[ELDK] [PATCH 03/10] META-ELDK: u-boot: Fix memory slowness on M53EVK
Marek Vasut
marex at denx.de
Tue Apr 1 22:41:41 CEST 2014
Add patches for M53EVK which make the DRAM access in U-Boot much faster.
Please see u-boot/m53evk/0004-arm-mx5-Fix-memory-slowness-on-M53EVK.patch
commit message for complete explanation of the issue and it's resolution.
Signed-off-by: Marek Vasut <marex at denx.de>
Cc: Wolfgang Denk <wd at denx.de>
---
...004-arm-mx5-Fix-memory-slowness-on-M53EVK.patch | 63 ++++++++++++
...5-Avoid-hardcoding-memory-sizes-on-M53EVK.patch | 111 +++++++++++++++++++++
meta-eldk/recipes-bsp/uboot/u-boot_2014.01.bb | 2 +
3 files changed, 176 insertions(+)
create mode 100644 meta-eldk/recipes-bsp/uboot/u-boot/m53evk/0004-arm-mx5-Fix-memory-slowness-on-M53EVK.patch
create mode 100644 meta-eldk/recipes-bsp/uboot/u-boot/m53evk/0005-arm-mx5-Avoid-hardcoding-memory-sizes-on-M53EVK.patch
diff --git a/meta-eldk/recipes-bsp/uboot/u-boot/m53evk/0004-arm-mx5-Fix-memory-slowness-on-M53EVK.patch b/meta-eldk/recipes-bsp/uboot/u-boot/m53evk/0004-arm-mx5-Fix-memory-slowness-on-M53EVK.patch
new file mode 100644
index 0000000..94e9cfe
--- /dev/null
+++ b/meta-eldk/recipes-bsp/uboot/u-boot/m53evk/0004-arm-mx5-Fix-memory-slowness-on-M53EVK.patch
@@ -0,0 +1,63 @@
+From 07469fd3ae3c64dbc9d014c92a3ca74cd97aa297 Mon Sep 17 00:00:00 2001
+From: Marek Vasut <marex at denx.de>
+Date: Fri, 28 Mar 2014 04:45:16 +0100
+Subject: [PATCH 1/2] arm: mx5: Fix memory slowness on M53EVK
+
+Fix memory access slowness on i.MX53 M53EVK board. Let us inspect the
+issue: First of all, the i.MX53 CPU has two memory banks mapped at
+0x7000_0000 and 0xb000_0000 and each of those can hold up to 1GiB of
+DRAM memory. Notice that the memory area is not continuous. On M53EVK,
+each of the banks contain 512MiB of DRAM, which makes a total of 1GiB
+of memory available to the system.
+
+The problem is how the relocation of U-Boot is treated on i.MX53 . The
+U-Boot is placed at the ((start of first DRAM partition) + (gd->ram_size)) .
+This in turn poses a problem, since in our case, the gd->ram_size is 1GiB,
+the first DRAM bank starts at 0x7000_0000 and contains 512MiB of memory.
+Thus, with this algorithm, U-Boot is placed at offset:
+
+ 0x7000_0000 + 1GiB - sizeof(u-boot and some small margin)
+
+This is past the DRAM available in the first bank on M53EVK, but is still
+within the address range of the first DRAM bank. Because of the memory
+wrap-around, the data can still be read and written to this area, but the
+access is much slower.
+
+There were two ideas how to solve this problem, first was to map both of
+the available DRAM chunks next to one another by using MMU, second was to
+define CONFIG_VERY_BIG_RAM and CONFIG_MAX_MEM_MAPPED to size of the memory
+in the first DRAM bank. We choose the later because it turns out the former
+is not applicable afterall. The former cannot be used in case Linux kernel
+was loaded into the second DRAM bank area, which would be remapped and one
+would try booting the kernel, since at some point before the kernel is started,
+the MMU would be turned off, which would destroy the mapping and hang the
+system.
+
+Signed-off-by: Marek Vasut <marex at denx.de>
+Cc: Fabio Estevam <fabio.estevam at freescale.com>
+Cc: Stefano Babic <sbabic at denx.de>
+Cc: Wolfgang Denk <wd at denx.de>
+
+V2: Reword the commit message
+---
+ include/configs/m53evk.h | 4 +++-
+ 1 file changed, 3 insertions(+), 1 deletion(-)
+
+diff --git a/include/configs/m53evk.h b/include/configs/m53evk.h
+index 9d41e75..d592318 100644
+--- a/include/configs/m53evk.h
++++ b/include/configs/m53evk.h
+@@ -62,7 +62,9 @@
+ #define PHYS_SDRAM_SIZE (PHYS_SDRAM_1_SIZE + PHYS_SDRAM_2_SIZE)
+ #define CONFIG_SYS_MALLOC_LEN (10 * 1024 * 1024)
+ #define CONFIG_SYS_MEMTEST_START 0x70000000
+-#define CONFIG_SYS_MEMTEST_END 0xaff00000
++#define CONFIG_SYS_MEMTEST_END 0x8ff00000
++#define CONFIG_VERY_BIG_RAM
++#define CONFIG_MAX_MEM_MAPPED PHYS_SDRAM_1_SIZE
+
+ #define CONFIG_SYS_SDRAM_BASE (PHYS_SDRAM_1)
+ #define CONFIG_SYS_INIT_RAM_ADDR (IRAM_BASE_ADDR)
+--
+1.9.0
+
diff --git a/meta-eldk/recipes-bsp/uboot/u-boot/m53evk/0005-arm-mx5-Avoid-hardcoding-memory-sizes-on-M53EVK.patch b/meta-eldk/recipes-bsp/uboot/u-boot/m53evk/0005-arm-mx5-Avoid-hardcoding-memory-sizes-on-M53EVK.patch
new file mode 100644
index 0000000..c6a7806
--- /dev/null
+++ b/meta-eldk/recipes-bsp/uboot/u-boot/m53evk/0005-arm-mx5-Avoid-hardcoding-memory-sizes-on-M53EVK.patch
@@ -0,0 +1,111 @@
+From 62bb0c9ef2772474d741f88c85f29e666f955e63 Mon Sep 17 00:00:00 2001
+From: Marek Vasut <marex at denx.de>
+Date: Fri, 28 Mar 2014 05:09:23 +0100
+Subject: [PATCH 2/2] arm: mx5: Avoid hardcoding memory sizes on M53EVK
+
+The DRAM size can be easily detected at runtime on i.MX53. Implement
+such detection on M53EVK and adjust the rest of the macros accordingly
+to use the detected values.
+
+An important thing to note here is that we had to override the function
+for trimming the effective DRAM address, get_effective_memsize(). That
+is because the function uses CONFIG_MAX_MEM_MAPPED as the upper bound of
+the available DRAM and we don't have gd->bd->bi_dram[0].size set up at
+the time the function is called, thus we cannot put this into the macro
+CONFIG_MAX_MEM_MAPPED . Instead, we use custom override where we use the
+size of the first DRAM block which we just detected.
+
+Signed-off-by: Marek Vasut <marex at denx.de>
+Cc: Fabio Estevam <fabio.estevam at freescale.com>
+Cc: Stefano Babic <sbabic at denx.de>
+Cc: Wolfgang Denk <wd at denx.de>
+
+V2: Use linux/sizes.h instead of asm/sizes.h
+V3: - Drop use of sizes.h completely
+ - Add beefy comment as to why we override get_effective_memsize()
+ - Drop CONFIG_VERY_BIG_RAM and CONFIG_MAX_MEM_MAPPED as we no longer
+ need it if we override get_effective_memsize()
+---
+ board/denx/m53evk/m53evk.c | 31 ++++++++++++++++++++++++-------
+ include/configs/m53evk.h | 8 +++-----
+ 2 files changed, 27 insertions(+), 12 deletions(-)
+
+diff --git a/board/denx/m53evk/m53evk.c b/board/denx/m53evk/m53evk.c
+index 0f71a16..74f9501 100644
+--- a/board/denx/m53evk/m53evk.c
++++ b/board/denx/m53evk/m53evk.c
+@@ -31,24 +31,41 @@
+
+ DECLARE_GLOBAL_DATA_PTR;
+
+-int dram_init(void)
++static uint32_t mx53_dram_size[2];
++
++phys_size_t get_effective_memsize(void)
+ {
+- u32 size1, size2;
++ /*
++ * WARNING: We must override get_effective_memsize() function here
++ * to report only the size of the first DRAM bank. This is to make
++ * U-Boot relocator place U-Boot into valid memory, that is, at the
++ * end of the first DRAM bank. If we did not override this function
++ * like so, U-Boot would be placed at the address of the first DRAM
++ * bank + total DRAM size - sizeof(uboot), which in the setup where
++ * each DRAM bank contains 512MiB of DRAM would result in placing
++ * U-Boot into invalid memory area close to the end of the first
++ * DRAM bank.
++ */
++ return mx53_dram_size[0];
++}
+
+- size1 = get_ram_size((void *)PHYS_SDRAM_1, PHYS_SDRAM_1_SIZE);
+- size2 = get_ram_size((void *)PHYS_SDRAM_2, PHYS_SDRAM_2_SIZE);
++int dram_init(void)
++{
++ mx53_dram_size[0] = get_ram_size((void *)PHYS_SDRAM_1, 1 << 30);
++ mx53_dram_size[1] = get_ram_size((void *)PHYS_SDRAM_2, 1 << 30);
+
+- gd->ram_size = size1 + size2;
++ gd->ram_size = mx53_dram_size[0] + mx53_dram_size[1];
+
+ return 0;
+ }
++
+ void dram_init_banksize(void)
+ {
+ gd->bd->bi_dram[0].start = PHYS_SDRAM_1;
+- gd->bd->bi_dram[0].size = PHYS_SDRAM_1_SIZE;
++ gd->bd->bi_dram[0].size = mx53_dram_size[0];
+
+ gd->bd->bi_dram[1].start = PHYS_SDRAM_2;
+- gd->bd->bi_dram[1].size = PHYS_SDRAM_2_SIZE;
++ gd->bd->bi_dram[1].size = mx53_dram_size[1];
+ }
+
+ static void setup_iomux_uart(void)
+diff --git a/include/configs/m53evk.h b/include/configs/m53evk.h
+index d592318..1324877 100644
+--- a/include/configs/m53evk.h
++++ b/include/configs/m53evk.h
+@@ -56,15 +56,13 @@
+ */
+ #define CONFIG_NR_DRAM_BANKS 2
+ #define PHYS_SDRAM_1 CSD0_BASE_ADDR
+-#define PHYS_SDRAM_1_SIZE (512 * 1024 * 1024)
++#define PHYS_SDRAM_1_SIZE (gd->bd->bi_dram[0].size)
+ #define PHYS_SDRAM_2 CSD1_BASE_ADDR
+-#define PHYS_SDRAM_2_SIZE (512 * 1024 * 1024)
+-#define PHYS_SDRAM_SIZE (PHYS_SDRAM_1_SIZE + PHYS_SDRAM_2_SIZE)
++#define PHYS_SDRAM_2_SIZE (gd->bd->bi_dram[1].size)
++#define PHYS_SDRAM_SIZE (gd->ram_size)
+ #define CONFIG_SYS_MALLOC_LEN (10 * 1024 * 1024)
+ #define CONFIG_SYS_MEMTEST_START 0x70000000
+ #define CONFIG_SYS_MEMTEST_END 0x8ff00000
+-#define CONFIG_VERY_BIG_RAM
+-#define CONFIG_MAX_MEM_MAPPED PHYS_SDRAM_1_SIZE
+
+ #define CONFIG_SYS_SDRAM_BASE (PHYS_SDRAM_1)
+ #define CONFIG_SYS_INIT_RAM_ADDR (IRAM_BASE_ADDR)
+--
+1.9.0
+
diff --git a/meta-eldk/recipes-bsp/uboot/u-boot_2014.01.bb b/meta-eldk/recipes-bsp/uboot/u-boot_2014.01.bb
index 7010cd3..e521dec 100644
--- a/meta-eldk/recipes-bsp/uboot/u-boot_2014.01.bb
+++ b/meta-eldk/recipes-bsp/uboot/u-boot_2014.01.bb
@@ -26,6 +26,8 @@ SRC_URI_append_m53evk = " \
file://0001-ARM-m53evk-add-needed-commands-and-options.patch \
file://0002-ARM-m53evk-Adjust-mtdparts-settings.patch \
file://0003-ARM-m53evk-Update-default-environment.patch \
+ file://0004-arm-mx5-Fix-memory-slowness-on-M53EVK.patch \
+ file://0005-arm-mx5-Avoid-hardcoding-memory-sizes-on-M53EVK.patch \
"
# Build u-boot-with-nand-spl.imx for the M53EVK so we can place it in the image
--
1.9.0
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