From 128c1ea2f838d3031a1c475607860e4271a8e9dc Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Tue, 28 Jun 2022 16:48:57 +0200 Subject: [PATCH] powerpc/64e: Move virtual memory closer to linear memory Today nohash/64 have linear memory based at 0xc000000000000000 and virtual memory based at 0x8000000000000000. In order to implement KASAN, we need to regroup both areas. Move virtual memmory at 0xc000100000000000. This complicates a bit TLB miss handlers. Until now, memory region was easily identified with the 4 higher bits of address: - 0 ==> User - c ==> Linear Memory - 8 ==> Virtual Memory Now we need to rely on the 20 higher bits, with: - 0xxxx ==> User - c0000 ==> Linear Memory - c0001 ==> Virtual Memory Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/4b225168031449fc34fc7132f3923cc8dc54af60.1656427701.git.christophe.leroy@csgroup.eu --- arch/powerpc/include/asm/nohash/64/pgtable.h | 2 +- arch/powerpc/mm/nohash/tlb_low_64e.S | 64 ++++++++++++++++------------ 2 files changed, 38 insertions(+), 28 deletions(-) diff --git a/arch/powerpc/include/asm/nohash/64/pgtable.h b/arch/powerpc/include/asm/nohash/64/pgtable.h index d29f1d6..9104cc4 100644 --- a/arch/powerpc/include/asm/nohash/64/pgtable.h +++ b/arch/powerpc/include/asm/nohash/64/pgtable.h @@ -25,7 +25,7 @@ /* * Define the address range of the kernel non-linear virtual area */ -#define KERN_VIRT_START ASM_CONST(0x8000000000000000) +#define KERN_VIRT_START ASM_CONST(0xc000100000000000) #define KERN_VIRT_SIZE ASM_CONST(0x0000100000000000) /* diff --git a/arch/powerpc/mm/nohash/tlb_low_64e.S b/arch/powerpc/mm/nohash/tlb_low_64e.S index a59485c..68ffbfd 100644 --- a/arch/powerpc/mm/nohash/tlb_low_64e.S +++ b/arch/powerpc/mm/nohash/tlb_low_64e.S @@ -213,10 +213,11 @@ itlb_miss_kernel_bolted: tlb_miss_kernel_bolted: mfspr r10,SPRN_MAS1 ld r14,PACA_KERNELPGD(r13) - cmpldi cr0,r15,8 /* Check for vmalloc region */ + srdi r15,r16,44 /* get kernel region */ + andi. r15,r15,1 /* Check for vmalloc region */ rlwinm r10,r10,0,16,1 /* Clear TID */ mtspr SPRN_MAS1,r10 - beq+ tlb_miss_common_bolted + bne+ tlb_miss_common_bolted tlb_miss_fault_bolted: /* We need to check if it was an instruction miss */ @@ -498,7 +499,9 @@ tlb_miss_huge_e6500: tlb_miss_kernel_e6500: ld r14,PACA_KERNELPGD(r13) - cmpldi cr1,r15,8 /* Check for vmalloc region */ + srdi r15,r16,44 /* get kernel region */ + xoris r15,r15,0xc /* Check for vmalloc region */ + cmplwi cr1,r15,1 beq+ cr1,tlb_miss_common_e6500 tlb_miss_fault_e6500: @@ -532,16 +535,18 @@ itlb_miss_fault_e6500: */ mfspr r14,SPRN_ESR mfspr r16,SPRN_DEAR /* get faulting address */ - srdi r15,r16,60 /* get region */ - cmpldi cr0,r15,0xc /* linear mapping ? */ + srdi r15,r16,44 /* get region */ + xoris r15,r15,0xc + cmpldi cr0,r15,0 /* linear mapping ? */ beq tlb_load_linear /* yes -> go to linear map load */ + cmpldi cr1,r15,1 /* vmalloc mapping ? */ /* The page tables are mapped virtually linear. At this point, though, * we don't know whether we are trying to fault in a first level * virtual address or a virtual page table address. We can get that * from bit 0x1 of the region ID which we have set for a page table */ - andi. r10,r15,0x1 + andis. r10,r15,0x1 bne- virt_page_table_tlb_miss std r14,EX_TLB_ESR(r12); /* save ESR */ @@ -553,7 +558,7 @@ itlb_miss_fault_e6500: /* We do the user/kernel test for the PID here along with the RW test */ - cmpldi cr0,r15,0 /* Check for user region */ + srdi. r15,r16,60 /* Check for user region */ /* We pre-test some combination of permissions to avoid double * faults: @@ -577,10 +582,9 @@ itlb_miss_fault_e6500: beq normal_tlb_miss_user /* XXX replace the RMW cycles with immediate loads + writes */ 1: mfspr r10,SPRN_MAS1 - cmpldi cr0,r15,8 /* Check for vmalloc region */ rlwinm r10,r10,0,16,1 /* Clear TID */ mtspr SPRN_MAS1,r10 - beq+ normal_tlb_miss + beq+ cr1,normal_tlb_miss /* We got a crappy address, just fault with whatever DEAR and ESR * are here @@ -606,16 +610,18 @@ itlb_miss_fault_e6500: * * Faulting address is SRR0 which is already in r16 */ - srdi r15,r16,60 /* get region */ - cmpldi cr0,r15,0xc /* linear mapping ? */ + srdi r15,r16,44 /* get region */ + xoris r15,r15,0xc + cmpldi cr0,r15,0 /* linear mapping ? */ beq tlb_load_linear /* yes -> go to linear map load */ + cmpldi cr1,r15,1 /* vmalloc mapping ? */ /* We do the user/kernel test for the PID here along with the RW test */ li r11,_PAGE_PRESENT|_PAGE_BAP_UX /* Base perm */ oris r11,r11,_PAGE_ACCESSED@h - cmpldi cr0,r15,0 /* Check for user region */ + srdi. r15,r16,60 /* Check for user region */ std r14,EX_TLB_ESR(r12) /* write crazy -1 to frame */ beq normal_tlb_miss_user @@ -623,10 +629,9 @@ itlb_miss_fault_e6500: oris r11,r11,_PAGE_ACCESSED@h /* XXX replace the RMW cycles with immediate loads + writes */ mfspr r10,SPRN_MAS1 - cmpldi cr0,r15,8 /* Check for vmalloc region */ rlwinm r10,r10,0,16,1 /* Clear TID */ mtspr SPRN_MAS1,r10 - beq+ normal_tlb_miss + beq+ cr1,normal_tlb_miss /* We got a crappy address, just fault */ TLB_MISS_EPILOG_ERROR @@ -659,10 +664,11 @@ normal_tlb_miss: * NOTE: For 64K pages, we do things slightly differently in * order to handle the weird page table format used by linux */ - ori r10,r15,0x1 + srdi r15,r16,44 + oris r10,r15,0x1 rldicl r14,r16,64-(PAGE_SHIFT-3),PAGE_SHIFT-3+4 - sldi r15,r10,60 - clrrdi r14,r14,3 + sldi r15,r10,44 + clrrdi r14,r14,19 or r10,r15,r14 ld r14,0(r10) @@ -763,6 +769,7 @@ normal_tlb_miss_access_fault: */ virt_page_table_tlb_miss: /* Are we hitting a kernel page table ? */ + srdi r15,r16,60 andi. r10,r15,0x8 /* The cool thing now is that r10 contains 0 for user and 8 for kernel, @@ -791,7 +798,8 @@ virt_page_table_tlb_miss: /* Now, we need to walk the page tables. First check if we are in * range. */ - rldicl. r10,r16,64-(VPTE_INDEX_SIZE+3),VPTE_INDEX_SIZE+3+4 + rldicl r10,r16,64-(VPTE_INDEX_SIZE+3),VPTE_INDEX_SIZE+3+4 + cmpldi r10,0x80 bne- virt_page_table_tlb_miss_fault /* Get the PGD pointer */ @@ -910,23 +918,24 @@ virt_page_table_tlb_miss_whacko_fault: */ mfspr r14,SPRN_ESR mfspr r16,SPRN_DEAR /* get faulting address */ - srdi r11,r16,60 /* get region */ - cmpldi cr0,r11,0xc /* linear mapping ? */ + srdi r11,r16,44 /* get region */ + xoris r11,r11,0xc + cmpldi cr0,r11,0 /* linear mapping ? */ beq tlb_load_linear /* yes -> go to linear map load */ + cmpldi cr1,r11,1 /* vmalloc mapping ? */ /* We do the user/kernel test for the PID here along with the RW test */ - cmpldi cr0,r11,0 /* Check for user region */ + srdi. r11,r16,60 /* Check for user region */ ld r15,PACAPGD(r13) /* Load user pgdir */ beq htw_tlb_miss /* XXX replace the RMW cycles with immediate loads + writes */ 1: mfspr r10,SPRN_MAS1 - cmpldi cr0,r11,8 /* Check for vmalloc region */ rlwinm r10,r10,0,16,1 /* Clear TID */ mtspr SPRN_MAS1,r10 ld r15,PACA_KERNELPGD(r13) /* Load kernel pgdir */ - beq+ htw_tlb_miss + beq+ cr1,htw_tlb_miss /* We got a crappy address, just fault with whatever DEAR and ESR * are here @@ -952,19 +961,20 @@ virt_page_table_tlb_miss_whacko_fault: * * Faulting address is SRR0 which is already in r16 */ - srdi r11,r16,60 /* get region */ - cmpldi cr0,r11,0xc /* linear mapping ? */ + srdi r11,r16,44 /* get region */ + xoris r11,r11,0xc + cmpldi cr0,r11,0 /* linear mapping ? */ beq tlb_load_linear /* yes -> go to linear map load */ + cmpldi cr1,r11,1 /* vmalloc mapping ? */ /* We do the user/kernel test for the PID here along with the RW test */ - cmpldi cr0,r11,0 /* Check for user region */ + srdi. r11,r16,60 /* Check for user region */ ld r15,PACAPGD(r13) /* Load user pgdir */ beq htw_tlb_miss /* XXX replace the RMW cycles with immediate loads + writes */ 1: mfspr r10,SPRN_MAS1 - cmpldi cr0,r11,8 /* Check for vmalloc region */ rlwinm r10,r10,0,16,1 /* Clear TID */ mtspr SPRN_MAS1,r10 ld r15,PACA_KERNELPGD(r13) /* Load kernel pgdir */ -- 2.7.4