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authorDavid S. Miller <davem@davemloft.net>2014-09-27 21:30:57 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-10-30 09:43:18 -0700
commit5c51a8b0cd0764d02fde570f274973ec182bc301 (patch)
tree3721b2865a1adce3e396fec2bcfae7348de0f235
parent82f230ed1fa89d515dc023fd277ca24e00b83f86 (diff)
downloadlinux-linaro-stable-5c51a8b0cd0764d02fde570f274973ec182bc301.tar.gz
sparc64: Kill unnecessary tables and increase MAX_BANKS.
[ Upstream commit d195b71bad4347d2df51072a537f922546a904f1 ] swapper_low_pmd_dir and swapper_pud_dir are actually completely useless and unnecessary. We just need swapper_pg_dir[]. Naturally the other page table chunks will be allocated on an as-needed basis. Since the kernel actually accesses these tables in the PAGE_OFFSET view, there is not even a TLB locality advantage of placing them in the kernel image. Use the hard coded vmlinux.ld.S slot for swapper_pg_dir which is naturally page aligned. Increase MAX_BANKS to 1024 in order to handle heavily fragmented virtual guests. Even with this MAX_BANKS increase, the kernel is 20K+ smaller. Signed-off-by: David S. Miller <davem@davemloft.net> Acked-by: Bob Picco <bob.picco@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--arch/sparc/include/asm/pgtable_64.h1
-rw-r--r--arch/sparc/kernel/vmlinux.lds.S5
-rw-r--r--arch/sparc/mm/init_64.c25
3 files changed, 5 insertions, 26 deletions
diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h
index c0939228e4b1..bfeb626085ac 100644
--- a/arch/sparc/include/asm/pgtable_64.h
+++ b/arch/sparc/include/asm/pgtable_64.h
@@ -927,7 +927,6 @@ static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr,
#endif
extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
-extern pmd_t swapper_low_pmd_dir[PTRS_PER_PMD];
void paging_init(void);
unsigned long find_ecache_flush_span(unsigned long size);
diff --git a/arch/sparc/kernel/vmlinux.lds.S b/arch/sparc/kernel/vmlinux.lds.S
index 0bacceb19150..09243057cb0b 100644
--- a/arch/sparc/kernel/vmlinux.lds.S
+++ b/arch/sparc/kernel/vmlinux.lds.S
@@ -35,8 +35,9 @@ jiffies = jiffies_64;
SECTIONS
{
- /* swapper_low_pmd_dir is sparc64 only */
- swapper_low_pmd_dir = 0x0000000000402000;
+#ifdef CONFIG_SPARC64
+ swapper_pg_dir = 0x0000000000402000;
+#endif
. = INITIAL_ADDRESS;
.text TEXTSTART :
{
diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
index 8c4909c722b4..04bc826135b4 100644
--- a/arch/sparc/mm/init_64.c
+++ b/arch/sparc/mm/init_64.c
@@ -87,7 +87,7 @@ extern struct tsb swapper_tsb[KERNEL_TSB_NENTRIES];
static unsigned long cpu_pgsz_mask;
-#define MAX_BANKS 32
+#define MAX_BANKS 1024
static struct linux_prom64_registers pavail[MAX_BANKS];
static int pavail_ents;
@@ -1943,12 +1943,6 @@ static void __init sun4v_linear_pte_xor_finalize(void)
static unsigned long last_valid_pfn;
-/* These must be page aligned in order to not trigger the
- * alignment tests of pgd_bad() and pud_bad().
- */
-pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__ ((aligned (PAGE_SIZE)));
-static pud_t swapper_pud_dir[PTRS_PER_PUD] __attribute__ ((aligned (PAGE_SIZE)));
-
static void sun4u_pgprot_init(void);
static void sun4v_pgprot_init(void);
@@ -1956,8 +1950,6 @@ void __init paging_init(void)
{
unsigned long end_pfn, shift, phys_base;
unsigned long real_end, i;
- pud_t *pud;
- pmd_t *pmd;
int node;
setup_page_offset();
@@ -2052,20 +2044,7 @@ void __init paging_init(void)
*/
init_mm.pgd += ((shift) / (sizeof(pgd_t)));
- memset(swapper_low_pmd_dir, 0, sizeof(swapper_low_pmd_dir));
-
- /* The kernel page tables we publish into what the rest of the
- * world sees must be adjusted so that they see the PAGE_OFFSET
- * address of these in-kerenel data structures. However right
- * here we must access them from the kernel image side, because
- * the trap tables haven't been taken over and therefore we cannot
- * take TLB misses in the PAGE_OFFSET linear mappings yet.
- */
- pud = swapper_pud_dir + (shift / sizeof(pud_t));
- pgd_set(&swapper_pg_dir[0], pud);
-
- pmd = swapper_low_pmd_dir + (shift / sizeof(pmd_t));
- pud_set(&swapper_pud_dir[0], pmd);
+ memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));
inherit_prom_mappings();