[PATCH v2 3/3] ddr: socfpga: Add ECC DRAM scrubbing support for Gen5/Arria10
Chee, Tien Fong
tien.fong.chee at altera.com
Tue May 5 08:54:19 CEST 2026
Hi Alif,
On 28/4/2026 11:32 am, alif.zakuan.yuslaimi at altera.com wrote:
> From: Alif Zakuan Yuslaimi <alif.zakuan.yuslaimi at altera.com>
>
> The SDRAM must first be rewritten by zeroes if ECC is used to initialize
> the ECC metadata. Make the CPU overwrite the DRAM with zeroes in such a
> case.
>
> This implementation turns the caches on temporarily, then overwrites the
> whole RAM with zeroes, flushes the caches and turns them off again.
> This provides satisfactory performance.
>
> Move common code sdram_init_ecc_bits() to new common file sdram_soc32.c.
> Preparation for Gen5 uses the same memory initialization function as
> Arria10.
>
> New Kconfig is introduced to enable this implementation only on the default
> Arria10 and CycloneV boards as this will increase the SPL size which
> will exceed some Gen5 devices' SPL size limit.
>
> Signed-off-by: Tien Fong Chee <tien.fong.chee at altera.com>
> Signed-off-by: Alif Zakuan Yuslaimi <alif.zakuan.yuslaimi at altera.com>
> ---
> arch/arm/mach-socfpga/Kconfig | 13 ++++-
> arch/arm/mach-socfpga/spl_a10.c | 4 ++
> arch/arm/mach-socfpga/spl_gen5.c | 17 ++++++
> drivers/ddr/altera/Makefile | 4 +-
> drivers/ddr/altera/sdram_arria10.c | 34 +++++-------
> drivers/ddr/altera/sdram_gen5.c | 41 ++++++++++++--
> drivers/ddr/altera/sdram_soc32.c | 85 ++++++++++++++++++++++++++++++
> drivers/ddr/altera/sdram_soc32.h | 15 ++++++
> 8 files changed, 187 insertions(+), 26 deletions(-)
> create mode 100644 drivers/ddr/altera/sdram_soc32.c
> create mode 100644 drivers/ddr/altera/sdram_soc32.h
>
> diff --git a/arch/arm/mach-socfpga/Kconfig b/arch/arm/mach-socfpga/Kconfig
> index 830585a72cc..dd71691b724 100644
> --- a/arch/arm/mach-socfpga/Kconfig
> +++ b/arch/arm/mach-socfpga/Kconfig
> @@ -6,6 +6,13 @@ config ERR_PTR_OFFSET
> config NR_DRAM_BANKS
> default 1
>
> +config SOCFPGA_ECC_SUPPORT
> + bool "Enable ECC support for DRAM"
> + help
> + Adds CPU-based ECC support for DRAM at boot. This will initialize
> + all DRAM ECC metadata to zero, preventing false ECC errors and
> + improving reliability.
> +
> config SOCFPGA_DRAM_SIZE_CHECK
> bool "Enable DRAM size checking for safety"
> help
> @@ -105,6 +112,7 @@ config ARCH_SOCFPGA_ARRIA10
> select ETH_DESIGNWARE_SOCFPGA
> imply FPGA_SOCFPGA
> imply SPL_USE_TINY_PRINTF
> + select SOCFPGA_ECC_SUPPORT
>
> config SOCFPGA_ARRIA10_ALWAYS_REPROGRAM
> bool "Always reprogram Arria 10 FPGA"
> @@ -117,6 +125,9 @@ config SOCFPGA_ARRIA10_ALWAYS_REPROGRAM
> config ARCH_SOCFPGA_CYCLONE5
> bool
> select ARCH_SOCFPGA_GEN5
> + select SOCFPGA_ECC_SUPPORT if \
> + !TARGET_SOCFPGA_TERASIC_SOCKIT && !TARGET_SOCFPGA_EBV_SOCRATES \
> + && !TARGET_SOCFPGA_SOFTING_VINING_FPGA
> select SOCFPGA_DRAM_SIZE_CHECK if !TARGET_SOCFPGA_TERASIC_SOCKIT \
> && !TARGET_SOCFPGA_EBV_SOCRATES && \
> !TARGET_SOCFPGA_SOFTING_VINING_FPGA
> @@ -124,7 +135,7 @@ config ARCH_SOCFPGA_CYCLONE5
> config ARCH_SOCFPGA_GEN5
> bool
> select SPL_ALTERA_SDRAM
> - select SPL_CACHE if SPL
> + select SPL_CACHE if SPL && SOCFPGA_ECC_SUPPORT
> imply FPGA_SOCFPGA
> imply SPL_SIZE_LIMIT_SUBTRACT_GD
> imply SPL_SIZE_LIMIT_SUBTRACT_MALLOC
> diff --git a/arch/arm/mach-socfpga/spl_a10.c b/arch/arm/mach-socfpga/spl_a10.c
> index c20376f7f8e..4d0696bbaf6 100644
> --- a/arch/arm/mach-socfpga/spl_a10.c
> +++ b/arch/arm/mach-socfpga/spl_a10.c
> @@ -25,6 +25,7 @@
> #include <asm/sections.h>
> #include <fdtdec.h>
> #include <watchdog.h>
> +#include <wdt.h>
> #include <asm/arch/pinmux.h>
> #include <asm/arch/fpga_manager.h>
> #include <mmc.h>
> @@ -265,6 +266,9 @@ void board_init_f(ulong dummy)
> /* Configure the clock based on handoff */
> cm_basic_init(gd->fdt_blob);
>
> + if (CONFIG_IS_ENABLED(WDT))
> + initr_watchdog();
> +
> #ifdef CONFIG_HW_WATCHDOG
> /* release osc1 watchdog timer 0 from reset */
> socfpga_reset_deassert_osc1wd0();
Why not remove this?
> diff --git a/arch/arm/mach-socfpga/spl_gen5.c b/arch/arm/mach-socfpga/spl_gen5.c
> index 08b756db2ca..530863b1564 100644
> --- a/arch/arm/mach-socfpga/spl_gen5.c
> +++ b/arch/arm/mach-socfpga/spl_gen5.c
> @@ -6,6 +6,7 @@
> #include <hang.h>
> #include <init.h>
> #include <log.h>
> +#include <asm/global_data.h>
> #include <asm/io.h>
> #include <asm/utils.h>
> #include <image.h>
> @@ -21,9 +22,17 @@
> #include <debug_uart.h>
> #include <fdtdec.h>
> #include <watchdog.h>
> +#include <wdt.h>
> #include <dm/uclass.h>
> #include <linux/bitops.h>
>
> +DECLARE_GLOBAL_DATA_PTR;
> +
> +#if IS_ENABLED(CONFIG_SOCFPGA_ECC_SUPPORT) || \
> + IS_ENABLED(CONFIG_SOCFPGA_DRAM_SIZE_CHECK)
> +static struct bd_info bdata __attribute__ ((section(".data")));
> +#endif
> +
> u32 spl_boot_device(void)
> {
> const u32 bsel = readl(socfpga_get_sysmgr_addr() +
> @@ -106,6 +115,9 @@ void board_init_f(ulong dummy)
> if (cm_basic_init(cm_default_cfg))
> hang();
>
> + if (CONFIG_IS_ENABLED(WDT))
> + initr_watchdog();
> +
> /* Enable bootrom to configure IOs. */
> sysmgr_config_warmrstcfgio(1);
>
> @@ -143,6 +155,11 @@ void board_init_f(ulong dummy)
> /* enable console uart printing */
> preloader_console_init();
>
> +#if IS_ENABLED(CONFIG_SOCFPGA_ECC_SUPPORT) || \
> + IS_ENABLED(CONFIG_SOCFPGA_DRAM_SIZE_CHECK)
> + gd->bd = &bdata;
> +#endif
> +
> ret = uclass_get_device(UCLASS_RAM, 0, &dev);
> if (ret) {
> debug("DRAM init failed: %d\n", ret);
> diff --git a/drivers/ddr/altera/Makefile b/drivers/ddr/altera/Makefile
> index 8259ab04a7e..ece6a131897 100644
> --- a/drivers/ddr/altera/Makefile
> +++ b/drivers/ddr/altera/Makefile
> @@ -7,8 +7,8 @@
> # Copyright (C) 2014-2025 Altera Corporation <www.altera.com>
>
> ifdef CONFIG_$(PHASE_)ALTERA_SDRAM
> -obj-$(CONFIG_ARCH_SOCFPGA_GEN5) += sdram_gen5.o sequencer.o
> -obj-$(CONFIG_ARCH_SOCFPGA_ARRIA10) += sdram_arria10.o
> +obj-$(CONFIG_ARCH_SOCFPGA_GEN5) += sdram_soc32.o sdram_gen5.o sequencer.o
> +obj-$(CONFIG_ARCH_SOCFPGA_ARRIA10) += sdram_soc32.o sdram_arria10.o
> obj-$(CONFIG_ARCH_SOCFPGA_STRATIX10) += sdram_soc64.o sdram_s10.o
> obj-$(CONFIG_ARCH_SOCFPGA_AGILEX) += sdram_soc64.o sdram_agilex.o
> obj-$(CONFIG_ARCH_SOCFPGA_N5X) += sdram_soc64.o sdram_n5x.o
> diff --git a/drivers/ddr/altera/sdram_arria10.c b/drivers/ddr/altera/sdram_arria10.c
> index c281f711fdf..09d3526603e 100644
> --- a/drivers/ddr/altera/sdram_arria10.c
> +++ b/drivers/ddr/altera/sdram_arria10.c
> @@ -22,9 +22,13 @@
> #include <linux/bitops.h>
> #include <linux/delay.h>
> #include <linux/kernel.h>
> +#include <linux/sizes.h>
> +#include "sdram_soc32.h"
>
> DECLARE_GLOBAL_DATA_PTR;
>
> +#define PGTABLE_OFF 0x4000
Dead code, remove PGTABLE_OFF, only sdram_soc32.c uses it
> +
> static void sdram_mmr_init(void);
> static u64 sdram_size_calc(void);
>
> @@ -193,24 +197,6 @@ static int sdram_is_ecc_enabled(void)
> ALT_ECC_HMC_OCP_ECCCTL_ECC_EN_SET_MSK);
> }
>
> -/* Initialize SDRAM ECC bits to avoid false DBE */
> -static void sdram_init_ecc_bits(u32 size)
> -{
> - icache_enable();
> -
> - memset(0, 0, 0x8000);
> - gd->arch.tlb_addr = 0x4000;
> - gd->arch.tlb_size = PGTABLE_SIZE;
> -
> - dcache_enable();
> -
> - printf("DDRCAL: Scrubbing ECC RAM (%i MiB).\n", size >> 20);
> - memset((void *)0x8000, 0, size - 0x8000);
> - flush_dcache_all();
> - printf("DDRCAL: Scrubbing ECC RAM done.\n");
> - dcache_disable();
> -}
> -
> /* Function to startup the SDRAM*/
> static int sdram_startup(void)
> {
> @@ -735,8 +721,16 @@ int ddr_calibration_sequence(void)
> if (of_sdram_firewall_setup(gd->fdt_blob))
> puts("FW: Error Configuring Firewall\n");
>
> - if (sdram_is_ecc_enabled())
> - sdram_init_ecc_bits(gd->ram_size);
> + if (sdram_is_ecc_enabled()) {
> +#if IS_ENABLED(CONFIG_SOCFPGA_ECC_SUPPORT)
> + sdram_init_ecc_bits();
> + }
> +#else
> + puts("DDR: Enable CONFIG_SOCFPGA_ECC_SUPPORT when SDRAM ");
> + puts("ECC is enabled.\n");
> + hang();
> + }
> +#endif
confusing pattern, moves the } outside the preprocessor block entirely
to here
>
> sdram_size_check();
>
> diff --git a/drivers/ddr/altera/sdram_gen5.c b/drivers/ddr/altera/sdram_gen5.c
> index 1c3c70ea8ae..76effb264e2 100644
> --- a/drivers/ddr/altera/sdram_gen5.c
> +++ b/drivers/ddr/altera/sdram_gen5.c
> @@ -2,6 +2,7 @@
> /*
> * Copyright Altera Corporation (C) 2014-2015
> */
> +#include <cpu_func.h>
> #include <dm.h>
> #include <errno.h>
> #include <div64.h>
> @@ -19,8 +20,11 @@
> #include <asm/global_data.h>
> #include <asm/io.h>
> #include <dm/device_compat.h>
> -
> +#include <linux/sizes.h>
> #include "sequencer.h"
> +#include "sdram_soc32.h"
> +
> +#define PGTABLE_OFF 0x4000
Dead code, remove PGTABLE_OFF, only sdram_soc32.c uses it
>
> #ifdef CONFIG_XPL_BUILD
>
> @@ -566,6 +570,19 @@ static unsigned long sdram_calculate_size(struct socfpga_sdr_ctrl *sdr_ctrl)
> return temp;
> }
>
> +#if IS_ENABLED(CONFIG_SOCFPGA_ECC_SUPPORT)
> +static int sdram_is_ecc_enabled(struct socfpga_sdr_ctrl *sdr_ctrl)
> +{
> + return !!(readl(&sdr_ctrl->ctrl_cfg) &
> + SDR_CTRLGRP_CTRLCFG_ECCEN_MASK);
> +}
> +#else
> +static int sdram_is_ecc_enabled(struct socfpga_sdr_ctrl *sdr_ctrl)
> +{
> + return 0;
4 spaces (WRONG, should be \t)
ERROR: code indent should use tabs where possible from checkpatch
> +}
> +#endif
> +
> static int altera_gen5_sdram_of_to_plat(struct udevice *dev)
> {
> struct altera_gen5_sdram_plat *plat = dev_get_plat(dev);
> @@ -608,10 +625,13 @@ static int altera_gen5_sdram_probe(struct udevice *dev)
> sdram_size = sdram_calculate_size(sdr_ctrl);
> debug("SDRAM: %ld MiB\n", sdram_size >> 20);
>
> -#if IS_ENABLED(CONFIG_SOCFPGA_DRAM_SIZE_CHECK)
> +#if IS_ENABLED(CONFIG_SOCFPGA_DRAM_SIZE_CHECK) || \
> + IS_ENABLED(CONFIG_SOCFPGA_ECC_SUPPORT)
> /* setup the dram info within bd */
> dram_init_banksize();
> +#endif
>
> +#if IS_ENABLED(CONFIG_SOCFPGA_DRAM_SIZE_CHECK)
> if (sdram_size != gd->bd->bi_dram[0].size) {
> printf("DDR: Warning: DRAM size from device tree (%lu MiB)\n",
> (ulong)(gd->bd->bi_dram[0].size >> 20));
> @@ -626,8 +646,23 @@ static int altera_gen5_sdram_probe(struct udevice *dev)
> }
> #endif
>
> + if (sdram_is_ecc_enabled(sdr_ctrl)) {
> +#if IS_ENABLED(CONFIG_SOCFPGA_ECC_SUPPORT)
> + /* Must set USEECCASDATA to 0 if ECC is enabled */
> + clrbits_le32(&sdr_ctrl->static_cfg,
> + SDR_CTRLGRP_STATICCFG_USEECCASDATA_MASK);
> + sdram_init_ecc_bits();
> +#else
> + puts("DDR: Enable CONFIG_SOCFPGA_ECC_SUPPORT when SDRAM ");
> + puts("ECC is enabled.\n");
> + puts("DDR: Without scrub, false ECC errors may occur.\n");
> + hang();
> +#endif
> +}
WRONG, should be \t
> +
> /* Sanity check ensure correct SDRAM size specified */
> -#if IS_ENABLED(CONFIG_SOCFPGA_DRAM_SIZE_CHECK)
> +#if IS_ENABLED(CONFIG_SOCFPGA_DRAM_SIZE_CHECK) || \
> + IS_ENABLED(CONFIG_SOCFPGA_ECC_SUPPORT)
> if (get_ram_size(0, gd->bd->bi_dram[0].size) !=
> gd->bd->bi_dram[0].size) {
> #else
> diff --git a/drivers/ddr/altera/sdram_soc32.c b/drivers/ddr/altera/sdram_soc32.c
> new file mode 100644
> index 00000000000..7556d4933f4
> --- /dev/null
> +++ b/drivers/ddr/altera/sdram_soc32.c
> @@ -0,0 +1,85 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2026 Altera Corporation <www.altera.com>
> + */
> +
> +#include "sdram_soc32.h"
> +#include <string.h>
> +#include <hang.h>
> +#include <linux/sizes.h>
> +#include <cpu_func.h>
> +#include <watchdog.h>
> +#include <wait_bit.h>
Unused header
> +#include <asm/global_data.h>
> +#include <asm/system.h>
Unused header, please check!
> +#if !defined(CONFIG_HW_WATCHDOG)
#if !IS_ENABLED(CONFIG_WATCHDOG)
> +#include <asm/arch/reset_manager.h>
> +#endif
> +
> +DECLARE_GLOBAL_DATA_PTR;
> +
> +#define PGTABLE_OFF 0x4000
> +#define PGTABLE_RESERVE (PGTABLE_OFF + PGTABLE_SIZE)
> +
> +#if IS_ENABLED(CONFIG_SOCFPGA_ECC_SUPPORT)
> +static void socfpga_prepare_watchdog_for_long_op(void)
> +{
> +#if !IS_ENABLED(CONFIG_WATCHDOG)
#if IS_ENABLED(CONFIG_WATCHDOG) || IS_ENABLED(CONFIG_WDT)
> + /*
> + * No DM watchdog support enabled. Previous boot stage may have left
> + * L4WD0 running, so stop it once before long DDR scrub operation.
> + */
> + socfpga_per_reset(SOCFPGA_RESET(L4WD0), 1);
> + socfpga_per_reset(SOCFPGA_RESET(L4WD0), 0);
> +#endif
> +}
> +
> +/* Initialize SDRAM ECC bits to avoid false DBE */
> +void sdram_init_ecc_bits(void)
> +{
> + u32 start;
> + phys_addr_t start_addr;
> + phys_size_t size, size_init;
> +
> + start = get_timer(0);
> +
> + start_addr = gd->bd->bi_dram[0].start;
> + size = gd->bd->bi_dram[0].size;
> +
> + printf("DDRCAL: Scrubbing ECC RAM (%lu MiB).\n",
> + (ulong)(size >> 20));
> +
> + if (size <= PGTABLE_RESERVE) {
> + printf("DDRCAL: Error: DRAM size %#llx smaller than scrub reserve %#x\n",
> + (unsigned long long)size, PGTABLE_RESERVE);
> + hang();
> + }
> +
> + memset((void *)start_addr, 0, PGTABLE_RESERVE);
> + gd->arch.tlb_addr = start_addr + PGTABLE_OFF;
> + gd->arch.tlb_size = PGTABLE_SIZE;
> + start_addr += PGTABLE_RESERVE;
> + size -= PGTABLE_RESERVE;
> +
> + dcache_enable();
> +
> + socfpga_prepare_watchdog_for_long_op();
> +
> + while (size > 0) {
> + size_init = min_t(phys_size_t, (phys_size_t)SZ_1G, size);
> + memset((void *)start_addr, 0, size_init);
> + size -= size_init;
> + start_addr += size_init;
> +
> +#if IS_ENABLED(CONFIG_WATCHDOG)
Can remove the guard, just call schedule() unconditionally, it is a
no-op when nothing is pending
Best regards,
Tien Fong
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