root/arch/mips/mm/cex-oct.S

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 2006 Cavium Networks
   7  * Cache error handler
   8  */
   9 
  10 #include <asm/asm.h>
  11 #include <asm/regdef.h>
  12 #include <asm/mipsregs.h>
  13 #include <asm/stackframe.h>
  14 
  15 /*
  16  * Handle cache error. Indicate to the second level handler whether
  17  * the exception is recoverable.
  18  */
  19         LEAF(except_vec2_octeon)
  20 
  21         .set    push
  22         .set    mips64r2
  23         .set    noreorder
  24         .set    noat
  25 
  26 
  27         /* due to an errata we need to read the COP0 CacheErr (Dcache)
  28          * before any cache/DRAM access  */
  29 
  30         rdhwr   k0, $0        /* get core_id */
  31         PTR_LA  k1, cache_err_dcache
  32         sll     k0, k0, 3
  33         PTR_ADDU k1, k0, k1    /* k1 = &cache_err_dcache[core_id] */
  34 
  35         dmfc0   k0, CP0_CACHEERR, 1
  36         sd      k0, (k1)
  37         dmtc0   $0, CP0_CACHEERR, 1
  38 
  39         /* check whether this is a nested exception */
  40         mfc0    k1, CP0_STATUS
  41         andi    k1, k1, ST0_EXL
  42         beqz    k1, 1f
  43          nop
  44         j       cache_parity_error_octeon_non_recoverable
  45          nop
  46 
  47         /* exception is recoverable */
  48 1:      j       handle_cache_err
  49          nop
  50 
  51         .set    pop
  52         END(except_vec2_octeon)
  53 
  54  /* We need to jump to handle_cache_err so that the previous handler
  55   * can fit within 0x80 bytes. We also move from 0xFFFFFFFFAXXXXXXX
  56   * space (uncached) to the 0xFFFFFFFF8XXXXXXX space (cached).  */
  57         LEAF(handle_cache_err)
  58         .set    push
  59         .set    noreorder
  60         .set    noat
  61 
  62         SAVE_ALL
  63         KMODE
  64         jal     cache_parity_error_octeon_recoverable
  65         nop
  66         j       ret_from_exception
  67         nop
  68 
  69         .set pop
  70         END(handle_cache_err)