[PATCH v4] remoteproc: xlnx: add sram support

[Tanmay Shah]

AMD-Xilinx zynqmp platform contains on-chip sram memory (OCM).
R5 cores can access OCM and access is faster than DDR memory but slower
than TCM memories available. Sram region can have optional multiple
power-domains. Platform management firmware is responsible
to operate these power-domains.

Signed-off-by: Tanmay Shah <tanmay.shah@xxxxxxx>
---

Changes in v4:
  - Free previously allocalted genpool if adding carveouts fail for any
    sram.
  - add comment about sram size used in creating carveouts.

Changes in v3:
  - make @sram an array rather than an array of pointers
  - fix of_node_put usage to maintain proper refcount of node
  - s/proprty/property
  - Use gen pool framework for mapping sram address space.

Changes in v2:
  - Expand commit message with power-domains related information.

 drivers/remoteproc/xlnx_r5_remoteproc.c | 165 ++++++++++++++++++++++++
 1 file changed, 165 insertions(+)

diff --git a/drivers/remoteproc/xlnx_r5_remoteproc.c b/drivers/remoteproc/xlnx_r5_remoteproc.c
index 2cea97c746fd..6d2ac7b85c8a 100644
--- a/drivers/remoteproc/xlnx_r5_remoteproc.c
+++ b/drivers/remoteproc/xlnx_r5_remoteproc.c
@@ -7,6 +7,7 @@
 #include <dt-bindings/power/xlnx-zynqmp-power.h>
 #include <linux/dma-mapping.h>
 #include <linux/firmware/xlnx-zynqmp.h>
+#include <linux/genalloc.h>
 #include <linux/kernel.h>
 #include <linux/mailbox_client.h>
 #include <linux/mailbox/zynqmp-ipi-message.h>
@@ -56,6 +57,21 @@ struct mem_bank_data {
 	char *bank_name;
 };
 
+/**
+ * struct zynqmp_sram_bank - sram bank description
+ *
+ * @sram_pool: gen pool for his sram
+ * @sram_res: sram address region information
+ * @va: virtual address of allocated genpool
+ * @da: device address of sram
+ */
+struct zynqmp_sram_bank {
+	struct gen_pool *sram_pool;
+	struct resource sram_res;
+	void __iomem *va;
+	u32 da;
+};
+
 /**
  * struct mbox_info
  *
@@ -120,6 +136,8 @@ static const struct mem_bank_data zynqmp_tcm_banks_lockstep[] = {
  * struct zynqmp_r5_core
  *
  * @rsc_tbl_va: resource table virtual address
+ * @sram: Array of sram memories assigned to this core
+ * @num_sram: number of sram for this core
  * @dev: device of RPU instance
  * @np: device node of RPU instance
  * @tcm_bank_count: number TCM banks accessible to this RPU
@@ -131,6 +149,8 @@ static const struct mem_bank_data zynqmp_tcm_banks_lockstep[] = {
  */
 struct zynqmp_r5_core {
 	void __iomem *rsc_tbl_va;
+	struct zynqmp_sram_bank *sram;
+	int num_sram;
 	struct device *dev;
 	struct device_node *np;
 	int tcm_bank_count;
@@ -494,6 +514,56 @@ static int add_mem_regions_carveout(struct rproc *rproc)
 	return 0;
 }
 
+static int add_sram_carveouts(struct rproc *rproc)
+{
+	struct zynqmp_r5_core *r5_core = rproc->priv;
+	struct rproc_mem_entry *rproc_mem;
+	struct zynqmp_sram_bank *sram;
+	size_t len, pool_size;
+	dma_addr_t dma_addr;
+	int da, i;
+
+	for (i = 0; i < r5_core->num_sram; i++) {
+		sram = &r5_core->sram[i];
+
+		dma_addr = (dma_addr_t)sram->sram_res.start;
+
+		/* Use actual resource size, as genpool size can be rounded up */
+		len = resource_size(&sram->sram_res);
+		da = sram->da;
+
+		pool_size = gen_pool_size(sram[i].sram_pool);
+		sram->va = (void __iomem *)gen_pool_alloc(sram->sram_pool, pool_size);
+		if (!sram->va) {
+			dev_err(r5_core->dev, "failed to alloc sram idx %d pool\n", i);
+			goto fail_add_sram_carveouts;
+		}
+
+		rproc_mem = rproc_mem_entry_init(&rproc->dev, sram->va,
+						 (dma_addr_t)dma_addr,
+						 len, da,
+						 NULL, NULL,
+						 sram->sram_res.name);
+
+		rproc_add_carveout(rproc, rproc_mem);
+		rproc_coredump_add_segment(rproc, da, len);
+
+		dev_dbg(&rproc->dev, "sram carveout %s addr=%llx, da=0x%x, size=0x%lx",
+			sram->sram_res.name, dma_addr, da, len);
+	}
+
+	return 0;
+
+fail_add_sram_carveouts:
+	while (--i > 0) {
+		pool_size = gen_pool_size(sram[i].sram_pool);
+		gen_pool_free(sram[i].sram_pool,
+			      (unsigned long)r5_core->sram[i].va, pool_size);
+	}
+
+	return -ENOMEM;
+}
+
 /*
  * tcm_mem_unmap()
  * @rproc: single R5 core's corresponding rproc instance
@@ -669,6 +739,12 @@ static int zynqmp_r5_rproc_prepare(struct rproc *rproc)
 		return ret;
 	}
 
+	ret = add_sram_carveouts(rproc);
+	if (ret) {
+		dev_err(&rproc->dev, "failed to get sram carveout %d\n", ret);
+		return ret;
+	}
+
 	return 0;
 }
 
@@ -695,6 +771,12 @@ static int zynqmp_r5_rproc_unprepare(struct rproc *rproc)
 				 "can't turn off TCM bank 0x%x", pm_domain_id);
 	}
 
+	for (i = 0; i < r5_core->num_sram; i++) {
+		gen_pool_free(r5_core->sram[i].sram_pool,
+			      (unsigned long)r5_core->sram[i].va,
+			      gen_pool_size(r5_core->sram[i].sram_pool));
+	}
+
 	return 0;
 }
 
@@ -881,6 +963,85 @@ static struct zynqmp_r5_core *zynqmp_r5_add_rproc_core(struct device *cdev)
 	return ERR_PTR(ret);
 }
 
+static int zynqmp_r5_get_sram_banks(struct zynqmp_r5_core *r5_core)
+{
+	struct device_node *np = r5_core->np;
+	struct device *dev = r5_core->dev;
+	struct zynqmp_sram_bank *sram;
+	struct device_node *sram_np;
+	int num_sram, i, ret;
+	u64 abs_addr, size;
+
+	/* "sram" is optional property. Do not fail, if unavailable. */
+	if (!of_property_present(r5_core->np, "sram"))
+		return 0;
+
+	num_sram = of_property_count_elems_of_size(np, "sram", sizeof(phandle));
+	if (num_sram <= 0) {
+		dev_err(dev, "Invalid sram property, ret = %d\n",
+			num_sram);
+		return -EINVAL;
+	}
+
+	sram = devm_kcalloc(dev, num_sram,
+			    sizeof(struct zynqmp_sram_bank), GFP_KERNEL);
+	if (!sram)
+		return -ENOMEM;
+
+	for (i = 0; i < num_sram; i++) {
+		sram_np = of_parse_phandle(np, "sram", i);
+		if (!sram_np) {
+			dev_err(dev, "failed to get sram %d phandle\n", i);
+			ret = -EINVAL;
+			goto fail_sram_get;
+		}
+
+		if (!of_device_is_available(sram_np)) {
+			dev_err(dev, "sram device not available\n");
+			ret = -EINVAL;
+			goto fail_sram_get;
+		}
+
+		ret = of_address_to_resource(sram_np, 0, &sram[i].sram_res);
+		if (ret) {
+			dev_err(dev, "addr to res failed\n");
+			goto fail_sram_get;
+		}
+
+		sram[i].sram_pool = of_gen_pool_get(np, "sram", i);
+		if (!sram[i].sram_pool) {
+			dev_err(dev, "failed to get sram idx %d gen pool\n", i);
+			ret = -ENOMEM;
+			goto fail_sram_get;
+		}
+
+		/* Get SRAM device address */
+		ret = of_property_read_reg(sram_np, i, &abs_addr, &size);
+		if (ret) {
+			dev_err(dev, "failed to get reg property\n");
+			goto fail_sram_get;
+		}
+
+		sram[i].da = (u32)abs_addr;
+
+		of_node_put(sram_np);
+
+		dev_dbg(dev, "sram %d: name=%s, addr=0x%llx, da=0x%x, size=0x%llx\n",
+			i, sram[i].sram_res.name, sram[i].sram_res.start,
+			sram[i].da, resource_size(&sram[i].sram_res));
+	}
+
+	r5_core->sram = sram;
+	r5_core->num_sram = num_sram;
+
+	return 0;
+
+fail_sram_get:
+	of_node_put(sram_np);
+
+	return ret;
+}
+
 static int zynqmp_r5_get_tcm_node_from_dt(struct zynqmp_r5_cluster *cluster)
 {
 	int i, j, tcm_bank_count, ret, tcm_pd_idx, pd_count;
@@ -1095,6 +1256,10 @@ static int zynqmp_r5_core_init(struct zynqmp_r5_cluster *cluster,
 				return ret;
 			}
 		}
+
+		ret = zynqmp_r5_get_sram_banks(r5_core);
+		if (ret)
+			return ret;
 	}
 
 	return 0;

base-commit: 1a491aaf1d1ce3a1cf5190394c36f21d805c7e96
-- 
2.25.1