[RFC PATCH u-boot] ARM: arch-meson: build memory banks using reported memory from registers

Neil Armstrong narmstrong at baylibre.com
Thu Oct 19 02:04:52 PDT 2017


As discussed at [1], the Amlogic Meson GX SoCs can embed a BL31 firmware
and a secondary BL32 firmware.
Since mid-2017, the reserved memory address of the BL31 firmware was moved
and grown for security reasons.

But mainline U-boot and Linux has the old address and size fixed.

These SoCs have a register interface to get the two firmware reserved
memory start and sizes.

This patch adds a dynamic memory bank redistribution according to the
values in the firmware.

Note that the memory address ordering between BL31 and BL32 is not etablished,
so it must be determined dynamically.

[1] http://lists.infradead.org/pipermail/linux-amlogic/2017-October/004860.html

Signed-off-by: Neil Armstrong <narmstrong at baylibre.com>
---
 arch/arm/include/asm/arch-meson/gxbb.h | 15 ++++++
 arch/arm/mach-meson/board.c            | 99 +++++++++++++++++++++++++++++++---
 include/configs/meson-gxbb-common.h    |  2 +-
 3 files changed, 109 insertions(+), 7 deletions(-)

diff --git a/arch/arm/include/asm/arch-meson/gxbb.h b/arch/arm/include/asm/arch-meson/gxbb.h
index 74d5290..57db37e 100644
--- a/arch/arm/include/asm/arch-meson/gxbb.h
+++ b/arch/arm/include/asm/arch-meson/gxbb.h
@@ -7,10 +7,25 @@
 #ifndef __GXBB_H__
 #define __GXBB_H__
 
+#define GXBB_AOBUS_BASE		0xc8100000
 #define GXBB_PERIPHS_BASE	0xc8834400
 #define GXBB_HIU_BASE		0xc883c000
 #define GXBB_ETH_BASE		0xc9410000
 
+/* Always-On Peripherals registers */
+#define GXBB_AO_ADDR(off)	(GXBB_AOBUS_BASE + ((off) << 2))
+
+#define GXBB_AO_SEC_GP_CFG0	GXBB_AO_ADDR(0x90)
+#define GXBB_AO_SEC_GP_CFG3	GXBB_AO_ADDR(0x93)
+#define GXBB_AO_SEC_GP_CFG4	GXBB_AO_ADDR(0x94)
+#define GXBB_AO_SEC_GP_CFG5	GXBB_AO_ADDR(0x95)
+
+#define GXBB_AO_MEM_SIZE_MASK	0xFFFF0000
+#define GXBB_AO_MEM_SIZE_SHIFT	16
+#define GXBB_AO_BL31_RSVMEM_SIZE_MASK	0xFFFF0000
+#define GXBB_AO_BL31_RSVMEM_SIZE_SHIFT	16
+#define GXBB_AO_BL32_RSVMEM_SIZE_MASK	0xFFFF
+
 /* Peripherals registers */
 #define GXBB_PERIPHS_ADDR(off)	(GXBB_PERIPHS_BASE + ((off) << 2))
 
diff --git a/arch/arm/mach-meson/board.c b/arch/arm/mach-meson/board.c
index e89c6aa..bd330af 100644
--- a/arch/arm/mach-meson/board.c
+++ b/arch/arm/mach-meson/board.c
@@ -11,6 +11,8 @@
 #include <asm/arch/sm.h>
 #include <asm/armv8/mmu.h>
 #include <asm/unaligned.h>
+#include <linux/sizes.h>
+#include <asm/io.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -34,14 +36,99 @@ int dram_init(void)
 	return 0;
 }
 
+phys_size_t get_effective_memsize(void)
+{
+	/* Size is reported in MiB, convert it in bytes */
+	return ((in_le32(GXBB_AO_SEC_GP_CFG0) & GXBB_AO_MEM_SIZE_MASK)
+			>> GXBB_AO_MEM_SIZE_SHIFT) * SZ_1M;
+}
+
 int dram_init_banksize(void)
 {
-	/* Reserve first 16 MiB of RAM for firmware */
-	gd->bd->bi_dram[0].start = 0x1000000;
-	gd->bd->bi_dram[0].size  = 0xf000000;
-	/* Reserve 2 MiB for ARM Trusted Firmware (BL31) */
-	gd->bd->bi_dram[1].start = 0x10000000;
-	gd->bd->bi_dram[1].size  = gd->ram_size - 0x10200000;
+	u32 bl31_size, bl31_start;
+	u32 bl32_size, bl32_start;
+	/* Start after first 16MiB reserved zone */
+	unsigned int next = 0;
+	u32 last = 0x1000000;
+	u32 reg;
+
+	/*
+	 * Get ARM Trusted Firmware reserved memory zones in :
+	 * - AO_SEC_GP_CFG3: bl32 & bl31 size in KiB, can be 0
+	 * - AO_SEC_GP_CFG5: bl31 physical start address, can be NULL
+	 * - AO_SEC_GP_CFG4: bl32 physical start address, can be NULL
+	 */
+
+	reg = in_le32(GXBB_AO_SEC_GP_CFG3);
+
+	bl31_size = ((reg & GXBB_AO_BL31_RSVMEM_SIZE_MASK)
+			>> GXBB_AO_BL31_RSVMEM_SIZE_SHIFT) * SZ_1K;
+	bl32_size = (reg & GXBB_AO_BL32_RSVMEM_SIZE_MASK) * SZ_1K;
+
+	bl31_start = in_le32(GXBB_AO_SEC_GP_CFG5);
+	bl32_start = in_le32(GXBB_AO_SEC_GP_CFG4);
+
+	if (bl31_size && bl31_start && bl32_size && bl32_start) {
+		/* Reserve memory for ARM Trusted Firmware (BL31 && BL32) */
+		gd->bd->bi_dram[next].start = last;
+		if (bl31_start > bl32_start)
+			gd->bd->bi_dram[next].size = bl32_start - last;
+		else
+			gd->bd->bi_dram[next].size = bl31_start - last;
+
+		last = gd->bd->bi_dram[next].start +
+			gd->bd->bi_dram[next].size;
+
+		if (bl31_start > bl32_start)
+			last += bl32_size;
+		else
+			last += bl31_size;
+		next++;
+
+		gd->bd->bi_dram[next].start = last;
+		if (bl31_start > bl32_start)
+			gd->bd->bi_dram[next].size = bl31_start - last;
+		else
+			gd->bd->bi_dram[next].size = bl32_start - last;
+
+		last = gd->bd->bi_dram[next].start +
+			gd->bd->bi_dram[next].size;
+
+		if (bl31_start > bl32_start)
+			last += bl31_size;
+		else
+			last += bl32_size;
+		next++;
+	} else if ((bl31_size && bl31_start) || (bl32_size && bl32_start)) {
+		/* Reserve memory for ARM Trusted Firmware (BL31 || BL32) */
+		gd->bd->bi_dram[next].start = last;
+		if (bl31_start && bl31_size)
+			gd->bd->bi_dram[next].size = bl31_start - last;
+		else
+			gd->bd->bi_dram[next].size = bl32_start - last;
+
+		last = gd->bd->bi_dram[next].start +
+			gd->bd->bi_dram[next].size;
+
+		if (bl31_start && bl31_size)
+			last += bl31_size;
+		else
+			last += bl32_size;
+
+		next++;
+	}
+
+	/* Add remaining memory */
+	gd->bd->bi_dram[next].start = last;
+	gd->bd->bi_dram[next].size = get_effective_memsize() - last;
+	next++;
+
+	/* Reset unused banks */
+	for ( ; next < CONFIG_NR_DRAM_BANKS ; ++next) {
+		gd->bd->bi_dram[next].start = 0;
+		gd->bd->bi_dram[next].size = 0;
+	}
+
 	return 0;
 }
 
diff --git a/include/configs/meson-gxbb-common.h b/include/configs/meson-gxbb-common.h
index d88d42d..e70fccd 100644
--- a/include/configs/meson-gxbb-common.h
+++ b/include/configs/meson-gxbb-common.h
@@ -10,7 +10,7 @@
 
 #define CONFIG_CPU_ARMV8
 #define CONFIG_REMAKE_ELF
-#define CONFIG_NR_DRAM_BANKS		2
+#define CONFIG_NR_DRAM_BANKS		3
 #define CONFIG_ENV_SIZE			0x2000
 #define CONFIG_SYS_MAXARGS		32
 #define CONFIG_SYS_MALLOC_LEN		(32 << 20)
-- 
2.7.4




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