AGESA: Implement POSTCAR_STAGE

Move all boards that have moved away from AGESA_LEGACY_WRAPPER
or BINARYPI_LEGACY_WRAPPER to use POSTCAR_STAGE.

We use POSTCAR_STAGE as a conditional in CAR teardown to tell
our MTRR setup is prepared such that invalidation without
writeback is a valid operation.

Change-Id: I3f4e2170054bdb84c72d2f7c956f8d51a6d7f0ca
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/21384
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

5 files changed, 166 insertions, 12 deletions

diff --git a/src/cpu/amd/agesa/Kconfig b/src/cpu/amd/agesa/Kconfig
index 95db82f982..6a7ec8750f 100644
--- a/src/cpu/amd/agesa/Kconfig
+++ b/src/cpu/amd/agesa/Kconfig
@@ -29,6 +29,7 @@ config CPU_AMD_AGESA
 	select UDELAY_LAPIC
 	select LAPIC_MONOTONIC_TIMER
 	select SPI_FLASH if HAVE_ACPI_RESUME
+	select POSTCAR_STAGE if !AGESA_LEGACY_WRAPPER
 
 if CPU_AMD_AGESA
 
diff --git a/src/cpu/amd/agesa/Makefile.inc b/src/cpu/amd/agesa/Makefile.inc
index c8e125e445..f4ec2ce0b0 100644
--- a/src/cpu/amd/agesa/Makefile.inc
+++ b/src/cpu/amd/agesa/Makefile.inc
@@ -24,11 +24,13 @@ ifeq ($(CONFIG_AGESA_LEGACY), y)
 cpu_incs-y += $(src)/cpu/amd/agesa/cache_as_ram_legacy.inc
 else
 cpu_incs-y += $(src)/cpu/amd/agesa/cache_as_ram.S
-romstage-y += romstage.c
+romstage-y += romstage.c mtrr_fixme.c
 endif
 
 romstage-$(CONFIG_AGESA_LEGACY_WRAPPER) += heapmanager.c
 
+postcar-y += cache_as_ram.S
+
 ramstage-y += heapmanager.c
 ramstage-$(CONFIG_AGESA_LEGACY_WRAPPER) += amd_late_init.c
 
diff --git a/src/cpu/amd/agesa/cache_as_ram.S b/src/cpu/amd/agesa/cache_as_ram.S
index b96a5e70e4..50242f7a54 100644
--- a/src/cpu/amd/agesa/cache_as_ram.S
+++ b/src/cpu/amd/agesa/cache_as_ram.S
@@ -29,6 +29,7 @@
 
 .code32
 .globl _cache_as_ram_setup, _cache_as_ram_setup_end
+.globl chipset_teardown_car
 
 _cache_as_ram_setup:
 
@@ -105,20 +106,44 @@ _cache_as_ram_setup:
   movd  %mm0, %eax		/* bist */
   pushl %eax
   call  romstage_main
-  movl  %eax, %esp
 
-/* Register %esp is new stacktop for remaining of romstage.
- * It is the only register preserved in AMD_DISABLE_STACK.
+#if IS_ENABLED(CONFIG_POSTCAR_STAGE)
+
+/* We do not return. Execution continues with run_postcar_phase()
+ * calling to chipset_teardown_car below.
+ */
+  jmp postcar_entry_failure
+
+chipset_teardown_car:
+
+/*
+ * Retrieve return address from stack as it will get trashed below if
+ * execution is utilizing the cache-as-ram stack.
  */
+  pop %esp
+
+#else
+
+  movl  %eax, %esp
+
+/* Register %esp is new stacktop for remaining of romstage. */
+
+#endif
 
-disable_cache_as_ram:
   /* Disable cache */
   movl	%cr0, %eax
   orl	$CR0_CacheDisable, %eax
   movl	%eax, %cr0
 
+/* Register %esp is preserved in AMD_DISABLE_STACK. */
   AMD_DISABLE_STACK
 
+#if IS_ENABLED(CONFIG_POSTCAR_STAGE)
+
+  jmp *%esp
+
+#else
+
   /* enable cache */
   movl %cr0, %eax
   andl $0x9fffffff, %eax
@@ -126,9 +151,22 @@ disable_cache_as_ram:
 
   call  romstage_after_car
 
+#endif
+
   /* Should never see this postcode */
   post_code(0xaf)
+
 stop:
+  hlt
+  jmp stop
+
+/* These are here for linking purposes. */
+.weak early_all_cores, romstage_main
+early_all_cores:
+romstage_main:
+postcar_entry_failure:
+  /* Should never see this postcode */
+  post_code(0xae)
   jmp stop
 
 _cache_as_ram_setup_end:
diff --git a/src/cpu/amd/agesa/mtrr_fixme.c b/src/cpu/amd/agesa/mtrr_fixme.c
new file mode 100644
index 0000000000..1fbb55318d
--- /dev/null
+++ b/src/cpu/amd/agesa/mtrr_fixme.c
@@ -0,0 +1,100 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <arch/cpu.h>
+#include <cbmem.h>
+#include <console/console.h>
+#include <cpu/amd/mtrr.h>
+#include <cpu/cpu.h>
+#include <cpu/x86/cache.h>
+#include <cpu/x86/msr.h>
+#include <cpu/x86/mtrr.h>
+#include <northbridge/amd/agesa/agesa_helper.h>
+
+static void set_range_uc(u32 base, u32 size)
+{
+	int i, max_var_mtrrs;
+	msr_t msr;
+	msr = rdmsr(MTRR_CAP_MSR);
+	max_var_mtrrs = msr.lo & MTRR_CAP_VCNT;
+
+	for (i = 0; i < max_var_mtrrs; i++) {
+		msr = rdmsr(MTRR_PHYS_MASK(i));
+		if (!(msr.lo & MTRR_PHYS_MASK_VALID))
+				break;
+	}
+	if (i == max_var_mtrrs)
+		die("Run out of unused MTRRs\n");
+
+	msr.hi = 0;
+	msr.lo = base | MTRR_TYPE_UNCACHEABLE;
+	wrmsr(MTRR_PHYS_BASE(i), msr);
+
+	msr.hi = (1 << (cpu_phys_address_size() - 32)) - 1;
+	msr.lo = ~(size - 1) | MTRR_PHYS_MASK_VALID;
+	wrmsr(MTRR_PHYS_MASK(i), msr);
+}
+
+void fixup_cbmem_to_UC(int s3resume)
+{
+	if (s3resume)
+		return;
+
+	/* For normal path, INIT_POST has returned with all
+	 * memory set WB cacheable. But we need CBMEM as UC
+	 * to make CAR teardown with invalidation without
+	 * writeback possible.
+	 */
+
+	uintptr_t top_of_ram = (uintptr_t) cbmem_top();
+	top_of_ram = ALIGN_UP(top_of_ram, 4 * MiB);
+
+	set_range_uc(top_of_ram - 4 * MiB, 4 * MiB);
+	set_range_uc(top_of_ram - 8 * MiB, 4 * MiB);
+}
+
+void recover_postcar_frame(struct postcar_frame *pcf, int s3resume)
+{
+	msr_t base, mask;
+	int i;
+
+	/* Replicate non-UC MTRRs as left behind by AGESA.
+	 */
+	for (i = 0; i < pcf->max_var_mtrrs; i++) {
+		mask = rdmsr(MTRR_PHYS_MASK(i));
+		base = rdmsr(MTRR_PHYS_BASE(i));
+		u32 size = ~(mask.lo & ~0xfff) + 1;
+		u8 type = base.lo & 0x7;
+		base.lo &= ~0xfff;
+
+		if (!(mask.lo & MTRR_PHYS_MASK_VALID) ||
+			(type == MTRR_TYPE_UNCACHEABLE))
+			continue;
+
+		postcar_frame_add_mtrr(pcf, base.lo, size, type);
+	}
+
+	/* For S3 resume path, INIT_RESUME does not return with
+	 * memory covering CBMEM set as WB cacheable. For better
+	 * speed make them WB after CAR teardown.
+	 */
+	if (s3resume) {
+		uintptr_t top_of_ram = (uintptr_t) cbmem_top();
+		top_of_ram = ALIGN_DOWN(top_of_ram, 4*MiB);
+
+		postcar_frame_add_mtrr(pcf, top_of_ram - 4*MiB, 4*MiB,
+			MTRR_TYPE_WRBACK);
+		postcar_frame_add_mtrr(pcf, top_of_ram - 8*MiB, 4*MiB,
+			MTRR_TYPE_WRBACK);
+	}
+}
diff --git a/src/cpu/amd/agesa/romstage.c b/src/cpu/amd/agesa/romstage.c
index f8b1e439d6..1b9757a934 100644
--- a/src/cpu/amd/agesa/romstage.c
+++ b/src/cpu/amd/agesa/romstage.c
@@ -18,7 +18,6 @@
 #include <cbmem.h>
 #include <cpu/amd/car.h>
 #include <cpu/x86/bist.h>
-#include <cpu/x86/mtrr.h>
 #include <console/console.h>
 #include <halt.h>
 #include <program_loading.h>
@@ -54,6 +53,7 @@ static void fill_sysinfo(struct sysinfo *cb)
 
 void * asmlinkage romstage_main(unsigned long bist)
 {
+	struct postcar_frame pcf;
 	struct sysinfo romstage_state;
 	struct sysinfo *cb = &romstage_state;
 	u8 initial_apic_id = (u8) (cpuid_ebx(1) >> 24);
@@ -100,6 +100,9 @@ void * asmlinkage romstage_main(unsigned long bist)
 
 	}
 
+	if (IS_ENABLED(CONFIG_POSTCAR_STAGE))
+		fixup_cbmem_to_UC(cb->s3resume);
+
 	cbmem_initted = !cbmem_recovery(cb->s3resume);
 
 	if (cb->s3resume && !cbmem_initted) {
@@ -107,16 +110,25 @@ void * asmlinkage romstage_main(unsigned long bist)
 		halt();
 	}
 
-	uintptr_t stack_top = romstage_ram_stack_base(HIGH_ROMSTAGE_STACK_SIZE,
-		ROMSTAGE_STACK_CBMEM);
-	stack_top += HIGH_ROMSTAGE_STACK_SIZE;
-
 	romstage_handoff_init(cb->s3resume);
 
-	printk(BIOS_DEBUG, "Move CAR stack.\n");
-	return (void*)stack_top;
+	if (!IS_ENABLED(CONFIG_POSTCAR_STAGE)) {
+		uintptr_t stack_top = romstage_ram_stack_base(
+			HIGH_ROMSTAGE_STACK_SIZE, ROMSTAGE_STACK_CBMEM);
+		stack_top += HIGH_ROMSTAGE_STACK_SIZE;
+		printk(BIOS_DEBUG, "Move CAR stack.\n");
+		return (void*)stack_top;
+	}
+
+	postcar_frame_init(&pcf, HIGH_ROMSTAGE_STACK_SIZE);
+	recover_postcar_frame(&pcf, cb->s3resume);
+
+	run_postcar_phase(&pcf);
+	/* We do not return. */
+	return NULL;
 }
 
+#if !IS_ENABLED(CONFIG_POSTCAR_STAGE)
 void asmlinkage romstage_after_car(void)
 {
 	struct sysinfo romstage_state;
@@ -131,3 +143,4 @@ void asmlinkage romstage_after_car(void)
 
 	run_ramstage();
 }
+#endif