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powerpc/mm: Add MMU features for TLB reservation & Paired MAS registers 

Support for TLB reservation (or TLB Write Conditional) and Paired MAS
registers are optional for a processor implementation so we handle
them via MMU feature sections.

We currently only used paired MAS registers to access the full RPN + perm
bits that are kept in MAS7||MAS3.  We assume that if an implementation has
hardware page table at this time it also implements in TLB reservations.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Kumar Gala 2009-08-24 15:52:48 +00:00 committed by Benjamin Herrenschmidt
parent 23e55f92d4
commit df5d6ecf81
2 changed files with 46 additions and 1 deletions
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9
arch/powerpc/include/asm/mmu.h
View File

@ -58,6 +58,15 @@
*/
#define MMU_FTR_TLBIE_206 ASM_CONST(0x00400000)
/* Enable use of TLB reservation. Processor should support tlbsrx.
* instruction and MAS0[WQ].
*/
#define MMU_FTR_USE_TLBRSRV ASM_CONST(0x00800000)
/* Use paired MAS registers (MAS7||MAS3, etc.)
*/
#define MMU_FTR_USE_PAIRED_MAS ASM_CONST(0x01000000)
#ifndef __ASSEMBLY__
#include <asm/cputable.h>

38
arch/powerpc/mm/tlb_low_64e.S
View File

@ -189,12 +189,16 @@ normal_tlb_miss:
clrrdi r14,r14,3
or r10,r15,r14
BEGIN_MMU_FTR_SECTION
/* Set the TLB reservation and seach for existing entry. Then load
* the entry.
*/
PPC_TLBSRX_DOT(0,r16)
ld r14,0(r10)
beq normal_tlb_miss_done
MMU_FTR_SECTION_ELSE
ld r14,0(r10)
ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_USE_TLBRSRV)
finish_normal_tlb_miss:
/* Check if required permissions are met */
@ -241,7 +245,14 @@ finish_normal_tlb_miss:
bne 1f
li r11,MAS3_SW|MAS3_UW
andc r15,r15,r11
1: mtspr SPRN_MAS7_MAS3,r15
1:
BEGIN_MMU_FTR_SECTION
srdi r16,r15,32
mtspr SPRN_MAS3,r15
mtspr SPRN_MAS7,r16
MMU_FTR_SECTION_ELSE
mtspr SPRN_MAS7_MAS3,r15
ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_USE_PAIRED_MAS)
tlbwe
@ -311,11 +322,13 @@ virt_page_table_tlb_miss:
rlwinm r10,r10,0,16,1 /* Clear TID */
mtspr SPRN_MAS1,r10
1:
BEGIN_MMU_FTR_SECTION
/* Search if we already have a TLB entry for that virtual address, and
* if we do, bail out.
*/
PPC_TLBSRX_DOT(0,r16)
beq virt_page_table_tlb_miss_done
END_MMU_FTR_SECTION_IFSET(MMU_FTR_USE_TLBRSRV)
/* Now, we need to walk the page tables. First check if we are in
* range.
@ -367,10 +380,18 @@ virt_page_table_tlb_miss:
*/
clrldi r11,r15,4 /* remove region ID from RPN */
ori r10,r11,1 /* Or-in SR */
BEGIN_MMU_FTR_SECTION
srdi r16,r10,32
mtspr SPRN_MAS3,r10
mtspr SPRN_MAS7,r16
MMU_FTR_SECTION_ELSE
mtspr SPRN_MAS7_MAS3,r10
ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_USE_PAIRED_MAS)
tlbwe
BEGIN_MMU_FTR_SECTION
virt_page_table_tlb_miss_done:
/* We have overriden MAS2:EPN but currently our primary TLB miss
@ -394,6 +415,7 @@ virt_page_table_tlb_miss_done:
addi r10,r11,-4
std r10,PACA_EXTLB+EX_TLB_SIZE+EX_TLB_SRR0(r13)
1:
END_MMU_FTR_SECTION_IFSET(MMU_FTR_USE_TLBRSRV)
/* Return to caller, normal case */
TLB_MISS_STATS_X(MMSTAT_TLB_MISS_PT_OK);
TLB_MISS_EPILOG_SUCCESS
@ -618,7 +640,14 @@ htw_tlb_miss:
#else
ori r10,r15,(BOOK3E_PAGESZ_4K << MAS3_SPSIZE_SHIFT)
#endif
BEGIN_MMU_FTR_SECTION
srdi r16,r10,32
mtspr SPRN_MAS3,r10
mtspr SPRN_MAS7,r16
MMU_FTR_SECTION_ELSE
mtspr SPRN_MAS7_MAS3,r10
ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_USE_PAIRED_MAS)
tlbwe
@ -700,7 +729,14 @@ tlb_load_linear:
clrrdi r10,r16,30 /* 1G page index */
clrldi r10,r10,4 /* clear region bits */
ori r10,r10,MAS3_SR|MAS3_SW|MAS3_SX
BEGIN_MMU_FTR_SECTION
srdi r16,r10,32
mtspr SPRN_MAS3,r10
mtspr SPRN_MAS7,r16
MMU_FTR_SECTION_ELSE
mtspr SPRN_MAS7_MAS3,r10
ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_USE_PAIRED_MAS)
tlbwe