/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Low level TLB miss handlers for Book3E
*
* Copyright (C) 2008-2009
* Ben. Herrenschmidt ([email protected]), IBM Corp.
*/
#include <linux/pgtable.h>
#include <asm/processor.h>
#include <asm/reg.h>
#include <asm/page.h>
#include <asm/mmu.h>
#include <asm/ppc_asm.h>
#include <asm/asm-offsets.h>
#include <asm/cputable.h>
#include <asm/exception-64e.h>
#include <asm/ppc-opcode.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_booke_hv_asm.h>
#include <asm/feature-fixups.h>
#define VPTE_PMD_SHIFT (PTE_INDEX_SIZE)
#define VPTE_PUD_SHIFT (VPTE_PMD_SHIFT + PMD_INDEX_SIZE)
#define VPTE_PGD_SHIFT (VPTE_PUD_SHIFT + PUD_INDEX_SIZE)
#define VPTE_INDEX_SIZE (VPTE_PGD_SHIFT + PGD_INDEX_SIZE)
/**********************************************************************
* *
* TLB miss handling for Book3E with a bolted linear mapping *
* No virtual page table, no nested TLB misses *
* *
**********************************************************************/
/*
* Note that, unlike non-bolted handlers, TLB_EXFRAME is not
* modified by the TLB miss handlers themselves, since the TLB miss
* handler code will not itself cause a recursive TLB miss.
*
* TLB_EXFRAME will be modified when crit/mc/debug exceptions are
* entered/exited.
*/
.macro tlb_prolog_bolted intnum addr
mtspr SPRN_SPRG_GEN_SCRATCH,r12
mfspr r12,SPRN_SPRG_TLB_EXFRAME
std r13,EX_TLB_R13(r12)
std r10,EX_TLB_R10(r12)
mfspr r13,SPRN_SPRG_PACA
mfcr r10
std r11,EX_TLB_R11(r12)
#ifdef CONFIG_KVM_BOOKE_HV
BEGIN_FTR_SECTION
mfspr r11, SPRN_SRR1
END_FTR_SECTION_IFSET(CPU_FTR_EMB_HV)
#endif
DO_KVM \intnum, SPRN_SRR1
std r16,EX_TLB_R16(r12)
mfspr r16,\addr /* get faulting address */
std r14,EX_TLB_R14(r12)
ld r14,PACAPGD(r13)
std r15,EX_TLB_R15(r12)
std r10,EX_TLB_CR(r12)
START_BTB_FLUSH_SECTION
mfspr r11, SPRN_SRR1
andi. r10,r11,MSR_PR
beq 1f
BTB_FLUSH(r10)
1:
END_BTB_FLUSH_SECTION
std r7,EX_TLB_R7(r12)
.endm
.macro tlb_epilog_bolted
ld r14,EX_TLB_CR(r12)
ld r7,EX_TLB_R7(r12)
ld r10,EX_TLB_R10(r12)
ld r11,EX_TLB_R11(r12)
ld r13,EX_TLB_R13(r12)
mtcr r14
ld r14,EX_TLB_R14(r12)
ld r15,EX_TLB_R15(r12)
ld r16,EX_TLB_R16(r12)
mfspr r12,SPRN_SPRG_GEN_SCRATCH
.endm
/* Data TLB miss */
START_EXCEPTION(data_tlb_miss_bolted)
tlb_prolog_bolted BOOKE_INTERRUPT_DTLB_MISS SPRN_DEAR
/* We need _PAGE_PRESENT and _PAGE_ACCESSED set */
/* We do the user/kernel test for the PID here along with the RW test
*/
/* We pre-test some combination of permissions to avoid double
* faults:
*
* We move the ESR:ST bit into the position of _PAGE_BAP_SW in the PTE
* ESR_ST is 0x00800000
* _PAGE_BAP_SW is 0x00000010
* So the shift is >> 19. This tests for supervisor writeability.
* If the page happens to be supervisor writeable and not user
* writeable, we will take a new fault later, but that should be
* a rare enough case.
*
* We also move ESR_ST in _PAGE_DIRTY position
* _PAGE_DIRTY is 0x00001000 so the shift is >> 11
*
* MAS1 is preset for all we need except for TID that needs to
* be cleared for kernel translations
*/
mfspr r11,SPRN_ESR
srdi r15,r16,60 /* get region */
rldicl. r10,r16,64-PGTABLE_EADDR_SIZE,PGTABLE_EADDR_SIZE+4
bne- dtlb_miss_fault_bolted /* Bail if fault addr is invalid */
rlwinm r10,r11,32-19,27,27
rlwimi r10,r11,32-16,19,19
cmpwi r15,0 /* user vs kernel check */
ori r10,r10,_PAGE_PRESENT
oris r11,r10,_PAGE_ACCESSED@h
bne tlb_miss_kernel_bolted
tlb_miss_user_bolted:
#ifdef CONFIG_PPC_KUAP
mfspr r10,SPRN_MAS1
rlwinm. r10,r10,0,0x3fff0000
beq- tlb_miss_fault_bolted /* KUAP fault */
#endif
tlb_miss_common_bolted:
/*
* This is the guts of the TLB miss handler for bolted-linear.
* We are entered with:
*
* r16 = faulting address
* r15 = crap (free to use)
* r14 = page table base
* r13 = PACA
* r11 = PTE permission mask
* r10 = crap (free to use)
*/
rldicl r15,r16,64-PGDIR_SHIFT+3,64-PGD_INDEX_SIZE-3
cmpldi cr0,r14,0
clrrdi r15,r15,3
beq tlb_miss_fault_bolted /* No PGDIR, bail */
ldx r14,r14,r15 /* grab pgd entry */
rldicl r15,r16,64-PUD_SHIFT+3,64-PUD_INDEX_SIZE-3
clrrdi r15,r15,3
cmpdi cr0,r14,0
bge tlb_miss_fault_bolted /* Bad pgd entry or hugepage; bail */
ldx r14,r14,r15 /* grab pud entry */
rldicl r15,r16,64-PMD_SHIFT+3,64-PMD_INDEX_SIZE-3
clrrdi r15,r15,3
cmpdi cr0,r14,0
bge tlb_miss_fault_bolted
ldx r14,r14,r15 /* Grab pmd entry */
rldicl r15,r16,64-PAGE_SHIFT+3,64-PTE_INDEX_SIZE-3
clrrdi r15,r15,3
cmpdi cr0,r14,0
bge tlb_miss_fault_bolted
ldx r14,r14,r15 /* Grab PTE, normal (!huge) page */
/* Check if required permissions are met */
andc. r15,r11,r14
rldicr r15,r14,64-(PTE_RPN_SHIFT-PAGE_SHIFT),63-PAGE_SHIFT
bne- tlb_miss_fault_bolted
/* Now we build the MAS:
*
* MAS 0 : Fully setup with defaults in MAS4 and TLBnCFG
* MAS 1 : Almost fully setup
* - PID already updated by caller if necessary
* - TSIZE need change if !base page size, not
* yet implemented for now
* MAS 2 : Defaults not useful, need to be redone
* MAS 3+7 : Needs to be done
*/
clrrdi r11,r16,12 /* Clear low crap in EA */
clrldi r15,r15,12 /* Clear crap at the top */
rlwimi r11,r14,32-19,27,31 /* Insert WIMGE */
rlwimi r15,r14,32-8,22,25 /* Move in U bits */
mtspr SPRN_MAS2,r11
andi. r11,r14,_PAGE_DIRTY
rlwimi r15,r14,32-2,26,31 /* Move in BAP bits */
/* Mask out SW and UW if !DIRTY (XXX optimize this !) */
bne 1f
li r11,MAS3_SW|MAS3_UW
andc r15,r15,r11
1:
mtspr SPRN_MAS7_MAS3,r15
tlbwe
tlb_miss_done_bolted:
tlb_epilog_bolted
rfi
itlb_miss_kernel_bolted:
li r11,_PAGE_PRESENT|_PAGE_BAP_SX /* Base perm */
oris r11,r11,_PAGE_ACCESSED@h
tlb_miss_kernel_bolted:
mfspr r10,SPRN_MAS1
ld r14,PACA_KERNELPGD(r13)
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
bne+ tlb_miss_common_bolted
tlb_miss_fault_bolted:
/* We need to check if it was an instruction miss */
andi. r10,r11,_PAGE_BAP_UX|_PAGE_BAP_SX
bne itlb_miss_fault_bolted
dtlb_miss_fault_bolted:
tlb_epilog_bolted
b exc_data_storage_book3e
itlb_miss_fault_bolted:
tlb_epilog_bolted
b exc_instruction_storage_book3e
/* Instruction TLB miss */
START_EXCEPTION(instruction_tlb_miss_bolted)
tlb_prolog_bolted BOOKE_INTERRUPT_ITLB_MISS SPRN_SRR0
rldicl. r10,r16,64-PGTABLE_EADDR_SIZE,PGTABLE_EADDR_SIZE+4
srdi r15,r16,60 /* get region */
bne- itlb_miss_fault_bolted
li r11,_PAGE_PRESENT|_PAGE_BAP_UX /* Base perm */
/* We do the user/kernel test for the PID here along with the RW test
*/
cmpldi cr0,r15,0 /* Check for user region */
oris r11,r11,_PAGE_ACCESSED@h
beq tlb_miss_user_bolted
b itlb_miss_kernel_bolted
/*
* TLB miss handling for e6500 and derivatives, using hardware tablewalk.
*
* Linear mapping is bolted: no virtual page table or nested TLB misses
* Indirect entries in TLB1, hardware loads resulting direct entries
* into TLB0
* No HES or NV hint on TLB1, so we need to do software round-robin
* No tlbsrx. so we need a spinlock, and we have to deal
* with MAS-damage caused by tlbsx
* 4K pages only
*/
START_EXCEPTION(instruction_tlb_miss_e6500)
tlb_prolog_bolted BOOKE_INTERRUPT_ITLB_MISS SPRN_SRR0
ld r11,PACA_TCD_PTR(r13)
srdi. r15,r16,60 /* get region */
ori r16,r16,1
bne tlb_miss_kernel_e6500 /* user/kernel test */
b tlb_miss_common_e6500
START_EXCEPTION(data_tlb_miss_e6500)
tlb_prolog_bolted BOOKE_INTERRUPT_DTLB_MISS SPRN_DEAR
ld r11,PACA_TCD_PTR(r13)
srdi. r15,r16,60 /* get region */
rldicr r16,r16,0,62
bne tlb_miss_kernel_e6500 /* user vs kernel check */
/*
* This is the guts of the TLB miss handler for e6500 and derivatives.
* We are entered with:
*
* r16 = page of faulting address (low bit 0 if data, 1 if instruction)
* r15 = crap (free to use)
* r14 = page table base
* r13 = PACA
* r11 = tlb_per_core ptr
* r10 = crap (free to use)
* r7 = esel_next
*/
tlb_miss_common_e6500:
crmove cr2*4+2,cr0*4+2 /* cr2.eq != 0 if kernel address */
BEGIN_FTR_SECTION /* CPU_FTR_SMT */
/*
* Search if we already have an indirect entry for that virtual
* address, and if we do, bail out.
*
* MAS6:IND should be already set based on MAS4
*/
lhz r10,PACAPACAINDEX(r13)
addi r10,r10,1
crclr cr1*4+eq /* set cr1.eq = 0 for non-recursive */
1: lbarx r15,0,r11
cmpdi r15,0
bne 2f
stbcx. r10,0,r11
bne 1b
3:
.subsection 1
2: cmpd cr1,r15,r10 /* recursive lock due to mcheck/crit/etc? */
beq cr1,3b /* unlock will happen if cr1.eq = 0 */
10: lbz r15,0(r11)
cmpdi r15,0
bne 10b
b 1b
.previous
END_FTR_SECTION_IFSET(CPU_FTR_SMT)
lbz r7,TCD_ESEL_NEXT(r11)
BEGIN_FTR_SECTION /* CPU_FTR_SMT */
/*
* Erratum A-008139 says that we can't use tlbwe to change
* an indirect entry in any way (including replacing or
* invalidating) if the other thread could be in the process
* of a lookup. The workaround is to invalidate the entry
* with tlbilx before overwriting.
*/
rlwinm r10,r7,16,0xff0000
oris r10,r10,MAS0_TLBSEL(1)@h
mtspr SPRN_MAS0,r10
isync
tlbre
mfspr r15,SPRN_MAS1
andis. r15,r15,MAS1_VALID@h
beq 5f
BEGIN_FTR_SECTION_NESTED(532)
mfspr r10,SPRN_MAS8
rlwinm r10,r10,0,0x80000fff /* tgs,tlpid -> sgs,slpid */
mtspr SPRN_MAS5,r10
END_FTR_SECTION_NESTED(CPU_FTR_EMB_HV,CPU_FTR_EMB_HV,532)
mfspr r10,SPRN_MAS1
rlwinm r15,r10,0,0x3fff0000 /* tid -> spid */
rlwimi r15,r10,20,0x00000003 /* ind,ts -> sind,sas */
mfspr r10,SPRN_MAS6
mtspr SPRN_MAS6,r15
mfspr r15,SPRN_MAS2
isync
PPC_TLBILX_VA(0,R15)
isync
mtspr SPRN_MAS6,r10
5:
BEGIN_FTR_SECTION_NESTED(532)
li r10,0
mtspr SPRN_MAS8,r10
mtspr SPRN_MAS5,r10
END_FTR_SECTION_NESTED(CPU_FTR_EMB_HV,CPU_FTR_EMB_HV,532)
tlbsx 0,r16
mfspr r10,SPRN_MAS1
andis. r15,r10,MAS1_VALID@h
bne tlb_miss_done_e6500
FTR_SECTION_ELSE
mfspr r10,SPRN_MAS1
ALT_FTR_SECTION_END_IFSET(CPU_FTR_SMT)
oris r10,r10,MAS1_VALID@h
beq cr2,4f
rlwinm r10,r10,0,16,1 /* Clear TID */
4: mtspr SPRN_MAS1,r10
/* Now, we need to walk the page tables. First check if we are in
* range.
*/
rldicl. r10,r16,64-PGTABLE_EADDR_SIZE,PGTABLE_EADDR_SIZE+4
bne- tlb_miss_fault_e6500
rldicl r15,r16,64-PGDIR_SHIFT+3,64-PGD_INDEX_SIZE-3
cmpldi cr0,r14,0
clrrdi r15,r15,3
beq- tlb_miss_fault_e6500 /* No PGDIR, bail */
ldx r14,r14,r15 /* grab pgd entry */
rldicl r15,r16,64-PUD_SHIFT+3,64-PUD_INDEX_SIZE-3
clrrdi r15,r15,3
cmpdi cr0,r14,0
bge tlb_miss_huge_e6500 /* Bad pgd entry or hugepage; bail */
ldx r14,r14,r15 /* grab pud entry */
rldicl r15,r16,64-PMD_SHIFT+3,64-PMD_INDEX_SIZE-3
clrrdi r15,r15,3
cmpdi cr0,r14,0
bge tlb_miss_huge_e6500
ldx r14,r14,r15 /* Grab pmd entry */
mfspr r10,SPRN_MAS0
cmpdi cr0,r14,0
bge tlb_miss_huge_e6500
/* Now we build the MAS for a 2M indirect page:
*
* MAS 0 : ESEL needs to be filled by software round-robin
* MAS 1 : Fully set up
* - PID already updated by caller if necessary
* - TSIZE for now is base ind page size always
* - TID already cleared if necessary
* MAS 2 : Default not 2M-aligned, need to be redone
* MAS 3+7 : Needs to be done
*/
ori r14,r14,(BOOK3E_PAGESZ_4K << MAS3_SPSIZE_SHIFT)
mtspr SPRN_MAS7_MAS3,r14
clrrdi r15,r16,21 /* make EA 2M-aligned */
mtspr SPRN_MAS2,r15
tlb_miss_huge_done_e6500:
lbz r16,TCD_ESEL_MAX(r11)
lbz r14,TCD_ESEL_FIRST(r11)
rlwimi r10,r7,16,0x00ff0000 /* insert esel_next into MAS0 */
addi r7,r7,1 /* increment esel_next */
mtspr SPRN_MAS0,r10
cmpw r7,r16
iseleq r7,r14,r7 /* if next == last use first */
stb r7,TCD_ESEL_NEXT(r11)
tlbwe
tlb_miss_done_e6500:
.macro tlb_unlock_e6500
BEGIN_FTR_SECTION
beq cr1,1f /* no unlock if lock was recursively grabbed */
li r15,0
isync
stb r15,0(r11)
1:
END_FTR_SECTION_IFSET(CPU_FTR_SMT)
.endm
tlb_unlock_e6500
tlb_epilog_bolted
rfi
tlb_miss_huge_e6500:
beq tlb_miss_fault_e6500
rlwinm r15,r14,32-_PAGE_PSIZE_SHIFT,0x1e
/*
* Now we build the MAS for a huge page.
*
* MAS 0 : ESEL needs to be filled by software round-robin
* - can be handled by indirect code
* MAS 1 : Need to clear IND and set TSIZE
* MAS 2,3+7: Needs to be redone similar to non-tablewalk handler
*/
mfspr r10,SPRN_MAS1
rlwinm r10,r10,0,~MAS1_IND
rlwimi r10,r15,MAS1_TSIZE_SHIFT,MAS1_TSIZE_MASK
mtspr SPRN_MAS1,r10
li r10,-0x400
sld r15,r10,r15 /* Generate mask based on size */
and r10,r16,r15
rldicr r15,r14,64-(PTE_RPN_SHIFT-PAGE_SHIFT),63-PAGE_SHIFT
rlwimi r10,r14,32-19,27,31 /* Insert WIMGE */
clrldi r15,r15,PAGE_SHIFT /* Clear crap at the top */
rlwimi r15,r14,32-8,22,25 /* Move in U bits */
mtspr SPRN_MAS2,r10
andi. r10,r14,_PAGE_DIRTY
rlwimi r15,r14,32-2,26,31 /* Move in BAP bits */
/* Mask out SW and UW if !DIRTY (XXX optimize this !) */
bne 1f
li r10,MAS3_SW|MAS3_UW
andc r15,r15,r10
1:
mtspr SPRN_MAS7_MAS3,r15
mfspr r10,SPRN_MAS0
b tlb_miss_huge_done_e6500
tlb_miss_kernel_e6500:
ld r14,PACA_KERNELPGD(r13)
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:
tlb_unlock_e6500
/* We need to check if it was an instruction miss */
andi. r16,r16,1
bne itlb_miss_fault_e6500
dtlb_miss_fault_e6500:
tlb_epilog_bolted
b exc_data_storage_book3e
itlb_miss_fault_e6500:
tlb_epilog_bolted
b exc_instruction_storage_book3e
/*
* This is the guts of the second-level TLB miss handler for direct
* misses. We are entered with:
*
* r16 = virtual page table faulting address
* r15 = region (top 4 bits of address)
* r14 = crap (free to use)
* r13 = PACA
* r12 = TLB exception frame in PACA
* r11 = crap (free to use)
* r10 = crap (free to use)
*
* Note that this should only ever be called as a second level handler
* with the current scheme when using SW load.
* That means we can always get the original fault DEAR at
* EX_TLB_DEAR-EX_TLB_SIZE(r12)
*
* It can be re-entered by the linear mapping miss handler. However, to
* avoid too much complication, it will restart the whole fault at level
* 0 so we don't care too much about clobbers
*
* XXX That code was written back when we couldn't clobber r14. We can now,
* so we could probably optimize things a bit
*/
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,
* and we happen to have the swapper_pg_dir at offset 8 from the user
* pgdir in the PACA :-).
*/
add r11,r10,r13
/* If kernel, we need to clear MAS1 TID */
beq 1f
/* XXX replace the RMW cycles with immediate loads + writes */
mfspr r10,SPRN_MAS1
rlwinm r10,r10,0,16,1 /* Clear TID */
mtspr SPRN_MAS1,r10
#ifdef CONFIG_PPC_KUAP
b 2f
1:
mfspr r10,SPRN_MAS1
rlwinm. r10,r10,0,0x3fff0000
beq- virt_page_table_tlb_miss_fault /* KUAP fault */
2:
#else
1:
#endif
/* 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
cmpldi r10,0x80
bne- virt_page_table_tlb_miss_fault
/* Get the PGD pointer */
ld r15,PACAPGD(r11)
cmpldi cr0,r15,0
beq- virt_page_table_tlb_miss_fault
/* Get to PGD entry */
rldicl r11,r16,64-VPTE_PGD_SHIFT,64-PGD_INDEX_SIZE-3
clrrdi r10,r11,3
ldx r15,r10,r15
cmpdi cr0,r15,0
bge virt_page_table_tlb_miss_fault
/* Get to PUD entry */
rldicl r11,r16,64-VPTE_PUD_SHIFT,64-PUD_INDEX_SIZE-3
clrrdi r10,r11,3
ldx r15,r10,r15
cmpdi cr0,r15,0
bge virt_page_table_tlb_miss_fault
/* Get to PMD entry */
rldicl r11,r16,64-VPTE_PMD_SHIFT,64-PMD_INDEX_SIZE-3
clrrdi r10,r11,3
ldx r15,r10,r15
cmpdi cr0,r15,0
bge virt_page_table_tlb_miss_fault
/* Ok, we're all right, we can now create a kernel translation for
* a 4K or 64K page from r16 -> r15.
*/
/* Now we build the MAS:
*
* MAS 0 : Fully setup with defaults in MAS4 and TLBnCFG
* MAS 1 : Almost fully setup
* - PID already updated by caller if necessary
* - TSIZE for now is base page size always
* MAS 2 : Use defaults
* MAS 3+7 : Needs to be done
*
* So we only do MAS 2 and 3 for now...
*/
clrldi r11,r15,4 /* remove region ID from RPN */
ori r10,r11,1 /* Or-in SR */
srdi r16,r10,32
mtspr SPRN_MAS3,r10
mtspr SPRN_MAS7,r16
tlbwe
/* Return to caller, normal case */
TLB_MISS_EPILOG_SUCCESS
rfi
virt_page_table_tlb_miss_fault:
/* If we fault here, things are a little bit tricky. We need to call
* either data or instruction store fault, and we need to retrieve
* the original fault address and ESR (for data).
*
* The thing is, we know that in normal circumstances, this is
* always called as a second level tlb miss for SW load or as a first
* level TLB miss for HW load, so we should be able to peek at the
* relevant information in the first exception frame in the PACA.
*
* However, we do need to double check that, because we may just hit
* a stray kernel pointer or a userland attack trying to hit those
* areas. If that is the case, we do a data fault. (We can't get here
* from an instruction tlb miss anyway).
*
* Note also that when going to a fault, we must unwind the previous
* level as well. Since we are doing that, we don't need to clear or
* restore the TLB reservation neither.
*/
subf r10,r13,r12
cmpldi cr0,r10,PACA_EXTLB+EX_TLB_SIZE
bne- virt_page_table_tlb_miss_whacko_fault
/* We dig the original DEAR and ESR from slot 0 */
ld r15,EX_TLB_DEAR+PACA_EXTLB(r13)
ld r16,EX_TLB_ESR+PACA_EXTLB(r13)
/* We check for the "special" ESR value for instruction faults */
cmpdi cr0,r16,-1
beq 1f
mtspr SPRN_DEAR,r15
mtspr SPRN_ESR,r16
TLB_MISS_EPILOG_ERROR
b exc_data_storage_book3e
1: TLB_MISS_EPILOG_ERROR
b exc_instruction_storage_book3e
virt_page_table_tlb_miss_whacko_fault:
/* The linear fault will restart everything so ESR and DEAR will
* not have been clobbered, let's just fault with what we have
*/
TLB_MISS_EPILOG_ERROR
b exc_data_storage_book3e
/*
* This is the guts of "any" level TLB miss handler for kernel linear
* mapping misses. We are entered with:
*
*
* r16 = faulting address
* r15 = crap (free to use)
* r14 = ESR (data) or -1 (instruction)
* r13 = PACA
* r12 = TLB exception frame in PACA
* r11 = crap (free to use)
* r10 = crap (free to use)
*
* In addition we know that we will not re-enter, so in theory, we could
* use a simpler epilog not restoring SRR0/1 etc.. but we'll do that later.
*
* We also need to be careful about MAS registers here & TLB reservation,
* as we know we'll have clobbered them if we interrupt the main TLB miss
* handlers in which case we probably want to do a full restart at level
* 0 rather than saving / restoring the MAS.
*
* Note: If we care about performance of that core, we can easily shuffle
* a few things around
*/
tlb_load_linear:
/* For now, we assume the linear mapping is contiguous and stops at
* linear_map_top. We also assume the size is a multiple of 1G, thus
* we only use 1G pages for now. That might have to be changed in a
* final implementation, especially when dealing with hypervisors
*/
__LOAD_PACA_TOC(r11)
LOAD_REG_ADDR_ALTTOC(r11, r11, linear_map_top)
ld r10,0(r11)
tovirt(10,10)
cmpld cr0,r16,r10
bge tlb_load_linear_fault
/* MAS1 need whole new setup. */
li r15,(BOOK3E_PAGESZ_1GB<<MAS1_TSIZE_SHIFT)
oris r15,r15,MAS1_VALID@h /* MAS1 needs V and TSIZE */
mtspr SPRN_MAS1,r15
/* Already somebody there ? */
PPC_TLBSRX_DOT(0,R16)
beq tlb_load_linear_done
/* Now we build the remaining MAS. MAS0 and 2 should be fine
* with their defaults, which leaves us with MAS 3 and 7. The
* mapping is linear, so we just take the address, clear the
* region bits, and or in the permission bits which are currently
* hard wired
*/
clrrdi r10,r16,30 /* 1G page index */
clrldi r10,r10,4 /* clear region bits */
ori r10,r10,MAS3_SR|MAS3_SW|MAS3_SX
srdi r16,r10,32
mtspr SPRN_MAS3,r10
mtspr SPRN_MAS7,r16
tlbwe
tlb_load_linear_done:
/* We use the "error" epilog for success as we do want to
* restore to the initial faulting context, whatever it was.
* We do that because we can't resume a fault within a TLB
* miss handler, due to MAS and TLB reservation being clobbered.
*/
TLB_MISS_EPILOG_ERROR
rfi
tlb_load_linear_fault:
/* We keep the DEAR and ESR around, this shouldn't have happened */
cmpdi cr0,r14,-1
beq 1f
TLB_MISS_EPILOG_ERROR_SPECIAL
b exc_data_storage_book3e
1: TLB_MISS_EPILOG_ERROR_SPECIAL
b exc_instruction_storage_book3e
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