG8@public.gmane.org>
Cc: Thomas Gleixner <tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>
Cc: Ingo Molnar <mingo-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Cc: "H. Peter Anvin" <hpa-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org>
Cc: Ard Biesheuvel <ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Cc: Mark Rutland <mark.rutland-5wv7dgnIgG8@public.gmane.org>
Cc: Roy Franz <roy.franz-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Cc: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
Cc: linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Cc: x86-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org
---
 arch/x86/platform/efi/efi_64.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
index 6e7242b..4cc2b96 100644
--- a/arch/x86/platform/efi/efi_64.c
+++ b/arch/x86/platform/efi/efi_64.c
@@ -469,18 +469,13 @@ extern efi_status_t efi64_thunk(u32, ...);
 	unsigned long flags;						\
 	u32 func;							\
 									\
-	efi_sync_low_kernel_mappings();					\
 	local_irq_save(flags);						\
-									\
-	efi_scratch.prev_cr3 = read_cr3();				\
-	write_cr3((unsigned long)efi_scratch.efi_pgt);			\
-	__flush_tlb_all();						\
+	arch_efi_call_virt_setup();					\
 									\
 	func = runtime_service32(f);					\
-	__s = efi64_thunk(func, __VA_ARGS__);			\
+	__s = efi64_thunk(func, __VA_ARGS__);				\
 									\
-	write_cr3(efi_scratch.prev_cr3);				\
-	__flush_tlb_all();						\
+	arch_efi_call_virt_teardown();					\
 	local_irq_restore(flags);					\
 									\
 	__s;								\
-- 
1.8.5.6

[PATCH 3/3] Update efi_thunk to use the the arch_efi_call_virt* macros

[Alex Thorlton]

Currently, the efi_thunk macro has some semi-duplicated code in it that
can be replaced with the arch_efi_call_virt_setup/teardown macros. This
commit simply replaces the duplicated code with those macros.

Signed-off-by: Alex Thorlton <athorlton@sgi.com>
Suggested-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Russ Anderson <rja@sgi.com>
Cc: Dimitri Sivanich <sivanich@sgi.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Roy Franz <roy.franz@linaro.org>
Cc: linux-arm-kernel at lists.infradead.org
Cc: linux-efi at vger.kernel.org
Cc: x86 at kernel.org
---
 arch/x86/platform/efi/efi_64.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
index 6e7242b..4cc2b96 100644
--- a/arch/x86/platform/efi/efi_64.c
+++ b/arch/x86/platform/efi/efi_64.c
@@ -469,18 +469,13 @@ extern efi_status_t efi64_thunk(u32, ...);
 	unsigned long flags;						\
 	u32 func;							\
 									\
-	efi_sync_low_kernel_mappings();					\
 	local_irq_save(flags);						\
-									\
-	efi_scratch.prev_cr3 = read_cr3();				\
-	write_cr3((unsigned long)efi_scratch.efi_pgt);			\
-	__flush_tlb_all();						\
+	arch_efi_call_virt_setup();					\
 									\
 	func = runtime_service32(f);					\
-	__s = efi64_thunk(func, __VA_ARGS__);			\
+	__s = efi64_thunk(func, __VA_ARGS__);				\
 									\
-	write_cr3(efi_scratch.prev_cr3);				\
-	__flush_tlb_all();						\
+	arch_efi_call_virt_teardown();					\
 	local_irq_restore(flags);					\
 									\
 	__s;								\
-- 
1.8.5.6

Re: [PATCHv2 0/3] x86/UV, x86/efi: Re-factor efi_call_virt for general use

[Matt Fleming]

On Wed, 15 Jun, at 02:04:12PM, Alex Thorlton wrote:
> Hey guys,
> 
> This patchset creates a general purpose version of the efi_call_virt
> macro that does not assume that the function pointer being passed in is
> inside of efi.systab->runtime.  It also fixes up uv_bios_call to use the
> new functionality, and does a bit of cleanup in the efi_thunk macro.
> 
> Quick breakdown of the patches:
> 
> Patch 1) Move necessary macros to locations where we can access them.
> 	 Remove hard-coded efi.systab reference from efi_call_virt.
> 	 Rename/create new macros as needed.
> Patch 2) Simple change to allow UV code to utilize the new
> 	 functionality.  Included a detailed explanation of how we got
> 	 here.
> Patch 3) Replace a few bits of the efi_thunk macro with the
> 	 arch_efi_call_setup/teardown macros.
> 
> The first two have been tested on simulators and hardware, but the third
> has only been compile-tested.  I don't have any hardware to test that
> on.
> 
> Updates for v2:
> 
> - Fix up arm and arm64 versions of arch_efi_call_virt.  I missed these
>   on my first pass 
> - Add some more detail to the commit message for the uv_bios_call fix.
> - Change the third patch to use the arch_efi_call_setup/teardown macros
>   inside of the efi_thunk macro, instead of replacing efi_thunk entirely
>   for the CONFIG_EFI_MIXED case.

Whole series looks good to me Alex, and everything works fine on my
mixed-mode config. Applied for v4.8, thanks!

Re: [PATCHv2 0/3] x86/UV, x86/efi: Re-factor efi_call_virt for general use

[Matt Fleming]

On Wed, 15 Jun, at 02:04:12PM, Alex Thorlton wrote:
> Hey guys,
> 
> This patchset creates a general purpose version of the efi_call_virt
> macro that does not assume that the function pointer being passed in is
> inside of efi.systab->runtime.  It also fixes up uv_bios_call to use the
> new functionality, and does a bit of cleanup in the efi_thunk macro.
> 
> Quick breakdown of the patches:
> 
> Patch 1) Move necessary macros to locations where we can access them.
> 	 Remove hard-coded efi.systab reference from efi_call_virt.
> 	 Rename/create new macros as needed.
> Patch 2) Simple change to allow UV code to utilize the new
> 	 functionality.  Included a detailed explanation of how we got
> 	 here.
> Patch 3) Replace a few bits of the efi_thunk macro with the
> 	 arch_efi_call_setup/teardown macros.
> 
> The first two have been tested on simulators and hardware, but the third
> has only been compile-tested.  I don't have any hardware to test that
> on.
> 
> Updates for v2:
> 
> - Fix up arm and arm64 versions of arch_efi_call_virt.  I missed these
>   on my first pass 
> - Add some more detail to the commit message for the uv_bios_call fix.
> - Change the third patch to use the arch_efi_call_setup/teardown macros
>   inside of the efi_thunk macro, instead of replacing efi_thunk entirely
>   for the CONFIG_EFI_MIXED case.

Whole series looks good to me Alex, and everything works fine on my
mixed-mode config. Applied for v4.8, thanks!

[PATCHv2 0/3] x86/UV, x86/efi: Re-factor efi_call_virt for general use

[Matt Fleming]

On Wed, 15 Jun, at 02:04:12PM, Alex Thorlton wrote:
> Hey guys,
> 
> This patchset creates a general purpose version of the efi_call_virt
> macro that does not assume that the function pointer being passed in is
> inside of efi.systab->runtime.  It also fixes up uv_bios_call to use the
> new functionality, and does a bit of cleanup in the efi_thunk macro.
> 
> Quick breakdown of the patches:
> 
> Patch 1) Move necessary macros to locations where we can access them.
> 	 Remove hard-coded efi.systab reference from efi_call_virt.
> 	 Rename/create new macros as needed.
> Patch 2) Simple change to allow UV code to utilize the new
> 	 functionality.  Included a detailed explanation of how we got
> 	 here.
> Patch 3) Replace a few bits of the efi_thunk macro with the
> 	 arch_efi_call_setup/teardown macros.
> 
> The first two have been tested on simulators and hardware, but the third
> has only been compile-tested.  I don't have any hardware to test that
> on.
> 
> Updates for v2:
> 
> - Fix up arm and arm64 versions of arch_efi_call_virt.  I missed these
>   on my first pass 
> - Add some more detail to the commit message for the uv_bios_call fix.
> - Change the third patch to use the arch_efi_call_setup/teardown macros
>   inside of the efi_thunk macro, instead of replacing efi_thunk entirely
>   for the CONFIG_EFI_MIXED case.

Whole series looks good to me Alex, and everything works fine on my
mixed-mode config. Applied for v4.8, thanks!