When using the reserved memory node in the device tree there are
two options - dynamic or static. If a dynamic allocation was
selected (where the kernel selects the address for the allocation)
convert it to a static allocation by inserting the reg property.
This will ensure the same memory is reused after a kexec()

Signed-off-by: Roy Pledge <roy.ple...@nxp.com>
---
 drivers/soc/fsl/qbman/dpaa_sys.c | 60 ++++++++++++++++++++++++----------------
 1 file changed, 36 insertions(+), 24 deletions(-)

diff --git a/drivers/soc/fsl/qbman/dpaa_sys.c b/drivers/soc/fsl/qbman/dpaa_sys.c
index 3e0a7f3..9dd8bb5 100644
--- a/drivers/soc/fsl/qbman/dpaa_sys.c
+++ b/drivers/soc/fsl/qbman/dpaa_sys.c
@@ -37,41 +37,53 @@
 int qbman_init_private_mem(struct device *dev, int idx, dma_addr_t *addr,
                                size_t *size)
 {
-       int ret;
        struct device_node *mem_node;
-       u64 size64;
        struct reserved_mem *rmem;
+       struct property *prop;
+       int len, err;
+       __be32 *res_array;
 
-       ret = of_reserved_mem_device_init_by_idx(dev, dev->of_node, idx);
-       if (ret) {
-               dev_err(dev,
-                       "of_reserved_mem_device_init_by_idx(%d) failed 0x%x\n",
-                       idx, ret);
-               return -ENODEV;
-       }
-       mem_node = of_parse_phandle(dev->of_node, "memory-region", 0);
-       if (mem_node) {
-               ret = of_property_read_u64(mem_node, "size", &size64);
-               if (ret) {
-                       dev_err(dev, "of_address_to_resource fails 0x%x\n",
-                               ret);
-                       return -ENODEV;
-               }
-               *size = size64;
-       } else {
+       mem_node = of_parse_phandle(dev->of_node, "memory-region", idx);
+       if (!mem_node) {
                dev_err(dev, "No memory-region found for index %d\n", idx);
                return -ENODEV;
        }
 
        rmem = of_reserved_mem_lookup(mem_node);
+       if (!rmem) {
+               dev_err(dev, "of_reserved_mem_lookup() returned NULL\n");
+               return -ENODEV;
+       }
        *addr = rmem->base;
+       *size = rmem->size;
 
        /*
-        * Disassociate the reserved memory area from the device
-        * because a device can only have one DMA memory area. This
-        * should be fine since the memory is allocated and initialized
-        * and only ever accessed by the QBMan device from now on
+        * Check if the reg property exists - if not insert the node
+        * so upon kexec() the same memory region address will be preserved.
+        * This is needed because QBMan HW does not allow the base address/
+        * size to be modified once set.
         */
-       of_reserved_mem_device_release(dev);
+       prop = of_find_property(mem_node, "reg", &len);
+       if (!prop) {
+               prop = devm_kzalloc(dev, sizeof(*prop), GFP_KERNEL);
+               if (!prop)
+                       return -ENOMEM;
+               prop->value = res_array = devm_kzalloc(dev, sizeof(__be32) * 4,
+                                                      GFP_KERNEL);
+               if (!prop->value)
+                       return -ENOMEM;
+               res_array[0] = cpu_to_be32(upper_32_bits(*addr));
+               res_array[1] = cpu_to_be32(lower_32_bits(*addr));
+               res_array[2] = cpu_to_be32(upper_32_bits(*size));
+               res_array[3] = cpu_to_be32(lower_32_bits(*size));
+               prop->length = sizeof(__be32) * 4;
+               prop->name = devm_kstrdup(dev, "reg", GFP_KERNEL);
+               if (!prop->name)
+                       return -ENOMEM;
+               err = of_add_property(mem_node, prop);
+               if (err)
+                       return err;
+       }
+
        return 0;
 }
-- 
2.7.4

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