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>

1 files changed, 50 insertions, 38 deletions

diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c
index 086522b7c60f..c0365eca7f81 100644
--- 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.