arch/microblaze/kernel/misc.S

   1 /*
   2  * Miscellaneous low-level MMU functions.
   3  *
   4  * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
   5  * Copyright (C) 2008-2009 PetaLogix
   6  * Copyright (C) 2007 Xilinx, Inc.  All rights reserved.
   7  *
   8  * Derived from arch/ppc/kernel/misc.S
   9  *
  10  * This file is subject to the terms and conditions of the GNU General
  11  * Public License. See the file COPYING in the main directory of this
  12  * archive for more details.
  13  */
  14
  15 #include <linux/linkage.h>
  16 #include <linux/sys.h>
  17 #include <asm/unistd.h>
  18 #include <linux/errno.h>
  19 #include <asm/mmu.h>
  20 #include <asm/page.h>
  21
  22         .text
  23 /*
  24  * Flush MMU TLB
  25  *
  26  * We avoid flushing the pinned 0, 1 and possibly 2 entries.
  27  */
  28 .globl _tlbia;
  29 .type  _tlbia, @function
  30 .align 4;
  31 _tlbia:
  32         addik   r12, r0, MICROBLAZE_TLB_SIZE - 1 /* flush all entries (63 - 3) */
  33         /* isync */
  34 _tlbia_1:
  35         mts     rtlbx, r12
  36         nop
  37         mts     rtlbhi, r0 /* flush: ensure V is clear */
  38         nop
  39         addik   r11, r12, -2
  40         bneid   r11, _tlbia_1 /* loop for all entries */
  41         addik   r12, r12, -1
  42         /* sync */
  43         rtsd    r15, 8
  44         nop
  45         .size  _tlbia, . - _tlbia
  46
  47 /*
  48  * Flush MMU TLB for a particular address (in r5)
  49  */
  50 .globl _tlbie;
  51 .type  _tlbie, @function
  52 .align 4;
  53 _tlbie:
  54         mts     rtlbsx, r5 /* look up the address in TLB */
  55         nop
  56         mfs     r12, rtlbx /* Retrieve index */
  57         nop
  58         blti    r12, _tlbie_1 /* Check if found */
  59         mts     rtlbhi, r0 /* flush: ensure V is clear */
  60         nop
  61 _tlbie_1:
  62         rtsd    r15, 8
  63         nop
  64
  65         .size  _tlbie, . - _tlbie
  66
  67 /*
  68  * Allocate TLB entry for early console
  69  */
  70 .globl early_console_reg_tlb_alloc;
  71 .type  early_console_reg_tlb_alloc, @function
  72 .align 4;
  73 early_console_reg_tlb_alloc:
  74         /*
  75          * Load a TLB entry for the UART, so that microblaze_progress() can use
  76          * the UARTs nice and early.  We use a 4k real==virtual mapping.
  77          */
  78         ori     r4, r0, MICROBLAZE_TLB_SIZE - 1
  79         mts     rtlbx, r4 /* TLB slot 2 */
  80
  81         or      r4,r5,r0
  82         andi    r4,r4,0xfffff000
  83         ori     r4,r4,(TLB_WR|TLB_I|TLB_M|TLB_G)
  84
  85         andi    r5,r5,0xfffff000
  86         ori     r5,r5,(TLB_VALID | TLB_PAGESZ(PAGESZ_4K))
  87
  88         mts     rtlblo,r4 /* Load the data portion of the entry */
  89         nop
  90         mts     rtlbhi,r5 /* Load the tag portion of the entry */
  91         nop
  92         rtsd    r15, 8
  93         nop
  94
  95         .size  early_console_reg_tlb_alloc, . - early_console_reg_tlb_alloc