MCHECK_EXCEPTION(0x0210, MachineCheckA, machine_check_exception)
/* Data Storage Interrupt */
- START_EXCEPTION(DataStorage)
- mtspr SPRN_SPRG0, r10 /* Save some working registers */
- mtspr SPRN_SPRG1, r11
- mtspr SPRN_SPRG4W, r12
- mtspr SPRN_SPRG5W, r13
- mfcr r11
- mtspr SPRN_SPRG7W, r11
-
- /*
- * Check if it was a store fault, if not then bail
- * because a user tried to access a kernel or
- * read-protected page. Otherwise, get the
- * offending address and handle it.
- */
- mfspr r10, SPRN_ESR
- andis. r10, r10, ESR_ST@h
- beq 2f
-
- mfspr r10, SPRN_DEAR /* Get faulting address */
-
- /* If we are faulting a kernel address, we have to use the
- * kernel page tables.
- */
- lis r11, PAGE_OFFSET@h
- cmplw r10, r11
- blt+ 3f
- lis r11, swapper_pg_dir@h
- ori r11, r11, swapper_pg_dir@l
-
- mfspr r12,SPRN_MMUCR
- rlwinm r12,r12,0,0,23 /* Clear TID */
-
- b 4f
-
- /* Get the PGD for the current thread */
-3:
- mfspr r11,SPRN_SPRG3
- lwz r11,PGDIR(r11)
-
- /* Load PID into MMUCR TID */
- mfspr r12,SPRN_MMUCR /* Get MMUCR */
- mfspr r13,SPRN_PID /* Get PID */
- rlwimi r12,r13,0,24,31 /* Set TID */
-
-4:
- mtspr SPRN_MMUCR,r12
-
- rlwinm r12, r10, 13, 19, 29 /* Compute pgdir/pmd offset */
- lwzx r11, r12, r11 /* Get pgd/pmd entry */
- rlwinm. r12, r11, 0, 0, 20 /* Extract pt base address */
- beq 2f /* Bail if no table */
-
- rlwimi r12, r10, 23, 20, 28 /* Compute pte address */
- lwz r11, 4(r12) /* Get pte entry */
-
- andi. r13, r11, _PAGE_RW /* Is it writeable? */
- beq 2f /* Bail if not */
-
- /* Update 'changed'.
- */
- ori r11, r11, _PAGE_DIRTY|_PAGE_ACCESSED|_PAGE_HWWRITE
- stw r11, 4(r12) /* Update Linux page table */
-
- li r13, PPC44x_TLB_SR@l /* Set SR */
- rlwimi r13, r11, 29, 29, 29 /* SX = _PAGE_HWEXEC */
- rlwimi r13, r11, 0, 30, 30 /* SW = _PAGE_RW */
- rlwimi r13, r11, 29, 28, 28 /* UR = _PAGE_USER */
- rlwimi r12, r11, 31, 26, 26 /* (_PAGE_USER>>1)->r12 */
- rlwimi r12, r11, 29, 30, 30 /* (_PAGE_USER>>3)->r12 */
- and r12, r12, r11 /* HWEXEC/RW & USER */
- rlwimi r13, r12, 0, 26, 26 /* UX = HWEXEC & USER */
- rlwimi r13, r12, 3, 27, 27 /* UW = RW & USER */
-
- rlwimi r11,r13,0,26,31 /* Insert static perms */
-
- /*
- * Clear U0-U3 and WL1 IL1I IL1D IL2I IL2D bits which are added
- * on newer 440 cores like the 440x6 used on AMCC 460EX/460GT (see
- * include/asm-powerpc/pgtable-ppc32.h for details).
- */
- rlwinm r11,r11,0,20,10
-
- /* find the TLB index that caused the fault. It has to be here. */
- tlbsx r10, 0, r10
-
- tlbwe r11, r10, PPC44x_TLB_ATTRIB /* Write ATTRIB */
-
- /* Done...restore registers and get out of here.
- */
- mfspr r11, SPRN_SPRG7R
- mtcr r11
- mfspr r13, SPRN_SPRG5R
- mfspr r12, SPRN_SPRG4R
+ DATA_STORAGE_EXCEPTION
- mfspr r11, SPRN_SPRG1
- mfspr r10, SPRN_SPRG0
- rfi /* Force context change */
-
-2:
- /*
- * The bailout. Restore registers to pre-exception conditions
- * and call the heavyweights to help us out.
- */
- mfspr r11, SPRN_SPRG7R
- mtcr r11
- mfspr r13, SPRN_SPRG5R
- mfspr r12, SPRN_SPRG4R
-
- mfspr r11, SPRN_SPRG1
- mfspr r10, SPRN_SPRG0
- b data_access
-
- /* Instruction Storage Interrupt */
+ /* Instruction Storage Interrupt */
INSTRUCTION_STORAGE_EXCEPTION
/* External Input Interrupt */
#else
EXCEPTION(0x2010, FloatingPointUnavailable, unknown_exception, EXC_XFER_EE)
#endif
-
/* System Call Interrupt */
START_EXCEPTION(SystemCall)
NORMAL_EXCEPTION_PROLOG
4:
mtspr SPRN_MMUCR,r12
+ /* Mask of required permission bits. Note that while we
+ * do copy ESR:ST to _PAGE_RW position as trying to write
+ * to an RO page is pretty common, we don't do it with
+ * _PAGE_DIRTY. We could do it, but it's a fairly rare
+ * event so I'd rather take the overhead when it happens
+ * rather than adding an instruction here. We should measure
+ * whether the whole thing is worth it in the first place
+ * as we could avoid loading SPRN_ESR completely in the first
+ * place...
+ *
+ * TODO: Is it worth doing that mfspr & rlwimi in the first
+ * place or can we save a couple of instructions here ?
+ */
+ mfspr r12,SPRN_ESR
+ li r13,_PAGE_PRESENT|_PAGE_ACCESSED
+ rlwimi r13,r12,10,30,30
+
+ /* Load the PTE */
rlwinm r12, r10, 13, 19, 29 /* Compute pgdir/pmd offset */
lwzx r11, r12, r11 /* Get pgd/pmd entry */
rlwinm. r12, r11, 0, 0, 20 /* Extract pt base address */
beq 2f /* Bail if no table */
rlwimi r12, r10, 23, 20, 28 /* Compute pte address */
- lwz r11, 4(r12) /* Get pte entry */
- andi. r13, r11, _PAGE_PRESENT /* Is the page present? */
- beq 2f /* Bail if not present */
+ lwz r11, 0(r12) /* Get high word of pte entry */
+ lwz r12, 4(r12) /* Get low word of pte entry */
- ori r11, r11, _PAGE_ACCESSED
- stw r11, 4(r12)
+ lis r10,tlb_44x_index@ha
+
+ andc. r13,r13,r12 /* Check permission */
+
+ /* Load the next available TLB index */
+ lwz r13,tlb_44x_index@l(r10)
+
+ bne 2f /* Bail if permission mismach */
+
+ /* Increment, rollover, and store TLB index */
+ addi r13,r13,1
+
+ /* Compare with watermark (instruction gets patched) */
+ .globl tlb_44x_patch_hwater_D
+tlb_44x_patch_hwater_D:
+ cmpwi 0,r13,1 /* reserve entries */
+ ble 5f
+ li r13,0
+5:
+ /* Store the next available TLB index */
+ stw r13,tlb_44x_index@l(r10)
+
+ /* Re-load the faulting address */
+ mfspr r10,SPRN_DEAR
/* Jump to common tlb load */
b finish_tlb_load
mfspr r12, SPRN_SPRG4R
mfspr r11, SPRN_SPRG1
mfspr r10, SPRN_SPRG0
- b data_access
+ b DataStorage
/* Instruction TLB Error Interrupt */
/*
4:
mtspr SPRN_MMUCR,r12
+ /* Make up the required permissions */
+ li r13,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_HWEXEC
+
rlwinm r12, r10, 13, 19, 29 /* Compute pgdir/pmd offset */
lwzx r11, r12, r11 /* Get pgd/pmd entry */
rlwinm. r12, r11, 0, 0, 20 /* Extract pt base address */
beq 2f /* Bail if no table */
rlwimi r12, r10, 23, 20, 28 /* Compute pte address */
- lwz r11, 4(r12) /* Get pte entry */
- andi. r13, r11, _PAGE_PRESENT /* Is the page present? */
- beq 2f /* Bail if not present */
+ lwz r11, 0(r12) /* Get high word of pte entry */
+ lwz r12, 4(r12) /* Get low word of pte entry */
- ori r11, r11, _PAGE_ACCESSED
- stw r11, 4(r12)
+ lis r10,tlb_44x_index@ha
+
+ andc. r13,r13,r12 /* Check permission */
+
+ /* Load the next available TLB index */
+ lwz r13,tlb_44x_index@l(r10)
+
+ bne 2f /* Bail if permission mismach */
+
+ /* Increment, rollover, and store TLB index */
+ addi r13,r13,1
+
+ /* Compare with watermark (instruction gets patched) */
+ .globl tlb_44x_patch_hwater_I
+tlb_44x_patch_hwater_I:
+ cmpwi 0,r13,1 /* reserve entries */
+ ble 5f
+ li r13,0
+5:
+ /* Store the next available TLB index */
+ stw r13,tlb_44x_index@l(r10)
+
+ /* Re-load the faulting address */
+ mfspr r10,SPRN_SRR0
/* Jump to common TLB load point */
b finish_tlb_load
/*
* Local functions
- */
- /*
- * Data TLB exceptions will bail out to this point
- * if they can't resolve the lightweight TLB fault.
- */
-data_access:
- NORMAL_EXCEPTION_PROLOG
- mfspr r5,SPRN_ESR /* Grab the ESR, save it, pass arg3 */
- stw r5,_ESR(r11)
- mfspr r4,SPRN_DEAR /* Grab the DEAR, save it, pass arg2 */
- EXC_XFER_EE_LITE(0x0300, handle_page_fault)
+ */
/*
* Both the instruction and data TLB miss get to this
* point to load the TLB.
* r10 - EA of fault
- * r11 - available to use
- * r12 - Pointer to the 64-bit PTE
- * r13 - available to use
+ * r11 - PTE high word value
+ * r12 - PTE low word value
+ * r13 - TLB index
* MMUCR - loaded with proper value when we get here
* Upon exit, we reload everything and RFI.
*/
finish_tlb_load:
- /*
- * We set execute, because we don't have the granularity to
- * properly set this at the page level (Linux problem).
- * If shared is set, we cause a zero PID->TID load.
- * Many of these bits are software only. Bits we don't set
- * here we (properly should) assume have the appropriate value.
- */
-
- /* Load the next available TLB index */
- lis r13, tlb_44x_index@ha
- lwz r13, tlb_44x_index@l(r13)
- /* Load the TLB high watermark */
- lis r11, tlb_44x_hwater@ha
- lwz r11, tlb_44x_hwater@l(r11)
-
- /* Increment, rollover, and store TLB index */
- addi r13, r13, 1
- cmpw 0, r13, r11 /* reserve entries */
- ble 7f
- li r13, 0
-7:
- /* Store the next available TLB index */
- lis r11, tlb_44x_index@ha
- stw r13, tlb_44x_index@l(r11)
-
- lwz r11, 0(r12) /* Get MS word of PTE */
- lwz r12, 4(r12) /* Get LS word of PTE */
- rlwimi r11, r12, 0, 0 , 19 /* Insert RPN */
- tlbwe r11, r13, PPC44x_TLB_XLAT /* Write XLAT */
+ /* Combine RPN & ERPN an write WS 0 */
+ rlwimi r11,r12,0,0,19
+ tlbwe r11,r13,PPC44x_TLB_XLAT
/*
- * Create PAGEID. This is the faulting address,
+ * Create WS1. This is the faulting address (EPN),
* page size, and valid flag.
*/
- li r11, PPC44x_TLB_VALID | PPC44x_TLB_4K
- rlwimi r10, r11, 0, 20, 31 /* Insert valid and page size */
- tlbwe r10, r13, PPC44x_TLB_PAGEID /* Write PAGEID */
-
- li r10, PPC44x_TLB_SR@l /* Set SR */
- rlwimi r10, r12, 0, 30, 30 /* Set SW = _PAGE_RW */
- rlwimi r10, r12, 29, 29, 29 /* SX = _PAGE_HWEXEC */
- rlwimi r10, r12, 29, 28, 28 /* UR = _PAGE_USER */
- rlwimi r11, r12, 31, 26, 26 /* (_PAGE_USER>>1)->r12 */
- and r11, r12, r11 /* HWEXEC & USER */
- rlwimi r10, r11, 0, 26, 26 /* UX = HWEXEC & USER */
-
- rlwimi r12, r10, 0, 26, 31 /* Insert static perms */
-
- /*
- * Clear U0-U3 and WL1 IL1I IL1D IL2I IL2D bits which are added
- * on newer 440 cores like the 440x6 used on AMCC 460EX/460GT (see
- * include/asm-powerpc/pgtable-ppc32.h for details).
- */
- rlwinm r12, r12, 0, 20, 10
-
- tlbwe r12, r13, PPC44x_TLB_ATTRIB /* Write ATTRIB */
+ li r11,PPC44x_TLB_VALID | PPC44x_TLB_4K
+ rlwimi r10,r11,0,20,31 /* Insert valid and page size*/
+ tlbwe r10,r13,PPC44x_TLB_PAGEID /* Write PAGEID */
+
+ /* And WS 2 */
+ li r10,0xf85 /* Mask to apply from PTE */
+ rlwimi r10,r12,29,30,30 /* DIRTY -> SW position */
+ and r11,r12,r10 /* Mask PTE bits to keep */
+ andi. r10,r12,_PAGE_USER /* User page ? */
+ beq 1f /* nope, leave U bits empty */
+ rlwimi r11,r11,3,26,28 /* yes, copy S bits to U */
+1: tlbwe r11,r13,PPC44x_TLB_ATTRIB /* Write ATTRIB */
/* Done...restore registers and get out of here.
*/
swapper_pg_dir:
.space PGD_TABLE_SIZE
-/* Reserved 4k for the critical exception stack & 4k for the machine
- * check stack per CPU for kernel mode exceptions */
- .section .bss
- .align 12
-exception_stack_bottom:
- .space BOOKE_EXCEPTION_STACK_SIZE
- .globl exception_stack_top
-exception_stack_top:
-
/*
* Room for two PTE pointers, usually the kernel and current user pointers
* to their respective root page table.
git.openpandora.org / pandora-kernel.git / blobdiff