linux-zen-desktop/arch/mips/mm/sc-r5k.c

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2023-08-30 17:31:07 +02:00
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 1997, 2001 Ralf Baechle (ralf@gnu.org),
* derived from r4xx0.c by David S. Miller (davem@davemloft.net).
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <asm/mipsregs.h>
#include <asm/bcache.h>
#include <asm/cacheops.h>
#include <asm/page.h>
#include <asm/mmu_context.h>
#include <asm/r4kcache.h>
/* Secondary cache size in bytes, if present. */
static unsigned long scache_size;
#define SC_LINE 32
#define SC_PAGE (128*SC_LINE)
static inline void blast_r5000_scache(void)
{
unsigned long start = INDEX_BASE;
unsigned long end = start + scache_size;
while(start < end) {
cache_op(R5K_Page_Invalidate_S, start);
start += SC_PAGE;
}
}
static void r5k_dma_cache_inv_sc(unsigned long addr, unsigned long size)
{
unsigned long end, a;
/* Catch bad driver code */
BUG_ON(size == 0);
if (size >= scache_size) {
blast_r5000_scache();
return;
}
/* On the R5000 secondary cache we cannot
* invalidate less than a page at a time.
* The secondary cache is physically indexed, write-through.
*/
a = addr & ~(SC_PAGE - 1);
end = (addr + size - 1) & ~(SC_PAGE - 1);
while (a <= end) {
cache_op(R5K_Page_Invalidate_S, a);
a += SC_PAGE;
}
}
static void r5k_sc_enable(void)
{
unsigned long flags;
local_irq_save(flags);
set_c0_config(R5K_CONF_SE);
blast_r5000_scache();
local_irq_restore(flags);
}
static void r5k_sc_disable(void)
{
unsigned long flags;
local_irq_save(flags);
blast_r5000_scache();
clear_c0_config(R5K_CONF_SE);
local_irq_restore(flags);
}
static inline int __init r5k_sc_probe(void)
{
unsigned long config = read_c0_config();
if (config & CONF_SC)
return 0;
scache_size = (512 * 1024) << ((config & R5K_CONF_SS) >> 20);
printk("R5000 SCACHE size %ldkB, linesize 32 bytes.\n",
scache_size >> 10);
return 1;
}
static struct bcache_ops r5k_sc_ops = {
.bc_enable = r5k_sc_enable,
.bc_disable = r5k_sc_disable,
.bc_wback_inv = r5k_dma_cache_inv_sc,
.bc_inv = r5k_dma_cache_inv_sc
};
void r5k_sc_init(void)
{
if (r5k_sc_probe()) {
r5k_sc_enable();
bcops = &r5k_sc_ops;
}
}