LXR linux/arch/mips/mm/sc-r5k.c

   1/*
   2 * Copyright (C) 1997, 2001 Ralf Baechle (ralf@gnu.org),
   3 * derived from r4xx0.c by David S. Miller (dm@engr.sgi.com).
   4 */
   5#include <linux/init.h>
   6#include <linux/kernel.h>
   7#include <linux/sched.h>
   8#include <linux/mm.h>
   9
  10#include <asm/mipsregs.h>
  11#include <asm/bcache.h>
  12#include <asm/cacheops.h>
  13#include <asm/page.h>
  14#include <asm/pgtable.h>
  15#include <asm/system.h>
  16#include <asm/mmu_context.h>
  17#include <asm/r4kcache.h>
  18
  19/* Secondary cache size in bytes, if present.  */
  20static unsigned long scache_size;
  21
  22#define SC_LINE 32
  23#define SC_PAGE (128*SC_LINE)
  24
  25static inline void blast_r5000_scache(void)
  26{
  27        unsigned long start = INDEX_BASE;
  28        unsigned long end = start + scache_size;
  29
  30        while(start < end) {
  31                cache_op(R5K_Page_Invalidate_S, start);
  32                start += SC_PAGE;
  33        }
  34}
  35
  36static void r5k_dma_cache_inv_sc(unsigned long addr, unsigned long size)
  37{
  38        unsigned long end, a;
  39
  40        /* Catch bad driver code */
  41        BUG_ON(size == 0);
  42
  43        if (size >= scache_size) {
  44                blast_r5000_scache();
  45                return;
  46        }
  47
  48        /* On the R5000 secondary cache we cannot
  49         * invalidate less than a page at a time.
  50         * The secondary cache is physically indexed, write-through.
  51         */
  52        a = addr & ~(SC_PAGE - 1);
  53        end = (addr + size - 1) & ~(SC_PAGE - 1);
  54        while (a <= end) {
  55                cache_op(R5K_Page_Invalidate_S, a);
  56                a += SC_PAGE;
  57        }
  58}
  59
  60static void r5k_sc_enable(void)
  61{
  62        unsigned long flags;
  63
  64        local_irq_save(flags);
  65        set_c0_config(R5K_CONF_SE);
  66        blast_r5000_scache();
  67        local_irq_restore(flags);
  68}
  69
  70static void r5k_sc_disable(void)
  71{
  72        unsigned long flags;
  73
  74        local_irq_save(flags);
  75        blast_r5000_scache();
  76        clear_c0_config(R5K_CONF_SE);
  77        local_irq_restore(flags);
  78}
  79
  80static inline int __init r5k_sc_probe(void)
  81{
  82        unsigned long config = read_c0_config();
  83
  84        if (config & CONF_SC)
  85                return(0);
  86
  87        scache_size = (512 * 1024) << ((config & R5K_CONF_SS) >> 20);
  88
  89        printk("R5000 SCACHE size %ldkB, linesize 32 bytes.\n",
  90                        scache_size >> 10);
  91
  92        return 1;
  93}
  94
  95static struct bcache_ops r5k_sc_ops = {
  96        .bc_enable = r5k_sc_enable,
  97        .bc_disable = r5k_sc_disable,
  98        .bc_wback_inv = r5k_dma_cache_inv_sc,
  99        .bc_inv = r5k_dma_cache_inv_sc
 100};
 101
 102void __cpuinit r5k_sc_init(void)
 103{
 104        if (r5k_sc_probe()) {
 105                r5k_sc_enable();
 106                bcops = &r5k_sc_ops;
 107        }
 108}
 109