soc/amd/picasso: Place early stages and data buffers at the bottom of DRAM

This change updates memlayout.ld for Picasso to place all early
stages (bootblock, romstage, FSP-M, verstage) and data buffers (vboot
workbuf, APOB, preram-cbmem console, timestamp, early BSP stack) at
the bottom of DRAM starting at 32MiB. This uses static allocation for
most components by defining Kconfig variables for base and size. It
relies on the linker to complain if any of the assumptions are broken.

This also allows romstage to use linker symbols for
_early_reserved_dram and _eearly_reserved_dram to store information in
CBMEM about the early DRAM usage by coreboot before ramstage starts
execution. This allows ramstage to reserve this memory region in BIOS
tables so that S3 resume can reuse the same space without corrupting
OS memory.

BUG=b:155322763
TEST=Verified memory reported by coreboot:
Writing coreboot table at 0xcc656000
 0. 0000000000000000-0000000000000fff: CONFIGURATION TABLES
 1. 0000000000001000-000000000009ffff: RAM
 2. 00000000000a0000-00000000000fffff: RESERVED
 3. 0000000000100000-0000000001ffffff: RAM
 4. 0000000002000000-000000000223ffff: RESERVED
 5. 0000000002240000-00000000cc512fff: RAM
 6. 00000000cc513000-00000000cc6bffff: CONFIGURATION TABLES
 7. 00000000cc6c0000-00000000cc7c7fff: RAMSTAGE
 8. 00000000cc7c8000-00000000cd7fffff: CONFIGURATION TABLES
 9. 00000000cd800000-00000000cfffffff: RESERVED
10. 00000000f8000000-00000000fbffffff: RESERVED
11. 0000000100000000-000000042f33ffff: RAM
12. 000000042f340000-000000042fffffff: RESERVED

Signed-off-by: Furquan Shaikh <furquan@google.com>
Change-Id: I009e1ea71b5b5a8e65eba16911897b2586ccfdb6
Reviewed-on: https://review.coreboot.org/c/coreboot/+/42264
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Raul Rangel <rrangel@chromium.org>

6 files changed, 313 insertions, 51 deletions

diff --git a/src/soc/amd/picasso/Kconfig b/src/soc/amd/picasso/Kconfig
index dba4e2fa5960..725bd16a27ab 100644
--- a/src/soc/amd/picasso/Kconfig
+++ b/src/soc/amd/picasso/Kconfig
@@ -60,12 +60,122 @@ config MEMLAYOUT_LD_FILE
 	string
 	default "src/soc/amd/picasso/memlayout.ld"
 
+config EARLY_RESERVED_DRAM_BASE
+	hex
+	default 0x2000000
+	help
+	  This variable defines the base address of the DRAM which is reserved
+	  for usage by coreboot in early stages (i.e. before ramstage is up).
+	  This memory gets reserved in BIOS tables to ensure that the OS does
+	  not use it, thus preventing corruption of OS memory in case of S3
+	  resume.
+
+config EARLYRAM_BSP_STACK_SIZE
+	hex
+	default 0x1000
+
+config PSP_APOB_DRAM_ADDRESS
+	hex
+	default 0x2001000
+	help
+	  Location in DRAM where the PSP will copy the AGESA PSP Output
+	  Block.
+
+config PSP_SHAREDMEM_BASE
+	hex
+	default 0x2011000 if VBOOT
+	default 0x0
+	help
+	  This variable defines the base address in DRAM memory where PSP copies
+	  vboot workbuf to. This is used in linker script to have a static
+	  allocation for the buffer as well as for adding relevant entries in
+	  BIOS directory table for the PSP.
+
+config PSP_SHAREDMEM_SIZE
+	hex
+	default 0x8000 if VBOOT
+	default 0x0
+	help
+	  Sets the maximum size for the PSP to pass the vboot workbuf and
+	  any logs or timestamps back to coreboot.  This will be copied
+	  into main memory by the PSP and will be available when the x86 is
+	  started.  The workbuf's base depends on the address of the reset
+	  vector.
+
 config PRERAM_CBMEM_CONSOLE_SIZE
 	hex
 	default 0x1600
 	help
 	  Increase this value if preram cbmem console is getting truncated
 
+config BOOTBLOCK_ADDR
+	hex
+	default 0x2030000
+	help
+	  Sets the address in DRAM where bootblock should be loaded.
+
+config C_ENV_BOOTBLOCK_SIZE
+	hex
+	default 0x10000
+	help
+	  Sets the size of the bootblock stage that should be loaded in DRAM.
+	  This variable controls the DRAM allocation size in linker script
+	  for bootblock stage.
+
+config X86_RESET_VECTOR
+	hex
+	depends on ARCH_X86
+	default 0x203fff0
+	help
+	  Sets the reset vector within bootblock where x86 starts execution.
+	  Reset vector is supposed to live at offset -0x10 from end of
+	  bootblock i.e. BOOTBLOCK_ADDR + C_ENV_BOOTBLOCK_SIZE - 0x10.
+
+config ROMSTAGE_ADDR
+	hex
+	default 0x2040000
+	help
+	  Sets the address in DRAM where romstage should be loaded.
+
+config ROMSTAGE_SIZE
+	hex
+	default 0x80000
+	help
+	  Sets the size of DRAM allocation for romstage in linker script.
+
+config FSP_M_ADDR
+	hex
+	default 0x20C0000
+	help
+	  Sets the address in DRAM where FSP-M should be loaded. cbfstool
+	  performs relocation of FSP-M to this address.
+
+config FSP_M_SIZE
+	hex
+	default 0x80000
+	help
+	  Sets the size of DRAM allocation for FSP-M in linker script.
+
+config VERSTAGE_ADDR
+	hex
+	depends on VBOOT_SEPARATE_VERSTAGE
+	default 0x2140000
+	help
+	  Sets the address in DRAM where verstage should be loaded if running
+	  as a separate stage on x86.
+
+config VERSTAGE_SIZE
+	hex
+	depends on VBOOT_SEPARATE_VERSTAGE
+	default 0x80000
+	help
+	  Sets the size of DRAM allocation for verstage in linker script if
+	  running as a separate stage on x86.
+
+config RAMBASE
+	hex
+	default 0x10000000
+
 config CPU_ADDR_BITS
 	int
 	default 48
@@ -234,18 +344,6 @@ config MAINBOARD_POWER_RESTORE
 	  return to S0.  Otherwise the system will remain in S5 once power
 	  is restored.
 
-config FSP_M_ADDR
-	hex
-	default 0x90000000
-
-config X86_RESET_VECTOR
-	hex
-	default 0x807fff0
-
-config EARLYRAM_BSP_STACK_SIZE
-	hex
-	default 0x800
-
 config FSP_TEMP_RAM_SIZE
 	hex
 	depends on FSP_USES_CB_STACK
@@ -300,13 +398,6 @@ config AMD_PUBKEY_FILE
 	string
 	default "3rdparty/amd_blobs/picasso/PSP/AmdPubKeyRV.bin"
 
-config PSP_APOB_DRAM_ADDRESS
-	hex
-	default 0x9f00000
-	help
-	  Location in DRAM where the PSP will copy the AGESA PSP Output
-	  Block.
-
 config USE_PSPSCUREOS
 	bool
 	default y
diff --git a/src/soc/amd/picasso/include/soc/memmap.h b/src/soc/amd/picasso/include/soc/memmap.h
new file mode 100644
index 000000000000..f8b13cc415df
--- /dev/null
+++ b/src/soc/amd/picasso/include/soc/memmap.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef __SOC_AMD_PICASSO_MEMMAP_H__
+#define __SOC_AMD_PICASSO_MEMMAP_H__
+
+#include <symbols.h>
+
+DECLARE_REGION(early_reserved_dram)
+
+struct memmap_early_dram {
+	uint32_t base;
+	uint32_t size;
+};
+
+void memmap_stash_early_dram_usage(void);
+const struct memmap_early_dram *memmap_get_early_dram_usage(void);
+
+#endif /* __SOC_AMD_PICASSO_MEMMAP_H__ */
diff --git a/src/soc/amd/picasso/memlayout.ld b/src/soc/amd/picasso/memlayout.ld
index 8b2390909e68..a82e303dad03 100644
--- a/src/soc/amd/picasso/memlayout.ld
+++ b/src/soc/amd/picasso/memlayout.ld
@@ -3,39 +3,94 @@
 #include <memlayout.h>
 #include <arch/header.ld>
 
-#define EARLY_MEMLAYOUT	"src/arch/x86/early_ram.ld"
+#define EARLY_RESERVED_DRAM_START(addr)		SYMBOL(early_reserved_dram, addr)
+#define EARLY_RESERVED_DRAM_END(addr)		SYMBOL(eearly_reserved_dram, addr)
 
+#define PSP_SHAREDMEM_DRAM_START(addr)		SYMBOL(psp_sharedmem_dram, addr)
+#define PSP_SHAREDMEM_DRAM_END(addr)		SYMBOL(epsp_sharedmem_dram, addr)
+
+/*
+ *
+ *                     +--------------------------------+
+ *                     |                                |
+ *                     |                                |
+ *                     |                                |
+ *                     |                                |
+ *                     |                                |
+ *                     |                                |
+ *                     |                                |
+ *   reserved_dram_end +--------------------------------+
+ *                     |                                |
+ *                     |       verstage (if reqd)       |
+ *                     |          (VERSTAGE_SIZE)       |
+ *                     +--------------------------------+ VERSTAGE_ADDR
+ *                     |                                |
+ *                     |            FSP-M               |
+ *                     |         (FSP_M_SIZE)           |
+ *                     +--------------------------------+ FSP_M_ADDR
+ *                     |                                |X86_RESET_VECTOR = ROMSTAGE_ADDR + ROMSTAGE_SIZE - 0x10
+ *                     |           romstage             |
+ *                     |        (ROMSTAGE_SIZE)         |
+ *                     +--------------------------------+ ROMSTAGE_ADDR
+ *                     |           bootblock            |
+ *                     |     (C_ENV_BOOTBLOCK_SIZE)     |
+ *                     +--------------------------------+ BOOTBLOCK_ADDR
+ *                     |          Unused hole           |
+ *                     +--------------------------------+
+ *                     |     FMAP cache (FMAP_SIZE)     |
+ *                     +--------------------------------+ PSP_SHAREDMEM_BASE + PSP_SHAREDMEM_SIZE + PRERAM_CBMEM_CONSOLE_SIZE + 0x200
+ *                     |  Early Timestamp region (512B) |
+ *                     +--------------------------------+ PSP_SHAREDMEM_BASE + PSP_SHAREDMEM_SIZE + PRERAM_CBMEM_CONSOLE_SIZE
+ *                     |      Preram CBMEM console      |
+ *                     |   (PRERAM_CBMEM_CONSOLE_SIZE)  |
+ *                     +--------------------------------+ PSP_SHAREDMEM_BASE + PSP_SHAREDMEM_SIZE
+ *                     |   PSP shared (vboot workbuf)   |
+ *                     |      (PSP_SHAREDMEM_SIZE)      |
+ *                     +--------------------------------+ PSP_SHAREDMEM_BASE
+ *                     |          APOB (64KiB)          |
+ *                     +--------------------------------+ PSP_APOB_DRAM_ADDRESS
+ *                     |        Early BSP stack         |
+ *                     |   (EARLYRAM_BSP_STACK_SIZE)    |
+ * reserved_dram_start +--------------------------------+ EARLY_RESERVED_DRAM_BASE
+ *                     |              DRAM              |
+ *                     +--------------------------------+ 0x100000
+ *                     |           Option ROM           |
+ *                     +--------------------------------+ 0xc0000
+ *                     |           Legacy VGA           |
+ *                     +--------------------------------+ 0xa0000
+ *                     |              DRAM              |
+ *                     +--------------------------------+ 0x0
+ */
 SECTIONS
 {
-	/*
-	 * It would be good to lay down RAMSTAGE, ROMSTAGE, etc consecutively
-	 * like other architectures/chipsets it's not possible because of
-	 * the linking games played during romstage creation by trying
-	 * to find the final landing place in CBFS for XIP. Therefore,
-	 * conditionalize with macros.
-	 */
-#if ENV_RAMSTAGE
-	RAMSTAGE(CONFIG_RAMBASE, (CONFIG(RELOCATABLE_RAMSTAGE) ? 8M :
-					CONFIG_RAMTOP - CONFIG_RAMBASE))
-
-#elif ENV_ROMSTAGE
-	/* The 1M size is not allocated. It's just for basic size checking.
-	 * Link at 32MiB address and rely on cbfstool to relocate to XIP. */
-	ROMSTAGE(CONFIG_ROMSTAGE_ADDR, 1M)
-
-	#include EARLY_MEMLAYOUT
-#elif ENV_SEPARATE_VERSTAGE
-	/* The 1M size is not allocated. It's just for basic size checking.
-	 * Link at 32MiB address and rely on cbfstool to relocate to XIP. */
-	VERSTAGE(CONFIG_VERSTAGE_ADDR, 1M)
-
-	#include EARLY_MEMLAYOUT
-#elif ENV_BOOTBLOCK
-	BOOTBLOCK(CONFIG_X86_RESET_VECTOR - CONFIG_C_ENV_BOOTBLOCK_SIZE + 0x10,
-			CONFIG_C_ENV_BOOTBLOCK_SIZE)
-
-	#include EARLY_MEMLAYOUT
+	DRAM_START(0x0)
+
+	EARLY_RESERVED_DRAM_START(CONFIG_EARLY_RESERVED_DRAM_BASE)
+
+	EARLYRAM_STACK(., CONFIG_EARLYRAM_BSP_STACK_SIZE)
+	REGION(apob, CONFIG_PSP_APOB_DRAM_ADDRESS, 64K, 1)
+
+#if CONFIG(VBOOT)
+	PSP_SHAREDMEM_DRAM_START(CONFIG_PSP_SHAREDMEM_BASE)
+	VBOOT2_WORK(., VB2_FIRMWARE_WORKBUF_RECOMMENDED_SIZE)
+	PSP_SHAREDMEM_DRAM_END(CONFIG_PSP_SHAREDMEM_BASE + CONFIG_PSP_SHAREDMEM_SIZE)
 #endif
+
+	PRERAM_CBMEM_CONSOLE(., CONFIG_PRERAM_CBMEM_CONSOLE_SIZE)
+	TIMESTAMP(., 0x200)
+	FMAP_CACHE(., FMAP_SIZE)
+
+	_ = ASSERT((CONFIG_BOOTBLOCK_ADDR + CONFIG_C_ENV_BOOTBLOCK_SIZE - 0x10) == CONFIG_X86_RESET_VECTOR, "Reset vector should be -0x10 from end of bootblock");
+	BOOTBLOCK(CONFIG_BOOTBLOCK_ADDR, CONFIG_C_ENV_BOOTBLOCK_SIZE)
+	ROMSTAGE(CONFIG_ROMSTAGE_ADDR, CONFIG_ROMSTAGE_SIZE)
+	REGION(fspm, CONFIG_FSP_M_ADDR, CONFIG_FSP_M_SIZE, 1)
+#if CONFIG(VBOOT_SEPARATE_VERSTAGE)
+	VERSTAGE(CONFIG_VERSTAGE_ADDR, CONFIG_VERSTAGE_SIZE)
+#endif
+
+	EARLY_RESERVED_DRAM_END(.)
+
+	RAMSTAGE(CONFIG_RAMBASE, 8M)
 }
 
 #if ENV_BOOTBLOCK
diff --git a/src/soc/amd/picasso/memmap.c b/src/soc/amd/picasso/memmap.c
index 5f4ba42da1a4..42a330726efd 100644
--- a/src/soc/amd/picasso/memmap.c
+++ b/src/soc/amd/picasso/memmap.c
@@ -4,12 +4,14 @@
 
 #include <assert.h>
 #include <stdint.h>
+#include <cbmem.h>
 #include <console/console.h>
 #include <cpu/x86/smm.h>
 #include <cpu/amd/msr.h>
 #include <memrange.h>
 #include <fsp/util.h>
 #include <FspGuids.h>
+#include <soc/memmap.h>
 
 /*
  * For data stored in TSEG, ensure TValid is clear so R/W access can reach
@@ -57,3 +59,26 @@ void smm_region(uintptr_t *start, size_t *size)
 		once = 1;
 	}
 }
+
+void memmap_stash_early_dram_usage(void)
+{
+	struct memmap_early_dram *e;
+
+	e = cbmem_add(CBMEM_ID_CB_EARLY_DRAM, sizeof(*e));
+
+	if (!e)
+		die("ERROR: Failed to stash early dram usage!\n");
+
+	e->base = (uint32_t)(uintptr_t)_early_reserved_dram;
+	e->size = REGION_SIZE(early_reserved_dram);
+}
+
+const struct memmap_early_dram *memmap_get_early_dram_usage(void)
+{
+	struct memmap_early_dram *e = cbmem_find(CBMEM_ID_CB_EARLY_DRAM);
+
+	if (!e)
+		die("ERROR: Failed to read early dram usage!\n");
+
+	return e;
+}
diff --git a/src/soc/amd/picasso/romstage.c b/src/soc/amd/picasso/romstage.c
index 5416e8ac5b02..83243d386da2 100644
--- a/src/soc/amd/picasso/romstage.c
+++ b/src/soc/amd/picasso/romstage.c
@@ -12,6 +12,7 @@
 #include <program_loading.h>
 #include <elog.h>
 #include <soc/romstage.h>
+#include <soc/memmap.h>
 #include <soc/mrc_cache.h>
 #include <types.h>
 #include "chip.h"
@@ -90,6 +91,8 @@ asmlinkage void car_stage_entry(void)
 	fsp_memory_init(s3_resume);
 	soc_update_mrc_cache();
 
+	memmap_stash_early_dram_usage();
+
 	post_code(0x44);
 	run_ramstage();
 
diff --git a/src/soc/amd/picasso/root_complex.c b/src/soc/amd/picasso/root_complex.c
index f621eeaf31d8..4930a0e87f40 100644
--- a/src/soc/amd/picasso/root_complex.c
+++ b/src/soc/amd/picasso/root_complex.c
@@ -10,7 +10,61 @@
 #include <device/pci_ids.h>
 #include <fsp/util.h>
 #include <stdint.h>
-
+#include <soc/memmap.h>
+
+/*
+ *
+ *                     +--------------------------------+
+ *                     |                                |
+ *                     |                                |
+ *                     |                                |
+ *                     |                                |
+ *                     |                                |
+ *                     |                                |
+ *                     |                                |
+ *   reserved_dram_end +--------------------------------+
+ *                     |                                |
+ *                     |       verstage (if reqd)       |
+ *                     |          (VERSTAGE_SIZE)       |
+ *                     +--------------------------------+ VERSTAGE_ADDR
+ *                     |                                |
+ *                     |            FSP-M               |
+ *                     |         (FSP_M_SIZE)           |
+ *                     +--------------------------------+ FSP_M_ADDR
+ *                     |                                |X86_RESET_VECTOR = ROMSTAGE_ADDR + ROMSTAGE_SIZE - 0x10
+ *                     |           romstage             |
+ *                     |        (ROMSTAGE_SIZE)         |
+ *                     +--------------------------------+ ROMSTAGE_ADDR
+ *                     |           bootblock            |
+ *                     |     (C_ENV_BOOTBLOCK_SIZE)     |
+ *                     +--------------------------------+ BOOTBLOCK_ADDR
+ *                     |          Unused hole           |
+ *                     |            (86KiB)             |
+ *                     +--------------------------------+
+ *                     |     FMAP cache (FMAP_SIZE)     |
+ *                     +--------------------------------+ PSP_SHAREDMEM_BASE + PSP_SHAREDMEM_SIZE + PRERAM_CBMEM_CONSOLE_SIZE + 0x200
+ *                     |  Early Timestamp region (512B) |
+ *                     +--------------------------------+ PSP_SHAREDMEM_BASE + PSP_SHAREDMEM_SIZE + PRERAM_CBMEM_CONSOLE_SIZE
+ *                     |      Preram CBMEM console      |
+ *                     |   (PRERAM_CBMEM_CONSOLE_SIZE)  |
+ *                     +--------------------------------+ PSP_SHAREDMEM_BASE + PSP_SHAREDMEM_SIZE
+ *                     |   PSP shared (vboot workbuf)   |
+ *                     |      (PSP_SHAREDMEM_SIZE)      |
+ *                     +--------------------------------+ PSP_SHAREDMEM_BASE
+ *                     |          APOB (64KiB)          |
+ *                     +--------------------------------+ PSP_APOB_DRAM_ADDRESS
+ *                     |        Early BSP stack         |
+ *                     |   (EARLYRAM_BSP_STACK_SIZE)    |
+ * reserved_dram_start +--------------------------------+ EARLY_RESERVED_DRAM_BASE
+ *                     |              DRAM              |
+ *                     +--------------------------------+ 0x100000
+ *                     |           Option ROM           |
+ *                     +--------------------------------+ 0xc0000
+ *                     |           Legacy VGA           |
+ *                     +--------------------------------+ 0xa0000
+ *                     |              DRAM              |
+ *                     +--------------------------------+ 0x0
+ */
 static void read_resources(struct device *dev)
 {
 	uint32_t mem_usable = (uintptr_t)cbmem_top();
@@ -18,6 +72,12 @@ static void read_resources(struct device *dev)
 	const struct hob_header *hob = fsp_get_hob_list();
 	const struct hob_resource *res;
 
+	uintptr_t early_reserved_dram_start, early_reserved_dram_end;
+	const struct memmap_early_dram *e = memmap_get_early_dram_usage();
+
+	early_reserved_dram_start = e->base;
+	early_reserved_dram_end = e->base + e->size;
+
 	/* 0x0 - 0x9ffff */
 	ram_resource(dev, idx++, 0, 0xa0000 / KiB);
 
@@ -27,8 +87,18 @@ static void read_resources(struct device *dev)
 	/* 0xc0000 - 0xfffff: Option ROM */
 	reserved_ram_resource(dev, idx++, 0xc0000 / KiB, 0x40000 / KiB);
 
-	/* 1MB to top of low usable RAM */
-	ram_resource(dev, idx++, 1 * MiB / KiB, (mem_usable - 1 * MiB) / KiB);
+	/* 1MB - bottom of DRAM reserved for early coreboot usage */
+	ram_resource(dev, idx++, (1 * MiB) / KiB,
+		     (early_reserved_dram_start - (1 * MiB)) / KiB);
+
+	/* DRAM reserved for early coreboot usage */
+	reserved_ram_resource(dev, idx++, early_reserved_dram_start / KiB,
+		(early_reserved_dram_end - early_reserved_dram_start) / KiB);
+
+	/* top of DRAM consumed early - low top usable RAM
+	 * cbmem_top() accounts for low UMA and TSEG if they are used. */
+	ram_resource(dev, idx++, early_reserved_dram_end / KiB,
+		     (mem_usable - early_reserved_dram_end) / KiB);
 
 	mmconf_resource(dev, MMIO_CONF_BASE);