powerpc/44x: Support 16K/64K base page sizes on 44x
This adds support for 16k and 64k page sizes on PowerPC 44x processors.
The PGDIR table is much smaller than a page when using 16k or 64k
pages (512 and 32 bytes respectively) so we allocate the PGDIR with
kzalloc() instead of __get_free_pages().
One PTE table covers rather a large memory area when using 16k or 64k
pages (32MB or 512MB respectively), so we can easily put FIXMAP and
PKMAP in the area covered by one PTE table.
Signed-off-by: Yuri Tikhonov <yur@emcraft.com>
Signed-off-by: Vladimir Panfilov <pvr@emcraft.com>
Signed-off-by: Ilya Yanok <yanok@emcraft.com>
Acked-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c
index 8cba46f..38ff35f 100644
--- a/arch/powerpc/mm/pgtable_32.c
+++ b/arch/powerpc/mm/pgtable_32.c
@@ -68,24 +68,29 @@
#define p_mapped_by_tlbcam(x) (0UL)
#endif /* HAVE_TLBCAM */
-#ifdef CONFIG_PTE_64BIT
-/* Some processors use an 8kB pgdir because they have 8-byte Linux PTEs. */
-#define PGDIR_ORDER 1
-#else
-#define PGDIR_ORDER 0
-#endif
+#define PGDIR_ORDER (32 + PGD_T_LOG2 - PGDIR_SHIFT)
pgd_t *pgd_alloc(struct mm_struct *mm)
{
pgd_t *ret;
- ret = (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, PGDIR_ORDER);
+ /* pgdir take page or two with 4K pages and a page fraction otherwise */
+#ifndef CONFIG_PPC_4K_PAGES
+ ret = (pgd_t *)kzalloc(1 << PGDIR_ORDER, GFP_KERNEL);
+#else
+ ret = (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,
+ PGDIR_ORDER - PAGE_SHIFT);
+#endif
return ret;
}
void pgd_free(struct mm_struct *mm, pgd_t *pgd)
{
- free_pages((unsigned long)pgd, PGDIR_ORDER);
+#ifndef CONFIG_PPC_4K_PAGES
+ kfree((void *)pgd);
+#else
+ free_pages((unsigned long)pgd, PGDIR_ORDER - PAGE_SHIFT);
+#endif
}
__init_refok pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
@@ -385,7 +390,7 @@
#endif /* CONFIG_DEBUG_PAGEALLOC */
static int fixmaps;
-unsigned long FIXADDR_TOP = 0xfffff000;
+unsigned long FIXADDR_TOP = (-PAGE_SIZE);
EXPORT_SYMBOL(FIXADDR_TOP);
void __set_fixmap (enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags)