remoteproc: k3-r5: Adjust TCM sizes in Split-mode on J7200 SoCs

The J7200 SoCs have a revised R5FSS IP that adds a unique feature w.r.t
TCM sizing. Each R5F core in a cluster typically has 32 KB each of ATCM
and BTCM, with only the Core0 TCMs usable in LockStep mode. This revised
IP however doubles the total available TCM in LockStep mode by making the
Core1 TCM visible immediately after the corresponding Core0 TCM.

The R5F DT nodes on the J7200 SoCs define double (64 KB) the normal TCM
size (32 KB) for R5F Core0 for each of ATCM and BTCM to represent the
above. This increased TCM memory is only usable in LockStep-mode, and
has to be adjusted to the normal 32 KB size in Split mode. Enhance the
TI K3 R5F remoteproc for this logic through a new function. The adjustment
is a no-op on prior SoCs and relies on the correct DTS node sizes in
LockStep-mode on applicable SoCs.
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suman Anna <s-anna@ti.com>
Link: https://lore.kernel.org/r/20201119010531.21083-4-s-anna@ti.comSigned-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

drivers/remoteproc/ti_k3_r5_remoteproc.c

@@ -71,9 +71,11 @@ enum cluster_mode {
 
 /**
  * struct k3_r5_soc_data - match data to handle SoC variations
+ * @tcm_is_double: flag to denote the larger unified TCMs in certain modes
  * @tcm_ecc_autoinit: flag to denote the auto-initialization of TCMs for ECC
  */
 struct k3_r5_soc_data {
+	bool tcm_is_double;
 	bool tcm_ecc_autoinit;
 };
 
@@ -886,6 +888,43 @@ static void k3_r5_reserved_mem_exit(struct k3_r5_rproc *kproc)
 	of_reserved_mem_device_release(kproc->dev);
 }
 
+/*
+ * Each R5F core within a typical R5FSS instance has a total of 64 KB of TCMs,
+ * split equally into two 32 KB banks between ATCM and BTCM. The TCMs from both
+ * cores are usable in Split-mode, but only the Core0 TCMs can be used in
+ * LockStep-mode. The newer revisions of the R5FSS IP maximizes these TCMs by
+ * leveraging the Core1 TCMs as well in certain modes where they would have
+ * otherwise been unusable (Eg: LockStep-mode on J7200 SoCs). This is done by
+ * making a Core1 TCM visible immediately after the corresponding Core0 TCM.
+ * The SoC memory map uses the larger 64 KB sizes for the Core0 TCMs, and the
+ * dts representation reflects this increased size on supported SoCs. The Core0
+ * TCM sizes therefore have to be adjusted to only half the original size in
+ * Split mode.
+ */
+static void k3_r5_adjust_tcm_sizes(struct k3_r5_rproc *kproc)
+{
+	struct k3_r5_cluster *cluster = kproc->cluster;
+	struct k3_r5_core *core = kproc->core;
+	struct device *cdev = core->dev;
+	struct k3_r5_core *core0;
+
+	if (cluster->mode == CLUSTER_MODE_LOCKSTEP ||
+	    !cluster->soc_data->tcm_is_double)
+		return;
+
+	core0 = list_first_entry(&cluster->cores, struct k3_r5_core, elem);
+	if (core == core0) {
+		WARN_ON(core->mem[0].size != SZ_64K);
+		WARN_ON(core->mem[1].size != SZ_64K);
+
+		core->mem[0].size /= 2;
+		core->mem[1].size /= 2;
+
+		dev_dbg(cdev, "adjusted TCM sizes, ATCM = 0x%zx BTCM = 0x%zx\n",
+			core->mem[0].size, core->mem[1].size);
+	}
+}
+
 static int k3_r5_cluster_rproc_init(struct platform_device *pdev)
 {
 	struct k3_r5_cluster *cluster = platform_get_drvdata(pdev);
@@ -933,6 +972,8 @@ static int k3_r5_cluster_rproc_init(struct platform_device *pdev)
 			goto err_config;
 		}
 
+		k3_r5_adjust_tcm_sizes(kproc);
+
 		ret = k3_r5_reserved_mem_init(kproc);
 		if (ret) {
 			dev_err(dev, "reserved memory init failed, ret = %d\n",
@@ -1407,10 +1448,12 @@ static int k3_r5_probe(struct platform_device *pdev)
 }
 
 static const struct k3_r5_soc_data am65_j721e_soc_data = {
+	.tcm_is_double = false,
 	.tcm_ecc_autoinit = false,
 };
 
 static const struct k3_r5_soc_data j7200_soc_data = {
+	.tcm_is_double = true,
 	.tcm_ecc_autoinit = true,
 };