staging: android: persistent_ram: Introduce persistent_ram_vmap()

Factor out vmap logic out of persistent_ram_buffer_map(), this will
make the code a bit more understandable when we'll add support for
non-bootmem memory.

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/android/persistent_ram.c b/drivers/staging/android/persistent_ram.c
index c0c3d32ffe8252dcc9edf5040b27c6e3ececabf1..ab8bff19dca0f18c54460970612b362add98d1b5 100644 (file)
--- a/drivers/staging/android/persistent_ram.c
+++ b/drivers/staging/android/persistent_ram.c
@@ -318,14 +318,14 @@ void persistent_ram_free_old(struct persistent_ram_zone *prz)
        prz->old_log_size = 0;
 }
 
-static int persistent_ram_buffer_map(phys_addr_t start, phys_addr_t size,
-               struct persistent_ram_zone *prz)
+static void *persistent_ram_vmap(phys_addr_t start, size_t size)
 {
        struct page **pages;
        phys_addr_t page_start;
        unsigned int page_count;
        pgprot_t prot;
        unsigned int i;
+       void *vaddr;
 
        page_start = start - offset_in_page(start);
        page_count = DIV_ROUND_UP(size + offset_in_page(start), PAGE_SIZE);
@@ -336,17 +336,26 @@ static int persistent_ram_buffer_map(phys_addr_t start, phys_addr_t size,
        if (!pages) {
                pr_err("%s: Failed to allocate array for %u pages\n", __func__,
                        page_count);
-               return -ENOMEM;
+               return NULL;
        }
 
        for (i = 0; i < page_count; i++) {
                phys_addr_t addr = page_start + i * PAGE_SIZE;
                pages[i] = pfn_to_page(addr >> PAGE_SHIFT);
        }
-       prz->vaddr = vmap(pages, page_count, VM_MAP, prot);
+       vaddr = vmap(pages, page_count, VM_MAP, prot);
        kfree(pages);
+
+       return vaddr;
+}
+
+static int persistent_ram_buffer_map(phys_addr_t start, phys_addr_t size,
+               struct persistent_ram_zone *prz)
+{
+       prz->vaddr = persistent_ram_vmap(start, size);
        if (!prz->vaddr) {
-               pr_err("%s: Failed to map %u pages\n", __func__, page_count);
+               pr_err("%s: Failed to map 0x%llx pages at 0x%llx\n", __func__,
+                       (unsigned long long)size, (unsigned long long)start);
                return -ENOMEM;
        }