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linux/arch/powerpc/mm/slb_low.S

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/*
* Low-level SLB routines
*
* Copyright (C) 2004 David Gibson <dwg@au.ibm.com>, IBM
*
* Based on earlier C version:
* Dave Engebretsen and Mike Corrigan {engebret|mikejc}@us.ibm.com
* Copyright (c) 2001 Dave Engebretsen
* Copyright (C) 2002 Anton Blanchard <anton@au.ibm.com>, IBM
*
* 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 <asm/processor.h>
#include <asm/ppc_asm.h>
#include <asm/asm-offsets.h>
#include <asm/cputable.h>
#include <asm/page.h>
#include <asm/mmu.h>
#include <asm/pgtable.h>
#include <asm/firmware.h>
/* void slb_allocate_realmode(unsigned long ea);
*
* Create an SLB entry for the given EA (user or kernel).
* r3 = faulting address, r13 = PACA
* r9, r10, r11 are clobbered by this function
* No other registers are examined or changed.
*/
_GLOBAL(slb_allocate_realmode)
/*
* check for bad kernel/user address
* (ea & ~REGION_MASK) >= PGTABLE_RANGE
*/
rldicr. r9,r3,4,(63 - 46 - 4)
bne- 8f
srdi r9,r3,60 /* get region */
srdi r10,r3,SID_SHIFT /* get esid */
cmpldi cr7,r9,0xc /* cmp PAGE_OFFSET for later use */
/* r3 = address, r10 = esid, cr7 = <> PAGE_OFFSET */
blt cr7,0f /* user or kernel? */
/* kernel address: proto-VSID = ESID */
/* WARNING - MAGIC: we don't use the VSID 0xfffffffff, but
* this code will generate the protoVSID 0xfffffffff for the
* top segment. That's ok, the scramble below will translate
* it to VSID 0, which is reserved as a bad VSID - one which
* will never have any pages in it. */
/* Check if hitting the linear mapping or some other kernel space
*/
bne cr7,1f
/* Linear mapping encoding bits, the "li" instruction below will
* be patched by the kernel at boot
*/
_GLOBAL(slb_miss_kernel_load_linear)
li r11,0
/*
* context = (MAX_USER_CONTEXT) + ((ea >> 60) - 0xc) + 1
* r9 = region id.
*/
addis r9,r9,(MAX_USER_CONTEXT - 0xc + 1)@ha
addi r9,r9,(MAX_USER_CONTEXT - 0xc + 1)@l
BEGIN_FTR_SECTION
b slb_finish_load
END_MMU_FTR_SECTION_IFCLR(MMU_FTR_1T_SEGMENT)
b slb_finish_load_1T
1:
#ifdef CONFIG_SPARSEMEM_VMEMMAP
/* Check virtual memmap region. To be patches at kernel boot */
cmpldi cr0,r9,0xf
bne 1f
_GLOBAL(slb_miss_kernel_load_vmemmap)
li r11,0
b 6f
1:
#endif /* CONFIG_SPARSEMEM_VMEMMAP */
/* vmalloc mapping gets the encoding from the PACA as the mapping
* can be demoted from 64K -> 4K dynamically on some machines
*/
clrldi r11,r10,48
cmpldi r11,(VMALLOC_SIZE >> 28) - 1
bgt 5f
lhz r11,PACAVMALLOCSLLP(r13)
b 6f
5:
/* IO mapping */
_GLOBAL(slb_miss_kernel_load_io)
li r11,0
6:
/*
* context = (MAX_USER_CONTEXT) + ((ea >> 60) - 0xc) + 1
* r9 = region id.
*/
addis r9,r9,(MAX_USER_CONTEXT - 0xc + 1)@ha
addi r9,r9,(MAX_USER_CONTEXT - 0xc + 1)@l
BEGIN_FTR_SECTION
b slb_finish_load
END_MMU_FTR_SECTION_IFCLR(MMU_FTR_1T_SEGMENT)
b slb_finish_load_1T
0:
/* when using slices, we extract the psize off the slice bitmaps
* and then we need to get the sllp encoding off the mmu_psize_defs
* array.
*
* XXX This is a bit inefficient especially for the normal case,
* so we should try to implement a fast path for the standard page
* size using the old sllp value so we avoid the array. We cannot
* really do dynamic patching unfortunately as processes might flip
* between 4k and 64k standard page size
*/
#ifdef CONFIG_PPC_MM_SLICES
/* r10 have esid */
cmpldi r10,16
/* below SLICE_LOW_TOP */
blt 5f
/*
* Handle hpsizes,
* r9 is get_paca()->context.high_slices_psize[index], r11 is mask_index
*/
srdi r11,r10,(SLICE_HIGH_SHIFT - SLICE_LOW_SHIFT + 1) /* index */
addi r9,r11,PACAHIGHSLICEPSIZE
lbzx r9,r13,r9 /* r9 is hpsizes[r11] */
/* r11 = (r10 >> (SLICE_HIGH_SHIFT - SLICE_LOW_SHIFT)) & 0x1 */
rldicl r11,r10,(64 - (SLICE_HIGH_SHIFT - SLICE_LOW_SHIFT)),63
b 6f
5:
/*
* Handle lpsizes
* r9 is get_paca()->context.low_slices_psize, r11 is index
*/
ld r9,PACALOWSLICESPSIZE(r13)
mr r11,r10
6:
sldi r11,r11,2 /* index * 4 */
/* Extract the psize and multiply to get an array offset */
srd r9,r9,r11
andi. r9,r9,0xf
mulli r9,r9,MMUPSIZEDEFSIZE
/* Now get to the array and obtain the sllp
*/
ld r11,PACATOC(r13)
ld r11,mmu_psize_defs@got(r11)
add r11,r11,r9
ld r11,MMUPSIZESLLP(r11)
ori r11,r11,SLB_VSID_USER
#else
/* paca context sllp already contains the SLB_VSID_USER bits */
lhz r11,PACACONTEXTSLLP(r13)
#endif /* CONFIG_PPC_MM_SLICES */
ld r9,PACACONTEXTID(r13)
BEGIN_FTR_SECTION
cmpldi r10,0x1000
bge slb_finish_load_1T
END_MMU_FTR_SECTION_IFSET(MMU_FTR_1T_SEGMENT)
b slb_finish_load
8: /* invalid EA */
li r10,0 /* BAD_VSID */
li r9,0 /* BAD_VSID */
li r11,SLB_VSID_USER /* flags don't much matter */
b slb_finish_load
#ifdef __DISABLED__
/* void slb_allocate_user(unsigned long ea);
*
* Create an SLB entry for the given EA (user or kernel).
* r3 = faulting address, r13 = PACA
* r9, r10, r11 are clobbered by this function
* No other registers are examined or changed.
*
* It is called with translation enabled in order to be able to walk the
* page tables. This is not currently used.
*/
_GLOBAL(slb_allocate_user)
/* r3 = faulting address */
srdi r10,r3,28 /* get esid */
crset 4*cr7+lt /* set "user" flag for later */
/* check if we fit in the range covered by the pagetables*/
srdi. r9,r3,PGTABLE_EADDR_SIZE
crnot 4*cr0+eq,4*cr0+eq
beqlr
/* now we need to get to the page tables in order to get the page
* size encoding from the PMD. In the future, we'll be able to deal
* with 1T segments too by getting the encoding from the PGD instead
*/
ld r9,PACAPGDIR(r13)
cmpldi cr0,r9,0
beqlr
rlwinm r11,r10,8,25,28
ldx r9,r9,r11 /* get pgd_t */
cmpldi cr0,r9,0
beqlr
rlwinm r11,r10,3,17,28
ldx r9,r9,r11 /* get pmd_t */
cmpldi cr0,r9,0
beqlr
/* build vsid flags */
andi. r11,r9,SLB_VSID_LLP
ori r11,r11,SLB_VSID_USER
/* get context to calculate proto-VSID */
ld r9,PACACONTEXTID(r13)
/* fall through slb_finish_load */
#endif /* __DISABLED__ */
/*
* Finish loading of an SLB entry and return
*
* r3 = EA, r9 = context, r10 = ESID, r11 = flags, clobbers r9, cr7 = <> PAGE_OFFSET
*/
slb_finish_load:
rldimi r10,r9,ESID_BITS,0
ASM_VSID_SCRAMBLE(r10,r9,256M)
/*
* bits above VSID_BITS_256M need to be ignored from r10
* also combine VSID and flags
*/
rldimi r11,r10,SLB_VSID_SHIFT,(64 - (SLB_VSID_SHIFT + VSID_BITS_256M))
/* r3 = EA, r11 = VSID data */
/*
* Find a slot, round robin. Previously we tried to find a
* free slot first but that took too long. Unfortunately we
* dont have any LRU information to help us choose a slot.
*/
7: ld r10,PACASTABRR(r13)
addi r10,r10,1
/* This gets soft patched on boot. */
_GLOBAL(slb_compare_rr_to_size)
cmpldi r10,0
blt+ 4f
li r10,SLB_NUM_BOLTED
4:
std r10,PACASTABRR(r13)
3:
rldimi r3,r10,0,36 /* r3= EA[0:35] | entry */
oris r10,r3,SLB_ESID_V@h /* r3 |= SLB_ESID_V */
/* r3 = ESID data, r11 = VSID data */
/*
* No need for an isync before or after this slbmte. The exception
* we enter with and the rfid we exit with are context synchronizing.
*/
slbmte r11,r10
/* we're done for kernel addresses */
crclr 4*cr0+eq /* set result to "success" */
bgelr cr7
/* Update the slb cache */
lhz r3,PACASLBCACHEPTR(r13) /* offset = paca->slb_cache_ptr */
cmpldi r3,SLB_CACHE_ENTRIES
bge 1f
/* still room in the slb cache */
sldi r11,r3,2 /* r11 = offset * sizeof(u32) */
srdi r10,r10,28 /* get the 36 bits of the ESID */
add r11,r11,r13 /* r11 = (u32 *)paca + offset */
stw r10,PACASLBCACHE(r11) /* paca->slb_cache[offset] = esid */
addi r3,r3,1 /* offset++ */
b 2f
1: /* offset >= SLB_CACHE_ENTRIES */
li r3,SLB_CACHE_ENTRIES+1
2:
sth r3,PACASLBCACHEPTR(r13) /* paca->slb_cache_ptr = offset */
crclr 4*cr0+eq /* set result to "success" */
blr
/*
* Finish loading of a 1T SLB entry (for the kernel linear mapping) and return.
*
* r3 = EA, r9 = context, r10 = ESID(256MB), r11 = flags, clobbers r9
*/
slb_finish_load_1T:
srdi r10,r10,(SID_SHIFT_1T - SID_SHIFT) /* get 1T ESID */
rldimi r10,r9,ESID_BITS_1T,0
ASM_VSID_SCRAMBLE(r10,r9,1T)
/*
* bits above VSID_BITS_1T need to be ignored from r10
* also combine VSID and flags
*/
rldimi r11,r10,SLB_VSID_SHIFT_1T,(64 - (SLB_VSID_SHIFT_1T + VSID_BITS_1T))
li r10,MMU_SEGSIZE_1T
rldimi r11,r10,SLB_VSID_SSIZE_SHIFT,0 /* insert segment size */
/* r3 = EA, r11 = VSID data */
clrrdi r3,r3,SID_SHIFT_1T /* clear out non-ESID bits */
b 7b
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