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289 lines
6.8 KiB
C
289 lines
6.8 KiB
C
/*
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* arch/sh/kernel/cpu/init.c
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*
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* CPU init code
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*
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* Copyright (C) 2002 - 2007 Paul Mundt
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* Copyright (C) 2003 Richard Curnow
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*/
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <asm/mmu_context.h>
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#include <asm/processor.h>
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#include <asm/uaccess.h>
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#include <asm/page.h>
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#include <asm/system.h>
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#include <asm/cacheflush.h>
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#include <asm/cache.h>
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#include <asm/io.h>
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#include <asm/smp.h>
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#ifdef CONFIG_SUPERH32
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#include <asm/ubc.h>
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#endif
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/*
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* Generic wrapper for command line arguments to disable on-chip
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* peripherals (nofpu, nodsp, and so forth).
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*/
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#define onchip_setup(x) \
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static int x##_disabled __initdata = 0; \
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\
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static int __init x##_setup(char *opts) \
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{ \
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x##_disabled = 1; \
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return 1; \
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} \
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__setup("no" __stringify(x), x##_setup);
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onchip_setup(fpu);
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onchip_setup(dsp);
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#ifdef CONFIG_SPECULATIVE_EXECUTION
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#define CPUOPM 0xff2f0000
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#define CPUOPM_RABD (1 << 5)
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static void __init speculative_execution_init(void)
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{
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/* Clear RABD */
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ctrl_outl(ctrl_inl(CPUOPM) & ~CPUOPM_RABD, CPUOPM);
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/* Flush the update */
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(void)ctrl_inl(CPUOPM);
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ctrl_barrier();
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}
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#else
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#define speculative_execution_init() do { } while (0)
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#endif
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/*
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* Generic first-level cache init
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*/
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#ifdef CONFIG_SUPERH32
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static void __init cache_init(void)
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{
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unsigned long ccr, flags;
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jump_to_P2();
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ccr = ctrl_inl(CCR);
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/*
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* At this point we don't know whether the cache is enabled or not - a
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* bootloader may have enabled it. There are at least 2 things that
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* could be dirty in the cache at this point:
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* 1. kernel command line set up by boot loader
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* 2. spilled registers from the prolog of this function
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* => before re-initialising the cache, we must do a purge of the whole
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* cache out to memory for safety. As long as nothing is spilled
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* during the loop to lines that have already been done, this is safe.
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* - RPC
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*/
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if (ccr & CCR_CACHE_ENABLE) {
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unsigned long ways, waysize, addrstart;
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waysize = current_cpu_data.dcache.sets;
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#ifdef CCR_CACHE_ORA
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/*
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* If the OC is already in RAM mode, we only have
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* half of the entries to flush..
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*/
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if (ccr & CCR_CACHE_ORA)
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waysize >>= 1;
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#endif
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waysize <<= current_cpu_data.dcache.entry_shift;
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#ifdef CCR_CACHE_EMODE
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/* If EMODE is not set, we only have 1 way to flush. */
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if (!(ccr & CCR_CACHE_EMODE))
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ways = 1;
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else
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#endif
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ways = current_cpu_data.dcache.ways;
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addrstart = CACHE_OC_ADDRESS_ARRAY;
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do {
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unsigned long addr;
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for (addr = addrstart;
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addr < addrstart + waysize;
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addr += current_cpu_data.dcache.linesz)
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ctrl_outl(0, addr);
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addrstart += current_cpu_data.dcache.way_incr;
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} while (--ways);
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}
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/*
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* Default CCR values .. enable the caches
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* and invalidate them immediately..
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*/
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flags = CCR_CACHE_ENABLE | CCR_CACHE_INVALIDATE;
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#ifdef CCR_CACHE_EMODE
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/* Force EMODE if possible */
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if (current_cpu_data.dcache.ways > 1)
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flags |= CCR_CACHE_EMODE;
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else
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flags &= ~CCR_CACHE_EMODE;
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#endif
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#if defined(CONFIG_CACHE_WRITETHROUGH)
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/* Write-through */
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flags |= CCR_CACHE_WT;
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#elif defined(CONFIG_CACHE_WRITEBACK)
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/* Write-back */
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flags |= CCR_CACHE_CB;
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#else
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/* Off */
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flags &= ~CCR_CACHE_ENABLE;
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#endif
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ctrl_outl(flags, CCR);
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back_to_P1();
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}
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#else
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#define cache_init() do { } while (0)
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#endif
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#ifdef CONFIG_SH_DSP
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static void __init release_dsp(void)
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{
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unsigned long sr;
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/* Clear SR.DSP bit */
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__asm__ __volatile__ (
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"stc\tsr, %0\n\t"
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"and\t%1, %0\n\t"
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"ldc\t%0, sr\n\t"
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: "=&r" (sr)
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: "r" (~SR_DSP)
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);
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}
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static void __init dsp_init(void)
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{
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unsigned long sr;
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/*
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* Set the SR.DSP bit, wait for one instruction, and then read
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* back the SR value.
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*/
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__asm__ __volatile__ (
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"stc\tsr, %0\n\t"
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"or\t%1, %0\n\t"
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"ldc\t%0, sr\n\t"
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"nop\n\t"
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"stc\tsr, %0\n\t"
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: "=&r" (sr)
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: "r" (SR_DSP)
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);
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/* If the DSP bit is still set, this CPU has a DSP */
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if (sr & SR_DSP)
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current_cpu_data.flags |= CPU_HAS_DSP;
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/* Now that we've determined the DSP status, clear the DSP bit. */
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release_dsp();
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}
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#endif /* CONFIG_SH_DSP */
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/**
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* sh_cpu_init
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*
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* This is our initial entry point for each CPU, and is invoked on the boot
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* CPU prior to calling start_kernel(). For SMP, a combination of this and
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* start_secondary() will bring up each processor to a ready state prior
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* to hand forking the idle loop.
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*
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* We do all of the basic processor init here, including setting up the
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* caches, FPU, DSP, kicking the UBC, etc. By the time start_kernel() is
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* hit (and subsequently platform_setup()) things like determining the
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* CPU subtype and initial configuration will all be done.
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*
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* Each processor family is still responsible for doing its own probing
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* and cache configuration in detect_cpu_and_cache_system().
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*/
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asmlinkage void __cpuinit sh_cpu_init(void)
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{
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current_thread_info()->cpu = hard_smp_processor_id();
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/* First, probe the CPU */
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detect_cpu_and_cache_system();
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if (current_cpu_data.type == CPU_SH_NONE)
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panic("Unknown CPU");
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/* First setup the rest of the I-cache info */
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current_cpu_data.icache.entry_mask = current_cpu_data.icache.way_incr -
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current_cpu_data.icache.linesz;
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current_cpu_data.icache.way_size = current_cpu_data.icache.sets *
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current_cpu_data.icache.linesz;
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/* And the D-cache too */
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current_cpu_data.dcache.entry_mask = current_cpu_data.dcache.way_incr -
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current_cpu_data.dcache.linesz;
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current_cpu_data.dcache.way_size = current_cpu_data.dcache.sets *
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current_cpu_data.dcache.linesz;
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/* Init the cache */
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cache_init();
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if (raw_smp_processor_id() == 0)
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shm_align_mask = max_t(unsigned long,
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current_cpu_data.dcache.way_size - 1,
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PAGE_SIZE - 1);
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/* Disable the FPU */
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if (fpu_disabled) {
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printk("FPU Disabled\n");
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current_cpu_data.flags &= ~CPU_HAS_FPU;
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disable_fpu();
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}
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/* FPU initialization */
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if ((current_cpu_data.flags & CPU_HAS_FPU)) {
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clear_thread_flag(TIF_USEDFPU);
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clear_used_math();
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}
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/*
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* Initialize the per-CPU ASID cache very early, since the
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* TLB flushing routines depend on this being setup.
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*/
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current_cpu_data.asid_cache = NO_CONTEXT;
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#ifdef CONFIG_SH_DSP
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/* Probe for DSP */
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dsp_init();
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/* Disable the DSP */
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if (dsp_disabled) {
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printk("DSP Disabled\n");
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current_cpu_data.flags &= ~CPU_HAS_DSP;
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release_dsp();
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}
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#endif
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/*
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* Some brain-damaged loaders decided it would be a good idea to put
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* the UBC to sleep. This causes some issues when it comes to things
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* like PTRACE_SINGLESTEP or doing hardware watchpoints in GDB. So ..
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* we wake it up and hope that all is well.
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*/
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#ifdef CONFIG_SUPERH32
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if (raw_smp_processor_id() == 0)
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ubc_wakeup();
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#endif
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speculative_execution_init();
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}
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