[coreboot-gerrit] Change in coreboot[master]: cpu/smm/ssm_stub: Add x86_64 support

[Patrick Rudolph (Code Review)]

Patrick Rudolph has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/37392 )

Change subject: cpu/smm/ssm_stub: Add x86_64 support
......................................................................

cpu/smm/ssm_stub: Add x86_64 support

Enable long mode in SMM handler.
x86_32 isn't affected from this change.

* Enter long mode
* Add 64bit entry to GDT
* Use x86_64 SysV ABI calling conventions for C code entry
* Change smm_module_params' cpu to size_t as 'push' is native integer

Tested on Lenovo T410 with additional x86_64 patches.

Change-Id: I26300492e4be62ddd5d80525022c758a019d63a1
Signed-off-by: Patrick Rudolph 
---
M src/cpu/x86/smm/smm_stub.S
M src/include/cpu/x86/smm.h
2 files changed, 25 insertions(+), 2 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/92/37392/1

diff --git a/src/cpu/x86/smm/smm_stub.S b/src/cpu/x86/smm/smm_stub.S
index f0e55f9..3feee9b 100644
--- a/src/cpu/x86/smm/smm_stub.S
+++ b/src/cpu/x86/smm/smm_stub.S
@@ -90,6 +90,10 @@
    /* gdt selector 0x10, flat data segment */
    .word	0xffff, 0x0000
    .byte	0x00, 0x93, 0xcf, 0x00
+
+	/* gdt selector 0x18, flat code segment (64-bit) */
+	.word   0xffff, 0x0000
+	.byte   0x00, 0x9b, 0xaf, 0x00
 smm_relocate_gdt_end:

.align 4
@@ -172,11 +176,30 @@
    /* Align stack to 16 bytes. Another 32 bytes are pushed below. */
    andl	$0xfffffff0, %esp

+#ifdef __x86_64__
+	/* entry64.inc preserves ebx, esi, edi */
+	mov	%ecx, %edi
+#include <cpu/x86/64bit/entry64.inc>
+	mov	%edi, %ecx
+
+#endif
+
    /* Call into the c-based SMM relocation function with the platform
     * parameters. Equivalent to:
     *   struct arg = { c_handler_params, cpu_num, smm_runtime, canary };
     *   c_handler(&arg)
     */
+#ifdef __x86_64__
+	push	%rbx /* uintptr_t *canary */
+	push	$(smm_runtime)
+	push	%rcx /* int cpu */
+	push	c_handler_arg /* void *arg */
+
+	mov	%rsp, %rdi	/* *arg */
+
+	movl	c_handler, %eax
+	call	*%rax
+#else
    push	$0x0 /* Padding */
    push	$0x0 /* Padding */
    push	$0x0 /* Padding */
@@ -187,7 +210,7 @@
    push	%esp /* smm_module_params *arg (allocated on stack). */
    mov	c_handler, %eax
    call	*%eax
-
+#endif
    /* Retrieve fxsave location. */
    mov	-4(%ebp), %edi
    test	%edi, %edi
diff --git a/src/include/cpu/x86/smm.h b/src/include/cpu/x86/smm.h
index cf107b1..0de08b6 100644
--- a/src/include/cpu/x86/smm.h
+++ b/src/include/cpu/x86/smm.h
@@ -75,7 +75,7 @@

struct smm_module_params {
    void *arg;
-	int cpu;
+	size_t cpu;
    const struct smm_runtime *runtime;
    /* A canary value that has been placed at the end of the stack.
     * If (uintptr_t)canary != *canary then a stack overflow has occurred.