soc: qcom: smem: Support reserved-memory description

Practically all modern Qualcomm platforms has a single reserved-memory
region for SMEM. So rather than having to describe SMEM in the form of a
node with a reference to a reserved-memory node, allow the SMEM device
to be instantiated directly from the reserved-memory node.

The current means of falling back to dereferencing the "memory-region"
is kept as a fallback, if it's determined that the SMEM node is a
reserved-memory node.

The "qcom,smem" compatible is added to the reserved_mem_matches list, to
allow the reserved-memory device to be probed.

In order to retain the readability of the code, the resolution of
resources is split from the actual ioremapping.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>
Link: https://lore.kernel.org/r/20210930182111.57353-4-bjorn.andersson@linaro.org

diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 74afbb7a4f5ecb5c7ee4424f84e754ad215b49ba..19ba8e4d4f8dcb5876c56d2032acf0dcd980827a 100644 (file)
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -509,6 +509,7 @@ EXPORT_SYMBOL_GPL(of_platform_default_populate);
 static const struct of_device_id reserved_mem_matches[] = {
        { .compatible = "qcom,rmtfs-mem" },
        { .compatible = "qcom,cmd-db" },
+       { .compatible = "qcom,smem" },
        { .compatible = "ramoops" },
        { .compatible = "nvmem-rmem" },
        {}

diff --git a/drivers/soc/qcom/smem.c b/drivers/soc/qcom/smem.c
index 4fb5aeeb08439853f675afb8ce0acf946c685702..c7e519bfdc8aecea9733b7cdc752e715fc8f58a1 100644 (file)
--- a/drivers/soc/qcom/smem.c
+++ b/drivers/soc/qcom/smem.c
@@ -9,6 +9,7 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
+#include <linux/of_reserved_mem.h>
 #include <linux/platform_device.h>
 #include <linux/sizes.h>
 #include <linux/slab.h>
@@ -240,7 +241,7 @@ static const u8 SMEM_INFO_MAGIC[] = { 0x53, 0x49, 0x49, 0x49 }; /* SIII */
  * @size:      size of the memory region
  */
 struct smem_region {
-       u32 aux_base;
+       phys_addr_t aux_base;
        void __iomem *virt_base;
        size_t size;
 };
@@ -499,7 +500,7 @@ static void *qcom_smem_get_global(struct qcom_smem *smem,
        for (i = 0; i < smem->num_regions; i++) {
                region = &smem->regions[i];
 
-               if (region->aux_base == aux_base || !aux_base) {
+               if ((u32)region->aux_base == aux_base || !aux_base) {
                        if (size != NULL)
                                *size = le32_to_cpu(entry->size);
                        return region->virt_base + le32_to_cpu(entry->offset);
@@ -664,7 +665,7 @@ phys_addr_t qcom_smem_virt_to_phys(void *p)
                if (p < region->virt_base + region->size) {
                        u64 offset = p - region->virt_base;
 
-                       return (phys_addr_t)region->aux_base + offset;
+                       return region->aux_base + offset;
                }
        }
 
@@ -863,12 +864,12 @@ qcom_smem_enumerate_partitions(struct qcom_smem *smem, u16 local_host)
        return 0;
 }
 
-static int qcom_smem_map_memory(struct qcom_smem *smem, struct device *dev,
-                               const char *name, int i)
+static int qcom_smem_resolve_mem(struct qcom_smem *smem, const char *name,
+                                struct smem_region *region)
 {
+       struct device *dev = smem->dev;
        struct device_node *np;
        struct resource r;
-       resource_size_t size;
        int ret;
 
        np = of_parse_phandle(dev->of_node, name, 0);
@@ -881,13 +882,9 @@ static int qcom_smem_map_memory(struct qcom_smem *smem, struct device *dev,
        of_node_put(np);
        if (ret)
                return ret;
-       size = resource_size(&r);
 
-       smem->regions[i].virt_base = devm_ioremap_wc(dev, r.start, size);
-       if (!smem->regions[i].virt_base)
-               return -ENOMEM;
-       smem->regions[i].aux_base = (u32)r.start;
-       smem->regions[i].size = size;
+       region->aux_base = r.start;
+       region->size = resource_size(&r);
 
        return 0;
 }
@@ -895,12 +892,14 @@ static int qcom_smem_map_memory(struct qcom_smem *smem, struct device *dev,
 static int qcom_smem_probe(struct platform_device *pdev)
 {
        struct smem_header *header;
+       struct reserved_mem *rmem;
        struct qcom_smem *smem;
        size_t array_size;
        int num_regions;
        int hwlock_id;
        u32 version;
        int ret;
+       int i;
 
        num_regions = 1;
        if (of_find_property(pdev->dev.of_node, "qcom,rpm-msg-ram", NULL))
@@ -914,13 +913,35 @@ static int qcom_smem_probe(struct platform_device *pdev)
        smem->dev = &pdev->dev;
        smem->num_regions = num_regions;
 
-       ret = qcom_smem_map_memory(smem, &pdev->dev, "memory-region", 0);
-       if (ret)
-               return ret;
+       rmem = of_reserved_mem_lookup(pdev->dev.of_node);
+       if (rmem) {
+               smem->regions[0].aux_base = rmem->base;
+               smem->regions[0].size = rmem->size;
+       } else {
+               /*
+                * Fall back to the memory-region reference, if we're not a
+                * reserved-memory node.
+                */
+               ret = qcom_smem_resolve_mem(smem, "memory-region", &smem->regions[0]);
+               if (ret)
+                       return ret;
+       }
 
-       if (num_regions > 1 && (ret = qcom_smem_map_memory(smem, &pdev->dev,
-                                       "qcom,rpm-msg-ram", 1)))
-               return ret;
+       if (num_regions > 1) {
+               ret = qcom_smem_resolve_mem(smem, "qcom,rpm-msg-ram", &smem->regions[1]);
+               if (ret)
+                       return ret;
+       }
+
+       for (i = 0; i < num_regions; i++) {
+               smem->regions[i].virt_base = devm_ioremap_wc(&pdev->dev,
+                                                            smem->regions[i].aux_base,
+                                                            smem->regions[i].size);
+               if (!smem->regions[i].virt_base) {
+                       dev_err(&pdev->dev, "failed to remap %pa\n", &smem->regions[i].aux_base);
+                       return -ENOMEM;
+               }
+       }
 
        header = smem->regions[0].virt_base;
        if (le32_to_cpu(header->initialized) != 1 ||