xtensa: allow fixmap and kmap span more than one page table

To support aliasing cache both kmap region sizes are multiplied by the
number of data cache colors. After that expansion page tables that cover
kmap regions may become larger than one page. Correctly allocate and
initialize page tables in this case.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

diff --git a/arch/xtensa/mm/mmu.c b/arch/xtensa/mm/mmu.c
index 3429b483d9f85cd2495e01c8c0a11d05bc22e16c..abe4513eb0ddf072f628406eb8af2d13b2774678 100644 (file)
--- a/arch/xtensa/mm/mmu.c
+++ b/arch/xtensa/mm/mmu.c
@@ -18,32 +18,38 @@
 #include <asm/io.h>
 
 #if defined(CONFIG_HIGHMEM)
-static void * __init init_pmd(unsigned long vaddr)
+static void * __init init_pmd(unsigned long vaddr, unsigned long n_pages)
 {
        pgd_t *pgd = pgd_offset_k(vaddr);
        pmd_t *pmd = pmd_offset(pgd, vaddr);
+       pte_t *pte;
+       unsigned long i;
 
-       if (pmd_none(*pmd)) {
-               unsigned i;
-               pte_t *pte = alloc_bootmem_low_pages(PAGE_SIZE);
+       n_pages = ALIGN(n_pages, PTRS_PER_PTE);
 
-               for (i = 0; i < 1024; i++)
-                       pte_clear(NULL, 0, pte + i);
+       pr_debug("%s: vaddr: 0x%08lx, n_pages: %ld\n",
+                __func__, vaddr, n_pages);
 
-               set_pmd(pmd, __pmd(((unsigned long)pte) & PAGE_MASK));
-               BUG_ON(pte != pte_offset_kernel(pmd, 0));
-               pr_debug("%s: vaddr: 0x%08lx, pmd: 0x%p, pte: 0x%p\n",
-                        __func__, vaddr, pmd, pte);
-               return pte;
-       } else {
-               return pte_offset_kernel(pmd, 0);
+       pte = alloc_bootmem_low_pages(n_pages * sizeof(pte_t));
+
+       for (i = 0; i < n_pages; ++i)
+               pte_clear(NULL, 0, pte + i);
+
+       for (i = 0; i < n_pages; i += PTRS_PER_PTE, ++pmd) {
+               pte_t *cur_pte = pte + i;
+
+               BUG_ON(!pmd_none(*pmd));
+               set_pmd(pmd, __pmd(((unsigned long)cur_pte) & PAGE_MASK));
+               BUG_ON(cur_pte != pte_offset_kernel(pmd, 0));
+               pr_debug("%s: pmd: 0x%p, pte: 0x%p\n",
+                        __func__, pmd, cur_pte);
        }
+       return pte;
 }
 
 static void __init fixedrange_init(void)
 {
-       BUILD_BUG_ON(FIXADDR_SIZE > PMD_SIZE);
-       init_pmd(__fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK);
+       init_pmd(__fix_to_virt(0), __end_of_fixed_addresses);
 }
 #endif
 
@@ -52,7 +58,7 @@ void __init paging_init(void)
        memset(swapper_pg_dir, 0, PAGE_SIZE);
 #ifdef CONFIG_HIGHMEM
        fixedrange_init();
-       pkmap_page_table = init_pmd(PKMAP_BASE);
+       pkmap_page_table = init_pmd(PKMAP_BASE, LAST_PKMAP);
        kmap_init();
 #endif
 }