diff options
Diffstat (limited to 'arch/mips/mm/sc-rm7k.c')
| -rw-r--r-- | arch/mips/mm/sc-rm7k.c | 270 |
1 files changed, 270 insertions, 0 deletions
diff --git a/arch/mips/mm/sc-rm7k.c b/arch/mips/mm/sc-rm7k.c new file mode 100644 index 000000000..e9e3777a7 --- /dev/null +++ b/arch/mips/mm/sc-rm7k.c @@ -0,0 +1,270 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * sc-rm7k.c: RM7000 cache management functions. + * + * Copyright (C) 1997, 2001, 2003, 2004 Ralf Baechle (ralf@linux-mips.org) + */ + +#undef DEBUG + +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/bitops.h> + +#include <asm/addrspace.h> +#include <asm/bcache.h> +#include <asm/cacheops.h> +#include <asm/mipsregs.h> +#include <asm/processor.h> +#include <asm/sections.h> +#include <asm/cacheflush.h> /* for run_uncached() */ + +/* Primary cache parameters. */ +#define sc_lsize 32 +#define tc_pagesize (32*128) + +/* Secondary cache parameters. */ +#define scache_size (256*1024) /* Fixed to 256KiB on RM7000 */ + +/* Tertiary cache parameters */ +#define tc_lsize 32 + +extern unsigned long icache_way_size, dcache_way_size; +static unsigned long tcache_size; + +#include <asm/r4kcache.h> + +static int rm7k_tcache_init; + +/* + * Writeback and invalidate the primary cache dcache before DMA. + * (XXX These need to be fixed ...) + */ +static void rm7k_sc_wback_inv(unsigned long addr, unsigned long size) +{ + unsigned long end, a; + + pr_debug("rm7k_sc_wback_inv[%08lx,%08lx]", addr, size); + + /* Catch bad driver code */ + BUG_ON(size == 0); + + blast_scache_range(addr, addr + size); + + if (!rm7k_tcache_init) + return; + + a = addr & ~(tc_pagesize - 1); + end = (addr + size - 1) & ~(tc_pagesize - 1); + while(1) { + invalidate_tcache_page(a); /* Page_Invalidate_T */ + if (a == end) + break; + a += tc_pagesize; + } +} + +static void rm7k_sc_inv(unsigned long addr, unsigned long size) +{ + unsigned long end, a; + + pr_debug("rm7k_sc_inv[%08lx,%08lx]", addr, size); + + /* Catch bad driver code */ + BUG_ON(size == 0); + + blast_inv_scache_range(addr, addr + size); + + if (!rm7k_tcache_init) + return; + + a = addr & ~(tc_pagesize - 1); + end = (addr + size - 1) & ~(tc_pagesize - 1); + while(1) { + invalidate_tcache_page(a); /* Page_Invalidate_T */ + if (a == end) + break; + a += tc_pagesize; + } +} + +static void blast_rm7k_tcache(void) +{ + unsigned long start = CKSEG0ADDR(0); + unsigned long end = start + tcache_size; + + write_c0_taglo(0); + + while (start < end) { + cache_op(Page_Invalidate_T, start); + start += tc_pagesize; + } +} + +/* + * This function is executed in uncached address space. + */ +static void __rm7k_tc_enable(void) +{ + int i; + + set_c0_config(RM7K_CONF_TE); + + write_c0_taglo(0); + write_c0_taghi(0); + + for (i = 0; i < tcache_size; i += tc_lsize) + cache_op(Index_Store_Tag_T, CKSEG0ADDR(i)); +} + +static void rm7k_tc_enable(void) +{ + if (read_c0_config() & RM7K_CONF_TE) + return; + + BUG_ON(tcache_size == 0); + + run_uncached(__rm7k_tc_enable); +} + +/* + * This function is executed in uncached address space. + */ +static void __rm7k_sc_enable(void) +{ + int i; + + set_c0_config(RM7K_CONF_SE); + + write_c0_taglo(0); + write_c0_taghi(0); + + for (i = 0; i < scache_size; i += sc_lsize) + cache_op(Index_Store_Tag_SD, CKSEG0ADDR(i)); +} + +static void rm7k_sc_enable(void) +{ + if (read_c0_config() & RM7K_CONF_SE) + return; + + pr_info("Enabling secondary cache...\n"); + run_uncached(__rm7k_sc_enable); + + if (rm7k_tcache_init) + rm7k_tc_enable(); +} + +static void rm7k_tc_disable(void) +{ + unsigned long flags; + + local_irq_save(flags); + blast_rm7k_tcache(); + clear_c0_config(RM7K_CONF_TE); + local_irq_restore(flags); +} + +static void rm7k_sc_disable(void) +{ + clear_c0_config(RM7K_CONF_SE); + + if (rm7k_tcache_init) + rm7k_tc_disable(); +} + +static struct bcache_ops rm7k_sc_ops = { + .bc_enable = rm7k_sc_enable, + .bc_disable = rm7k_sc_disable, + .bc_wback_inv = rm7k_sc_wback_inv, + .bc_inv = rm7k_sc_inv +}; + +/* + * This is a probing function like the one found in c-r4k.c, we look for the + * wrap around point with different addresses. + */ +static void __probe_tcache(void) +{ + unsigned long flags, addr, begin, end, pow2; + + begin = (unsigned long) &_stext; + begin &= ~((8 * 1024 * 1024) - 1); + end = begin + (8 * 1024 * 1024); + + local_irq_save(flags); + + set_c0_config(RM7K_CONF_TE); + + /* Fill size-multiple lines with a valid tag */ + pow2 = (256 * 1024); + for (addr = begin; addr <= end; addr = (begin + pow2)) { + unsigned long *p = (unsigned long *) addr; + __asm__ __volatile__("nop" : : "r" (*p)); + pow2 <<= 1; + } + + /* Load first line with a 0 tag, to check after */ + write_c0_taglo(0); + write_c0_taghi(0); + cache_op(Index_Store_Tag_T, begin); + + /* Look for the wrap-around */ + pow2 = (512 * 1024); + for (addr = begin + (512 * 1024); addr <= end; addr = begin + pow2) { + cache_op(Index_Load_Tag_T, addr); + if (!read_c0_taglo()) + break; + pow2 <<= 1; + } + + addr -= begin; + tcache_size = addr; + + clear_c0_config(RM7K_CONF_TE); + + local_irq_restore(flags); +} + +void rm7k_sc_init(void) +{ + struct cpuinfo_mips *c = ¤t_cpu_data; + unsigned int config = read_c0_config(); + + if ((config & RM7K_CONF_SC)) + return; + + c->scache.linesz = sc_lsize; + c->scache.ways = 4; + c->scache.waybit= __ffs(scache_size / c->scache.ways); + c->scache.waysize = scache_size / c->scache.ways; + c->scache.sets = scache_size / (c->scache.linesz * c->scache.ways); + printk(KERN_INFO "Secondary cache size %dK, linesize %d bytes.\n", + (scache_size >> 10), sc_lsize); + + if (!(config & RM7K_CONF_SE)) + rm7k_sc_enable(); + + bcops = &rm7k_sc_ops; + + /* + * While we're at it let's deal with the tertiary cache. + */ + + rm7k_tcache_init = 0; + tcache_size = 0; + + if (config & RM7K_CONF_TC) + return; + + /* + * No efficient way to ask the hardware for the size of the tcache, + * so must probe for it. + */ + run_uncached(__probe_tcache); + rm7k_tc_enable(); + rm7k_tcache_init = 1; + c->tcache.linesz = tc_lsize; + c->tcache.ways = 1; + pr_info("Tertiary cache size %ldK.\n", (tcache_size >> 10)); +} |