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Diffstat (limited to 'arch/mips/mm/sc-mips.c')
| -rw-r--r-- | arch/mips/mm/sc-mips.c | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/arch/mips/mm/sc-mips.c b/arch/mips/mm/sc-mips.c new file mode 100644 index 000000000..4ceafd138 --- /dev/null +++ b/arch/mips/mm/sc-mips.c @@ -0,0 +1,150 @@ +/* + * Copyright (C) 2006 Chris Dearman (chris@mips.com), + */ +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/mm.h> + +#include <asm/cpu-type.h> +#include <asm/mipsregs.h> +#include <asm/bcache.h> +#include <asm/cacheops.h> +#include <asm/page.h> +#include <asm/pgtable.h> +#include <asm/mmu_context.h> +#include <asm/r4kcache.h> + +/* + * MIPS32/MIPS64 L2 cache handling + */ + +/* + * Writeback and invalidate the secondary cache before DMA. + */ +static void mips_sc_wback_inv(unsigned long addr, unsigned long size) +{ + blast_scache_range(addr, addr + size); +} + +/* + * Invalidate the secondary cache before DMA. + */ +static void mips_sc_inv(unsigned long addr, unsigned long size) +{ + unsigned long lsize = cpu_scache_line_size(); + unsigned long almask = ~(lsize - 1); + + cache_op(Hit_Writeback_Inv_SD, addr & almask); + cache_op(Hit_Writeback_Inv_SD, (addr + size - 1) & almask); + blast_inv_scache_range(addr, addr + size); +} + +static void mips_sc_enable(void) +{ + /* L2 cache is permanently enabled */ +} + +static void mips_sc_disable(void) +{ + /* L2 cache is permanently enabled */ +} + +static struct bcache_ops mips_sc_ops = { + .bc_enable = mips_sc_enable, + .bc_disable = mips_sc_disable, + .bc_wback_inv = mips_sc_wback_inv, + .bc_inv = mips_sc_inv +}; + +/* + * Check if the L2 cache controller is activated on a particular platform. + * MTI's L2 controller and the L2 cache controller of Broadcom's BMIPS + * cores both use c0_config2's bit 12 as "L2 Bypass" bit, that is the + * cache being disabled. However there is no guarantee for this to be + * true on all platforms. In an act of stupidity the spec defined bits + * 12..15 as implementation defined so below function will eventually have + * to be replaced by a platform specific probe. + */ +static inline int mips_sc_is_activated(struct cpuinfo_mips *c) +{ + unsigned int config2 = read_c0_config2(); + unsigned int tmp; + + /* Check the bypass bit (L2B) */ + switch (current_cpu_type()) { + case CPU_34K: + case CPU_74K: + case CPU_1004K: + case CPU_1074K: + case CPU_INTERAPTIV: + case CPU_PROAPTIV: + case CPU_P5600: + case CPU_BMIPS5000: + case CPU_QEMU_GENERIC: + if (config2 & (1 << 12)) + return 0; + } + + tmp = (config2 >> 4) & 0x0f; + if (0 < tmp && tmp <= 7) + c->scache.linesz = 2 << tmp; + else + return 0; + return 1; +} + +static inline int __init mips_sc_probe(void) +{ + struct cpuinfo_mips *c = ¤t_cpu_data; + unsigned int config1, config2; + unsigned int tmp; + + /* Mark as not present until probe completed */ + c->scache.flags |= MIPS_CACHE_NOT_PRESENT; + + /* Ignore anything but MIPSxx processors */ + if (!(c->isa_level & (MIPS_CPU_ISA_M32R1 | MIPS_CPU_ISA_M32R2 | + MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R1 | + MIPS_CPU_ISA_M64R2 | MIPS_CPU_ISA_M64R6))) + return 0; + + /* Does this MIPS32/MIPS64 CPU have a config2 register? */ + config1 = read_c0_config1(); + if (!(config1 & MIPS_CONF_M)) + return 0; + + config2 = read_c0_config2(); + + if (!mips_sc_is_activated(c)) + return 0; + + tmp = (config2 >> 8) & 0x0f; + if (0 <= tmp && tmp <= 7) + c->scache.sets = 64 << tmp; + else + return 0; + + tmp = (config2 >> 0) & 0x0f; + if (0 <= tmp && tmp <= 7) + c->scache.ways = tmp + 1; + else + return 0; + + c->scache.waysize = c->scache.sets * c->scache.linesz; + c->scache.waybit = __ffs(c->scache.waysize); + + c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT; + + return 1; +} + +int mips_sc_init(void) +{ + int found = mips_sc_probe(); + if (found) { + mips_sc_enable(); + bcops = &mips_sc_ops; + } + return found; +} |