| /* tlb-miss.S: TLB miss handlers |
| * |
| * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. |
| * Written by David Howells (dhowells@redhat.com) |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| */ |
| |
| #include <linux/sys.h> |
| #include <linux/linkage.h> |
| #include <asm/page.h> |
| #include <asm/pgtable.h> |
| #include <asm/highmem.h> |
| #include <asm/spr-regs.h> |
| |
| .section .text.tlbmiss |
| .balign 4 |
| |
| .globl __entry_insn_mmu_miss |
| __entry_insn_mmu_miss: |
| break |
| nop |
| |
| .globl __entry_insn_mmu_exception |
| __entry_insn_mmu_exception: |
| break |
| nop |
| |
| .globl __entry_data_mmu_miss |
| __entry_data_mmu_miss: |
| break |
| nop |
| |
| .globl __entry_data_mmu_exception |
| __entry_data_mmu_exception: |
| break |
| nop |
| |
| ############################################################################### |
| # |
| # handle a lookup failure of one sort or another in a kernel TLB handler |
| # On entry: |
| # GR29 - faulting address |
| # SCR2 - saved CCR |
| # |
| ############################################################################### |
| .type __tlb_kernel_fault,@function |
| __tlb_kernel_fault: |
| # see if we're supposed to re-enable single-step mode upon return |
| sethi.p %hi(__break_tlb_miss_return_break),gr30 |
| setlo %lo(__break_tlb_miss_return_break),gr30 |
| movsg pcsr,gr31 |
| |
| subcc gr31,gr30,gr0,icc0 |
| beq icc0,#0,__tlb_kernel_fault_sstep |
| |
| movsg scr2,gr30 |
| movgs gr30,ccr |
| movgs gr29,scr2 /* save EAR0 value */ |
| sethi.p %hi(__kernel_current_task),gr29 |
| setlo %lo(__kernel_current_task),gr29 |
| ldi.p @(gr29,#0),gr29 /* restore GR29 */ |
| |
| bra __entry_kernel_handle_mmu_fault |
| |
| # we've got to re-enable single-stepping |
| __tlb_kernel_fault_sstep: |
| sethi.p %hi(__break_tlb_miss_real_return_info),gr30 |
| setlo %lo(__break_tlb_miss_real_return_info),gr30 |
| lddi @(gr30,0),gr30 |
| movgs gr30,pcsr |
| movgs gr31,psr |
| |
| movsg scr2,gr30 |
| movgs gr30,ccr |
| movgs gr29,scr2 /* save EAR0 value */ |
| sethi.p %hi(__kernel_current_task),gr29 |
| setlo %lo(__kernel_current_task),gr29 |
| ldi.p @(gr29,#0),gr29 /* restore GR29 */ |
| bra __entry_kernel_handle_mmu_fault_sstep |
| |
| .size __tlb_kernel_fault, .-__tlb_kernel_fault |
| |
| ############################################################################### |
| # |
| # handle a lookup failure of one sort or another in a user TLB handler |
| # On entry: |
| # GR28 - faulting address |
| # SCR2 - saved CCR |
| # |
| ############################################################################### |
| .type __tlb_user_fault,@function |
| __tlb_user_fault: |
| # see if we're supposed to re-enable single-step mode upon return |
| sethi.p %hi(__break_tlb_miss_return_break),gr30 |
| setlo %lo(__break_tlb_miss_return_break),gr30 |
| movsg pcsr,gr31 |
| subcc gr31,gr30,gr0,icc0 |
| beq icc0,#0,__tlb_user_fault_sstep |
| |
| movsg scr2,gr30 |
| movgs gr30,ccr |
| bra __entry_uspace_handle_mmu_fault |
| |
| # we've got to re-enable single-stepping |
| __tlb_user_fault_sstep: |
| sethi.p %hi(__break_tlb_miss_real_return_info),gr30 |
| setlo %lo(__break_tlb_miss_real_return_info),gr30 |
| lddi @(gr30,0),gr30 |
| movgs gr30,pcsr |
| movgs gr31,psr |
| movsg scr2,gr30 |
| movgs gr30,ccr |
| bra __entry_uspace_handle_mmu_fault_sstep |
| |
| .size __tlb_user_fault, .-__tlb_user_fault |
| |
| ############################################################################### |
| # |
| # Kernel instruction TLB miss handler |
| # On entry: |
| # GR1 - kernel stack pointer |
| # GR28 - saved exception frame pointer |
| # GR29 - faulting address |
| # GR31 - EAR0 ^ SCR0 |
| # SCR0 - base of virtual range covered by cached PGE from last ITLB miss (or 0xffffffff) |
| # DAMR3 - mapped page directory |
| # DAMR4 - mapped page table as matched by SCR0 |
| # |
| ############################################################################### |
| .globl __entry_kernel_insn_tlb_miss |
| .type __entry_kernel_insn_tlb_miss,@function |
| __entry_kernel_insn_tlb_miss: |
| #if 0 |
| sethi.p %hi(0xe1200004),gr30 |
| setlo %lo(0xe1200004),gr30 |
| st gr0,@(gr30,gr0) |
| sethi.p %hi(0xffc00100),gr30 |
| setlo %lo(0xffc00100),gr30 |
| sth gr30,@(gr30,gr0) |
| membar |
| #endif |
| |
| movsg ccr,gr30 /* save CCR */ |
| movgs gr30,scr2 |
| |
| # see if the cached page table mapping is appropriate |
| srlicc.p gr31,#26,gr0,icc0 |
| setlos 0x3ffc,gr30 |
| srli.p gr29,#12,gr31 /* use EAR0[25:14] as PTE index */ |
| bne icc0,#0,__itlb_k_PTD_miss |
| |
| __itlb_k_PTD_mapped: |
| # access the PTD with EAR0[25:14] |
| # - DAMLR4 points to the virtual address of the appropriate page table |
| # - the PTD holds 4096 PTEs |
| # - the PTD must be accessed uncached |
| # - the PTE must be marked accessed if it was valid |
| # |
| and gr31,gr30,gr31 |
| movsg damlr4,gr30 |
| add gr30,gr31,gr31 |
| ldi @(gr31,#0),gr30 /* fetch the PTE */ |
| andicc gr30,#_PAGE_PRESENT,gr0,icc0 |
| ori.p gr30,#_PAGE_ACCESSED,gr30 |
| beq icc0,#0,__tlb_kernel_fault /* jump if PTE invalid */ |
| sti.p gr30,@(gr31,#0) /* update the PTE */ |
| andi gr30,#~_PAGE_ACCESSED,gr30 |
| |
| # we're using IAMR1 as an extra TLB entry |
| # - punt the entry here (if valid) to the real TLB and then replace with the new PTE |
| # - need to check DAMR1 lest we cause an multiple-DAT-hit exception |
| # - IAMPR1 has no WP bit, and we mustn't lose WP information |
| movsg iampr1,gr31 |
| andicc gr31,#xAMPRx_V,gr0,icc0 |
| setlos.p 0xfffff000,gr31 |
| beq icc0,#0,__itlb_k_nopunt /* punt not required */ |
| |
| movsg iamlr1,gr31 |
| movgs gr31,tplr /* set TPLR.CXN */ |
| tlbpr gr31,gr0,#4,#0 /* delete matches from TLB, IAMR1, DAMR1 */ |
| |
| movsg dampr1,gr31 |
| ori gr31,#xAMPRx_V,gr31 /* entry was invalidated by tlbpr #4 */ |
| movgs gr31,tppr |
| movsg iamlr1,gr31 /* set TPLR.CXN */ |
| movgs gr31,tplr |
| tlbpr gr31,gr0,#2,#0 /* save to the TLB */ |
| movsg tpxr,gr31 /* check the TLB write error flag */ |
| andicc.p gr31,#TPXR_E,gr0,icc0 |
| setlos #0xfffff000,gr31 |
| bne icc0,#0,__tlb_kernel_fault |
| |
| __itlb_k_nopunt: |
| |
| # assemble the new TLB entry |
| and gr29,gr31,gr29 |
| movsg cxnr,gr31 |
| or gr29,gr31,gr29 |
| movgs gr29,iamlr1 /* xAMLR = address | context number */ |
| movgs gr30,iampr1 |
| movgs gr29,damlr1 |
| movgs gr30,dampr1 |
| |
| # return, restoring registers |
| movsg scr2,gr30 |
| movgs gr30,ccr |
| sethi.p %hi(__kernel_current_task),gr29 |
| setlo %lo(__kernel_current_task),gr29 |
| ldi @(gr29,#0),gr29 |
| rett #0 |
| beq icc0,#3,0 /* prevent icache prefetch */ |
| |
| # the PTE we want wasn't in the PTD we have mapped, so we need to go looking for a more |
| # appropriate page table and map that instead |
| # - access the PGD with EAR0[31:26] |
| # - DAMLR3 points to the virtual address of the page directory |
| # - the PGD holds 64 PGEs and each PGE/PME points to a set of page tables |
| __itlb_k_PTD_miss: |
| srli gr29,#26,gr31 /* calculate PGE offset */ |
| slli gr31,#8,gr31 /* and clear bottom bits */ |
| |
| movsg damlr3,gr30 |
| ld @(gr31,gr30),gr30 /* access the PGE */ |
| |
| andicc.p gr30,#_PAGE_PRESENT,gr0,icc0 |
| andicc gr30,#xAMPRx_SS,gr0,icc1 |
| |
| # map this PTD instead and record coverage address |
| ori.p gr30,#xAMPRx_L|xAMPRx_SS_16Kb|xAMPRx_S|xAMPRx_C|xAMPRx_V,gr30 |
| beq icc0,#0,__tlb_kernel_fault /* jump if PGE not present */ |
| slli.p gr31,#18,gr31 |
| bne icc1,#0,__itlb_k_bigpage |
| movgs gr30,dampr4 |
| movgs gr31,scr0 |
| |
| # we can now resume normal service |
| setlos 0x3ffc,gr30 |
| srli.p gr29,#12,gr31 /* use EAR0[25:14] as PTE index */ |
| bra __itlb_k_PTD_mapped |
| |
| __itlb_k_bigpage: |
| break |
| nop |
| |
| .size __entry_kernel_insn_tlb_miss, .-__entry_kernel_insn_tlb_miss |
| |
| ############################################################################### |
| # |
| # Kernel data TLB miss handler |
| # On entry: |
| # GR1 - kernel stack pointer |
| # GR28 - saved exception frame pointer |
| # GR29 - faulting address |
| # GR31 - EAR0 ^ SCR1 |
| # SCR1 - base of virtual range covered by cached PGE from last DTLB miss (or 0xffffffff) |
| # DAMR3 - mapped page directory |
| # DAMR5 - mapped page table as matched by SCR1 |
| # |
| ############################################################################### |
| .globl __entry_kernel_data_tlb_miss |
| .type __entry_kernel_data_tlb_miss,@function |
| __entry_kernel_data_tlb_miss: |
| #if 0 |
| sethi.p %hi(0xe1200004),gr30 |
| setlo %lo(0xe1200004),gr30 |
| st gr0,@(gr30,gr0) |
| sethi.p %hi(0xffc00100),gr30 |
| setlo %lo(0xffc00100),gr30 |
| sth gr30,@(gr30,gr0) |
| membar |
| #endif |
| |
| movsg ccr,gr30 /* save CCR */ |
| movgs gr30,scr2 |
| |
| # see if the cached page table mapping is appropriate |
| srlicc.p gr31,#26,gr0,icc0 |
| setlos 0x3ffc,gr30 |
| srli.p gr29,#12,gr31 /* use EAR0[25:14] as PTE index */ |
| bne icc0,#0,__dtlb_k_PTD_miss |
| |
| __dtlb_k_PTD_mapped: |
| # access the PTD with EAR0[25:14] |
| # - DAMLR5 points to the virtual address of the appropriate page table |
| # - the PTD holds 4096 PTEs |
| # - the PTD must be accessed uncached |
| # - the PTE must be marked accessed if it was valid |
| # |
| and gr31,gr30,gr31 |
| movsg damlr5,gr30 |
| add gr30,gr31,gr31 |
| ldi @(gr31,#0),gr30 /* fetch the PTE */ |
| andicc gr30,#_PAGE_PRESENT,gr0,icc0 |
| ori.p gr30,#_PAGE_ACCESSED,gr30 |
| beq icc0,#0,__tlb_kernel_fault /* jump if PTE invalid */ |
| sti.p gr30,@(gr31,#0) /* update the PTE */ |
| andi gr30,#~_PAGE_ACCESSED,gr30 |
| |
| # we're using DAMR1 as an extra TLB entry |
| # - punt the entry here (if valid) to the real TLB and then replace with the new PTE |
| # - need to check IAMR1 lest we cause an multiple-DAT-hit exception |
| movsg dampr1,gr31 |
| andicc gr31,#xAMPRx_V,gr0,icc0 |
| setlos.p 0xfffff000,gr31 |
| beq icc0,#0,__dtlb_k_nopunt /* punt not required */ |
| |
| movsg damlr1,gr31 |
| movgs gr31,tplr /* set TPLR.CXN */ |
| tlbpr gr31,gr0,#4,#0 /* delete matches from TLB, IAMR1, DAMR1 */ |
| |
| movsg dampr1,gr31 |
| ori gr31,#xAMPRx_V,gr31 /* entry was invalidated by tlbpr #4 */ |
| movgs gr31,tppr |
| movsg damlr1,gr31 /* set TPLR.CXN */ |
| movgs gr31,tplr |
| tlbpr gr31,gr0,#2,#0 /* save to the TLB */ |
| movsg tpxr,gr31 /* check the TLB write error flag */ |
| andicc.p gr31,#TPXR_E,gr0,icc0 |
| setlos #0xfffff000,gr31 |
| bne icc0,#0,__tlb_kernel_fault |
| |
| __dtlb_k_nopunt: |
| |
| # assemble the new TLB entry |
| and gr29,gr31,gr29 |
| movsg cxnr,gr31 |
| or gr29,gr31,gr29 |
| movgs gr29,iamlr1 /* xAMLR = address | context number */ |
| movgs gr30,iampr1 |
| movgs gr29,damlr1 |
| movgs gr30,dampr1 |
| |
| # return, restoring registers |
| movsg scr2,gr30 |
| movgs gr30,ccr |
| sethi.p %hi(__kernel_current_task),gr29 |
| setlo %lo(__kernel_current_task),gr29 |
| ldi @(gr29,#0),gr29 |
| rett #0 |
| beq icc0,#3,0 /* prevent icache prefetch */ |
| |
| # the PTE we want wasn't in the PTD we have mapped, so we need to go looking for a more |
| # appropriate page table and map that instead |
| # - access the PGD with EAR0[31:26] |
| # - DAMLR3 points to the virtual address of the page directory |
| # - the PGD holds 64 PGEs and each PGE/PME points to a set of page tables |
| __dtlb_k_PTD_miss: |
| srli gr29,#26,gr31 /* calculate PGE offset */ |
| slli gr31,#8,gr31 /* and clear bottom bits */ |
| |
| movsg damlr3,gr30 |
| ld @(gr31,gr30),gr30 /* access the PGE */ |
| |
| andicc.p gr30,#_PAGE_PRESENT,gr0,icc0 |
| andicc gr30,#xAMPRx_SS,gr0,icc1 |
| |
| # map this PTD instead and record coverage address |
| ori.p gr30,#xAMPRx_L|xAMPRx_SS_16Kb|xAMPRx_S|xAMPRx_C|xAMPRx_V,gr30 |
| beq icc0,#0,__tlb_kernel_fault /* jump if PGE not present */ |
| slli.p gr31,#18,gr31 |
| bne icc1,#0,__dtlb_k_bigpage |
| movgs gr30,dampr5 |
| movgs gr31,scr1 |
| |
| # we can now resume normal service |
| setlos 0x3ffc,gr30 |
| srli.p gr29,#12,gr31 /* use EAR0[25:14] as PTE index */ |
| bra __dtlb_k_PTD_mapped |
| |
| __dtlb_k_bigpage: |
| break |
| nop |
| |
| .size __entry_kernel_data_tlb_miss, .-__entry_kernel_data_tlb_miss |
| |
| ############################################################################### |
| # |
| # Userspace instruction TLB miss handler (with PGE prediction) |
| # On entry: |
| # GR28 - faulting address |
| # GR31 - EAR0 ^ SCR0 |
| # SCR0 - base of virtual range covered by cached PGE from last ITLB miss (or 0xffffffff) |
| # DAMR3 - mapped page directory |
| # DAMR4 - mapped page table as matched by SCR0 |
| # |
| ############################################################################### |
| .globl __entry_user_insn_tlb_miss |
| .type __entry_user_insn_tlb_miss,@function |
| __entry_user_insn_tlb_miss: |
| #if 0 |
| sethi.p %hi(0xe1200004),gr30 |
| setlo %lo(0xe1200004),gr30 |
| st gr0,@(gr30,gr0) |
| sethi.p %hi(0xffc00100),gr30 |
| setlo %lo(0xffc00100),gr30 |
| sth gr30,@(gr30,gr0) |
| membar |
| #endif |
| |
| movsg ccr,gr30 /* save CCR */ |
| movgs gr30,scr2 |
| |
| # see if the cached page table mapping is appropriate |
| srlicc.p gr31,#26,gr0,icc0 |
| setlos 0x3ffc,gr30 |
| srli.p gr28,#12,gr31 /* use EAR0[25:14] as PTE index */ |
| bne icc0,#0,__itlb_u_PTD_miss |
| |
| __itlb_u_PTD_mapped: |
| # access the PTD with EAR0[25:14] |
| # - DAMLR4 points to the virtual address of the appropriate page table |
| # - the PTD holds 4096 PTEs |
| # - the PTD must be accessed uncached |
| # - the PTE must be marked accessed if it was valid |
| # |
| and gr31,gr30,gr31 |
| movsg damlr4,gr30 |
| add gr30,gr31,gr31 |
| ldi @(gr31,#0),gr30 /* fetch the PTE */ |
| andicc gr30,#_PAGE_PRESENT,gr0,icc0 |
| ori.p gr30,#_PAGE_ACCESSED,gr30 |
| beq icc0,#0,__tlb_user_fault /* jump if PTE invalid */ |
| sti.p gr30,@(gr31,#0) /* update the PTE */ |
| andi gr30,#~_PAGE_ACCESSED,gr30 |
| |
| # we're using IAMR1/DAMR1 as an extra TLB entry |
| # - punt the entry here (if valid) to the real TLB and then replace with the new PTE |
| movsg dampr1,gr31 |
| andicc gr31,#xAMPRx_V,gr0,icc0 |
| setlos.p 0xfffff000,gr31 |
| beq icc0,#0,__itlb_u_nopunt /* punt not required */ |
| |
| movsg dampr1,gr31 |
| movgs gr31,tppr |
| movsg damlr1,gr31 /* set TPLR.CXN */ |
| movgs gr31,tplr |
| tlbpr gr31,gr0,#2,#0 /* save to the TLB */ |
| movsg tpxr,gr31 /* check the TLB write error flag */ |
| andicc.p gr31,#TPXR_E,gr0,icc0 |
| setlos #0xfffff000,gr31 |
| bne icc0,#0,__tlb_user_fault |
| |
| __itlb_u_nopunt: |
| |
| # assemble the new TLB entry |
| and gr28,gr31,gr28 |
| movsg cxnr,gr31 |
| or gr28,gr31,gr28 |
| movgs gr28,iamlr1 /* xAMLR = address | context number */ |
| movgs gr30,iampr1 |
| movgs gr28,damlr1 |
| movgs gr30,dampr1 |
| |
| # return, restoring registers |
| movsg scr2,gr30 |
| movgs gr30,ccr |
| rett #0 |
| beq icc0,#3,0 /* prevent icache prefetch */ |
| |
| # the PTE we want wasn't in the PTD we have mapped, so we need to go looking for a more |
| # appropriate page table and map that instead |
| # - access the PGD with EAR0[31:26] |
| # - DAMLR3 points to the virtual address of the page directory |
| # - the PGD holds 64 PGEs and each PGE/PME points to a set of page tables |
| __itlb_u_PTD_miss: |
| srli gr28,#26,gr31 /* calculate PGE offset */ |
| slli gr31,#8,gr31 /* and clear bottom bits */ |
| |
| movsg damlr3,gr30 |
| ld @(gr31,gr30),gr30 /* access the PGE */ |
| |
| andicc.p gr30,#_PAGE_PRESENT,gr0,icc0 |
| andicc gr30,#xAMPRx_SS,gr0,icc1 |
| |
| # map this PTD instead and record coverage address |
| ori.p gr30,#xAMPRx_L|xAMPRx_SS_16Kb|xAMPRx_S|xAMPRx_C|xAMPRx_V,gr30 |
| beq icc0,#0,__tlb_user_fault /* jump if PGE not present */ |
| slli.p gr31,#18,gr31 |
| bne icc1,#0,__itlb_u_bigpage |
| movgs gr30,dampr4 |
| movgs gr31,scr0 |
| |
| # we can now resume normal service |
| setlos 0x3ffc,gr30 |
| srli.p gr28,#12,gr31 /* use EAR0[25:14] as PTE index */ |
| bra __itlb_u_PTD_mapped |
| |
| __itlb_u_bigpage: |
| break |
| nop |
| |
| .size __entry_user_insn_tlb_miss, .-__entry_user_insn_tlb_miss |
| |
| ############################################################################### |
| # |
| # Userspace data TLB miss handler |
| # On entry: |
| # GR28 - faulting address |
| # GR31 - EAR0 ^ SCR1 |
| # SCR1 - base of virtual range covered by cached PGE from last DTLB miss (or 0xffffffff) |
| # DAMR3 - mapped page directory |
| # DAMR5 - mapped page table as matched by SCR1 |
| # |
| ############################################################################### |
| .globl __entry_user_data_tlb_miss |
| .type __entry_user_data_tlb_miss,@function |
| __entry_user_data_tlb_miss: |
| #if 0 |
| sethi.p %hi(0xe1200004),gr30 |
| setlo %lo(0xe1200004),gr30 |
| st gr0,@(gr30,gr0) |
| sethi.p %hi(0xffc00100),gr30 |
| setlo %lo(0xffc00100),gr30 |
| sth gr30,@(gr30,gr0) |
| membar |
| #endif |
| |
| movsg ccr,gr30 /* save CCR */ |
| movgs gr30,scr2 |
| |
| # see if the cached page table mapping is appropriate |
| srlicc.p gr31,#26,gr0,icc0 |
| setlos 0x3ffc,gr30 |
| srli.p gr28,#12,gr31 /* use EAR0[25:14] as PTE index */ |
| bne icc0,#0,__dtlb_u_PTD_miss |
| |
| __dtlb_u_PTD_mapped: |
| # access the PTD with EAR0[25:14] |
| # - DAMLR5 points to the virtual address of the appropriate page table |
| # - the PTD holds 4096 PTEs |
| # - the PTD must be accessed uncached |
| # - the PTE must be marked accessed if it was valid |
| # |
| and gr31,gr30,gr31 |
| movsg damlr5,gr30 |
| |
| __dtlb_u_using_iPTD: |
| add gr30,gr31,gr31 |
| ldi @(gr31,#0),gr30 /* fetch the PTE */ |
| andicc gr30,#_PAGE_PRESENT,gr0,icc0 |
| ori.p gr30,#_PAGE_ACCESSED,gr30 |
| beq icc0,#0,__tlb_user_fault /* jump if PTE invalid */ |
| sti.p gr30,@(gr31,#0) /* update the PTE */ |
| andi gr30,#~_PAGE_ACCESSED,gr30 |
| |
| # we're using DAMR1 as an extra TLB entry |
| # - punt the entry here (if valid) to the real TLB and then replace with the new PTE |
| movsg dampr1,gr31 |
| andicc gr31,#xAMPRx_V,gr0,icc0 |
| setlos.p 0xfffff000,gr31 |
| beq icc0,#0,__dtlb_u_nopunt /* punt not required */ |
| |
| movsg dampr1,gr31 |
| movgs gr31,tppr |
| movsg damlr1,gr31 /* set TPLR.CXN */ |
| movgs gr31,tplr |
| tlbpr gr31,gr0,#2,#0 /* save to the TLB */ |
| movsg tpxr,gr31 /* check the TLB write error flag */ |
| andicc.p gr31,#TPXR_E,gr0,icc0 |
| setlos #0xfffff000,gr31 |
| bne icc0,#0,__tlb_user_fault |
| |
| __dtlb_u_nopunt: |
| |
| # assemble the new TLB entry |
| and gr28,gr31,gr28 |
| movsg cxnr,gr31 |
| or gr28,gr31,gr28 |
| movgs gr28,iamlr1 /* xAMLR = address | context number */ |
| movgs gr30,iampr1 |
| movgs gr28,damlr1 |
| movgs gr30,dampr1 |
| |
| # return, restoring registers |
| movsg scr2,gr30 |
| movgs gr30,ccr |
| rett #0 |
| beq icc0,#3,0 /* prevent icache prefetch */ |
| |
| # the PTE we want wasn't in the PTD we have mapped, so we need to go looking for a more |
| # appropriate page table and map that instead |
| # - first of all, check the insn PGE cache - we may well get a hit there |
| # - access the PGD with EAR0[31:26] |
| # - DAMLR3 points to the virtual address of the page directory |
| # - the PGD holds 64 PGEs and each PGE/PME points to a set of page tables |
| __dtlb_u_PTD_miss: |
| movsg scr0,gr31 /* consult the insn-PGE-cache key */ |
| xor gr28,gr31,gr31 |
| srlicc gr31,#26,gr0,icc0 |
| srli gr28,#12,gr31 /* use EAR0[25:14] as PTE index */ |
| bne icc0,#0,__dtlb_u_iPGE_miss |
| |
| # what we're looking for is covered by the insn-PGE-cache |
| setlos 0x3ffc,gr30 |
| and gr31,gr30,gr31 |
| movsg damlr4,gr30 |
| bra __dtlb_u_using_iPTD |
| |
| __dtlb_u_iPGE_miss: |
| srli gr28,#26,gr31 /* calculate PGE offset */ |
| slli gr31,#8,gr31 /* and clear bottom bits */ |
| |
| movsg damlr3,gr30 |
| ld @(gr31,gr30),gr30 /* access the PGE */ |
| |
| andicc.p gr30,#_PAGE_PRESENT,gr0,icc0 |
| andicc gr30,#xAMPRx_SS,gr0,icc1 |
| |
| # map this PTD instead and record coverage address |
| ori.p gr30,#xAMPRx_L|xAMPRx_SS_16Kb|xAMPRx_S|xAMPRx_C|xAMPRx_V,gr30 |
| beq icc0,#0,__tlb_user_fault /* jump if PGE not present */ |
| slli.p gr31,#18,gr31 |
| bne icc1,#0,__dtlb_u_bigpage |
| movgs gr30,dampr5 |
| movgs gr31,scr1 |
| |
| # we can now resume normal service |
| setlos 0x3ffc,gr30 |
| srli.p gr28,#12,gr31 /* use EAR0[25:14] as PTE index */ |
| bra __dtlb_u_PTD_mapped |
| |
| __dtlb_u_bigpage: |
| break |
| nop |
| |
| .size __entry_user_data_tlb_miss, .-__entry_user_data_tlb_miss |
