[SPARC64]: Move away from virtual page tables, part 1.

We now use the TSB hardware assist features of the UltraSPARC
MMUs.

SMP is currently knowingly broken, we need to find another place
to store the per-cpu base pointers.  We hid them away in the TSB
base register, and that obviously will not work any more :-)

Another known broken case is non-8KB base page size.

Also noticed that flush_tlb_all() is not referenced anywhere, only
the internal __flush_tlb_all() (local cpu only) is used by the
sparc64 port, so we can get rid of flush_tlb_all().

The kernel gets it's own 8KB TSB (swapper_tsb) and each address space
gets it's own private 8K TSB.  Later we can add code to dynamically
increase the size of per-process TSB as the RSS grows.  An 8KB TSB is
good enough for up to about a 4MB RSS, after which the TSB starts to
incur many capacity and conflict misses.

We even accumulate OBP translations into the kernel TSB.

Another area for refinement is large page size support.  We could use
a secondary address space TSB to handle those.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 6 deletions

diff --git a/include/asm-sparc64/pgtable.h b/include/asm-sparc64/pgtable.h
index f0a9b44d3eb5..f3ba1e058195 100644
--- a/include/asm-sparc64/pgtable.h
+++ b/include/asm-sparc64/pgtable.h
@@ -25,7 +25,8 @@
 #include <asm/const.h>
 
 /* The kernel image occupies 0x4000000 to 0x1000000 (4MB --> 32MB).
- * The page copy blockops can use 0x2000000 to 0x10000000.
+ * The page copy blockops can use 0x2000000 to 0x4000000.
+ * The TSB is mapped in the 0x4000000 to 0x6000000 range.
  * The PROM resides in an area spanning 0xf0000000 to 0x100000000.
  * The vmalloc area spans 0x100000000 to 0x200000000.
  * Since modules need to be in the lowest 32-bits of the address space,
@@ -34,6 +35,7 @@
  * 0x400000000.
  */
 #define TLBTEMP_BASE            _AC(0x0000000002000000,UL)
+#define TSBMAP_BASE             _AC(0x0000000004000000,UL)
 #define MODULES_VADDR           _AC(0x0000000010000000,UL)
 #define MODULES_LEN             _AC(0x00000000e0000000,UL)
 #define MODULES_END             _AC(0x00000000f0000000,UL)
@@ -296,11 +298,6 @@ static inline pte_t pte_modify(pte_t orig_pte, pgprot_t new_prot)
 /* to find an entry in a kernel page-table-directory */
 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
 
-/* extract the pgd cache used for optimizing the tlb miss
- * slow path when executing 32-bit compat processes
- */
-#define get_pgd_cache(pgd)      ((unsigned long) pgd_val(*pgd) << 11)
-
 /* Find an entry in the second-level page table.. */
 #define pmd_offset(pudp, address)       \
         ((pmd_t *) pud_page(*(pudp)) + \