[PATCH 05/18] EDAC/synopsys: Add DDRC basic parameters infrastructure

From: Serge Semin
Date: Mon Aug 22 2022 - 15:15:06 EST


Currently the driver supports a single DW uMCTL2 DDRC IP-core: 64-bit DQ
bus, ECC SEC/DED with always on Scrub (HW-src scrub). This makes the
driver application being very limited. In addition to that lacking of any
controller capabilities/parameters infrastructure makes it harder to add
optional features support. Let's overcome all of that by adding a simple
DW uMCTL2 DDRC IP-core parameters infrastructure. It's made of the
snps_ddrc_info structure and a new method snps_get_ddrc_info() introduced
to fill the structure fields in. The structure contains the IP-core
parameters needed to create a more comprehensive driver and will be used
in the driver to activate/de-activate various features:
- ECC Mode: SEC/DED or Advanced X4/X8 ECC features. (Currently SEC/DED is
only supported.)
- SDRAM mode: (LP)DDR[2-4] memory interfaces. (Required for the HIF/SDRAM
address translation.)
- Memory Device config: Memory chips detected on the platform. (Applicable
for DDR4 setups only.)
- DQ-bus width: Maximal DQ-bus width utilized by the device. (Required for
the Application/HIF address translation.)
- DQ-bus mode: Actual DQ-bus width used to access the memory devices.
(Required for the HIF/SDRAM address translation and ECC grain calc.)
- HIF/SDRAM burst length: Required for the Scrubber bandwidth
calculation.
- HIF/SDRAM frequency ratio: Required for the SDRAM bandwidth
calculation.
- SDRAM ranks number: Required for the Application/HIF address
translation.

The list can be easily updated should any additional features support is
required to be added in future, but at this stage the driver is fixed in a
few places to have the new infrastructure utilized: SDRAM column address
mapper, MCI csrows initialization.

Note getting all of these parameters in a single method is very suitable
from two perspectives. First it localizes the IP-core parameters detection
thus improving the code readability and maintainability. Second it's very
suitable for the platform-specific quirks implementation. Since some of
the IP-core parameters can't be auto-detected at run-time, they will be
able to be fixed right in the parameters getter by means of the platform
quirks.

Signed-off-by: Serge Semin <Sergey.Semin@xxxxxxxxxxxxxxxxxxxx>
---
drivers/edac/synopsys_edac.c | 268 +++++++++++++++++++++++++++--------
1 file changed, 211 insertions(+), 57 deletions(-)

diff --git a/drivers/edac/synopsys_edac.c b/drivers/edac/synopsys_edac.c
index 10dc9e9d66d9..5e0673b0df44 100644
--- a/drivers/edac/synopsys_edac.c
+++ b/drivers/edac/synopsys_edac.c
@@ -12,6 +12,7 @@
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/platform_device.h>
+#include <linux/seq_file.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/of.h>
@@ -87,16 +88,21 @@
/* DDR Software control register */
#define DDR_SWCTL 0x320

+/* ECC Poison pattern registers */
+#define ECC_POISONPAT0_OFST 0x37C
+#define ECC_POISONPAT1_OFST 0x380
+#define ECC_POISONPAT2_OFST 0x384
+
/* DDR Master Register 0 definitions */
#define DDR_MSTR_DEV_CFG_MASK GENMASK(31, 30)
#define DDR_MSTR_DEV_X4 0x0
#define DDR_MSTR_DEV_X8 0x1
#define DDR_MSTR_DEV_X16 0x2
#define DDR_MSTR_DEV_X32 0x3
+#define DDR_MSTR_ACT_RANKS_MASK GENMASK(27, 24)
+#define DDR_MSTR_FREQ_RATIO11 BIT(22)
+#define DDR_MSTR_BURST_RDWR GENMASK(19, 16)
#define DDR_MSTR_BUSWIDTH_MASK GENMASK(13, 12)
-#define DDRCTL_EWDTH_16 2
-#define DDRCTL_EWDTH_32 1
-#define DDRCTL_EWDTH_64 0
#define DDR_MSTR_MEM_MASK GENMASK(5, 0)
#define DDR_MSTR_MEM_DDR2 0
#define DDR_MSTR_MEM_DDR3 BIT(0)
@@ -108,7 +114,6 @@

/* ECC CFG0 register definitions */
#define ECC_CFG0_MODE_MASK GENMASK(2, 0)
-#define ECC_CFG0_MODE_SECDED 0x4

/* ECC status register definitions */
#define ECC_STAT_UE_MASK GENMASK(23, 16)
@@ -206,6 +211,91 @@

#define RANK_B0_BASE 6

+/**
+ * enum snps_dq_width - SDRAM DQ bus width (ECC capable).
+ * SNPS_DQ_32: 32-bit memory data width.
+ * SNPS_DQ_64: 64-bit memory data width.
+ */
+enum snps_dq_width {
+ SNPS_DQ_32 = 2,
+ SNPS_DQ_64 = 3,
+};
+
+/**
+ * enum snps_dq_mode - SDRAM DQ bus mode.
+ * @SNPS_DQ_FULL: Full DQ bus width.
+ * @SNPS_DQ_HALF: Half DQ bus width.
+ * @SNPS_DQ_QRTR: Quarter DQ bus width.
+ */
+enum snps_dq_mode {
+ SNPS_DQ_FULL = 0,
+ SNPS_DQ_HALF = 1,
+ SNPS_DQ_QRTR = 2,
+};
+
+/**
+ * enum snps_burst_length - HIF/SDRAM burst transactions length.
+ * @SNPS_DDR_BL2: Burst length 2xSDRAM-words.
+ * @SNPS_DDR_BL4: Burst length 4xSDRAM-words.
+ * @SNPS_DDR_BL8: Burst length 8xSDRAM-words.
+ * @SNPS_DDR_BL16: Burst length 16xSDRAM-words.
+ */
+enum snps_burst_length {
+ SNPS_DDR_BL2 = 2,
+ SNPS_DDR_BL4 = 4,
+ SNPS_DDR_BL8 = 8,
+ SNPS_DDR_BL16 = 16,
+};
+
+/**
+ * enum snps_freq_ratio - HIF:SDRAM frequency ratio mode.
+ * @SNPS_FREQ_RATIO11: 1:1 frequency mode.
+ * @SNPS_FREQ_RATIO12: 1:2 frequency mode.
+ */
+enum snps_freq_ratio {
+ SNPS_FREQ_RATIO11 = 1,
+ SNPS_FREQ_RATIO12 = 2,
+};
+
+/**
+ * enum snps_ecc_mode - ECC mode.
+ * @SNPS_ECC_DISABLED: ECC is disabled/unavailable.
+ * @SNPS_ECC_SECDED: SEC/DED over 1 beat ECC (SideBand/Inline).
+ * @SNPS_ECC_ADVX4X8: Advanced ECC X4/X8 (SideBand).
+ */
+enum snps_ecc_mode {
+ SNPS_ECC_DISABLED = 0,
+ SNPS_ECC_SECDED = 4,
+ SNPS_ECC_ADVX4X8 = 5,
+};
+
+/**
+ * struct snps_ddrc_info - DDR controller platform parameters.
+ * @caps: DDR controller capabilities.
+ * @sdram_mode: Current SDRAM mode selected.
+ * @dev_cfg: Current memory device config (if applicable).
+ * @dq_width: Memory data bus width (width of the DQ signals
+ * connected to SDRAM chips).
+ * @dq_mode: Proportion of the DQ bus utilized to access SDRAM.
+ * @sdram_burst_len: SDRAM burst transaction length.
+ * @hif_burst_len: HIF burst transaction length (Host Interface).
+ * @freq_ratio: HIF/SDRAM frequency ratio mode.
+ * @ecc_mode: ECC mode enabled for the DDR controller (SEC/DED, etc).
+ * @ranks: Number of ranks enabled to access DIMM (1, 2 or 4).
+ */
+struct snps_ddrc_info {
+ unsigned int caps;
+ enum mem_type sdram_mode;
+ enum dev_type dev_cfg;
+ enum snps_dq_width dq_width;
+ enum snps_dq_mode dq_mode;
+ enum snps_burst_length sdram_burst_len;
+ enum snps_burst_length hif_burst_len;
+ enum snps_freq_ratio freq_ratio;
+ enum snps_ecc_mode ecc_mode;
+ unsigned int ranks;
+};
+
/**
* struct snps_ecc_error_info - ECC error log information.
* @row: Row number.
@@ -240,6 +330,7 @@ struct snps_ecc_status {

/**
* struct snps_edac_priv - DDR memory controller private data.
+ * @info: DDR controller config info.
* @pdev: Platform device.
* @baseaddr: Base address of the DDR controller.
* @lock: Concurrent CSRs access lock.
@@ -254,6 +345,7 @@ struct snps_ecc_status {
* @rank_shift: Bit shifts for rank bit.
*/
struct snps_edac_priv {
+ struct snps_ddrc_info info;
struct platform_device *pdev;
void __iomem *baseaddr;
spinlock_t lock;
@@ -492,23 +584,19 @@ static struct snps_edac_priv *snps_create_data(struct platform_device *pdev)

/**
* snps_get_dtype - Return the controller memory width.
- * @base: DDR memory controller base address.
+ * @mstr: Master CSR value.
*
* Get the EDAC device type width appropriate for the current controller
* configuration.
*
* Return: a device type width enumeration.
*/
-static enum dev_type snps_get_dtype(const void __iomem *base)
+static inline enum dev_type snps_get_dtype(u32 mstr)
{
- u32 regval;
-
- regval = readl(base + DDR_MSTR_OFST);
- if (!(regval & DDR_MSTR_MEM_DDR4))
+ if (!(mstr & DDR_MSTR_MEM_DDR4))
return DEV_UNKNOWN;

- regval = FIELD_GET(DDR_MSTR_DEV_CFG_MASK, regval);
- switch (regval) {
+ switch (FIELD_GET(DDR_MSTR_DEV_CFG_MASK, mstr)) {
case DDR_MSTR_DEV_X4:
return DEV_X4;
case DDR_MSTR_DEV_X8:
@@ -522,24 +610,6 @@ static enum dev_type snps_get_dtype(const void __iomem *base)
return DEV_UNKNOWN;
}

-/**
- * snps_get_ecc_state - Return the controller ECC enable/disable status.
- * @base: DDR memory controller base address.
- *
- * Get the ECC enable/disable status for the controller.
- *
- * Return: a ECC status boolean i.e true/false - enabled/disabled.
- */
-static bool snps_get_ecc_state(void __iomem *base)
-{
- u32 regval;
-
- regval = readl(base + ECC_CFG0_OFST);
- regval = FIELD_GET(ECC_CFG0_MODE_MASK, regval);
-
- return (regval == ECC_CFG0_MODE_SECDED);
-}
-
/**
* snps_get_memsize - Read the size of the attached memory device.
*
@@ -556,21 +626,16 @@ static u32 snps_get_memsize(void)

/**
* snps_get_mtype - Returns controller memory type.
- * @base: Synopsys ECC status structure.
+ * @mstr: Master CSR value.
*
* Get the EDAC memory type appropriate for the current controller
* configuration.
*
* Return: a memory type enumeration.
*/
-static enum mem_type snps_get_mtype(const void __iomem *base)
+static inline enum mem_type snps_get_mtype(u32 mstr)
{
- u32 regval;
-
- regval = readl(base + DDR_MSTR_OFST);
- regval = FIELD_GET(DDR_MSTR_MEM_MASK, regval);
-
- switch (regval) {
+ switch (FIELD_GET(DDR_MSTR_MEM_MASK, mstr)) {
case DDR_MSTR_MEM_DDR2:
return MEM_DDR2;
case DDR_MSTR_MEM_DDR3:
@@ -590,6 +655,69 @@ static enum mem_type snps_get_mtype(const void __iomem *base)
return MEM_RESERVED;
}

+/**
+ * snps_get_ddrc_info - Get the DDR controller config data.
+ * @priv: DDR memory controller private data.
+ *
+ * Return: negative errno if no ECC detected, otherwise - zero.
+ */
+static int snps_get_ddrc_info(struct snps_edac_priv *priv)
+{
+ int (*init_plat)(struct snps_edac_priv *priv);
+ u32 regval;
+
+ /* Before getting the DDRC parameters make sure ECC is enabled */
+ regval = readl(priv->baseaddr + ECC_CFG0_OFST);
+
+ priv->info.ecc_mode = FIELD_GET(ECC_CFG0_MODE_MASK, regval);
+ if (priv->info.ecc_mode != SNPS_ECC_SECDED) {
+ edac_printk(KERN_INFO, EDAC_MC, "SEC/DED ECC not enabled\n");
+ return -ENXIO;
+ }
+
+ /* Auto-detect the basic HIF/SDRAM bus parameters */
+ regval = readl(priv->baseaddr + DDR_MSTR_OFST);
+
+ priv->info.sdram_mode = snps_get_mtype(regval);
+ priv->info.dev_cfg = snps_get_dtype(regval);
+
+ priv->info.dq_mode = FIELD_GET(DDR_MSTR_BUSWIDTH_MASK, regval);
+
+ /*
+ * Assume HIF burst length matches the SDRAM burst length since it's
+ * not auto-detectable
+ */
+ priv->info.sdram_burst_len = FIELD_GET(DDR_MSTR_BURST_RDWR, regval) << 1;
+ priv->info.hif_burst_len = priv->info.sdram_burst_len;
+
+ /* Retrieve the current HIF/SDRAM frequency ratio: 1:1 vs 1:2 */
+ priv->info.freq_ratio = !(regval & DDR_MSTR_FREQ_RATIO11) + 1;
+
+ /* Activated ranks field: set bit corresponds to populated rank */
+ priv->info.ranks = FIELD_GET(DDR_MSTR_ACT_RANKS_MASK, regval);
+ priv->info.ranks = hweight_long(priv->info.ranks);
+
+ /* Auto-detect the DQ bus width by using the ECC-poison pattern CSR */
+ writel(0, priv->baseaddr + DDR_SWCTL);
+
+ /*
+ * If poison pattern [32:64] is changeable then DQ is 64-bit wide.
+ * Note the feature has been available since IP-core v2.51a.
+ */
+ regval = readl(priv->baseaddr + ECC_POISONPAT1_OFST);
+ writel(~regval, priv->baseaddr + ECC_POISONPAT1_OFST);
+ if (regval != readl(priv->baseaddr + ECC_POISONPAT1_OFST)) {
+ priv->info.dq_width = SNPS_DQ_64;
+ writel(regval, priv->baseaddr + ECC_POISONPAT1_OFST);
+ } else {
+ priv->info.dq_width = SNPS_DQ_32;
+ }
+
+ writel(1, priv->baseaddr + DDR_SWCTL);
+
+ return 0;
+}
+
/**
* snps_init_csrows - Initialize the csrow data.
* @mci: EDAC memory controller instance.
@@ -612,10 +740,10 @@ static void snps_init_csrows(struct mem_ctl_info *mci)
for (j = 0; j < csi->nr_channels; j++) {
dimm = csi->channels[j]->dimm;
dimm->edac_mode = EDAC_SECDED;
- dimm->mtype = snps_get_mtype(priv->baseaddr);
+ dimm->mtype = priv->info.sdram_mode;
dimm->nr_pages = (size >> PAGE_SHIFT) / csi->nr_channels;
dimm->grain = SNPS_EDAC_ERR_GRAIN;
- dimm->dtype = snps_get_dtype(priv->baseaddr);
+ dimm->dtype = priv->info.dev_cfg;
}
}
}
@@ -729,6 +857,33 @@ static int snps_setup_irq(struct mem_ctl_info *mci)

#define SNPS_DBGFS_BUF_LEN 128

+static int snps_ddrc_info_show(struct seq_file *s, void *data)
+{
+ struct mem_ctl_info *mci = s->private;
+ struct snps_edac_priv *priv = mci->pvt_info;
+
+ seq_printf(s, "SDRAM: %s\n", edac_mem_types[priv->info.sdram_mode]);
+
+ seq_printf(s, "DQ bus: %u/%s\n", (BITS_PER_BYTE << priv->info.dq_width),
+ priv->info.dq_mode == SNPS_DQ_FULL ? "Full" :
+ priv->info.dq_mode == SNPS_DQ_HALF ? "Half" :
+ priv->info.dq_mode == SNPS_DQ_QRTR ? "Quarter" :
+ "Unknown");
+ seq_printf(s, "Burst: SDRAM %u HIF %u\n", priv->info.sdram_burst_len,
+ priv->info.hif_burst_len);
+
+ seq_printf(s, "Ranks: %u\n", priv->info.ranks);
+
+ seq_printf(s, "ECC: %s\n",
+ priv->info.ecc_mode == SNPS_ECC_SECDED ? "SEC/DED" :
+ priv->info.ecc_mode == SNPS_ECC_ADVX4X8 ? "Advanced X4/X8" :
+ "Unknown");
+
+ return 0;
+}
+
+DEFINE_SHOW_ATTRIBUTE(snps_ddrc_info);
+
/**
* snps_data_poison_setup - Update poison registers.
* @priv: DDR memory controller private instance data.
@@ -850,12 +1005,8 @@ static void snps_setup_row_address_map(struct snps_edac_priv *priv, u32 *addrmap

static void snps_setup_column_address_map(struct snps_edac_priv *priv, u32 *addrmap)
{
- u32 width, memtype;
int index;

- memtype = readl(priv->baseaddr + DDR_MSTR_OFST);
- width = FIELD_GET(DDR_MSTR_BUSWIDTH_MASK, memtype);
-
priv->col_shift[0] = 0;
priv->col_shift[1] = 1;
priv->col_shift[2] = (addrmap[2] & COL_MAX_VAL_MASK) + COL_B2_BASE;
@@ -879,8 +1030,8 @@ static void snps_setup_column_address_map(struct snps_edac_priv *priv, u32 *addr
priv->col_shift[9] = (((addrmap[3] >> 24) & COL_MAX_VAL_MASK) ==
COL_MAX_VAL_MASK) ? 0 : (((addrmap[3] >> 24) &
COL_MAX_VAL_MASK) + COL_B9_BASE);
- if (width == DDRCTL_EWDTH_64) {
- if (memtype & DDR_MSTR_MEM_LPDDR3) {
+ if (priv->info.dq_mode == SNPS_DQ_FULL) {
+ if (priv->info.sdram_mode == MEM_LPDDR3) {
priv->col_shift[10] = ((addrmap[4] &
COL_MAX_VAL_MASK) == COL_MAX_VAL_MASK) ? 0 :
((addrmap[4] & COL_MAX_VAL_MASK) +
@@ -899,8 +1050,8 @@ static void snps_setup_column_address_map(struct snps_edac_priv *priv, u32 *addr
(((addrmap[4] >> 8) & COL_MAX_VAL_MASK) +
COL_B11_BASE);
}
- } else if (width == DDRCTL_EWDTH_32) {
- if (memtype & DDR_MSTR_MEM_LPDDR3) {
+ } else if (priv->info.dq_mode == SNPS_DQ_HALF) {
+ if (priv->info.sdram_mode == MEM_LPDDR3) {
priv->col_shift[10] = (((addrmap[3] >> 24) &
COL_MAX_VAL_MASK) == COL_MAX_VAL_MASK) ? 0 :
(((addrmap[3] >> 24) & COL_MAX_VAL_MASK) +
@@ -920,7 +1071,7 @@ static void snps_setup_column_address_map(struct snps_edac_priv *priv, u32 *addr
COL_B10_BASE);
}
} else {
- if (memtype & DDR_MSTR_MEM_LPDDR3) {
+ if (priv->info.sdram_mode == MEM_LPDDR3) {
priv->col_shift[10] = (((addrmap[3] >> 16) &
COL_MAX_VAL_MASK) == COL_MAX_VAL_MASK) ? 0 :
(((addrmap[3] >> 16) & COL_MAX_VAL_MASK) +
@@ -941,10 +1092,11 @@ static void snps_setup_column_address_map(struct snps_edac_priv *priv, u32 *addr
}
}

- if (width) {
- for (index = 9; index > width; index--) {
- priv->col_shift[index] = priv->col_shift[index - width];
- priv->col_shift[index - width] = 0;
+ if (priv->info.dq_mode) {
+ for (index = 9; index > priv->info.dq_mode; index--) {
+ priv->col_shift[index] =
+ priv->col_shift[index - priv->info.dq_mode];
+ priv->col_shift[index - priv->info.dq_mode] = 0;
}
}

@@ -1106,6 +1258,9 @@ static void snps_create_debugfs_nodes(struct mem_ctl_info *mci)

snps_setup_address_map(priv);

+ edac_debugfs_create_file("ddrc_info", 0400, mci->debugfs, mci,
+ &snps_ddrc_info_fops);
+
edac_debugfs_create_file("inject_data_error", 0600, mci->debugfs, mci,
&snps_inject_data_error);

@@ -1138,10 +1293,9 @@ static int snps_mc_probe(struct platform_device *pdev)
if (IS_ERR(priv))
return PTR_ERR(priv);

- if (!snps_get_ecc_state(baseaddr)) {
- edac_printk(KERN_INFO, EDAC_MC, "ECC not enabled\n");
- return -ENXIO;
- }
+ rc = snps_get_ddrc_info(priv);
+ if (rc)
+ return rc;

mci = snps_mc_create(priv);
if (IS_ERR(mci))
--
2.35.1