New patch to review for coreboot: 673c105 AMD (K8/fam10): Rewrite CAR migration in post_cache_as_ram

[Kyösti Mälkki]

Kyösti Mälkki ([e-mail]) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/4583

-gerrit

commit 673c1050457c42d8162a0d47434a7ed86cf56d2a
Author: Kyösti Mälkki 
Date:   Sun Dec 29 12:07:54 2013 +0200

AMD (K8/fam10): Rewrite CAR migration in post_cache_as_ram

Old routine copied all of CAR region as-is right below CONFIG_RAMTOP.
    Most of this region was reserved to interleave AP CPU address spaces
    and unused on BSP CPU. The only part of CAR region requiring a copy
    in RAM is the sysinfo structure.

Improved routine changes this as follows:

A region of size 'backup_size' below CONFIG_RAMTOP is cleared. In
    case of S3 resume, OS context from this region is first copied to
    high memory (CBMEM_ID_RESUME).

At stack switch, CAR stack is discarded. Top of the stack for BSP
    is located at 'CONFIG_RAMTOP - car_size' for the remaining part
    of the romstage. This region is part of 'backup_size' and was zeroed
    before the switch took place.

Before CAR is torn down the region of CAR_GLOBALS (and CAR_CBMEM),
    including the relevant sysinfo data for AP nodes memory training,
    is copied at 'CONFIG_RAMTOP - car_size'.

Change-Id: Ie45b576aec6a2e006bfcb26b52fdb77c24f72e3b
    Signed-off-by: Kyösti Mälkki 
---
 src/cpu/amd/car/cache_as_ram.inc    |   5 +-
 src/cpu/amd/car/post_cache_as_ram.c | 170 ++++++++++++++++++++----------------
 2 files changed, 96 insertions(+), 79 deletions(-)

diff --git a/src/cpu/amd/car/cache_as_ram.inc b/src/cpu/amd/car/cache_as_ram.inc
index 8f0abce..6d704c5 100644
--- a/src/cpu/amd/car/cache_as_ram.inc
+++ b/src/cpu/amd/car/cache_as_ram.inc
@@ -424,10 +424,9 @@ CAR_FAM10_ap_out:
 cache_as_ram_switch_stack:
    /* Return address.  */
    popl	%eax
-	/* Resume memory.  */
+	/* New stack.  */
    popl	%eax
-	subl	$(( (CONFIG_DCACHE_RAM_BASE + CONFIG_DCACHE_RAM_SIZE)- (CONFIG_RAMTOP) )), %esp
-	pushl	%eax
+	movl	%eax, %esp
    call	cache_as_ram_new_stack

all_mtrr_msrs:
diff --git a/src/cpu/amd/car/post_cache_as_ram.c b/src/cpu/amd/car/post_cache_as_ram.c
index 81175da..08505ad 100644
--- a/src/cpu/amd/car/post_cache_as_ram.c
+++ b/src/cpu/amd/car/post_cache_as_ram.c
@@ -8,10 +8,9 @@
 #include "cbmem.h"
 #include "cpu/amd/car/disable_cache_as_ram.c"

-static inline void print_debug_pcar(const char *strval, uint32_t val)
-{
-	printk(BIOS_DEBUG, "%s%08x\n", strval, val);
-}
+#if CONFIG_RAMTOP <= 0x100000
+	#error "You need to set CONFIG_RAMTOP greater than 1M"
+#endif

/* from linux kernel 2.6.32 asm/string_32.h */

@@ -29,37 +28,80 @@ static void inline __attribute__((always_inline))  memcopy(void *dest, const voi
    		: "memory", "cc");
 }

-#if CONFIG_HAVE_ACPI_RESUME
+#define PRINTK_IN_CAR	1
+#define ACTUAL_CAR_SIZE	1

-static inline void *backup_resume(void) {
-	void *resume_backup_memory;
-	int suspend = acpi_is_wakeup_early();
+#if PRINTK_IN_CAR
+#define print_car_debug(x) print_debug(x)
+#else
+#define print_car_debug(x)
+#endif
+
+extern char _car_data_start[];
+extern char _car_data_end[];

-	if (!suspend)
-		return NULL;
+#if ACTUAL_CAR_SIZE
+static size_t car_data_size(void)
+{
+	size_t car_size = &_car_data_end[0] - &_car_data_start[0];
+	return ALIGN(64, car_size);
+}

-	if (!cbmem_reinit())
-		return NULL;
+static size_t backup_size(void)
+{
+	size_t car_size = &_car_data_end[0] - &_car_data_start[0];
+	return ALIGN(1024, car_size + 1024);
+}
+#else
+#define car_data_size() 0x1000
+#define backup_size() 0x2000
+#endif

-	resume_backup_memory = cbmem_find(CBMEM_ID_RESUME);
+static void memcpy_(void *d, const void *s, size_t len)
+{
+#if PRINTK_IN_CAR
+	printk(BIOS_SPEW, " Copy [%08x-%08x] to [%08x - %08x] ... ",
+		(u32) s, (u32) (s + len), (u32) d, (u32) (d + len));
+#endif
+	memcpy(d, s, len);
+}

-	/* copy 1MB - 64K to high tables ram_base to prevent memory corruption
-	 * through stage 2. We could keep stuff like stack and heap in high tables
-	 * memory completely, but that's a wonderful clean up task for another
-	 * day.
-	 */
+static void memset_(void *d, int val, size_t len)
+{
+#if PRINTK_IN_CAR
+	printk(BIOS_SPEW, " Fill [%08x-%08x] ... ", (u32) d, (u32) (d + len));
+#endif
+	memset(d, val, len);
+}

+static void prepare_romstage_ramstack(void *resume_backup_memory)
+{
+	size_t backup_top = backup_size();
+	print_car_debug("Prepare CAR migration and stack regions...");
+#if CONFIG_HAVE_ACPI_RESUME
    if (resume_backup_memory) {
-		print_debug_pcar("Will copy coreboot region to: ", (uint32_t) resume_backup_memory);
-		/* copy only backup only memory used for CAR */
-		memcopy(resume_backup_memory+HIGH_MEMORY_SAVE-CONFIG_DCACHE_RAM_SIZE,
-			(void *)((CONFIG_RAMTOP)-CONFIG_DCACHE_RAM_SIZE),
-			 CONFIG_DCACHE_RAM_SIZE); //inline
+		memcpy_(resume_backup_memory + HIGH_MEMORY_SAVE - backup_top,
+			(void *)(CONFIG_RAMTOP - backup_top), backup_top);
    }
-
-	return resume_backup_memory;
+#endif
+	memset_((void *)(CONFIG_RAMTOP - backup_top), 0, backup_top);
+	print_car_debug("Done\n");
 }
+
+static void prepare_ramstage_region(void *resume_backup_memory)
+{
+	size_t backup_top = backup_size();
+	print_car_debug("Prepare ramstage memory region... ");
+#if CONFIG_HAVE_ACPI_RESUME
+	if (resume_backup_memory) {
+		memcpy_(resume_backup_memory, (void *) CONFIG_RAMBASE, HIGH_MEMORY_SAVE - backup_top);
+		memset_((void*) CONFIG_RAMBASE, 0, HIGH_MEMORY_SAVE - backup_top);
+	}
 #endif
+	if (!resume_backup_memory)
+		memset_((void*)0, 0, CONFIG_RAMTOP - backup_top);
+	print_car_debug("Done\n");
+}

/* Disable Erratum 343 Workaround, see RevGuide for Fam10h, Pub#41322 Rev 3.33 */

@@ -75,56 +117,45 @@ static void vErrata343(void)
 #endif
 }

-void cache_as_ram_switch_stack(void *resume_backup_memory);
+void cache_as_ram_switch_stack(void * new_stack);
+void cache_as_ram_new_stack (void);

void post_cache_as_ram(void)
 {
    void *resume_backup_memory = NULL;
-#if 1
-	{
-	/* Check value of esp to verify if we have enough room for stack in Cache as RAM */
-	unsigned v_esp;
-	__asm__ volatile (
-		"movl   %%esp, %0\n\t"
-		: "=a" (v_esp)
-	);
-	print_debug_pcar("v_esp=", v_esp);
-	}
-#endif
-
-	/* copy data from cache as ram to
-		ram need to set CONFIG_RAMTOP to 2M and use var mtrr instead.
-	 */
-#if CONFIG_RAMTOP <= 0x100000
-	#error "You need to set CONFIG_RAMTOP greater than 1M"
-#endif

#if CONFIG_HAVE_ACPI_RESUME
- 	resume_backup_memory = backup_resume();
+	if (acpi_is_wakeup_early()) {
+		cbmem_reinit();
+		resume_backup_memory = cbmem_find(CBMEM_ID_RESUME);
+	}
 #endif
-
-	print_debug("Copying data from cache to RAM -- switching to use RAM as stack... ");
+	prepare_romstage_ramstack(resume_backup_memory);

/* from here don't store more data in CAR */
    vErrata343();

-	memcopy((void *)((CONFIG_RAMTOP)-CONFIG_DCACHE_RAM_SIZE), (void *)CONFIG_DCACHE_RAM_BASE, CONFIG_DCACHE_RAM_SIZE); //inline
-	cache_as_ram_switch_stack(resume_backup_memory);
-}
+	size_t car_size = car_data_size();
+	void *migrated_car = (void *)(CONFIG_RAMTOP - car_size);

-void
-cache_as_ram_new_stack (void *resume_backup_memory);
+	print_car_debug("Copying data from cache to RAM... ");
+	memcpy_(migrated_car, &_car_data_start[0], car_size);
+	print_car_debug("Done\n");

-void
-cache_as_ram_new_stack (void *resume_backup_memory __attribute__ ((unused)))
-{
-	/* We can put data to stack again */
+	/* New stack grows right below migrated_car. */
+	print_car_debug("Switching to use RAM as stack... ");
+	cache_as_ram_switch_stack(migrated_car);
+
+	/* We do not come back. */
+}

-	/* only global variable sysinfo in cache need to be offset */
-	print_debug("Done\n");
+void cache_as_ram_new_stack (void)
+{
+	void *resume_backup_memory = NULL;

-	print_debug("Disabling cache as ram now \n");
+	print_car_debug("Done\n");

+	print_car_debug("Disabling cache as ram now\n");
    disable_cache_as_ram_bsp();

disable_cache();
@@ -132,24 +163,11 @@ cache_as_ram_new_stack (void *resume_backup_memory __attribute__ ((unused)))
    enable_cache();

#if CONFIG_HAVE_ACPI_RESUME
-	/* now copy the rest of the area, using the WB method because we already
-	   run normal RAM */
-	if (resume_backup_memory) {
-		memcopy(resume_backup_memory,
-				(void *)(CONFIG_RAMBASE),
-				(CONFIG_RAMTOP) - CONFIG_RAMBASE - CONFIG_DCACHE_RAM_SIZE);
+	if (acpi_is_wakeup_early()) {
+		resume_backup_memory = cbmem_find(CBMEM_ID_RESUME);
    }
 #endif
-
-	print_debug("Clearing initial memory region: ");
-
-#if CONFIG_HAVE_ACPI_RESUME
-	/* clear only coreboot used region of memory. Note: this may break ECC enabled boards */
-	memset((void*) CONFIG_RAMBASE, 0, (CONFIG_RAMTOP) - CONFIG_RAMBASE - CONFIG_DCACHE_RAM_SIZE);
-#else
-	memset((void*)0, 0, ((CONFIG_RAMTOP) - CONFIG_DCACHE_RAM_SIZE));
-#endif
-	print_debug("Done\n");
+	prepare_ramstage_region(resume_backup_memory);

set_sysinfo_in_ram(1); // So other core0 could start to train mem

@@ -157,5 +175,5 @@ cache_as_ram_new_stack (void *resume_backup_memory __attribute__ ((unused)))
    copy_and_run();
    /* We will not return */

-	print_debug("should not be here -\n");
+	print_car_debug("should not be here -\n");
 }