powerpc/mm: refactor radix physical page mapping

Move the page mapping code in radix_init_pgtable() into a separate
function that will also be used for memory hotplug.

The current goto loop progressively decreases its mapping size as it
covers the tail of a range whose end is unaligned. Change this to a for
loop which can do the same for both ends of the range.

Signed-off-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c
index 086522b7c60f488ac599a6d8a50ed4abd568855f..c0365eca7f81f1cb553b6c89d370c2beffbc5579 100644 (file)
--- a/arch/powerpc/mm/pgtable-radix.c
+++ b/arch/powerpc/mm/pgtable-radix.c
@@ -108,54 +108,66 @@ set_the_pte:
        return 0;
 }
 
+static inline void __meminit print_mapping(unsigned long start,
+                                          unsigned long end,
+                                          unsigned long size)
+{
+       if (end <= start)
+               return;
+
+       pr_info("Mapped range 0x%lx - 0x%lx with 0x%lx\n", start, end, size);
+}
+
+static int __meminit create_physical_mapping(unsigned long start,
+                                            unsigned long end)
+{
+       unsigned long addr, mapping_size = 0;
+
+       start = _ALIGN_UP(start, PAGE_SIZE);
+       for (addr = start; addr < end; addr += mapping_size) {
+               unsigned long gap, previous_size;
+               int rc;
+
+               gap = end - addr;
+               previous_size = mapping_size;
+
+               if (IS_ALIGNED(addr, PUD_SIZE) && gap >= PUD_SIZE &&
+                   mmu_psize_defs[MMU_PAGE_1G].shift)
+                       mapping_size = PUD_SIZE;
+               else if (IS_ALIGNED(addr, PMD_SIZE) && gap >= PMD_SIZE &&
+                        mmu_psize_defs[MMU_PAGE_2M].shift)
+                       mapping_size = PMD_SIZE;
+               else
+                       mapping_size = PAGE_SIZE;
+
+               if (mapping_size != previous_size) {
+                       print_mapping(start, addr, previous_size);
+                       start = addr;
+               }
+
+               rc = radix__map_kernel_page((unsigned long)__va(addr), addr,
+                                           PAGE_KERNEL_X, mapping_size);
+               if (rc)
+                       return rc;
+       }
+
+       print_mapping(start, addr, mapping_size);
+       return 0;
+}
+
 static void __init radix_init_pgtable(void)
 {
-       int loop_count;
-       u64 base, end, start_addr;
        unsigned long rts_field;
        struct memblock_region *reg;
-       unsigned long linear_page_size;
 
        /* We don't support slb for radix */
        mmu_slb_size = 0;
        /*
         * Create the linear mapping, using standard page size for now
         */
-       loop_count = 0;
-       for_each_memblock(memory, reg) {
-
-               start_addr = reg->base;
-
-redo:
-               if (loop_count < 1 && mmu_psize_defs[MMU_PAGE_1G].shift)
-                       linear_page_size = PUD_SIZE;
-               else if (loop_count < 2 && mmu_psize_defs[MMU_PAGE_2M].shift)
-                       linear_page_size = PMD_SIZE;
-               else
-                       linear_page_size = PAGE_SIZE;
-
-               base = _ALIGN_UP(start_addr, linear_page_size);
-               end = _ALIGN_DOWN(reg->base + reg->size, linear_page_size);
-
-               pr_info("Mapping range 0x%lx - 0x%lx with 0x%lx\n",
-                       (unsigned long)base, (unsigned long)end,
-                       linear_page_size);
-
-               while (base < end) {
-                       radix__map_kernel_page((unsigned long)__va(base),
-                                             base, PAGE_KERNEL_X,
-                                             linear_page_size);
-                       base += linear_page_size;
-               }
-               /*
-                * map the rest using lower page size
-                */
-               if (end < reg->base + reg->size) {
-                       start_addr = end;
-                       loop_count++;
-                       goto redo;
-               }
-       }
+       for_each_memblock(memory, reg)
+               WARN_ON(create_physical_mapping(reg->base,
+                                               reg->base + reg->size));
        /*
         * Allocate Partition table and process table for the
         * host.