sparc64: Kill unnecessary tables and increase MAX_BANKS.

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>

diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h
index c093922..bfeb626 100644 (file)
--- 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 0bacceb..0924305 100644 (file)
--- 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 0ead74b..2d91c62 100644 (file)
--- 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);
 
@@ -2002,8 +1996,6 @@ 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();
@@ -2099,20 +2091,7 @@ 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();