arch/powerpc/mm/slb_low.S - kernel/msm-4.19 - Gitiles

 /*
  * 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 <linux/config.h>
 #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>

 /* 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)
 	/* r3 = faulting address */

 	srdi	r9,r3,60		/* get region */
 	srdi	r10,r3,28		/* 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 of the vmalloc/ioremap
 	 * 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
 	b	slb_finish_load

 1:	/* vmalloc/ioremap mapping encoding bits, the "li" instruction below
 	 * will be patched by the kernel at boot
 	 */
 _GLOBAL(slb_miss_kernel_load_virtual)
 	li	r11,0
 	b	slb_finish_load


 0:	/* user address: proto-VSID = context << 15 | ESID. First check
 	 * if the address is within the boundaries of the user region
 	 */
 	srdi.	r9,r10,USER_ESID_BITS
 	bne-	8f			/* invalid ea bits set */

 	/* Figure out if the segment contains huge pages */
 #ifdef CONFIG_HUGETLB_PAGE
 BEGIN_FTR_SECTION
 	b	1f
 END_FTR_SECTION_IFCLR(CPU_FTR_16M_PAGE)
 	cmpldi	r10,16

 	lhz	r9,PACALOWHTLBAREAS(r13)
 	mr	r11,r10
 	blt	5f

 	lhz	r9,PACAHIGHHTLBAREAS(r13)
 	srdi	r11,r10,(HTLB_AREA_SHIFT-SID_SHIFT)

 5:	srd	r9,r9,r11
 	andi.	r9,r9,1
 	beq	1f
 _GLOBAL(slb_miss_user_load_huge)
 	li	r11,0
 	b	2f
 1:
 #endif /* CONFIG_HUGETLB_PAGE */

 _GLOBAL(slb_miss_user_load_normal)
 	li	r11,0

 2:
 	ld	r9,PACACONTEXTID(r13)
 	rldimi	r10,r9,USER_ESID_BITS,0
 	b	slb_finish_load

 8:	/* invalid EA */
 	li	r10,0			/* 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)
 	rldimi	r10,r9,USER_ESID_BITS,0

 	/* fall through slb_finish_load */

 #endif /* __DISABLED__ */


 /*
  * Finish loading of an SLB entry and return
  *
  * r3 = EA, r10 = proto-VSID, r11 = flags, clobbers r9, cr7 = <> PAGE_OFFSET
  */
 slb_finish_load:
 	ASM_VSID_SCRAMBLE(r10,r9)
 	rldimi	r11,r10,SLB_VSID_SHIFT,16	/* combine VSID and flags */

 	/* 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.
  	 */
 #ifdef CONFIG_PPC_ISERIES
 	/*
 	 * On iSeries, the "bolted" stack segment can be cast out on
 	 * shared processor switch so we need to check for a miss on
 	 * it and restore it to the right slot.
 	 */
 	ld	r9,PACAKSAVE(r13)
 	clrrdi	r9,r9,28
 	clrrdi	r3,r3,28
 	li	r10,SLB_NUM_BOLTED-1	/* Stack goes in last bolted slot */
 	cmpld	r9,r3
 	beq	3f
 #endif /* CONFIG_PPC_ISERIES */

 	ld	r10,PACASTABRR(r13)
 	addi	r10,r10,1
 	/* use a cpu feature mask if we ever change our slb size */
 	cmpldi	r10,SLB_NUM_ENTRIES

 	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,r3,1		/* r11 = offset * sizeof(u16) */
 	rldicl	r10,r10,36,28		/* get low 16 bits of the ESID */
 	add	r11,r11,r13		/* r11 = (u16 *)paca + offset */
 	sth	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
	/*
	* 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 <linux/config.h>
	#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>

	/* 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)
	/* r3 = faulting address */

	srdi r9,r3,60 /* get region */
	srdi r10,r3,28 /* 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 of the vmalloc/ioremap
	* 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
	b slb_finish_load

	1: /* vmalloc/ioremap mapping encoding bits, the "li" instruction below
	* will be patched by the kernel at boot
	*/
	_GLOBAL(slb_miss_kernel_load_virtual)
	li r11,0
	b slb_finish_load


	0: /* user address: proto-VSID = context << 15 \| ESID. First check
	* if the address is within the boundaries of the user region
	*/
	srdi. r9,r10,USER_ESID_BITS
	bne- 8f /* invalid ea bits set */

	/* Figure out if the segment contains huge pages */
	#ifdef CONFIG_HUGETLB_PAGE
	BEGIN_FTR_SECTION
	b 1f
	END_FTR_SECTION_IFCLR(CPU_FTR_16M_PAGE)
	cmpldi r10,16

	lhz r9,PACALOWHTLBAREAS(r13)
	mr r11,r10
	blt 5f

	lhz r9,PACAHIGHHTLBAREAS(r13)
	srdi r11,r10,(HTLB_AREA_SHIFT-SID_SHIFT)

	5: srd r9,r9,r11
	andi. r9,r9,1
	beq 1f
	_GLOBAL(slb_miss_user_load_huge)
	li r11,0
	b 2f
	1:
	#endif /* CONFIG_HUGETLB_PAGE */

	_GLOBAL(slb_miss_user_load_normal)
	li r11,0

	2:
	ld r9,PACACONTEXTID(r13)
	rldimi r10,r9,USER_ESID_BITS,0
	b slb_finish_load

	8: /* invalid EA */
	li r10,0 /* 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 4cr7+lt / set "user" flag for later */

	/* check if we fit in the range covered by the pagetables*/
	srdi. r9,r3,PGTABLE_EADDR_SIZE
	crnot 4cr0+eq,4cr0+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)
	rldimi r10,r9,USER_ESID_BITS,0

	/* fall through slb_finish_load */

	#endif /* __DISABLED__ */


	/*
	* Finish loading of an SLB entry and return
	*
	* r3 = EA, r10 = proto-VSID, r11 = flags, clobbers r9, cr7 = <> PAGE_OFFSET
	*/
	slb_finish_load:
	ASM_VSID_SCRAMBLE(r10,r9)
	rldimi r11,r10,SLB_VSID_SHIFT,16 /* combine VSID and flags */

	/* 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.
	*/
	#ifdef CONFIG_PPC_ISERIES
	/*
	* On iSeries, the "bolted" stack segment can be cast out on
	* shared processor switch so we need to check for a miss on
	* it and restore it to the right slot.
	*/
	ld r9,PACAKSAVE(r13)
	clrrdi r9,r9,28
	clrrdi r3,r3,28
	li r10,SLB_NUM_BOLTED-1 /* Stack goes in last bolted slot */
	cmpld r9,r3
	beq 3f
	#endif /* CONFIG_PPC_ISERIES */

	ld r10,PACASTABRR(r13)
	addi r10,r10,1
	/* use a cpu feature mask if we ever change our slb size */
	cmpldi r10,SLB_NUM_ENTRIES

	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 4cr0+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,r3,1 /* r11 = offset * sizeof(u16) */
	rldicl r10,r10,36,28 /* get low 16 bits of the ESID */
	add r11,r11,r13 /* r11 = (u16 )paca + offset /
	sth 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 4cr0+eq / set result to "success" */
	blr