From df5d6ecf8157245ef733db87597adb2c6e2510da Mon Sep 17 00:00:00 2001 From: Kumar Gala <galak@kernel.crashing.org> Date: Mon, 24 Aug 2009 15:52:48 +0000 Subject: [PATCH] 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> --- arch/powerpc/include/asm/mmu.h | 9 ++++++++ arch/powerpc/mm/tlb_low_64e.S | 38 +++++++++++++++++++++++++++++++++- 2 files changed, 46 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/include/asm/mmu.h b/arch/powerpc/include/asm/mmu.h index 2fcfefc60894..7ffbb65ff7a9 100644 --- a/arch/powerpc/include/asm/mmu.h +++ b/arch/powerpc/include/asm/mmu.h @@ -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> diff --git a/arch/powerpc/mm/tlb_low_64e.S b/arch/powerpc/mm/tlb_low_64e.S index cd92f62f9cf5..ef1cccf71173 100644 --- a/arch/powerpc/mm/tlb_low_64e.S +++ b/arch/powerpc/mm/tlb_low_64e.S @@ -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