[PATCH 8/8] ram: k3-ddrss: Add support for partial inline ECC in multi-DDR systems

[Neha Malcom Francis]

The existing approach does not account for interleaving in the DDRs when
setting up regions. There is support for MSMC to calculate the regions
for each DDR, so modify k3_ddrss_probe to set the regions accordingly
for multi-DDR systems.

Signed-off-by: Neha Malcom Francis <n-francis at ti.com>
---
 drivers/ram/k3-ddrss/k3-ddrss.c | 43 +++++++++++++++++++++++++++++++--
 1 file changed, 41 insertions(+), 2 deletions(-)

diff --git a/drivers/ram/k3-ddrss/k3-ddrss.c b/drivers/ram/k3-ddrss/k3-ddrss.c
index 205dce51799..8429dddeb58 100644
--- a/drivers/ram/k3-ddrss/k3-ddrss.c
+++ b/drivers/ram/k3-ddrss/k3-ddrss.c
@@ -808,8 +808,10 @@ static int k3_ddrss_probe(struct udevice *dev)
 	u64 end;
 	int ret;
 	struct k3_ddrss_desc *ddrss = dev_get_priv(dev);
+	__maybe_unused u32 inst, ddr_ram_size, ecc_res;
 	__maybe_unused struct k3_ddrss_data *ddrss_data = (struct k3_ddrss_data *)dev_get_driver_data(dev);
 	__maybe_unused struct k3_ddrss_ecc_region *range = &ddrss->ecc_range;
+	__maybe_unused struct k3_msmc *msmc_parent = NULL;
 
 	debug("%s(dev=%p)\n", __func__, dev);
 
@@ -863,14 +865,51 @@ static int k3_ddrss_probe(struct udevice *dev)
 			ddrss->ecc_range.range = range->range;
 		}
 
+#if !CONFIG_IS_ENABLED(K3_MULTI_DDR)
 		end = ddrss->ecc_range.start + ddrss->ecc_range.range;
+		inst = ddrss->instance;
+		ddr_ram_size = ddrss->ddr_ram_size;
+		ecc_res = ddrss->ecc_reserved_space;
 
-		if (end > (ddrss->ddr_ram_size - ddrss->ecc_reserved_space))
-			ddrss->ecc_regions[0].range = ddrss->ddr_ram_size - ddrss->ecc_reserved_space;
+		if (end > (ddr_ram_size - ecc_res))
+			ddrss->ecc_regions[0].range = ddr_ram_size - ecc_res;
 		else
 			ddrss->ecc_regions[0].range = ddrss->ecc_range.range;
 
 		ddrss->ecc_regions[0].start = ddrss->ecc_range.start - ddrss->ddr_bank_base[0];
+#else
+
+		/* In case multi-DDR, we rely on MSMC's calculation of regions for each DDR */
+		msmc_parent = kzalloc(sizeof(msmc_parent), GFP_KERNEL);
+		if (!msmc_parent) {
+			debug("%s: failed to allocate msmc_parent\n", __func__);
+			return -ENOMEM;
+		}
+		msmc_parent = dev_get_priv(dev->parent);
+		if (!msmc_parent) {
+			printf("%s: could not get MSMC parent to set up inline ECC regions\n",
+			       __func__);
+			kfree(msmc_parent);
+			return -EINVAL;
+		}
+
+		if (msmc_parent->R0[0].start < 0) {
+			/* Configure entire DDR space by default */
+			ddrss->ecc_regions[0].start = ddrss->ddr_bank_base[0];
+			ddrss->ecc_regions[0].range = ddr_ram_size - ecc_res;
+		} else {
+			end = msmc_parent->R0[inst].start + msmc_parent->R0[inst].range;
+
+			if (end > (ddr_ram_size - ecc_res))
+				ddrss->ecc_regions[0].range = ddr_ram_size - ecc_res;
+			else
+				ddrss->ecc_regions[0].range = msmc_parent->R0[inst].range;
+
+			ddrss->ecc_regions[0].start =  msmc_parent->R0[inst].start;
+		}
+
+		kfree(msmc_parent);
+#endif
 
 		k3_ddrss_lpddr4_ecc_init(ddrss);
 	}
-- 
2.34.1