[PATCH v3 3/3] ddr: socfpga: Implement ECC DRAM scrubbing support for both Gen5/Arria10

Yuslaimi, Alif Zakuan alif.zakuan.yuslaimi at altera.com
Mon Jun 8 08:07:27 CEST 2026


Hi Tien Fong,

On 5/6/2026 12:56 pm, Chee, Tien Fong wrote:
> Hi Alif,
> 
> 
> On 12/5/2026 2:49 pm, alif.zakuan.yuslaimi at altera.com wrote:
>> From: Alif Zakuan Yuslaimi <alif.zakuan.yuslaimi at altera.com>
>>
>> Enable ECC scrubbing support for Gen5 by moving sdram_init_ecc_bits() 
>> from
>> sdram_arria10.c to a new common file, sdram_soc32.c which is shared by 
>> both
>> Arria10 and Gen5 devices. This makes ECC scrubbing support no longer
>> exclusive only to 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>
>> ---
>>
>> Changes in v3:
>> - Updated commit message
>> - Removed legacy HW watchdog check in favor of current WDT DM for 
>> Gen5/Arria10
>> - Dead code cleanups, indentation fixes
>>
>> Changes in v2:
>> - ECC scrubbing is set as optional via Kconfig and defaulted on only for
>>    the reference Arria10/CycloneV boards to avoid SPL overflows on
>>    size-limited Gen5 defconfigs.
>>
>>   arch/arm/mach-socfpga/Kconfig      | 12 +++++
>>   arch/arm/mach-socfpga/spl_a10.c    | 11 ++--
>>   arch/arm/mach-socfpga/spl_gen5.c   | 10 +++-
>>   drivers/ddr/altera/Makefile        |  4 +-
>>   drivers/ddr/altera/sdram_arria10.c | 31 ++++-------
>>   drivers/ddr/altera/sdram_gen5.c    | 39 ++++++++++++--
>>   drivers/ddr/altera/sdram_soc32.c   | 85 ++++++++++++++++++++++++++++++
>>   drivers/ddr/altera/sdram_soc32.h   | 15 ++++++
>>   8 files changed, 172 insertions(+), 35 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 b814e034ecd..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
>> @@ -124,6 +135,7 @@ config ARCH_SOCFPGA_CYCLONE5
>>   config ARCH_SOCFPGA_GEN5
>>       bool
>>       select SPL_ALTERA_SDRAM
>> +    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..0d0412d3507 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>
>> @@ -265,14 +266,8 @@ void board_init_f(ulong dummy)
>>       /* Configure the clock based on handoff */
>>       cm_basic_init(gd->fdt_blob);
>> -#ifdef CONFIG_HW_WATCHDOG
>> -    /* release osc1 watchdog timer 0 from reset */
>> -    socfpga_reset_deassert_osc1wd0();
>> -
>> -    /* reconfigure and enable the watchdog */
>> -    hw_watchdog_init();
>> -    schedule();
>> -#endif /* CONFIG_HW_WATCHDOG */
>> +    if (CONFIG_IS_ENABLED(WDT))
>> +        initr_watchdog();
>>       config_dedicated_pins(gd->fdt_blob);
>>       schedule();
>> diff --git a/arch/arm/mach-socfpga/spl_gen5.c b/arch/arm/mach-socfpga/ 
>> spl_gen5.c
>> index a9825173189..530863b1564 100644
>> --- a/arch/arm/mach-socfpga/spl_gen5.c
>> +++ b/arch/arm/mach-socfpga/spl_gen5.c
>> @@ -22,12 +22,14 @@
>>   #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_DRAM_SIZE_CHECK)
>> +#if IS_ENABLED(CONFIG_SOCFPGA_ECC_SUPPORT) || \
>> +    IS_ENABLED(CONFIG_SOCFPGA_DRAM_SIZE_CHECK)
>>   static struct bd_info bdata __attribute__ ((section(".data")));
>>   #endif
>> @@ -113,6 +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);
>> @@ -150,7 +155,8 @@ void board_init_f(ulong dummy)
>>       /* enable console uart printing */
>>       preloader_console_init();
>> -#if IS_ENABLED(CONFIG_SOCFPGA_DRAM_SIZE_CHECK)
>> +#if IS_ENABLED(CONFIG_SOCFPGA_ECC_SUPPORT) || \
>> +    IS_ENABLED(CONFIG_SOCFPGA_DRAM_SIZE_CHECK)
>>       gd->bd = &bdata;
>>   #endif
>> 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..ac5d3f03f05 100644
>> --- a/drivers/ddr/altera/sdram_arria10.c
>> +++ b/drivers/ddr/altera/sdram_arria10.c
>> @@ -22,6 +22,8 @@
>>   #include <linux/bitops.h>
>>   #include <linux/delay.h>
>>   #include <linux/kernel.h>
>> +#include <linux/sizes.h>
>> +#include "sdram_soc32.h"
>>   DECLARE_GLOBAL_DATA_PTR;
>> @@ -193,24 +195,6 @@ 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 +719,15 @@ 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
>> +    }
>>       sdram_size_check();
>> diff --git a/drivers/ddr/altera/sdram_gen5.c b/drivers/ddr/altera/ 
>> sdram_gen5.c
>> index 1c3c70ea8ae..9c58e4355ae 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 +20,9 @@
>>   #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"
>>   #ifdef CONFIG_XPL_BUILD
>> @@ -566,6 +568,19 @@ 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;
>> +}
>> +#endif
>> +
>>   static int altera_gen5_sdram_of_to_plat(struct udevice *dev)
>>   {
>>       struct altera_gen5_sdram_plat *plat = dev_get_plat(dev);
>> @@ -608,10 +623,13 @@ 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 +644,23 @@ 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
>> +    }
>> +
>>       /* 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..2fc06fddd4c
>> --- /dev/null
>> +++ b/drivers/ddr/altera/sdram_soc32.c
>> @@ -0,0 +1,85 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Copyright (C) 2025 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>
>> +#include <asm/global_data.h>
>> +#include <asm/system.h>
>> +#if !IS_ENABLED(CONFIG_WATCHDOG) && !CONFIG_IS_ENABLED(WDT)
>> +#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) && !CONFIG_IS_ENABLED(WDT)
> 
> 
> note in commit that legacy HW_WATCHDOG path was removed in v3
> 
> 
>> +    /*
>> +     * No watchdog driver is active in U-Boot. The bootrom or a
>> +     * previous boot stage may have left L4WD0 running. Assert and
>> +     * deassert its reset to stop it before the long ECC scrub,
>> +     * preventing a spurious watchdog reset during DDR init.
>> +    */
> 
> 
> checkpatch BLOCK_COMMENT_STYLE on */
> 
> 
>> +    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;
>> +
>> +        /* Service DM watchdog cyclic callbacks */
>> +        schedule();
>> +    }
>> +
>> +    dcache_disable();
>> +
>> +    printf("DDRCAL: SDRAM-ECC initialized success with %u ms\n",
> 
> 
>   “initialized success” → “initialized successfully”
> 
> Best regards,
> 
> Tien Fong
> 

Thank you for your input. Further clean up will be done for v4 
submission based on your comments

Alif


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