cregit-Linux how code gets into the kernel

Release 4.14 arch/sh/kernel/cpu/init.c

/*
 * arch/sh/kernel/cpu/init.c
 *
 * CPU init code
 *
 * Copyright (C) 2002 - 2009  Paul Mundt
 * Copyright (C) 2003  Richard Curnow
 *
 * 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 <linux/mm.h>
#include <linux/log2.h>
#include <asm/mmu_context.h>
#include <asm/processor.h>
#include <linux/uaccess.h>
#include <asm/page.h>
#include <asm/cacheflush.h>
#include <asm/cache.h>
#include <asm/elf.h>
#include <asm/io.h>
#include <asm/smp.h>
#include <asm/sh_bios.h>
#include <asm/setup.h>

#ifdef CONFIG_SH_FPU

#define cpu_has_fpu	1
#else

#define cpu_has_fpu	0
#endif

#ifdef CONFIG_SH_DSP

#define cpu_has_dsp	1
#else

#define cpu_has_dsp	0
#endif

/*
 * Generic wrapper for command line arguments to disable on-chip
 * peripherals (nofpu, nodsp, and so forth).
 */

#define onchip_setup(x)					\
static int x##_disabled = !cpu_has_##x;                 \
                                                        \
static int x##_setup(char *opts)                        \
{                                                       \
        x##_disabled = 1;                               \
        return 1;                                       \
}                                                       \
__setup("no" __stringify(x), x##_setup);


onchip_setup(fpu);

onchip_setup(dsp);

#ifdef CONFIG_SPECULATIVE_EXECUTION

#define CPUOPM		0xff2f0000

#define CPUOPM_RABD	(1 << 5)


static void speculative_execution_init(void) { /* Clear RABD */ __raw_writel(__raw_readl(CPUOPM) & ~CPUOPM_RABD, CPUOPM); /* Flush the update */ (void)__raw_readl(CPUOPM); ctrl_barrier(); }

Contributors

PersonTokensPropCommitsCommitProp
Paul Mundt34100.00%2100.00%
Total34100.00%2100.00%

#else #define speculative_execution_init() do { } while (0) #endif #ifdef CONFIG_CPU_SH4A #define EXPMASK 0xff2f0004 #define EXPMASK_RTEDS (1 << 0) #define EXPMASK_BRDSSLP (1 << 1) #define EXPMASK_MMCAW (1 << 4)
static void expmask_init(void) { unsigned long expmask = __raw_readl(EXPMASK); /* * Future proofing. * * Disable support for slottable sleep instruction, non-nop * instructions in the rte delay slot, and associative writes to * the memory-mapped cache array. */ expmask &= ~(EXPMASK_RTEDS | EXPMASK_BRDSSLP | EXPMASK_MMCAW); __raw_writel(expmask, EXPMASK); ctrl_barrier(); }

Contributors

PersonTokensPropCommitsCommitProp
Paul Mundt39100.00%2100.00%
Total39100.00%2100.00%

#else #define expmask_init() do { } while (0) #endif /* 2nd-level cache init */ void __attribute__ ((weak)) l2_cache_init(void) { } /* * Generic first-level cache init */ #if defined(CONFIG_SUPERH32) && !defined(CONFIG_CPU_J2)
static void cache_init(void) { unsigned long ccr, flags; jump_to_uncached(); ccr = __raw_readl(SH_CCR); /* * At this point we don't know whether the cache is enabled or not - a * bootloader may have enabled it. There are at least 2 things that * could be dirty in the cache at this point: * 1. kernel command line set up by boot loader * 2. spilled registers from the prolog of this function * => before re-initialising the cache, we must do a purge of the whole * cache out to memory for safety. As long as nothing is spilled * during the loop to lines that have already been done, this is safe. * - RPC */ if (ccr & CCR_CACHE_ENABLE) { unsigned long ways, waysize, addrstart; waysize = current_cpu_data.dcache.sets; #ifdef CCR_CACHE_ORA /* * If the OC is already in RAM mode, we only have * half of the entries to flush.. */ if (ccr & CCR_CACHE_ORA) waysize >>= 1; #endif waysize <<= current_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 = current_cpu_data.dcache.ways; addrstart = CACHE_OC_ADDRESS_ARRAY; do { unsigned long addr; for (addr = addrstart; addr < addrstart + waysize; addr += current_cpu_data.dcache.linesz) __raw_writel(0, addr); addrstart += current_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 (current_cpu_data.dcache.ways > 1) flags |= CCR_CACHE_EMODE; else flags &= ~CCR_CACHE_EMODE; #endif #if defined(CONFIG_CACHE_WRITETHROUGH) /* Write-through */ flags |= CCR_CACHE_WT; #elif defined(CONFIG_CACHE_WRITEBACK) /* Write-back */ flags |= CCR_CACHE_CB; #else /* Off */ flags &= ~CCR_CACHE_ENABLE; #endif l2_cache_init(); __raw_writel(flags, SH_CCR); back_to_cached(); }

Contributors

PersonTokensPropCommitsCommitProp
Andrew Morton17475.32%218.18%
Paul Mundt3816.45%436.36%
Richard Curnow73.03%19.09%
Yoshinori Sato52.16%19.09%
Kuninori Morimoto31.30%19.09%
Stuart Menefy20.87%19.09%
Geert Uytterhoeven20.87%19.09%
Total231100.00%11100.00%

#else #define cache_init() do { } while (0) #endif #define CSHAPE(totalsize, linesize, assoc) \ ((totalsize & ~0xff) | (linesize << 4) | assoc) #define CACHE_DESC_SHAPE(desc) \ CSHAPE((desc).way_size * (desc).ways, ilog2((desc).linesz), (desc).ways)
static void detect_cache_shape(void) { l1d_cache_shape = CACHE_DESC_SHAPE(current_cpu_data.dcache); if (current_cpu_data.dcache.flags & SH_CACHE_COMBINED) l1i_cache_shape = l1d_cache_shape; else l1i_cache_shape = CACHE_DESC_SHAPE(current_cpu_data.icache); if (current_cpu_data.flags & CPU_HAS_L2_CACHE) l2_cache_shape = CACHE_DESC_SHAPE(current_cpu_data.scache); else l2_cache_shape = -1; /* No S-cache */ }

Contributors

PersonTokensPropCommitsCommitProp
Paul Mundt65100.00%1100.00%
Total65100.00%1100.00%


static void fpu_init(void) { /* Disable the FPU */ if (fpu_disabled && (current_cpu_data.flags & CPU_HAS_FPU)) { printk("FPU Disabled\n"); current_cpu_data.flags &= ~CPU_HAS_FPU; } disable_fpu(); clear_used_math(); }

Contributors

PersonTokensPropCommitsCommitProp
Paul Mundt41100.00%1100.00%
Total41100.00%1100.00%

#ifdef CONFIG_SH_DSP
static void 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) ); }

Contributors

PersonTokensPropCommitsCommitProp
Andrew Morton16100.00%1100.00%
Total16100.00%1100.00%


static void 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) current_cpu_data.flags |= CPU_HAS_DSP; /* Disable the DSP */ if (dsp_disabled && (current_cpu_data.flags & CPU_HAS_DSP)) { printk("DSP Disabled\n"); current_cpu_data.flags &= ~CPU_HAS_DSP; } /* Now that we've determined the DSP status, clear the DSP bit. */ release_dsp(); }

Contributors

PersonTokensPropCommitsCommitProp
Andrew Morton3151.67%250.00%
Paul Mundt2948.33%250.00%
Total60100.00%4100.00%

#else
static inline void dsp_init(void) { }

Contributors

PersonTokensPropCommitsCommitProp
Paul Mundt8100.00%1100.00%
Total8100.00%1100.00%

#endif /* CONFIG_SH_DSP */ /** * 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, 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 cpu_probe(). */
asmlinkage void cpu_init(void) { current_thread_info()->cpu = hard_smp_processor_id(); /* First, probe the CPU */ cpu_probe(); if (current_cpu_data.type == CPU_SH_NONE) panic("Unknown CPU"); /* First setup the rest of the I-cache info */ current_cpu_data.icache.entry_mask = current_cpu_data.icache.way_incr - current_cpu_data.icache.linesz; current_cpu_data.icache.way_size = current_cpu_data.icache.sets * current_cpu_data.icache.linesz; /* And the D-cache too */ current_cpu_data.dcache.entry_mask = current_cpu_data.dcache.way_incr - current_cpu_data.dcache.linesz; current_cpu_data.dcache.way_size = current_cpu_data.dcache.sets * current_cpu_data.dcache.linesz; /* Init the cache */ cache_init(); if (raw_smp_processor_id() == 0) { #ifdef CONFIG_MMU shm_align_mask = max_t(unsigned long, current_cpu_data.dcache.way_size - 1, PAGE_SIZE - 1); #else shm_align_mask = PAGE_SIZE - 1; #endif /* Boot CPU sets the cache shape */ detect_cache_shape(); } fpu_init(); dsp_init(); /* * Initialize the per-CPU ASID cache very early, since the * TLB flushing routines depend on this being setup. */ current_cpu_data.asid_cache = NO_CONTEXT; current_cpu_data.phys_bits = __in_29bit_mode() ? 29 : 32; speculative_execution_init(); expmask_init(); /* Do the rest of the boot processor setup */ if (raw_smp_processor_id() == 0) { /* Save off the BIOS VBR, if there is one */ sh_bios_vbr_init(); /* * Setup VBR for boot CPU. Secondary CPUs do this through * start_secondary(). */ per_cpu_trap_init(); /* * Boot processor to setup the FP and extended state * context info. */ init_thread_xstate(); } }

Contributors

PersonTokensPropCommitsCommitProp
Paul Mundt16782.67%1477.78%
Andrew Morton209.90%15.56%
Rich Felker136.44%15.56%
Stuart Menefy10.50%15.56%
Andrea Arcangeli10.50%15.56%
Total202100.00%18100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Paul Mundt55461.35%2058.82%
Andrew Morton28631.67%25.88%
Rich Felker242.66%25.88%
Kuninori Morimoto161.77%12.94%
Richard Curnow70.78%12.94%
Yoshinori Sato50.55%12.94%
David Howells30.33%12.94%
Stuart Menefy30.33%25.88%
Geert Uytterhoeven20.22%12.94%
Paul Gortmaker10.11%12.94%
Linus Torvalds10.11%12.94%
Andrea Arcangeli10.11%12.94%
Total903100.00%34100.00%
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