Merge with /shiny/git/linux-2.6/.git

1 files changed, 141 insertions, 0 deletions

diff --git a/arch/cris/arch-v32/mm/mmu.S b/arch/cris/arch-v32/mm/mmu.S
new file mode 100644
index 000000000000..27b70e5006af
--- /dev/null
+++ b/arch/cris/arch-v32/mm/mmu.S
@@ -0,0 +1,141 @@
+/*
+ *  Copyright (C) 2003 Axis Communications AB
+ *
+ *  Authors:	Mikael Starvik (starvik@axis.com)
+ *
+ * Code for the fault low-level handling routines.
+ *
+ */
+
+#include <asm/page.h>
+#include <asm/pgtable.h>
+
+; Save all register. Must save in same order as struct pt_regs.
+.macro SAVE_ALL
+	subq	12, $sp
+	move	$erp, [$sp]
+	subq	4, $sp
+	move	$srp, [$sp]
+	subq	4, $sp
+	move	$ccs, [$sp]
+	subq	4, $sp
+	move	$spc, [$sp]
+	subq	4, $sp
+	move	$mof, [$sp]
+	subq	4, $sp
+	move	$srs, [$sp]
+	subq	4, $sp
+	move.d	$acr, [$sp]
+	subq	14*4, $sp
+	movem	$r13, [$sp]
+	subq	4, $sp
+	move.d	$r10, [$sp]
+.endm
+
+; Bus fault handler. Extracts relevant information and calls mm subsystem
+; to handle the fault.
+.macro	MMU_BUS_FAULT_HANDLER handler, mmu, we, ex
+	.globl	\handler
+\handler:
+	SAVE_ALL
+	move	\mmu, $srs	; Select MMU support register bank
+	move.d  $sp, $r11	; regs
+	moveq	1, $r12		; protection fault
+	moveq   \we, $r13	; write exception?
+	orq	\ex << 1, $r13	; execute?
+	move    $s3, $r10	; rw_mm_cause
+	and.d	~8191, $r10	; Get faulting page start address
+
+	jsr	do_page_fault
+	nop
+	ba	ret_from_intr
+	nop
+.endm
+
+; Refill handler. Three cases may occur:
+;   1. PMD and PTE exists in mm subsystem but not in TLB
+;   2. PMD exists but not PTE
+;   3. PMD doesn't exist
+; The code below handles case 1 and calls the mm subsystem for case 2 and 3.
+; Do not touch this code without very good reasons and extensive testing.
+; Note that the code is optimized to minimize stalls (makes the code harder
+; to read).
+;
+; Each page is 8 KB. Each PMD holds 8192/4 PTEs (each PTE is 4 bytes) so each
+; PMD holds 16 MB of virtual memory.
+;   Bits  0-12 : Offset within a page
+;   Bits 13-23 : PTE offset within a PMD
+;   Bits 24-31 : PMD offset within the PGD
+
+.macro MMU_REFILL_HANDLER handler, mmu
+	.globl \handler
+\handler:
+	subq	4, $sp
+; (The pipeline stalls for one cycle; $sp used as address in the next cycle.)
+	move	$srs, [$sp]
+	subq	4, $sp
+	move	\mmu, $srs	; Select MMU support register bank
+	move.d	$acr, [$sp]
+	subq	4, $sp
+	move.d	$r0, [$sp]
+#ifdef CONFIG_SMP
+	move    $s7, $acr	; PGD
+#else
+	move.d  per_cpu__current_pgd, $acr ; PGD
+#endif
+	; Look up PMD in PGD
+	move	$s3, $r0	; rw_mm_cause
+	lsrq	24, $r0	; Get PMD index into PGD (bit 24-31)
+	move.d  [$acr], $acr	; PGD for the current process
+	addi	$r0.d, $acr, $acr
+	move	$s3, $r0	; rw_mm_cause
+	move.d  [$acr], $acr	; Get PMD
+	beq	1f
+	; Look up PTE in PMD
+	lsrq	PAGE_SHIFT, $r0
+	and.w	PAGE_MASK, $acr	; Remove PMD flags
+	and.d	0x7ff, $r0	; Get PTE index into PMD (bit 13-23)
+	addi    $r0.d, $acr, $acr
+	move.d  [$acr], $acr	; Get PTE
+	beq	2f
+	move.d  [$sp+], $r0	; Pop r0 in delayslot
+	; Store in TLB
+	move	$acr, $s5
+	; Return
+	move.d	[$sp+], $acr
+	move  	[$sp], $srs
+	addq	4, $sp
+	rete
+	rfe
+1:	; PMD missing, let the mm subsystem fix it up.
+	move.d  [$sp+], $r0	; Pop r0
+2:      ; PTE missing, let the mm subsystem fix it up.
+	move.d	[$sp+], $acr
+	move  	[$sp], $srs
+	addq	4, $sp
+	SAVE_ALL
+	move    \mmu, $srs
+	move.d	$sp, $r11	; regs
+	clear.d	$r12		; Not a protection fault
+	move.w  PAGE_MASK, $acr
+	move    $s3, $r10	; rw_mm_cause
+	btstq   9, $r10		; Check if write access
+	smi     $r13
+	and.w	PAGE_MASK, $r10	; Get VPN (virtual address)
+	jsr	do_page_fault
+	and.w   $acr, $r10
+	; Return
+	ba	ret_from_intr
+	nop
+.endm
+
+	; This is the MMU bus fault handlers.
+
+MMU_REFILL_HANDLER i_mmu_refill, 1
+MMU_BUS_FAULT_HANDLER i_mmu_invalid, 1, 0, 0
+MMU_BUS_FAULT_HANDLER i_mmu_access,  1, 0, 0
+MMU_BUS_FAULT_HANDLER i_mmu_execute, 1, 0, 1
+MMU_REFILL_HANDLER d_mmu_refill,  2
+MMU_BUS_FAULT_HANDLER d_mmu_invalid, 2, 0, 0
+MMU_BUS_FAULT_HANDLER d_mmu_access,  2, 0, 0
+MMU_BUS_FAULT_HANDLER d_mmu_write,   2, 1, 0