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>
diff --git a/arch/powerpc/mm/tlb_low_64e.S b/arch/powerpc/mm/tlb_low_64e.S
index cd92f62..ef1cccf 100644
--- a/arch/powerpc/mm/tlb_low_64e.S
+++ b/arch/powerpc/mm/tlb_low_64e.S
@@ -189,12 +189,16 @@
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 @@
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 @@
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 @@
*/
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 @@
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 @@
#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 @@
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