From d10e025f0e4ba4b96d7b5786d232ac5b0b232b11 Mon Sep 17 00:00:00 2001 From: Atsushi Nemoto Date: Tue, 19 Aug 2008 22:55:09 +0900 Subject: MIPS: TXx9: Cache fixup TX39/TX49 can enable/disable I/D cache at runtime. Add kernel options to control them. This is useful to debug some cache-related issues, such as aliasing or I/D coherency. Also enable CWF bit for TX49 SoCs. Signed-off-by: Atsushi Nemoto Signed-off-by: Ralf Baechle --- arch/mips/txx9/generic/setup.c | 113 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 113 insertions(+) (limited to 'arch/mips/txx9/generic/setup.c') diff --git a/arch/mips/txx9/generic/setup.c b/arch/mips/txx9/generic/setup.c index dc5dbcc53a9..fa88aefea9e 100644 --- a/arch/mips/txx9/generic/setup.c +++ b/arch/mips/txx9/generic/setup.c @@ -25,6 +25,7 @@ #include #include #include +#include #include #include #ifdef CONFIG_CPU_TX49XX @@ -186,6 +187,110 @@ static void __init prom_init_cmdline(void) } } +static int txx9_ic_disable __initdata; +static int txx9_dc_disable __initdata; + +#if defined(CONFIG_CPU_TX49XX) +/* flush all cache on very early stage (before 4k_cache_init) */ +static void __init early_flush_dcache(void) +{ + unsigned int conf = read_c0_config(); + unsigned int dc_size = 1 << (12 + ((conf & CONF_DC) >> 6)); + unsigned int linesz = 32; + unsigned long addr, end; + + end = INDEX_BASE + dc_size / 4; + /* 4way, waybit=0 */ + for (addr = INDEX_BASE; addr < end; addr += linesz) { + cache_op(Index_Writeback_Inv_D, addr | 0); + cache_op(Index_Writeback_Inv_D, addr | 1); + cache_op(Index_Writeback_Inv_D, addr | 2); + cache_op(Index_Writeback_Inv_D, addr | 3); + } +} + +static void __init txx9_cache_fixup(void) +{ + unsigned int conf; + + conf = read_c0_config(); + /* flush and disable */ + if (txx9_ic_disable) { + conf |= TX49_CONF_IC; + write_c0_config(conf); + } + if (txx9_dc_disable) { + early_flush_dcache(); + conf |= TX49_CONF_DC; + write_c0_config(conf); + } + + /* enable cache */ + conf = read_c0_config(); + if (!txx9_ic_disable) + conf &= ~TX49_CONF_IC; + if (!txx9_dc_disable) + conf &= ~TX49_CONF_DC; + write_c0_config(conf); + + if (conf & TX49_CONF_IC) + pr_info("TX49XX I-Cache disabled.\n"); + if (conf & TX49_CONF_DC) + pr_info("TX49XX D-Cache disabled.\n"); +} +#elif defined(CONFIG_CPU_TX39XX) +/* flush all cache on very early stage (before tx39_cache_init) */ +static void __init early_flush_dcache(void) +{ + unsigned int conf = read_c0_config(); + unsigned int dc_size = 1 << (10 + ((conf & TX39_CONF_DCS_MASK) >> + TX39_CONF_DCS_SHIFT)); + unsigned int linesz = 16; + unsigned long addr, end; + + end = INDEX_BASE + dc_size / 2; + /* 2way, waybit=0 */ + for (addr = INDEX_BASE; addr < end; addr += linesz) { + cache_op(Index_Writeback_Inv_D, addr | 0); + cache_op(Index_Writeback_Inv_D, addr | 1); + } +} + +static void __init txx9_cache_fixup(void) +{ + unsigned int conf; + + conf = read_c0_config(); + /* flush and disable */ + if (txx9_ic_disable) { + conf &= ~TX39_CONF_ICE; + write_c0_config(conf); + } + if (txx9_dc_disable) { + early_flush_dcache(); + conf &= ~TX39_CONF_DCE; + write_c0_config(conf); + } + + /* enable cache */ + conf = read_c0_config(); + if (!txx9_ic_disable) + conf |= TX39_CONF_ICE; + if (!txx9_dc_disable) + conf |= TX39_CONF_DCE; + write_c0_config(conf); + + if (!(conf & TX39_CONF_ICE)) + pr_info("TX39XX I-Cache disabled.\n"); + if (!(conf & TX39_CONF_DCE)) + pr_info("TX39XX D-Cache disabled.\n"); +} +#else +static inline void txx9_cache_fixup(void) +{ +} +#endif + static void __init preprocess_cmdline(void) { char cmdline[CL_SIZE]; @@ -204,11 +309,19 @@ static void __init preprocess_cmdline(void) if (strict_strtoul(str + 10, 10, &val) == 0) txx9_master_clock = val; continue; + } else if (strcmp(str, "icdisable") == 0) { + txx9_ic_disable = 1; + continue; + } else if (strcmp(str, "dcdisable") == 0) { + txx9_dc_disable = 1; + continue; } if (arcs_cmdline[0]) strcat(arcs_cmdline, " "); strcat(arcs_cmdline, str); } + + txx9_cache_fixup(); } static void __init select_board(void) -- cgit v1.2.3