Better interface to run uncached cache setup code. (ba5187db) · Commits · EulixOS / Software / Kernel

arch/mips/lib/Makefile

+2 −2

Original line number	Diff line number	Diff line
		@@ -2,8 +2,8 @@
		# Makefile for MIPS-specific library files..
		#

		lib-y += csum_partial_copy.o memcpy.o promlib.o \
		strlen_user.o strncpy_user.o strnlen_user.o
		lib-y += csum_partial_copy.o memcpy.o promlib.o strlen_user.o strncpy_user.o \
		strnlen_user.o uncached.o

		obj-y += iomap.o

arch/mips/lib/uncached.c

0 → 100644

+76 −0

Original line number	Diff line number	Diff line
		/*
		* 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.
		*
		* Copyright (C) 2005 Thiemo Seufer
		* Copyright (C) 2005 MIPS Technologies, Inc. All rights reserved.
		* Author: Maciej W. Rozycki <macro@mips.com>
		*/

		#include <linux/init.h>

		#include <asm/addrspace.h>
		#include <asm/bug.h>

		#ifndef CKSEG2
		#define CKSEG2 CKSSEG
		#endif
		#ifndef TO_PHYS_MASK
		#define TO_PHYS_MASK -1
		#endif

		/*
		* FUNC is executed in one of the uncached segments, depending on its
		* original address as follows:
		*
		* 1. If the original address is in CKSEG0 or CKSEG1, then the uncached
		* segment used is CKSEG1.
		* 2. If the original address is in XKPHYS, then the uncached segment
		* used is XKPHYS(2).
		* 3. Otherwise it's a bug.
		*
		* The same remapping is done with the stack pointer. Stack handling
		* works because we don't handle stack arguments or more complex return
		* values, so we can avoid sharing the same stack area between a cached
		* and the uncached mode.
		*/
		unsigned long __init run_uncached(void *func)
		{
		register long sp __asm__("$sp");
		register long ret __asm__("$2");
		long lfunc = (long)func, ufunc;
		long usp;

		if (sp >= (long)CKSEG0 && sp < (long)CKSEG2)
		usp = CKSEG1ADDR(sp);
		else if ((long long)sp >= (long long)PHYS_TO_XKPHYS(0LL, 0) &&
		(long long)sp < (long long)PHYS_TO_XKPHYS(8LL, 0))
		usp = PHYS_TO_XKPHYS((long long)K_CALG_UNCACHED,
		XKPHYS_TO_PHYS((long long)sp));
		else {
		BUG();
		usp = sp;
		}
		if (lfunc >= (long)CKSEG0 && lfunc < (long)CKSEG2)
		ufunc = CKSEG1ADDR(lfunc);
		else if ((long long)lfunc >= (long long)PHYS_TO_XKPHYS(0LL, 0) &&
		(long long)lfunc < (long long)PHYS_TO_XKPHYS(8LL, 0))
		ufunc = PHYS_TO_XKPHYS((long long)K_CALG_UNCACHED,
		XKPHYS_TO_PHYS((long long)lfunc));
		else {
		BUG();
		ufunc = lfunc;
		}

		__asm__ __volatile__ (
		" move $16, $sp\n"
		" move $sp, %1\n"
		" jalr %2\n"
		" move $sp, $16"
		: "=r" (ret)
		: "r" (usp), "r" (ufunc)
		: "$16", "$31");

		return ret;
		}

arch/mips/mm/c-r4k.c

+2 −4

Original line number	Diff line number	Diff line
		@@ -26,6 +26,7 @@
		#include <asm/system.h>
		#include <asm/mmu_context.h>
		#include <asm/war.h>
		#include <asm/cacheflush.h> /* for run_uncached() */

		static unsigned long icache_size, dcache_size, scache_size;

		@@ -1119,7 +1120,6 @@ static int __init probe_scache(void)
		return 1;
		}

		typedef int (*probe_func_t)(unsigned long);
		extern int r5k_sc_init(void);
		extern int rm7k_sc_init(void);

		@@ -1127,7 +1127,6 @@ static void __init setup_scache(void)
		{
		struct cpuinfo_mips *c = &current_cpu_data;
		unsigned int config = read_c0_config();
		probe_func_t probe_scache_kseg1;
		int sc_present = 0;

		/*
		@@ -1140,8 +1139,7 @@ static void __init setup_scache(void)
		case CPU_R4000MC:
		case CPU_R4400SC:
		case CPU_R4400MC:
		probe_scache_kseg1 = (probe_func_t) (CKSEG1ADDR(&probe_scache));
		sc_present = probe_scache_kseg1(config);
		sc_present = run_uncached(probe_scache);
		if (sc_present)
		c->options \|= MIPS_CPU_CACHE_CDEX_S;
		break;

arch/mips/mm/sc-rm7k.c

+8 −21

Original line number	Diff line number	Diff line
		@@ -15,6 +15,7 @@
		#include <asm/cacheops.h>
		#include <asm/mipsregs.h>
		#include <asm/processor.h>
		#include <asm/cacheflush.h> /* for run_uncached() */

		/* Primary cache parameters. */
		#define sc_lsize 32
		@@ -96,25 +97,13 @@ static void rm7k_sc_inv(unsigned long addr, unsigned long size)
		}

		/*
		* This function is executed in the uncached segment CKSEG1.
		* It must not touch the stack, because the stack pointer still points
		* into CKSEG0.
		*
		* Three options:
		* - Write it in assembly and guarantee that we don't use the stack.
		* - Disable caching for CKSEG0 before calling it.
		* - Pray that GCC doesn't randomly start using the stack.
		*
		* This being Linux, we obviously take the least sane of those options -
		* following DaveM's lead in c-r4k.c
		*
		* It seems we get our kicks from relying on unguaranteed behaviour in GCC
		* This function is executed in uncached address space.
		*/
		static __init void __rm7k_sc_enable(void)
		{
		int i;

		set_c0_config(1 << 3); /* CONF_SE */
		set_c0_config(R7K_CONF_SE);

		write_c0_taglo(0);
		write_c0_taghi(0);
		@@ -127,24 +116,22 @@ static __init void __rm7k_sc_enable(void)
		".set mips0\n\t"
		".set reorder"
		:
		: "r" (KSEG0ADDR(i)), "i" (Index_Store_Tag_SD));
		: "r" (CKSEG0ADDR(i)), "i" (Index_Store_Tag_SD));
		}
		}

		static __init void rm7k_sc_enable(void)
		{
		void (func)(void) = (void ) KSEG1ADDR(&__rm7k_sc_enable);

		if (read_c0_config() & 0x08) /* CONF_SE */
		if (read_c0_config() & R7K_CONF_SE)
		return;

		printk(KERN_INFO "Enabling secondary cache...");
		func();
		run_uncached(__rm7k_sc_enable);
		}

		static void rm7k_sc_disable(void)
		{
		clear_c0_config(1<<3); /* CONF_SE */
		clear_c0_config(R7K_CONF_SE);
		}

		struct bcache_ops rm7k_sc_ops = {
		@@ -164,7 +151,7 @@ void __init rm7k_sc_init(void)
		printk(KERN_INFO "Secondary cache size %dK, linesize %d bytes.\n",
		(scache_size >> 10), sc_lsize);

		if (!((config >> 3) & 1)) /* CONF_SE */
		if (!(config & R7K_CONF_SE))
		rm7k_sc_enable();

		/*

include/asm-mips/cacheflush.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -90,4 +90,7 @@ extern void (*flush_data_cache_page)(unsigned long addr);
		#define ClearPageDcacheDirty(page) \
		clear_bit(PG_dcache_dirty, &(page)->flags)

		/* Run kernel code uncached, useful for cache probing functions. */
		unsigned long __init run_uncached(void *func);

		#endif /* _ASM_CACHEFLUSH_H */