percpu: factor out pcpu_addr_in_first/reserved_chunk() and update per_cpu_ptr_to_phys()

Factor out pcpu_addr_in_first/reserved_chunk() from
pcpu_chunk_addr_search() and use it to update per_cpu_ptr_to_phys()
such that it handles first chunk differently from the rest.

This patch doesn't cause any functional change and is to prepare for
percpu nommu support.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: David Howells <dhowells@redhat.com>
Cc: Graff Yang <graff.yang@gmail.com>
Cc: Sonic Zhang <sonic.adi@gmail.com>

1 files changed, 24 insertions, 8 deletions

diff --git a/mm/percpu.c b/mm/percpu.c
index 6e09741ddc62..1aeb081f30ec 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -177,6 +177,21 @@ static struct list_head *pcpu_slot __read_mostly; /* chunk list slots */
 static void pcpu_reclaim(struct work_struct *work);
 static DECLARE_WORK(pcpu_reclaim_work, pcpu_reclaim);
 
+static bool pcpu_addr_in_first_chunk(void *addr)
+{
+        void *first_start = pcpu_first_chunk->base_addr;
+
+        return addr >= first_start && addr < first_start + pcpu_unit_size;
+}
+
+static bool pcpu_addr_in_reserved_chunk(void *addr)
+{
+        void *first_start = pcpu_first_chunk->base_addr;
+
+        return addr >= first_start &&
+                addr < first_start + pcpu_reserved_chunk_limit;
+}
+
 static int __pcpu_size_to_slot(int size)
 {
         int highbit = fls(size);        /* size is in bytes */
@@ -334,12 +349,10 @@ static void pcpu_chunk_relocate(struct pcpu_chunk *chunk, int oslot)
  */
 static struct pcpu_chunk *pcpu_chunk_addr_search(void *addr)
 {
-        void *first_start = pcpu_first_chunk->base_addr;
-
         /* is it in the first chunk? */
-        if (addr >= first_start && addr < first_start + pcpu_unit_size) {
+        if (pcpu_addr_in_first_chunk(addr)) {
                 /* is it in the reserved area? */
-                if (addr < first_start + pcpu_reserved_chunk_limit)
+                if (pcpu_addr_in_reserved_chunk(addr))
                         return pcpu_reserved_chunk;
                 return pcpu_first_chunk;
         }
@@ -1343,10 +1356,13 @@ bool is_kernel_percpu_address(unsigned long addr)
  */
 phys_addr_t per_cpu_ptr_to_phys(void *addr)
 {
-        if ((unsigned long)addr < VMALLOC_START ||
-                        (unsigned long)addr >= VMALLOC_END)
-                return __pa(addr);
-        else
+        if (pcpu_addr_in_first_chunk(addr)) {
+                if ((unsigned long)addr < VMALLOC_START ||
+                    (unsigned long)addr >= VMALLOC_END)
+                        return __pa(addr);
+                else
+                        return page_to_phys(vmalloc_to_page(addr));
+        } else
                 return page_to_phys(vmalloc_to_page(addr));
 }