diff options
Diffstat (limited to 'arch/sh/kernel/cpu/init.c')
| -rw-r--r-- | arch/sh/kernel/cpu/init.c | 222 |
1 files changed, 222 insertions, 0 deletions
diff --git a/arch/sh/kernel/cpu/init.c b/arch/sh/kernel/cpu/init.c new file mode 100644 index 0000000..cf94e8e --- /dev/null +++ b/arch/sh/kernel/cpu/init.c @@ -0,0 +1,222 @@ +/* + * arch/sh/kernel/cpu/init.c + * + * CPU init code + * + * Copyright (C) 2002, 2003 Paul Mundt + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ +#include <linux/init.h> +#include <linux/kernel.h> +#include <asm/processor.h> +#include <asm/uaccess.h> +#include <asm/system.h> +#include <asm/cacheflush.h> +#include <asm/cache.h> +#include <asm/io.h> + +extern void detect_cpu_and_cache_system(void); + +/* + * Generic wrapper for command line arguments to disable on-chip + * peripherals (nofpu, nodsp, and so forth). + */ +#define onchip_setup(x) \ +static int x##_disabled __initdata = 0; \ + \ +static int __init x##_setup(char *opts) \ +{ \ + x##_disabled = 1; \ + return 0; \ +} \ +__setup("no" __stringify(x), x##_setup); + +onchip_setup(fpu); +onchip_setup(dsp); + +/* + * Generic first-level cache init + */ +static void __init cache_init(void) +{ + unsigned long ccr, flags; + + if (cpu_data->type == CPU_SH_NONE) + panic("Unknown CPU"); + + jump_to_P2(); + ccr = ctrl_inl(CCR); + + /* + * If the cache is already enabled .. flush it. + */ + if (ccr & CCR_CACHE_ENABLE) { + unsigned long ways, waysize, addrstart; + + waysize = cpu_data->dcache.sets; + + /* + * If the OC is already in RAM mode, we only have + * half of the entries to flush.. + */ + if (ccr & CCR_CACHE_ORA) + waysize >>= 1; + + waysize <<= cpu_data->dcache.entry_shift; + +#ifdef CCR_CACHE_EMODE + /* If EMODE is not set, we only have 1 way to flush. */ + if (!(ccr & CCR_CACHE_EMODE)) + ways = 1; + else +#endif + ways = cpu_data->dcache.ways; + + addrstart = CACHE_OC_ADDRESS_ARRAY; + do { + unsigned long addr; + + for (addr = addrstart; + addr < addrstart + waysize; + addr += cpu_data->dcache.linesz) + ctrl_outl(0, addr); + + addrstart += cpu_data->dcache.way_incr; + } while (--ways); + } + + /* + * Default CCR values .. enable the caches + * and invalidate them immediately.. + */ + flags = CCR_CACHE_ENABLE | CCR_CACHE_INVALIDATE; + +#ifdef CCR_CACHE_EMODE + /* Force EMODE if possible */ + if (cpu_data->dcache.ways > 1) + flags |= CCR_CACHE_EMODE; +#endif + +#ifdef CONFIG_SH_WRITETHROUGH + /* Turn on Write-through caching */ + flags |= CCR_CACHE_WT; +#else + /* .. or default to Write-back */ + flags |= CCR_CACHE_CB; +#endif + +#ifdef CONFIG_SH_OCRAM + /* Turn on OCRAM -- halve the OC */ + flags |= CCR_CACHE_ORA; + cpu_data->dcache.sets >>= 1; +#endif + + ctrl_outl(flags, CCR); + back_to_P1(); +} + +#ifdef CONFIG_SH_DSP +static void __init release_dsp(void) +{ + unsigned long sr; + + /* Clear SR.DSP bit */ + __asm__ __volatile__ ( + "stc\tsr, %0\n\t" + "and\t%1, %0\n\t" + "ldc\t%0, sr\n\t" + : "=&r" (sr) + : "r" (~SR_DSP) + ); +} + +static void __init dsp_init(void) +{ + unsigned long sr; + + /* + * Set the SR.DSP bit, wait for one instruction, and then read + * back the SR value. + */ + __asm__ __volatile__ ( + "stc\tsr, %0\n\t" + "or\t%1, %0\n\t" + "ldc\t%0, sr\n\t" + "nop\n\t" + "stc\tsr, %0\n\t" + : "=&r" (sr) + : "r" (SR_DSP) + ); + + /* If the DSP bit is still set, this CPU has a DSP */ + if (sr & SR_DSP) + cpu_data->flags |= CPU_HAS_DSP; + + /* Now that we've determined the DSP status, clear the DSP bit. */ + release_dsp(); +} +#endif /* CONFIG_SH_DSP */ + +/** + * sh_cpu_init + * + * This is our initial entry point for each CPU, and is invoked on the boot + * CPU prior to calling start_kernel(). For SMP, a combination of this and + * start_secondary() will bring up each processor to a ready state prior + * to hand forking the idle loop. + * + * We do all of the basic processor init here, including setting up the + * caches, FPU, DSP, kicking the UBC, etc. By the time start_kernel() is + * hit (and subsequently platform_setup()) things like determining the + * CPU subtype and initial configuration will all be done. + * + * Each processor family is still responsible for doing its own probing + * and cache configuration in detect_cpu_and_cache_system(). + */ +asmlinkage void __init sh_cpu_init(void) +{ + /* First, probe the CPU */ + detect_cpu_and_cache_system(); + + /* Init the cache */ + cache_init(); + + /* Disable the FPU */ + if (fpu_disabled) { + printk("FPU Disabled\n"); + cpu_data->flags &= ~CPU_HAS_FPU; + disable_fpu(); + } + + /* FPU initialization */ + if ((cpu_data->flags & CPU_HAS_FPU)) { + clear_thread_flag(TIF_USEDFPU); + clear_used_math(); + } + +#ifdef CONFIG_SH_DSP + /* Probe for DSP */ + dsp_init(); + + /* Disable the DSP */ + if (dsp_disabled) { + printk("DSP Disabled\n"); + cpu_data->flags &= ~CPU_HAS_DSP; + release_dsp(); + } +#endif + +#ifdef CONFIG_UBC_WAKEUP + /* + * Some brain-damaged loaders decided it would be a good idea to put + * the UBC to sleep. This causes some issues when it comes to things + * like PTRACE_SINGLESTEP or doing hardware watchpoints in GDB. So .. + * we wake it up and hope that all is well. + */ + ubc_wakeup(); +#endif +} + |
