net: ipa: separate memory validation from initialization

Currently, memory regions are validated in the loop that initializes
them.  Instead, validate them separately.

Rename ipa_mem_valid() to be ipa_mem_valid_one().  Define a *new*
function named ipa_mem_valid() that performs validation of the array
of memory regions provided.  This function calls ipa_mem_valid_one()
for each region in turn.

Skip validation for any "empty" region descriptors, which have zero
size and are not preceded by any canary values.  Issue a warning for
such descriptors if the offset is non-zero.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ipa/ipa_mem.c b/drivers/net/ipa/ipa_mem.c
index effaa74..62e1b82 100644 (file)
--- a/drivers/net/ipa/ipa_mem.c
+++ b/drivers/net/ipa/ipa_mem.c
@@ -99,7 +99,7 @@ int ipa_mem_setup(struct ipa *ipa)
        return 0;
 }
 
-static bool ipa_mem_valid(struct ipa *ipa, const struct ipa_mem *mem)
+static bool ipa_mem_valid_one(struct ipa *ipa, const struct ipa_mem *mem)
 {
        struct device *dev = &ipa->pdev->dev;
        enum ipa_mem_id mem_id = mem->id;
@@ -126,6 +126,31 @@ static bool ipa_mem_valid(struct ipa *ipa, const struct ipa_mem *mem)
        return false;
 }
 
+/* Verify each defined memory region is valid. */
+static bool ipa_mem_valid(struct ipa *ipa)
+{
+       struct device *dev = &ipa->pdev->dev;
+       enum ipa_mem_id mem_id;
+
+       for (mem_id = 0; mem_id < ipa->mem_count; mem_id++) {
+               const struct ipa_mem *mem = &ipa->mem[mem_id];
+
+               /* Defined regions have non-zero size and/or canary count */
+               if (mem->size || mem->canary_count) {
+                       if (ipa_mem_valid_one(ipa, mem))
+                               continue;
+                       return false;
+               }
+
+               /* It's harmless, but warn if an offset is provided */
+               if (mem->offset)
+                       dev_warn(dev, "empty region %u has non-zero offset\n",
+                                mem_id);
+       }
+
+       return true;
+}
+
 /**
  * ipa_mem_config() - Configure IPA shared memory
  * @ipa:       IPA pointer
@@ -167,19 +192,18 @@ int ipa_mem_config(struct ipa *ipa)
        ipa->zero_virt = virt;
        ipa->zero_size = IPA_MEM_MAX;
 
-       /* Verify each defined memory region is valid, and if indicated
-        * for the region, write "canary" values in the space prior to
-        * the region's base address.
+       /* Make sure all defined memory regions are valid */
+       if (!ipa_mem_valid(ipa))
+               goto err_dma_free;
+
+       /* For each region, write "canary" values in the space prior to
+        * the region's base address if indicated.
         */
        for (mem_id = 0; mem_id < ipa->mem_count; mem_id++) {
                const struct ipa_mem *mem = &ipa->mem[mem_id];
                u16 canary_count;
                __le32 *canary;
 
-               /* Validate all regions (even undefined ones) */
-               if (!ipa_mem_valid(ipa, mem))
-                       goto err_dma_free;
-
                /* Skip over undefined regions */
                if (!mem->offset && !mem->size)
                        continue;