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kernel/linux-rt-4.4.41/arch/score/mm/tlb-miss.S 4.02 KB
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  /*
   * arch/score/mm/tlbex.S
   *
   * Score Processor version.
   *
   * Copyright (C) 2009 Sunplus Core Technology Co., Ltd.
   *  Lennox Wu <lennox.wu@sunplusct.com>
   *  Chen Liqin <liqin.chen@sunplusct.com>
   *
   * 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.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, see the file COPYING, or write
   * to the Free Software Foundation, Inc.,
   * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
   */
  
  #include <asm/asmmacro.h>
  #include <asm/pgtable-bits.h>
  #include <asm/scoreregs.h>
  
  /*
  * After this macro runs, the pte faulted on is
  * in register PTE, a ptr into the table in which
  * the pte belongs is in PTR.
  */
  	.macro	load_pte, pte, ptr
  	la	\ptr, pgd_current
  	lw	\ptr, [\ptr, 0]
  	mfcr	\pte, cr6
  	srli	\pte, \pte, 22
  	slli	\pte, \pte, 2
  	add	\ptr, \ptr, \pte
  	lw	\ptr, [\ptr, 0]
  	mfcr	\pte, cr6
  	srli	\pte, \pte, 10
  	andi	\pte, 0xffc
  	add	\ptr, \ptr, \pte
  	lw	\pte, [\ptr, 0]
  	.endm
  
  	.macro	pte_reload, ptr
  	lw	\ptr, [\ptr, 0]
  	mtcr	\ptr, cr12
  	nop
  	nop
  	nop
  	nop
  	nop
  	.endm
  
  	.macro do_fault, write
  	SAVE_ALL
  	mfcr	r6, cr6
  	mv	r4, r0
  	ldi	r5, \write
  	la	r8, do_page_fault
  	brl	r8
  	j	ret_from_exception
  	.endm
  
  	.macro	pte_writable, pte, ptr, label
  	andi	\pte, 0x280
  	cmpi.c	\pte, 0x280
  	bne	\label
  	lw	\pte, [\ptr, 0]		/*reload PTE*/
  	.endm
  
  /*
   * Make PTE writable, update software status bits as well,
   * then store at PTR.
   */
  	.macro	pte_makewrite, pte, ptr
  	ori	\pte, 0x426
  	sw	\pte, [\ptr, 0]
  	.endm
  
  	.text
  ENTRY(score7_FTLB_refill_Handler)
  	la	r31, pgd_current	/* get pgd pointer */
  	lw	r31, [r31, 0]		/* get the address of PGD */
  	mfcr	r30, cr6
  	srli	r30, r30, 22		/* PGDIR_SHIFT = 22*/
  	slli	r30, r30, 2
  	add	r31, r31, r30
  	lw	r31, [r31, 0]		/* get the address of the start address of PTE table */
  
  	mfcr	r30, cr9
  	andi	r30, 0xfff 		/* equivalent to get PET index and right shift 2 bits */
  	add	r31, r31, r30
  	lw	r30, [r31, 0]		/* load pte entry */
  	mtcr	r30, cr12
  	nop
  	nop
  	nop
  	nop
  	nop
  	mtrtlb
  	nop
  	nop
  	nop
  	nop
  	nop
  	rte				/* 6 cycles to make sure tlb entry works */
  
  ENTRY(score7_KSEG_refill_Handler)
  	la	r31, pgd_current	/* get pgd pointer */
  	lw	r31, [r31, 0]		/* get the address of PGD */
  	mfcr	r30, cr6
  	srli	r30, r30, 22		/* PGDIR_SHIFT = 22 */
  	slli	r30, r30, 2
  	add	r31, r31, r30
  	lw	r31, [r31, 0]		/* get the address of the start address of PTE table */
  
  	mfcr	r30, cr6		/* get Bad VPN */
  	srli	r30, r30, 10
  	andi	r30, 0xffc		/* PTE VPN mask (bit 11~2) */
  
  	add	r31, r31, r30
  	lw	r30, [r31, 0]		/* load pte entry */
  	mtcr	r30, cr12
  	nop
  	nop
  	nop
  	nop
  	nop
  	mtrtlb
  	nop
  	nop
  	nop
  	nop
  	nop
  	rte				/* 6 cycles to make sure tlb entry works */
  
  nopage_tlbl:
  	do_fault	0		/* Read */
  
  ENTRY(handle_tlb_refill)
  	load_pte	r30, r31
  	pte_writable	r30, r31, handle_tlb_refill_nopage
  	pte_makewrite	r30, r31	/* Access|Modify|Dirty|Valid */
  	pte_reload	r31
  	mtrtlb
  	nop
  	nop
  	nop
  	nop
  	nop
  	rte
  handle_tlb_refill_nopage:
  	do_fault	0		/* Read */
  
  ENTRY(handle_tlb_invaild)
  	load_pte	r30, r31
  	stlb				/* find faulting entry */
  	pte_writable	r30, r31, handle_tlb_invaild_nopage
  	pte_makewrite	r30, r31	/* Access|Modify|Dirty|Valid */
  	pte_reload	r31
  	mtptlb
  	nop
  	nop
  	nop
  	nop
  	nop
  	rte
  handle_tlb_invaild_nopage:
  	do_fault	0		/* Read */
  
  ENTRY(handle_mod)
  	load_pte	r30, r31
  	stlb				/* find faulting entry */
  	andi	r30, _PAGE_WRITE	/* Writable? */
  	cmpz.c	r30
  	beq	nowrite_mod
  	lw	r30, [r31, 0]		/* reload into r30 */
  
  	/* Present and writable bits set, set accessed and dirty bits. */
  	pte_makewrite	r30, r31
  
  	/* Now reload the entry into the tlb. */
  	pte_reload	r31
  	mtptlb
  	nop
  	nop
  	nop
  	nop
  	nop
  	rte
  
  nowrite_mod:
  	do_fault	1	/* Write */