aboutsummaryrefslogtreecommitdiffstats
path: root/arch/powerpc/kernel/head_8xx.S
diff options
context:
space:
mode:
Diffstat (limited to 'arch/powerpc/kernel/head_8xx.S')
-rw-r--r--arch/powerpc/kernel/head_8xx.S230
1 files changed, 122 insertions, 108 deletions
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index fafff8dbd5d9..d99aac0d69f1 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -33,13 +33,31 @@
/* Macro to make the code more readable. */
#ifdef CONFIG_8xx_CPU6
-#define DO_8xx_CPU6(val, reg) \
- li reg, val; \
- stw reg, 12(r0); \
- lwz reg, 12(r0);
+#define SPRN_MI_TWC_ADDR 0x2b80
+#define SPRN_MI_RPN_ADDR 0x2d80
+#define SPRN_MD_TWC_ADDR 0x3b80
+#define SPRN_MD_RPN_ADDR 0x3d80
+
+#define MTSPR_CPU6(spr, reg, treg) \
+ li treg, spr##_ADDR; \
+ stw treg, 12(r0); \
+ lwz treg, 12(r0); \
+ mtspr spr, reg
#else
-#define DO_8xx_CPU6(val, reg)
+#define MTSPR_CPU6(spr, reg, treg) \
+ mtspr spr, reg
#endif
+
+/*
+ * Value for the bits that have fixed value in RPN entries.
+ * Also used for tagging DAR for DTLBerror.
+ */
+#ifdef CONFIG_PPC_16K_PAGES
+#define RPN_PATTERN (0x00f0 | MD_SPS16K)
+#else
+#define RPN_PATTERN 0x00f0
+#endif
+
__HEAD
_ENTRY(_stext);
_ENTRY(_start);
@@ -65,13 +83,6 @@ _ENTRY(_start);
* 8M 1:1. I also mapped an additional I/O space 1:1 so we can get to
* the "internal" processor registers before MMU_init is called.
*
- * The TLB code currently contains a major hack. Since I use the condition
- * code register, I have to save and restore it. I am out of registers, so
- * I just store it in memory location 0 (the TLB handlers are not reentrant).
- * To avoid making any decisions, I need to use the "segment" valid bit
- * in the first level table, but that would require many changes to the
- * Linux page directory/table functions that I don't want to do right now.
- *
* -- Dan
*/
.globl __start
@@ -211,7 +222,7 @@ MachineCheck:
EXCEPTION_PROLOG
mfspr r4,SPRN_DAR
stw r4,_DAR(r11)
- li r5,0x00f0
+ li r5,RPN_PATTERN
mtspr SPRN_DAR,r5 /* Tag DAR, to be used in DTLB Error */
mfspr r5,SPRN_DSISR
stw r5,_DSISR(r11)
@@ -219,30 +230,16 @@ MachineCheck:
EXC_XFER_STD(0x200, machine_check_exception)
/* Data access exception.
- * This is "never generated" by the MPC8xx. We jump to it for other
- * translation errors.
+ * This is "never generated" by the MPC8xx.
*/
. = 0x300
DataAccess:
- EXCEPTION_PROLOG
- mfspr r10,SPRN_DSISR
- stw r10,_DSISR(r11)
- mr r5,r10
- mfspr r4,SPRN_DAR
- li r10,0x00f0
- mtspr SPRN_DAR,r10 /* Tag DAR, to be used in DTLB Error */
- EXC_XFER_LITE(0x300, handle_page_fault)
/* Instruction access exception.
- * This is "never generated" by the MPC8xx. We jump to it for other
- * translation errors.
+ * This is "never generated" by the MPC8xx.
*/
. = 0x400
InstructionAccess:
- EXCEPTION_PROLOG
- mr r4,r12
- mr r5,r9
- EXC_XFER_LITE(0x400, handle_page_fault)
/* External interrupt */
EXCEPTION(0x500, HardwareInterrupt, do_IRQ, EXC_XFER_LITE)
@@ -253,7 +250,7 @@ Alignment:
EXCEPTION_PROLOG
mfspr r4,SPRN_DAR
stw r4,_DAR(r11)
- li r5,0x00f0
+ li r5,RPN_PATTERN
mtspr SPRN_DAR,r5 /* Tag DAR, to be used in DTLB Error */
mfspr r5,SPRN_DSISR
stw r5,_DSISR(r11)
@@ -292,8 +289,8 @@ SystemCall:
. = 0x1100
/*
* For the MPC8xx, this is a software tablewalk to load the instruction
- * TLB. It is modelled after the example in the Motorola manual. The task
- * switch loads the M_TWB register with the pointer to the first level table.
+ * TLB. The task switch loads the M_TW register with the pointer to the first
+ * level table.
* If we discover there is no second level table (value is zero) or if there
* is an invalid pte, we load that into the TLB, which causes another fault
* into the TLB Error interrupt where we can handle such problems.
@@ -302,20 +299,17 @@ SystemCall:
*/
InstructionTLBMiss:
#ifdef CONFIG_8xx_CPU6
- stw r3, 8(r0)
+ mtspr SPRN_DAR, r3
#endif
EXCEPTION_PROLOG_0
mtspr SPRN_SPRG_SCRATCH2, r10
mfspr r10, SPRN_SRR0 /* Get effective address of fault */
#ifdef CONFIG_8xx_CPU15
- addi r11, r10, 0x1000
+ addi r11, r10, PAGE_SIZE
tlbie r11
- addi r11, r10, -0x1000
+ addi r11, r10, -PAGE_SIZE
tlbie r11
#endif
- DO_8xx_CPU6(0x3780, r3)
- mtspr SPRN_MD_EPN, r10 /* Have to use MD_EPN for walk, MI_EPN can't */
- mfspr r10, SPRN_M_TWB /* Get level 1 table entry address */
/* If we are faulting a kernel address, we have to use the
* kernel page tables.
@@ -323,32 +317,37 @@ InstructionTLBMiss:
#ifdef CONFIG_MODULES
/* Only modules will cause ITLB Misses as we always
* pin the first 8MB of kernel memory */
- andi. r11, r10, 0x0800 /* Address >= 0x80000000 */
+ andis. r11, r10, 0x8000 /* Address >= 0x80000000 */
+#endif
+ mfspr r11, SPRN_M_TW /* Get level 1 table base address */
+#ifdef CONFIG_MODULES
beq 3f
- lis r11, swapper_pg_dir@h
- ori r11, r11, swapper_pg_dir@l
- rlwimi r10, r11, 0, 2, 19
+ lis r11, (swapper_pg_dir-PAGE_OFFSET)@h
+ ori r11, r11, (swapper_pg_dir-PAGE_OFFSET)@l
3:
#endif
- lwz r11, 0(r10) /* Get the level 1 entry */
+ /* Extract level 1 index */
+ rlwinm r10, r10, 32 - ((PAGE_SHIFT - 2) << 1), (PAGE_SHIFT - 2) << 1, 29
+ lwzx r11, r10, r11 /* Get the level 1 entry */
rlwinm. r10, r11,0,0,19 /* Extract page descriptor page address */
beq 2f /* If zero, don't try to find a pte */
/* We have a pte table, so load the MI_TWC with the attributes
* for this "segment."
*/
- ori r11,r11,1 /* Set valid bit */
- DO_8xx_CPU6(0x2b80, r3)
- mtspr SPRN_MI_TWC, r11 /* Set segment attributes */
- DO_8xx_CPU6(0x3b80, r3)
- mtspr SPRN_MD_TWC, r11 /* Load pte table base address */
- mfspr r11, SPRN_MD_TWC /* ....and get the pte address */
- lwz r10, 0(r11) /* Get the pte */
+ MTSPR_CPU6(SPRN_MI_TWC, r11, r3) /* Set segment attributes */
+ mfspr r11, SPRN_SRR0 /* Get effective address of fault */
+ /* Extract level 2 index */
+ rlwinm r11, r11, 32 - (PAGE_SHIFT - 2), 32 - PAGE_SHIFT, 29
+ lwzx r10, r10, r11 /* Get the pte */
#ifdef CONFIG_SWAP
andi. r11, r10, _PAGE_ACCESSED | _PAGE_PRESENT
cmpwi cr0, r11, _PAGE_ACCESSED | _PAGE_PRESENT
+ li r11, RPN_PATTERN
bne- cr0, 2f
+#else
+ li r11, RPN_PATTERN
#endif
/* The Linux PTE won't go exactly into the MMU TLB.
* Software indicator bits 21 and 28 must be clear.
@@ -356,62 +355,63 @@ InstructionTLBMiss:
* set. All other Linux PTE bits control the behavior
* of the MMU.
*/
- li r11, 0x00f0
rlwimi r10, r11, 0, 0x07f8 /* Set 24-27, clear 21-23,28 */
- DO_8xx_CPU6(0x2d80, r3)
- mtspr SPRN_MI_RPN, r10 /* Update TLB entry */
+ MTSPR_CPU6(SPRN_MI_RPN, r10, r3) /* Update TLB entry */
/* Restore registers */
#ifdef CONFIG_8xx_CPU6
- lwz r3, 8(r0)
+ mfspr r3, SPRN_DAR
+ mtspr SPRN_DAR, r11 /* Tag DAR */
#endif
mfspr r10, SPRN_SPRG_SCRATCH2
EXCEPTION_EPILOG_0
rfi
2:
- mfspr r11, SPRN_SRR1
+ mfspr r10, SPRN_SRR1
/* clear all error bits as TLB Miss
* sets a few unconditionally
*/
- rlwinm r11, r11, 0, 0xffff
- mtspr SPRN_SRR1, r11
+ rlwinm r10, r10, 0, 0xffff
+ mtspr SPRN_SRR1, r10
/* Restore registers */
#ifdef CONFIG_8xx_CPU6
- lwz r3, 8(r0)
+ mfspr r3, SPRN_DAR
+ mtspr SPRN_DAR, r11 /* Tag DAR */
#endif
mfspr r10, SPRN_SPRG_SCRATCH2
- EXCEPTION_EPILOG_0
- b InstructionAccess
+ b InstructionTLBError1
. = 0x1200
DataStoreTLBMiss:
#ifdef CONFIG_8xx_CPU6
- stw r3, 8(r0)
+ mtspr SPRN_DAR, r3
#endif
EXCEPTION_PROLOG_0
mtspr SPRN_SPRG_SCRATCH2, r10
- mfspr r10, SPRN_M_TWB /* Get level 1 table entry address */
+ mfspr r10, SPRN_MD_EPN
/* If we are faulting a kernel address, we have to use the
* kernel page tables.
*/
- andi. r11, r10, 0x0800
+ andis. r11, r10, 0x8000
+ mfspr r11, SPRN_M_TW /* Get level 1 table base address */
beq 3f
- lis r11, swapper_pg_dir@h
- ori r11, r11, swapper_pg_dir@l
- rlwimi r10, r11, 0, 2, 19
+ lis r11, (swapper_pg_dir-PAGE_OFFSET)@h
+ ori r11, r11, (swapper_pg_dir-PAGE_OFFSET)@l
3:
- lwz r11, 0(r10) /* Get the level 1 entry */
+ /* Extract level 1 index */
+ rlwinm r10, r10, 32 - ((PAGE_SHIFT - 2) << 1), (PAGE_SHIFT - 2) << 1, 29
+ lwzx r11, r10, r11 /* Get the level 1 entry */
rlwinm. r10, r11,0,0,19 /* Extract page descriptor page address */
beq 2f /* If zero, don't try to find a pte */
/* We have a pte table, so load fetch the pte from the table.
*/
- ori r11, r11, 1 /* Set valid bit in physical L2 page */
- DO_8xx_CPU6(0x3b80, r3)
- mtspr SPRN_MD_TWC, r11 /* Load pte table base address */
- mfspr r10, SPRN_MD_TWC /* ....and get the pte address */
+ mfspr r10, SPRN_MD_EPN /* Get address of fault */
+ /* Extract level 2 index */
+ rlwinm r10, r10, 32 - (PAGE_SHIFT - 2), 32 - PAGE_SHIFT, 29
+ rlwimi r10, r11, 0, 0, 32 - PAGE_SHIFT - 1 /* Add level 2 base */
lwz r10, 0(r10) /* Get the pte */
/* Insert the Guarded flag into the TWC from the Linux PTE.
@@ -425,8 +425,7 @@ DataStoreTLBMiss:
* It is bit 25 in the Linux PTE and bit 30 in the TWC
*/
rlwimi r11, r10, 32-5, 30, 30
- DO_8xx_CPU6(0x3b80, r3)
- mtspr SPRN_MD_TWC, r11
+ MTSPR_CPU6(SPRN_MD_TWC, r11, r3)
/* Both _PAGE_ACCESSED and _PAGE_PRESENT has to be set.
* We also need to know if the insn is a load/store, so:
@@ -442,14 +441,8 @@ DataStoreTLBMiss:
and r11, r11, r10
rlwimi r10, r11, 0, _PAGE_PRESENT
#endif
- /* Honour kernel RO, User NA */
- /* 0x200 == Extended encoding, bit 22 */
- rlwimi r10, r10, 32-2, 0x200 /* Copy USER to bit 22, 0x200 */
- /* r11 = (r10 & _PAGE_RW) >> 1 */
- rlwinm r11, r10, 32-1, 0x200
- or r10, r11, r10
- /* invert RW and 0x200 bits */
- xori r10, r10, _PAGE_RW | 0x200
+ /* invert RW */
+ xori r10, r10, _PAGE_RW
/* The Linux PTE won't go exactly into the MMU TLB.
* Software indicator bits 22 and 28 must be clear.
@@ -457,14 +450,13 @@ DataStoreTLBMiss:
* set. All other Linux PTE bits control the behavior
* of the MMU.
*/
-2: li r11, 0x00f0
+2: li r11, RPN_PATTERN
rlwimi r10, r11, 0, 24, 28 /* Set 24-27, clear 28 */
- DO_8xx_CPU6(0x3d80, r3)
- mtspr SPRN_MD_RPN, r10 /* Update TLB entry */
+ MTSPR_CPU6(SPRN_MD_RPN, r10, r3) /* Update TLB entry */
/* Restore registers */
#ifdef CONFIG_8xx_CPU6
- lwz r3, 8(r0)
+ mfspr r3, SPRN_DAR
#endif
mtspr SPRN_DAR, r11 /* Tag DAR */
mfspr r10, SPRN_SPRG_SCRATCH2
@@ -477,7 +469,17 @@ DataStoreTLBMiss:
*/
. = 0x1300
InstructionTLBError:
- b InstructionAccess
+ EXCEPTION_PROLOG_0
+InstructionTLBError1:
+ EXCEPTION_PROLOG_1
+ EXCEPTION_PROLOG_2
+ mr r4,r12
+ mr r5,r9
+ andis. r10,r5,0x4000
+ beq+ 1f
+ tlbie r4
+ /* 0x400 is InstructionAccess exception, needed by bad_page_fault() */
+1: EXC_XFER_LITE(0x400, handle_page_fault)
/* This is the data TLB error on the MPC8xx. This could be due to
* many reasons, including a dirty update to a pte. We bail out to
@@ -488,11 +490,21 @@ DataTLBError:
EXCEPTION_PROLOG_0
mfspr r11, SPRN_DAR
- cmpwi cr0, r11, 0x00f0
+ cmpwi cr0, r11, RPN_PATTERN
beq- FixupDAR /* must be a buggy dcbX, icbi insn. */
DARFixed:/* Return from dcbx instruction bug workaround */
- EXCEPTION_EPILOG_0
- b DataAccess
+ EXCEPTION_PROLOG_1
+ EXCEPTION_PROLOG_2
+ mfspr r5,SPRN_DSISR
+ stw r5,_DSISR(r11)
+ mfspr r4,SPRN_DAR
+ andis. r10,r5,0x4000
+ beq+ 1f
+ tlbie r4
+1: li r10,RPN_PATTERN
+ mtspr SPRN_DAR,r10 /* Tag DAR, to be used in DTLB Error */
+ /* 0x300 is DataAccess exception, needed by bad_page_fault() */
+ EXC_XFER_LITE(0x300, handle_page_fault)
EXCEPTION(0x1500, Trap_15, unknown_exception, EXC_XFER_EE)
EXCEPTION(0x1600, Trap_16, unknown_exception, EXC_XFER_EE)
@@ -521,29 +533,30 @@ DARFixed:/* Return from dcbx instruction bug workaround */
#define NO_SELF_MODIFYING_CODE
FixupDAR:/* Entry point for dcbx workaround. */
#ifdef CONFIG_8xx_CPU6
- stw r3, 8(r0)
+ mtspr SPRN_DAR, r3
#endif
mtspr SPRN_SPRG_SCRATCH2, r10
/* fetch instruction from memory. */
mfspr r10, SPRN_SRR0
andis. r11, r10, 0x8000 /* Address >= 0x80000000 */
- DO_8xx_CPU6(0x3780, r3)
- mtspr SPRN_MD_EPN, r10
- mfspr r11, SPRN_M_TWB /* Get level 1 table entry address */
+ mfspr r11, SPRN_M_TW /* Get level 1 table base address */
beq- 3f /* Branch if user space */
lis r11, (swapper_pg_dir-PAGE_OFFSET)@h
ori r11, r11, (swapper_pg_dir-PAGE_OFFSET)@l
- rlwimi r11, r10, 32-20, 0xffc /* r11 = r11&~0xffc|(r10>>20)&0xffc */
-3: lwz r11, 0(r11) /* Get the level 1 entry */
- DO_8xx_CPU6(0x3b80, r3)
- mtspr SPRN_MD_TWC, r11 /* Load pte table base address */
- mfspr r11, SPRN_MD_TWC /* ....and get the pte address */
- lwz r11, 0(r11) /* Get the pte */
+ /* Extract level 1 index */
+3: rlwinm r10, r10, 32 - ((PAGE_SHIFT - 2) << 1), (PAGE_SHIFT - 2) << 1, 29
+ lwzx r11, r10, r11 /* Get the level 1 entry */
+ rlwinm r10, r11,0,0,19 /* Extract page descriptor page address */
+ mfspr r11, SPRN_SRR0 /* Get effective address of fault */
+ /* Extract level 2 index */
+ rlwinm r11, r11, 32 - (PAGE_SHIFT - 2), 32 - PAGE_SHIFT, 29
+ lwzx r11, r10, r11 /* Get the pte */
#ifdef CONFIG_8xx_CPU6
- lwz r3, 8(r0) /* restore r3 from memory */
+ mfspr r3, SPRN_DAR
#endif
/* concat physical page address(r11) and page offset(r10) */
- rlwimi r11, r10, 0, 20, 31
+ mfspr r10, SPRN_SRR0
+ rlwimi r11, r10, 0, 32 - PAGE_SHIFT, 31
lwz r11,0(r11)
/* Check if it really is a dcbx instruction. */
/* dcbt and dcbtst does not generate DTLB Misses/Errors,
@@ -698,11 +711,11 @@ start_here:
#ifdef CONFIG_8xx_CPU6
lis r4, cpu6_errata_word@h
ori r4, r4, cpu6_errata_word@l
- li r3, 0x3980
+ li r3, 0x3f80
stw r3, 12(r4)
lwz r3, 12(r4)
#endif
- mtspr SPRN_M_TWB, r6
+ mtspr SPRN_M_TW, r6
lis r4,2f@h
ori r4,r4,2f@l
tophys(r4,r4)
@@ -876,10 +889,10 @@ _GLOBAL(set_context)
lis r6, cpu6_errata_word@h
ori r6, r6, cpu6_errata_word@l
tophys (r4, r4)
- li r7, 0x3980
+ li r7, 0x3f80
stw r7, 12(r6)
lwz r7, 12(r6)
- mtspr SPRN_M_TWB, r4 /* Update MMU base address */
+ mtspr SPRN_M_TW, r4 /* Update MMU base address */
li r7, 0x3380
stw r7, 12(r6)
lwz r7, 12(r6)
@@ -887,7 +900,7 @@ _GLOBAL(set_context)
#else
mtspr SPRN_M_CASID,r3 /* Update context */
tophys (r4, r4)
- mtspr SPRN_M_TWB, r4 /* and pgd */
+ mtspr SPRN_M_TW, r4 /* and pgd */
#endif
SYNC
blr
@@ -919,12 +932,13 @@ set_dec_cpu6:
.globl sdata
sdata:
.globl empty_zero_page
+ .align PAGE_SHIFT
empty_zero_page:
- .space 4096
+ .space PAGE_SIZE
.globl swapper_pg_dir
swapper_pg_dir:
- .space 4096
+ .space PGD_TABLE_SIZE
/* Room for two PTE table poiners, usually the kernel and current user
* pointer to their respective root page table (pgdir).
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.