![Maciej W. Rozycki](/assets/img/avatar_default.png)
Contrary to the belief of some, the R3000 and related processors did have caches, both a data and an instruction cache. Here is an implementation of r3k_flush_cache_page(), which is the processor-specific back-end for flush_cache_range(), done according to the spec in Documentation/cachetlb.txt. While at it, remove an unused local function: get_phys_page(), do some trivial formatting fixes and modernise debugging facilities. Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
340 lines
7.8 KiB
C
340 lines
7.8 KiB
C
/*
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* r2300.c: R2000 and R3000 specific mmu/cache code.
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*
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* Copyright (C) 1996 David S. Miller (dm@engr.sgi.com)
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*
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* with a lot of changes to make this thing work for R3000s
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* Tx39XX R4k style caches added. HK
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* Copyright (C) 1998, 1999, 2000 Harald Koerfgen
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* Copyright (C) 1998 Gleb Raiko & Vladimir Roganov
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* Copyright (C) 2001, 2004, 2007 Maciej W. Rozycki
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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/sched.h>
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#include <linux/mm.h>
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#include <asm/page.h>
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#include <asm/pgtable.h>
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#include <asm/mmu_context.h>
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#include <asm/system.h>
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#include <asm/isadep.h>
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#include <asm/io.h>
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#include <asm/bootinfo.h>
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#include <asm/cpu.h>
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static unsigned long icache_size, dcache_size; /* Size in bytes */
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static unsigned long icache_lsize, dcache_lsize; /* Size in bytes */
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unsigned long __init r3k_cache_size(unsigned long ca_flags)
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{
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unsigned long flags, status, dummy, size;
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volatile unsigned long *p;
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p = (volatile unsigned long *) KSEG0;
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flags = read_c0_status();
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/* isolate cache space */
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write_c0_status((ca_flags|flags)&~ST0_IEC);
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*p = 0xa5a55a5a;
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dummy = *p;
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status = read_c0_status();
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if (dummy != 0xa5a55a5a || (status & ST0_CM)) {
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size = 0;
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} else {
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for (size = 128; size <= 0x40000; size <<= 1)
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*(p + size) = 0;
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*p = -1;
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for (size = 128;
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(size <= 0x40000) && (*(p + size) == 0);
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size <<= 1)
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;
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if (size > 0x40000)
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size = 0;
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}
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write_c0_status(flags);
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return size * sizeof(*p);
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}
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unsigned long __init r3k_cache_lsize(unsigned long ca_flags)
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{
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unsigned long flags, status, lsize, i;
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volatile unsigned long *p;
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p = (volatile unsigned long *) KSEG0;
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flags = read_c0_status();
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/* isolate cache space */
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write_c0_status((ca_flags|flags)&~ST0_IEC);
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for (i = 0; i < 128; i++)
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*(p + i) = 0;
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*(volatile unsigned char *)p = 0;
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for (lsize = 1; lsize < 128; lsize <<= 1) {
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*(p + lsize);
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status = read_c0_status();
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if (!(status & ST0_CM))
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break;
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}
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for (i = 0; i < 128; i += lsize)
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*(volatile unsigned char *)(p + i) = 0;
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write_c0_status(flags);
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return lsize * sizeof(*p);
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}
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static void __init r3k_probe_cache(void)
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{
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dcache_size = r3k_cache_size(ST0_ISC);
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if (dcache_size)
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dcache_lsize = r3k_cache_lsize(ST0_ISC);
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icache_size = r3k_cache_size(ST0_ISC|ST0_SWC);
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if (icache_size)
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icache_lsize = r3k_cache_lsize(ST0_ISC|ST0_SWC);
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}
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static void r3k_flush_icache_range(unsigned long start, unsigned long end)
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{
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unsigned long size, i, flags;
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volatile unsigned char *p;
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size = end - start;
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if (size > icache_size || KSEGX(start) != KSEG0) {
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start = KSEG0;
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size = icache_size;
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}
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p = (char *)start;
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flags = read_c0_status();
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/* isolate cache space */
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write_c0_status((ST0_ISC|ST0_SWC|flags)&~ST0_IEC);
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for (i = 0; i < size; i += 0x080) {
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asm( "sb\t$0, 0x000(%0)\n\t"
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"sb\t$0, 0x004(%0)\n\t"
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"sb\t$0, 0x008(%0)\n\t"
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"sb\t$0, 0x00c(%0)\n\t"
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"sb\t$0, 0x010(%0)\n\t"
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"sb\t$0, 0x014(%0)\n\t"
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"sb\t$0, 0x018(%0)\n\t"
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"sb\t$0, 0x01c(%0)\n\t"
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"sb\t$0, 0x020(%0)\n\t"
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"sb\t$0, 0x024(%0)\n\t"
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"sb\t$0, 0x028(%0)\n\t"
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"sb\t$0, 0x02c(%0)\n\t"
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"sb\t$0, 0x030(%0)\n\t"
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"sb\t$0, 0x034(%0)\n\t"
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"sb\t$0, 0x038(%0)\n\t"
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"sb\t$0, 0x03c(%0)\n\t"
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"sb\t$0, 0x040(%0)\n\t"
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"sb\t$0, 0x044(%0)\n\t"
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"sb\t$0, 0x048(%0)\n\t"
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"sb\t$0, 0x04c(%0)\n\t"
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"sb\t$0, 0x050(%0)\n\t"
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"sb\t$0, 0x054(%0)\n\t"
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"sb\t$0, 0x058(%0)\n\t"
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"sb\t$0, 0x05c(%0)\n\t"
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"sb\t$0, 0x060(%0)\n\t"
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"sb\t$0, 0x064(%0)\n\t"
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"sb\t$0, 0x068(%0)\n\t"
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"sb\t$0, 0x06c(%0)\n\t"
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"sb\t$0, 0x070(%0)\n\t"
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"sb\t$0, 0x074(%0)\n\t"
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"sb\t$0, 0x078(%0)\n\t"
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"sb\t$0, 0x07c(%0)\n\t"
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: : "r" (p) );
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p += 0x080;
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}
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write_c0_status(flags);
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}
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static void r3k_flush_dcache_range(unsigned long start, unsigned long end)
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{
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unsigned long size, i, flags;
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volatile unsigned char *p;
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size = end - start;
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if (size > dcache_size || KSEGX(start) != KSEG0) {
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start = KSEG0;
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size = dcache_size;
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}
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p = (char *)start;
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flags = read_c0_status();
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/* isolate cache space */
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write_c0_status((ST0_ISC|flags)&~ST0_IEC);
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for (i = 0; i < size; i += 0x080) {
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asm( "sb\t$0, 0x000(%0)\n\t"
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"sb\t$0, 0x004(%0)\n\t"
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"sb\t$0, 0x008(%0)\n\t"
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"sb\t$0, 0x00c(%0)\n\t"
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"sb\t$0, 0x010(%0)\n\t"
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"sb\t$0, 0x014(%0)\n\t"
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"sb\t$0, 0x018(%0)\n\t"
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"sb\t$0, 0x01c(%0)\n\t"
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"sb\t$0, 0x020(%0)\n\t"
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"sb\t$0, 0x024(%0)\n\t"
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"sb\t$0, 0x028(%0)\n\t"
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"sb\t$0, 0x02c(%0)\n\t"
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"sb\t$0, 0x030(%0)\n\t"
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"sb\t$0, 0x034(%0)\n\t"
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"sb\t$0, 0x038(%0)\n\t"
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"sb\t$0, 0x03c(%0)\n\t"
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"sb\t$0, 0x040(%0)\n\t"
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"sb\t$0, 0x044(%0)\n\t"
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"sb\t$0, 0x048(%0)\n\t"
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"sb\t$0, 0x04c(%0)\n\t"
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"sb\t$0, 0x050(%0)\n\t"
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"sb\t$0, 0x054(%0)\n\t"
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"sb\t$0, 0x058(%0)\n\t"
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"sb\t$0, 0x05c(%0)\n\t"
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"sb\t$0, 0x060(%0)\n\t"
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"sb\t$0, 0x064(%0)\n\t"
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"sb\t$0, 0x068(%0)\n\t"
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"sb\t$0, 0x06c(%0)\n\t"
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"sb\t$0, 0x070(%0)\n\t"
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"sb\t$0, 0x074(%0)\n\t"
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"sb\t$0, 0x078(%0)\n\t"
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"sb\t$0, 0x07c(%0)\n\t"
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: : "r" (p) );
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p += 0x080;
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}
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write_c0_status(flags);
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}
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static inline void r3k_flush_cache_all(void)
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{
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}
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static inline void r3k___flush_cache_all(void)
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{
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r3k_flush_dcache_range(KSEG0, KSEG0 + dcache_size);
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r3k_flush_icache_range(KSEG0, KSEG0 + icache_size);
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}
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static void r3k_flush_cache_mm(struct mm_struct *mm)
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{
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}
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static void r3k_flush_cache_range(struct vm_area_struct *vma,
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unsigned long start, unsigned long end)
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{
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}
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static void r3k_flush_cache_page(struct vm_area_struct *vma,
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unsigned long addr, unsigned long pfn)
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{
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unsigned long kaddr = KSEG0ADDR(pfn << PAGE_SHIFT);
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int exec = vma->vm_flags & VM_EXEC;
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struct mm_struct *mm = vma->vm_mm;
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pgd_t *pgdp;
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pud_t *pudp;
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pmd_t *pmdp;
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pte_t *ptep;
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pr_debug("cpage[%08lx,%08lx]\n",
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cpu_context(smp_processor_id(), mm), addr);
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/* No ASID => no such page in the cache. */
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if (cpu_context(smp_processor_id(), mm) == 0)
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return;
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pgdp = pgd_offset(mm, addr);
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pudp = pud_offset(pgdp, addr);
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pmdp = pmd_offset(pudp, addr);
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ptep = pte_offset(pmdp, addr);
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/* Invalid => no such page in the cache. */
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if (!(pte_val(*ptep) & _PAGE_PRESENT))
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return;
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r3k_flush_dcache_range(kaddr, kaddr + PAGE_SIZE);
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if (exec)
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r3k_flush_icache_range(kaddr, kaddr + PAGE_SIZE);
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}
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static void local_r3k_flush_data_cache_page(void *addr)
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{
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}
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static void r3k_flush_data_cache_page(unsigned long addr)
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{
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}
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static void r3k_flush_cache_sigtramp(unsigned long addr)
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{
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unsigned long flags;
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pr_debug("csigtramp[%08lx]\n", addr);
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flags = read_c0_status();
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write_c0_status(flags&~ST0_IEC);
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/* Fill the TLB to avoid an exception with caches isolated. */
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asm( "lw\t$0, 0x000(%0)\n\t"
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"lw\t$0, 0x004(%0)\n\t"
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: : "r" (addr) );
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write_c0_status((ST0_ISC|ST0_SWC|flags)&~ST0_IEC);
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asm( "sb\t$0, 0x000(%0)\n\t"
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"sb\t$0, 0x004(%0)\n\t"
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: : "r" (addr) );
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write_c0_status(flags);
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}
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static void r3k_dma_cache_wback_inv(unsigned long start, unsigned long size)
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{
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/* Catch bad driver code */
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BUG_ON(size == 0);
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iob();
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r3k_flush_dcache_range(start, start + size);
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}
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void __init r3k_cache_init(void)
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{
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extern void build_clear_page(void);
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extern void build_copy_page(void);
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r3k_probe_cache();
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flush_cache_all = r3k_flush_cache_all;
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__flush_cache_all = r3k___flush_cache_all;
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flush_cache_mm = r3k_flush_cache_mm;
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flush_cache_range = r3k_flush_cache_range;
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flush_cache_page = r3k_flush_cache_page;
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flush_icache_range = r3k_flush_icache_range;
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flush_cache_sigtramp = r3k_flush_cache_sigtramp;
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local_flush_data_cache_page = local_r3k_flush_data_cache_page;
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flush_data_cache_page = r3k_flush_data_cache_page;
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_dma_cache_wback_inv = r3k_dma_cache_wback_inv;
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_dma_cache_wback = r3k_dma_cache_wback_inv;
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_dma_cache_inv = r3k_dma_cache_wback_inv;
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printk("Primary instruction cache %ldkB, linesize %ld bytes.\n",
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icache_size >> 10, icache_lsize);
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printk("Primary data cache %ldkB, linesize %ld bytes.\n",
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dcache_size >> 10, dcache_lsize);
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build_clear_page();
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build_copy_page();
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}
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