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

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (C) 1997, 2001 Ralf Baechle (ralf@gnu.org),
   4 * derived from r4xx0.c by David S. Miller (davem@davemloft.net).
   5 */
   6#include <linux/init.h>
   7#include <linux/kernel.h>
   8#include <linux/sched.h>
   9#include <linux/mm.h>
  10
  11#include <asm/mipsregs.h>
  12#include <asm/bcache.h>
  13#include <asm/cacheops.h>
  14#include <asm/page.h>
  15#include <asm/mmu_context.h>
  16#include <asm/r4kcache.h>
  17
  18/* Secondary cache size in bytes, if present.  */
  19static unsigned long scache_size;
  20
  21#define SC_LINE 32
  22#define SC_PAGE (128*SC_LINE)
  23
  24static inline void blast_r5000_scache(void)
  25{
  26        unsigned long start = INDEX_BASE;
  27        unsigned long end = start + scache_size;
  28
  29        while(start < end) {
  30                cache_op(R5K_Page_Invalidate_S, start);
  31                start += SC_PAGE;
  32        }
  33}
  34
  35static void r5k_dma_cache_inv_sc(unsigned long addr, unsigned long size)
  36{
  37        unsigned long end, a;
  38
  39        /* Catch bad driver code */
  40        BUG_ON(size == 0);
  41
  42        if (size >= scache_size) {
  43                blast_r5000_scache();
  44                return;
  45        }
  46
  47        /* On the R5000 secondary cache we cannot
  48         * invalidate less than a page at a time.
  49         * The secondary cache is physically indexed, write-through.
  50         */
  51        a = addr & ~(SC_PAGE - 1);
  52        end = (addr + size - 1) & ~(SC_PAGE - 1);
  53        while (a <= end) {
  54                cache_op(R5K_Page_Invalidate_S, a);
  55                a += SC_PAGE;
  56        }
  57}
  58
  59static void r5k_sc_enable(void)
  60{
  61        unsigned long flags;
  62
  63        local_irq_save(flags);
  64        set_c0_config(R5K_CONF_SE);
  65        blast_r5000_scache();
  66        local_irq_restore(flags);
  67}
  68
  69static void r5k_sc_disable(void)
  70{
  71        unsigned long flags;
  72
  73        local_irq_save(flags);
  74        blast_r5000_scache();
  75        clear_c0_config(R5K_CONF_SE);
  76        local_irq_restore(flags);
  77}
  78
  79static inline int __init r5k_sc_probe(void)
  80{
  81        unsigned long config = read_c0_config();
  82
  83        if (config & CONF_SC)
  84                return 0;
  85
  86        scache_size = (512 * 1024) << ((config & R5K_CONF_SS) >> 20);
  87
  88        printk("R5000 SCACHE size %ldkB, linesize 32 bytes.\n",
  89                        scache_size >> 10);
  90
  91        return 1;
  92}
  93
  94static struct bcache_ops r5k_sc_ops = {
  95        .bc_enable = r5k_sc_enable,
  96        .bc_disable = r5k_sc_disable,
  97        .bc_wback_inv = r5k_dma_cache_inv_sc,
  98        .bc_inv = r5k_dma_cache_inv_sc
  99};
 100
 101void r5k_sc_init(void)
 102{
 103        if (r5k_sc_probe()) {
 104                r5k_sc_enable();
 105                bcops = &r5k_sc_ops;
 106        }
 107}
 108