[S] Change in coreboot[main]: arch/x86/include/mode_switch: Add more wrapper functions

[Felix Held (Code Review)]

Felix Held has submitted this change. ( https://review.coreboot.org/c/coreboot/+/79756?usp=email )

Change subject: arch/x86/include/mode_switch: Add more wrapper functions
......................................................................

arch/x86/include/mode_switch: Add more wrapper functions

Add a protected mode wrapper function that takes three arguments.
This is already supported by the called assembly code.

Change-Id: Ia8c91eebae17e4ca27e391454c2d130a71c4c9f3
Signed-off-by: Patrick Rudolph 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/79756
Tested-by: build bot (Jenkins) 
Reviewed-by: Arthur Heymans 
---
M src/arch/x86/include/mode_switch.h
M src/cpu/x86/64bit/mode_switch.S
2 files changed, 31 insertions(+), 9 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Arthur Heymans: Looks good to me, approved

diff --git a/src/arch/x86/include/mode_switch.h b/src/arch/x86/include/mode_switch.h
index 4235db9..54969b2 100644
--- a/src/arch/x86/include/mode_switch.h
+++ b/src/arch/x86/include/mode_switch.h
@@ -11,10 +11,10 @@
  *
  * The called function has 0-3 arguments and returns an int.
  */
-int protected_mode_call_3arg(uint32_t func_ptr,
-			     uint32_t opt_arg1,
-			     uint32_t opt_arg2,
-			     uint32_t opt_arg3);
+int protected_mode_call_wrapper(uint32_t func_ptr,
+				uint32_t opt_arg1,
+				uint32_t opt_arg2,
+				uint32_t opt_arg3);

/*
  * Drops into protected mode and calls the function, which must have been compiled for x86_32.
@@ -25,7 +25,7 @@
  */
 static inline int protected_mode_call(void *func)
 {
-	return protected_mode_call_3arg((uintptr_t)func, 0, 0, 0);
+	return protected_mode_call_wrapper((uintptr_t)func, 0, 0, 0);
 }

/*
@@ -38,7 +38,7 @@
  */
 static inline int protected_mode_call_1arg(void *func, uint32_t arg1)
 {
-	return protected_mode_call_3arg((uintptr_t)func, arg1, 0, 0);
+	return protected_mode_call_wrapper((uintptr_t)func, arg1, 0, 0);
 }

/*
@@ -51,7 +51,21 @@
  */
 static inline int protected_mode_call_2arg(void *func, uint32_t arg1, uint32_t arg2)
 {
-	return protected_mode_call_3arg((uintptr_t)func, arg1, arg2, 0);
+	return protected_mode_call_wrapper((uintptr_t)func, arg1, arg2, 0);
+}
+
+/*
+ * Drops into protected mode and calls the function, which must have been compiled for x86_32.
+ * After the function returns it enters long mode again.
+ * The function pointer destination must be below 4GiB in physical memory.
+ * Only the lower 32bits of the argument are passed to the called function.
+ *
+ * The called function has two arguments and returns an int.
+ */
+static inline int protected_mode_call_3arg(void *func, uint32_t arg1, uint32_t arg2,
+					   uint32_t arg3)
+{
+	return protected_mode_call_wrapper((uintptr_t)func, arg1, arg2, arg3);
 }
 #else
 static inline int protected_mode_call(void *func)
@@ -74,4 +88,12 @@

return doit(arg1, arg2);
 }
+
+static inline int protected_mode_call_3arg(void *func, uint32_t arg1, uint32_t arg2,
+					   uint32_t arg3)
+{
+	int (*doit)(uint32_t arg1, uint32_t arg2, uint32_t arg3) = func;
+
+	return doit(arg1, arg2, arg3);
+}
 #endif
diff --git a/src/cpu/x86/64bit/mode_switch.S b/src/cpu/x86/64bit/mode_switch.S
index f9f784e..c4198f3 100644
--- a/src/cpu/x86/64bit/mode_switch.S
+++ b/src/cpu/x86/64bit/mode_switch.S
@@ -4,8 +4,8 @@
 .text
 .code64
    .section ".text.protected_mode_call", "ax", @progbits
-	.globl protected_mode_call_3arg
-protected_mode_call_3arg:
+	.globl protected_mode_call_wrapper
+protected_mode_call_wrapper:
    /* Preserve registers */
    push	%rbp
    push	%rbx