Re: [PATCH v6 3/3] EDAC: nuvoton: Add NPCM memory controller driver

Medad Young
2022-04-11T08:06:45Z

Dear Borislav,

thanks for your comments

Borislav Petkov <bp@alien8.de> 於 2022年4月9日 週六 上午3:05寫道：
>
> On Tue, Mar 22, 2022 at 11:01:52AM +0800, Medad CChien wrote:
> > Add support for Nuvoton NPCM SoC.
> >
> > Signed-off-by: Medad CChien <ctcchien@nuvoton.com>
> >
> > Reported-by: kernel test robot <lkp@intel.com>
> >
> > All errors (new ones prefixed by >>):
>
> I'm sure you can summarize this in one sentence instead of pasting all
> the warnings in the commit message where they don't belong.

OK

>
> ...
>
> > diff --git a/drivers/edac/npcm_edac.c b/drivers/edac/npcm_edac.c
> > new file mode 100644
> > index 000000000000..9dd05bec0b7f
> > --- /dev/null
> > +++ b/drivers/edac/npcm_edac.c
> > @@ -0,0 +1,706 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +// Copyright (c) 2022 Nuvoton Technology corporation.
> > +
> > +#include <linux/delay.h>
> > +#include <linux/of_device.h>
> > +
> > +#include "edac_module.h"
> > +
> > +#define NPCM_EDAC_MOD_NAME "npcm-edac"
> > +#define FORCED_ECC_ERR_EVENT_SUPPORT BIT(1)
> > +#define EDAC_MSG_SIZE 256
> > +/* Granularity of reported error in bytes */
> > +#define NPCM_EDAC_ERR_GRAIN 1
> > +
> > +#define MEM_TYPE_DDR4 0xA
> > +
> > +#define NPCM8XX_CHIP 0x800
> > +#define NPCM7XX_CHIP 0x700
> > +
> > +/* Control register width definitions */
> > +#define WDTH_16 (2)
> > +#define WDTH_32 (1)
> > +#define WDTH_64 (0)
> > +#define CTL_MEM_MAX_WIDTH_MASK GENMASK(4, 0)
> > +#define CTL_REG_WIDTH_SHIFT (32)
> > +#define XOR_CHECK_BIT_SPLIT_WIDTH (16)
> > +#define CTL_CONTROLLER_BUSY_FLAG BIT(0)
> > +#define NPCM_ECC_CTL_FORCE_WC BIT(8)
> > +#define NPCM_ECC_CTL_AUTO_WRITEBACK_EN BIT(24)
> > +#define NPCM_ECC_CTL_XOR_BITS_MASK GENMASK(23, 16)
> > +#define NPCM_ECC_CTL_MTYPE_MASK GENMASK(11, 8)
> > +#define NPCM_ECC_CTL_GLOBAL_INT_DISABLE BIT(31)
>
> Align those values vertically pls.

Ok

>
> > +
> > +#ifdef CONFIG_EDAC_DEBUG
> > +
> > +/* Syndrome values */
> > +#define ECC_DOUBLE_MULTI_ERR_SYND 0x03
> > +
> > +static char data_synd[] = {
> > + 0xf4, 0xf1, 0xec, 0xea, 0xe9, 0xe6, 0xe5, 0xe3,
> > + 0xdc, 0xda, 0xd9, 0xd6, 0xd5, 0xd3, 0xce, 0xcb,
> > + 0xb5, 0xb0, 0xad, 0xab, 0xa8, 0xa7, 0xa4, 0xa2,
> > + 0x9d, 0x9b, 0x98, 0x97, 0x94, 0x92, 0x8f, 0x8a,
> > + 0x75, 0x70, 0x6d, 0x6b, 0x68, 0x67, 0x64, 0x62,
> > + 0x5e, 0x5b, 0x58, 0x57, 0x54, 0x52, 0x4f, 0x4a,
> > + 0x34, 0x31, 0x2c, 0x2a, 0x29, 0x26, 0x25, 0x23,
> > + 0x1c, 0x1a, 0x19, 0x16, 0x15, 0x13, 0x0e, 0x0b
> > + };
> > +
> > +static char check_synd[] = {0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80};
> > +#endif
> > +
> > +struct npcm_edac_platform_data {
> > + /* force ECC event */
> > + u32 ip_features;
> > + u32 ddr_ctl_controller_busy_reg;
> > + u32 ecc_ctl_xor_check_bits_reg;
> > +
> > + u32 chip;
> > +
> > + /* DDR4 Controller Registers */
> > + u32 ddr_ctl_mem_type_reg;
> > + u32 ddr_ctl_mem_width_reg;
> > +
> > + u32 ecc_ctl_en_reg;
> > + u32 ecc_ctl_int_mask;
> > + u32 ecc_ctl_int_status;
> > + u32 ecc_ctl_int_ack;
> > + u32 ecc_ctl_int_mask_master;
> > + u32 ecc_ctl_int_mask_ecc;
> > +
> > + u32 ecc_sig_ecc_c_addr_l;
> > + u32 ecc_sig_ecc_c_addr_h;
> > + u32 ecc_sig_ecc_c_data_l;
> > + u32 ecc_sig_ecc_c_data_h;
> > + u32 ecc_sig_ecc_c_id;
> > + u32 ecc_sig_ecc_c_synd;
> > +
> > + u32 ecc_sig_ecc_u_addr_l;
> > + u32 ecc_sig_ecc_u_addr_h;
> > + u32 ecc_sig_ecc_u_data_l;
> > + u32 ecc_sig_ecc_u_data_h;
> > + u32 ecc_sig_ecc_u_id;
> > + u32 ecc_sig_ecc_u_synd;
> > +
> > + /* MASK */
> > + u32 ecc_ctl_ecc_enable_mask;
> > + u32 ecc_ctl_en_int_master_mask;
> > + u32 ecc_ctl_en_int_ecc_mask;
> > +
> > + /* ECC IRQ Macros */
> > + u32 ecc_int_ce_event;
> > + u32 ecc_int_second_ce_event;
> > + u32 ecc_int_ue_event;
> > + u32 ecc_int_second_ue_event;
> > + u32 ecc_int_ce_ue_mask;
> > + u32 ecc_ce_intr_mask;
> > + u32 ecc_ue_intr_mask;
> > +
> > + /* ECC Signature Macros */
> > + u32 ecc_sig_ecc_c_id_shift;
> > + u32 ecc_sig_ecc_c_synd_shift;
> > + u32 ecc_sig_ecc_c_addr_h_mask;
> > + u32 ecc_sig_ecc_c_id_mask;
> > + u32 ecc_sig_ecc_c_synd_mask;
> > +
> > + u32 ecc_sig_ecc_u_id_shift;
> > + u32 ecc_sig_ecc_u_synd_shift;
> > + u32 ecc_sig_ecc_u_addr_h_mask;
> > + u32 ecc_sig_ecc_u_id_mask;
> > + u32 ecc_sig_ecc_u_synd_mask;
>
> I'd try to shorten those if I were you - "ecc_sig_" could go, "ecc_int_"
> too. Then the code accessing them would become more readable and you
> won't have to break long lines.

OK

>
> > +};
> > +
> > +struct priv_data {
> > + void __iomem *reg;
> > + u32 ce_cnt;
> > + u32 ue_cnt;
> > + char message[EDAC_MSG_SIZE];
> > + const struct npcm_edac_platform_data *npcm_chip;
> > +};
> > +
> > +#ifdef CONFIG_EDAC_DEBUG
>
> Move that ifdeffery...
>
> > +static void init_mem_layout(struct mem_ctl_info *mci)
> > +{
>
> ... here and then you won't need the ifdeffery at the call site below.
>

OK

> > + struct priv_data *priv = mci->pvt_info;
> > + const struct npcm_edac_platform_data *npcm_chip = priv->npcm_chip;
> > + struct csrow_info *csi;
> > + struct dimm_info *dimm;
> > + struct sysinfo inf;
> > + enum mem_type mtype;
> > + u32 val, width;
> > + u32 size, row;
> > + u8 j;
> > +
> > + dimm = edac_get_dimm(mci, 0, 0, 0);
> > + if (!dimm) {
>
> Save an indentation level:
>

OK

> if (dimm)
> return;
>
> si_meminfo(&inf);
> ...
>
> > + si_meminfo(&inf);
> > + for (row = 0; row < mci->nr_csrows; row++) {
> > + csi = mci->csrows[row];
> > + size = inf.totalram * inf.mem_unit;
> > +
> > + for (j = 0; j < csi->nr_channels; j++) {
> > + dimm = csi->channels[j]->dimm;
> > + dimm->edac_mode = EDAC_FLAG_SECDED;
> > + /* Get memory type by reading hw registers*/
> > + val = readl(priv->reg + npcm_chip->ddr_ctl_mem_type_reg);
> > + mtype = val & NPCM_ECC_CTL_MTYPE_MASK;
> > +
> > + if (mtype == MEM_TYPE_DDR4)
> > + dimm->mtype = MEM_DDR4;
> > + else
> > + dimm->mtype = MEM_EMPTY;
> > +
> > + /*Get EDAC devtype width for the current mc*/
>
> Put spaces between the * and the text. There are other comments who have
> this, pls fix them all.
>

OK

> > + width = readl(priv->reg + npcm_chip->ddr_ctl_mem_width_reg)
> > + & CTL_MEM_MAX_WIDTH_MASK;
> > + switch (width) {
> > + case WDTH_16:
> > + dimm->dtype = DEV_X2;
> > + break;
> > + case WDTH_32:
> > + dimm->dtype = DEV_X4;
> > + break;
> > + case WDTH_64:
> > + dimm->dtype = DEV_X8;
> > + break;
> > + default:
> > + dimm->dtype = DEV_UNKNOWN;
> > + }
> > +
> > + dimm->nr_pages = (size >> PAGE_SHIFT) /
> > + csi->nr_channels;
> > + dimm->grain = NPCM_EDAC_ERR_GRAIN;
> > + }
> > + }
> > + }
> > +}
> > +#endif
> > +
> > +static void handle_ce(struct mem_ctl_info *mci)
> > +{
> > + struct priv_data *priv = mci->pvt_info;
> > + const struct npcm_edac_platform_data *npcm_chip = priv->npcm_chip;
> > + u64 err_c_addr = 0x0;
> > + u64 err_c_data = 0x0;
> > + u32 err_c_synd, err_c_id;
> > + u32 sig_val_l, sig_val_h;
> > +
> > + sig_val_l = readl(priv->reg + npcm_chip->ecc_sig_ecc_c_addr_l);
> > +
> > + if (npcm_chip->chip == NPCM8XX_CHIP)
> > + sig_val_h = (readl(priv->reg + npcm_chip->ecc_sig_ecc_c_addr_h) &
> > + npcm_chip->ecc_sig_ecc_c_addr_h_mask);
> > + else
> > + sig_val_h = 0x0;
>
> assign those vars to 0 at declaration time and you won't need the else
> branch here...
>

OK

> > +
> > + err_c_addr = (((err_c_addr | sig_val_h) <<
> > + CTL_REG_WIDTH_SHIFT) | sig_val_l);
> > +
> > + sig_val_l = readl(priv->reg + npcm_chip->ecc_sig_ecc_c_data_l);
> > +
> > + if (npcm_chip->chip == NPCM8XX_CHIP)
> > + sig_val_h = readl(priv->reg + npcm_chip->ecc_sig_ecc_c_data_h);
> > + else
> > + sig_val_h = 0x0;
>
> ... and here.
>
> Ditto for handle_ue() below.

OK

>
> > + err_c_data = (((err_c_data | sig_val_h) <<
> > + CTL_REG_WIDTH_SHIFT) | sig_val_l);
> > +
> > + err_c_id = ((readl(priv->reg + npcm_chip->ecc_sig_ecc_c_id) &
> > + npcm_chip->ecc_sig_ecc_c_id_mask) >>
> > + npcm_chip->ecc_sig_ecc_c_id_shift);
> > +
> > + err_c_synd = ((readl(priv->reg + npcm_chip->ecc_sig_ecc_c_synd) &
> > + npcm_chip->ecc_sig_ecc_c_synd_mask) >>
> > + npcm_chip->ecc_sig_ecc_c_synd_shift);
> > +
> > + priv->ce_cnt = priv->ce_cnt + 1;
> > +
> > + snprintf(priv->message,
> > + EDAC_MSG_SIZE, "DDR ECC %s: data=0x%llx source_id=%#08x",
> > + mci->ctl_name, err_c_data, err_c_id);
> > +
> > + edac_mc_handle_error(HW_EVENT_ERR_CORRECTED, mci,
> > + 1,
> > + err_c_addr >> PAGE_SHIFT,
> > + err_c_addr & ~PAGE_MASK,
> > + err_c_synd, 0, 0, -1,
> > + priv->message, "");
> > +}
> >
>
> ...
>
> > +static ssize_t forced_ecc_error_store(struct device *dev,
> > + struct device_attribute *mattr,
> > + const char *data, size_t count)
> > +{
> > + struct mem_ctl_info *mci = to_mci(dev);
> > + struct priv_data *priv = mci->pvt_info;
> > + const struct npcm_edac_platform_data *npcm_chip = priv->npcm_chip;
> > + int args_cnt;
> > + int ret;
> > + char **args;
> > + u32 regval;
> > + u8 bit_no;
> > +
> > + /* Split string buffer into separate parameters */
> > + args = argv_split(GFP_KERNEL, data, &args_cnt);
>
> Move that args splitting...
>
> > +
> > + /* Check ecc enabled */
> > + if (!(readl(priv->reg + npcm_chip->ecc_ctl_en_reg) & npcm_chip->ecc_ctl_ecc_enable_mask))
> > + return count;
> > +
> > + /* Check no write operation pending to controller*/
> > + while (readl(priv->reg + npcm_chip->ddr_ctl_controller_busy_reg) &
> > + CTL_CONTROLLER_BUSY_FLAG) {
> > + usleep_range(1000, 10000);
> > + }
>
> ... here.
>

OK

> > +
> > + /* Write appropriate syndrome to xor_check_bit*/
>
> Any documentation about the string being written to debugfs here? I
> wouldn't want to read the source each time :)
>
> > + if (!strcmp(args[0], "CE") && args_cnt == 3) {
> > + ret = kstrtou8(args[2], 0, &bit_no);
> > + if (ret)
> > + return ret;
> > + if (!strcmp(args[1], "checkcode")) {
> > + if (bit_no > 7) {
> > + edac_printk(KERN_INFO, NPCM_EDAC_MOD_NAME, "bit_no for checkcode must be 0~7\n");
> > + return count;
> > + }
> > + regval = readl(priv->reg + npcm_chip->ecc_ctl_xor_check_bits_reg);
> > + regval = (regval & ~(NPCM_ECC_CTL_XOR_BITS_MASK)) |
> > + (check_synd[bit_no] << XOR_CHECK_BIT_SPLIT_WIDTH);
> > + writel(regval, priv->reg + npcm_chip->ecc_ctl_xor_check_bits_reg);
> > + } else if (!strcmp(args[1], "data")) {
> > + if (bit_no > 63) {
> > + edac_printk(KERN_INFO, NPCM_EDAC_MOD_NAME, "bit_no for data must be 0~63\n");
> > + return count;
> > + }
> > + regval = readl(priv->reg + npcm_chip->ecc_ctl_xor_check_bits_reg);
> > + regval = (regval & ~(NPCM_ECC_CTL_XOR_BITS_MASK)) |
> > + (data_synd[bit_no] << XOR_CHECK_BIT_SPLIT_WIDTH);
> > + writel(regval, priv->reg + npcm_chip->ecc_ctl_xor_check_bits_reg);
> > + }
> > + /* Enable the ECC writeback_en for corrected error */
> > + regval = readl(priv->reg + npcm_chip->ecc_ctl_xor_check_bits_reg);
> > + writel((regval | NPCM_ECC_CTL_AUTO_WRITEBACK_EN),
> > + priv->reg + npcm_chip->ecc_ctl_xor_check_bits_reg);
> > + } else if (!strcmp(args[0], "UE")) {
> > + regval = readl(priv->reg + npcm_chip->ecc_ctl_xor_check_bits_reg);
> > + regval = (regval & ~(NPCM_ECC_CTL_XOR_BITS_MASK)) |
> > + (ECC_DOUBLE_MULTI_ERR_SYND << XOR_CHECK_BIT_SPLIT_WIDTH);
> > + writel(regval, priv->reg + npcm_chip->ecc_ctl_xor_check_bits_reg);
> > + }
> > +
> > + /* Assert fwc */
> > + writel((NPCM_ECC_CTL_FORCE_WC | readl(priv->reg + npcm_chip->ecc_ctl_xor_check_bits_reg)),
> > + priv->reg + npcm_chip->ecc_ctl_xor_check_bits_reg);
> > +
> > + return count;
> > +}
>
> ...
>
> > +#ifdef CONFIG_EDAC_DEBUG
> > + if ((npcm_chip->ip_features & FORCED_ECC_ERR_EVENT_SUPPORT) &&
> > + npcm_chip->chip == NPCM8XX_CHIP) {
> > + if (create_sysfs_attributes(mci)) {
> > + edac_printk(KERN_ERR, NPCM_EDAC_MOD_NAME,
> > + "Failed to create sysfs entries\n");
> > + goto err1;
> > + }
> > + }
> > +#endif
> > +
> > + /* Only enable MC interrupts with ECC - clear global int mask bit and ecc bit */
> > + writel(npcm_chip->ecc_ctl_en_int_master_mask,
> > + priv_data->reg + npcm_chip->ecc_ctl_int_mask_master);
> > +
> > + if (npcm_chip->chip == NPCM8XX_CHIP) {
> > + /* clear single and multi for ce and ue */
> > + writel(npcm_chip->ecc_ctl_en_int_ecc_mask,
> > + priv_data->reg + npcm_chip->ecc_ctl_int_mask_ecc);
> > + }
> > +
> > + return 0;
> > +
> > +#ifdef CONFIG_EDAC_DEBUG
> > +err1:
> > +#endif
>
> This is just silly. Why should loading of the driver fail when it cannot
> create a couple of sysfs debugging helpers? I think you're fine if you
> simply issue the error message but continue.

I will revise it

>
> > +
> > + edac_mc_del_mc(&pdev->dev);
> > +
> > +err:
> > + edac_mc_free(mci);
> > + return ret;
> > +}
> > +
> > +static int npcm_edac_mc_remove(struct platform_device *pdev)
> > +{
> > + struct mem_ctl_info *mci = platform_get_drvdata(pdev);
> > + struct priv_data *priv = mci->pvt_info;
> > + const struct npcm_edac_platform_data *npcm_chip = priv->npcm_chip;
> > +
> > + writel(NPCM_ECC_CTL_GLOBAL_INT_DISABLE, priv->reg + npcm_chip->ecc_ctl_int_mask_master);
> > +
> > + /* Disable ecc feature before removing driver by writing 0 */
> > + writel((unsigned int)(~(npcm_chip->ecc_ctl_ecc_enable_mask)),
> > + priv->reg + npcm_chip->ecc_ctl_en_reg);
> > +
> > +#ifdef CONFIG_EDAC_DEBUG
> > + remove_sysfs_attributes(mci);
> > +#endif
> > + edac_mc_del_mc(&pdev->dev);
> > + edac_mc_free(mci);
> > +
> > + return 0;
> > +}
> > +
> > +static struct platform_driver npcm_edac_mc_driver = {
> > + .driver = {
> > + .name = "npcm-edac",
> > + .of_match_table = npcm_edac_of_match,
> > + },
> > + .probe = npcm_edac_mc_probe,
> > + .remove = npcm_edac_mc_remove,
> > +};
> > +
> > +module_platform_driver(npcm_edac_mc_driver);
> > +
> > +MODULE_AUTHOR("Medad <ctcchien@nuvoton.com>");
> ^^
>
> Your surname too pls.
>

Got it

> > +MODULE_DESCRIPTION("Nuvoton NPCM EDAC Driver");
> > +MODULE_LICENSE("GPL v2");
> > --
> > 2.17.1
> >
>
> --
> Regards/Gruss,
> Boris.
>
> https://people.kernel.org/tglx/notes-about-netiquette