[PATCH 7/8] ram: k3-ddrss: Add support for MSMC calculation of DDR inline ECC regions

[Neha Malcom Francis]

Add support for calculation of the protected regions for each DDR in
multi-DDR systems. Since MSMC is the parent node of the individual DDRs
as well as responsible for their interleaving, it only makes sense for
MSMC to contain the logic for dividing the regions.

Signed-off-by: Neha Malcom Francis <n-francis at ti.com>
---
 drivers/ram/k3-ddrss/k3-ddrss.c | 122 ++++++++++++++++++++++++++++++--
 1 file changed, 115 insertions(+), 7 deletions(-)

diff --git a/drivers/ram/k3-ddrss/k3-ddrss.c b/drivers/ram/k3-ddrss/k3-ddrss.c
index 51b4c1bf45a..205dce51799 100644
--- a/drivers/ram/k3-ddrss/k3-ddrss.c
+++ b/drivers/ram/k3-ddrss/k3-ddrss.c
@@ -53,6 +53,7 @@
 
 #define SINGLE_DDR_SUBSYSTEM	0x1
 #define MULTI_DDR_SUBSYSTEM	0x2
+#define MAX_MULTI_DDR 4
 
 #define MULTI_DDR_CFG0  0x00114100
 #define MULTI_DDR_CFG1  0x00114104
@@ -76,6 +77,24 @@ enum intrlv_gran {
 	GRAN_16GB
 };
 
+u64 gran_bytes[] = {
+	0x80,
+	0x200,
+	0x800,
+	0x1000,
+	0x4000,
+	0x8000,
+	0x80000,
+	0x40000000,
+	0x60000000,
+	0x80000000,
+	0xC0000000,
+	0x100000000,
+	0x180000000,
+	0x200000000,
+	0x400000000
+};
+
 enum intrlv_size {
 	SIZE_0,
 	SIZE_128MB,
@@ -115,6 +134,13 @@ enum emif_active {
 	EMIF_ALL
 };
 
+#define K3_DDRSS_MAX_ECC_REGIONS		3
+
+struct k3_ddrss_ecc_region {
+	u64 start;
+	u64 range;
+};
+
 struct k3_msmc {
 	enum intrlv_gran gran;
 	enum intrlv_size size;
@@ -122,13 +148,7 @@ struct k3_msmc {
 	enum emif_config config;
 	enum emif_active active;
 	u32 num_ddr;
-};
-
-#define K3_DDRSS_MAX_ECC_REGIONS		3
-
-struct k3_ddrss_ecc_region {
-	u64 start;
-	u64 range;
+	struct k3_ddrss_ecc_region R0[MAX_MULTI_DDR];
 };
 
 struct k3_ddrss_desc {
@@ -914,6 +934,83 @@ U_BOOT_DRIVER(k3_ddrss) = {
 	.priv_auto		= sizeof(struct k3_ddrss_desc),
 };
 
+#if IS_ENABLED(CONFIG_K3_MULTI_DDR)
+static int k3_msmc_calculate_r0_regions(struct k3_msmc *msmc)
+{
+	u32 n1;
+	u32 size, ret = 0;
+	u32 gran = gran_bytes[msmc->gran];
+	u32 num_ddr = msmc->num_ddr;
+	struct k3_ddrss_ecc_region *range = NULL;
+	struct k3_ddrss_ecc_region R[num_ddr];
+
+	range = kzalloc(sizeof(range), GFP_KERNEL);
+	if (!range) {
+		debug("%s: failed to allocate range\n", __func__);
+		ret = -ENOMEM;
+		return ret;
+	}
+
+	k3_ddrss_ddr_inline_ecc_base_size_calc(range);
+
+	if (!range->range) {
+		ret = -EINVAL;
+		goto range_err;
+	}
+
+	memset(R, 0, num_ddr);
+
+	/* Find the first controller in the range */
+	n1 = ((range->start / gran) % num_ddr);
+	size = range->range;
+
+	if (size < gran) {
+		R[n1].start = range->start - 0x80000000;
+		R[n1].range = range->start + range->range - 0x80000000;
+	} else {
+		u32 chunk_start_addr = range->start;
+		u32 chunk_size = range->range;
+
+		while (chunk_size > 0) {
+			u32 edge;
+			u32 end = range->start + range->range;
+
+			if ((chunk_start_addr % gran) == 0)
+				edge = chunk_start_addr + gran;
+			else
+				edge = ((chunk_start_addr + (gran - 1)) & (-gran));
+
+			if (edge > end)
+				break;
+
+			if (R[n1].start == 0)
+				R[n1].start = chunk_start_addr;
+
+			R[n1].range = edge - R[n1].start;
+			chunk_size = end - edge;
+			chunk_start_addr = edge;
+
+			if (n1 == (num_ddr - 1))
+				n1 = 0;
+			else
+				n1++;
+		}
+
+		for (int i = 0; i < num_ddr; i++)
+			R[i].start = (R[i].start - 0x80000000 - (gran * i)) / num_ddr;
+	}
+
+	for (int i = 0; i < num_ddr; i++) {
+		msmc->R0[i].start = R[i].start;
+		msmc->R0[i].range = R[i].range;
+	}
+
+range_err:
+	free(range);
+	return ret;
+}
+#endif
+
 static int k3_msmc_set_config(struct k3_msmc *msmc)
 {
 	u32 ddr_cfg0 = 0;
@@ -993,6 +1090,17 @@ static int k3_msmc_probe(struct udevice *dev)
 	}
 	msmc->num_ddr = ret;
 
+#if IS_ENABLED(CONFIG_K3_MULTI_DDR) && IS_ENABLED(CONFIG_K3_INLINE_ECC)
+	ret = k3_msmc_calculate_r0_regions(msmc);
+	if (ret) {
+		/* Default to enabling inline ECC for entire DDR region */
+		debug("%s: calculation of inline ECC regions failed, defaulting to entire region\n",
+		      __func__);
+
+		/* Use first R0 entry as a flag to denote MSMC calculation failure */
+		msmc->R0[0].start = -1;
+	}
+#endif
 	return 0;
 }
 
-- 
2.34.1