arch/mips/mm/sc-ip22.c

Source file repositories/reference/linux-study-clean/arch/mips/mm/sc-ip22.c

File Facts

System
Linux kernel
Corpus path
arch/mips/mm/sc-ip22.c
Extension
.c
Size
4334 bytes
Lines
191
Domain
Architecture Layer
Bucket
arch/mips
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0
/*
 * sc-ip22.c: Indy cache management functions.
 *
 * Copyright (C) 1997, 2001 Ralf Baechle (ralf@gnu.org),
 * derived from r4xx0.c by David S. Miller (davem@davemloft.net).
 */
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>

#include <asm/bcache.h>
#include <asm/page.h>
#include <asm/bootinfo.h>
#include <asm/sgi/ip22.h>
#include <asm/sgi/mc.h>

/* Secondary cache size in bytes, if present.  */
static unsigned long scache_size;

#undef DEBUG_CACHE

#define SC_SIZE 0x00080000
#define SC_LINE 32
#define CI_MASK (SC_SIZE - SC_LINE)
#define SC_INDEX(n) ((n) & CI_MASK)

static inline void indy_sc_wipe(unsigned long first, unsigned long last)
{
	unsigned long tmp;

	__asm__ __volatile__(
	"	.set	push			# indy_sc_wipe		\n"
	"	.set	noreorder					\n"
	"	.set	mips3						\n"
	"	.set	noat						\n"
	"	mfc0	%2, $12						\n"
	"	li	$1, 0x80		# Go 64 bit		\n"
	"	mtc0	$1, $12						\n"
	"								\n"
	"	#							\n"
	"	# Open code a dli $1, 0x9000000080000000		\n"
	"	#							\n"
	"	# Required because binutils 2.25 will happily accept	\n"
	"	# 64 bit instructions in .set mips3 mode but puke on	\n"
	"	# 64 bit constants when generating 32 bit ELF		\n"
	"	#							\n"
	"	lui	$1,0x9000					\n"
	"	dsll	$1,$1,0x10					\n"
	"	ori	$1,$1,0x8000					\n"
	"	dsll	$1,$1,0x10					\n"
	"								\n"
	"	or	%0, $1			# first line to flush	\n"
	"	or	%1, $1			# last line to flush	\n"
	"	.set	at						\n"
	"								\n"
	"1:	sw	$0, 0(%0)					\n"
	"	bne	%0, %1, 1b					\n"
	"	 daddu	%0, 32						\n"
	"								\n"
	"	mtc0	%2, $12			# Back to 32 bit	\n"
	"	nop				# pipeline hazard	\n"
	"	nop							\n"
	"	nop							\n"
	"	nop							\n"
	"	.set	pop						\n"
	: "=r" (first), "=r" (last), "=&r" (tmp)
	: "0" (first), "1" (last));
}

static void indy_sc_wback_invalidate(unsigned long addr, unsigned long size)
{
	unsigned long first_line, last_line;
	unsigned long flags;

#ifdef DEBUG_CACHE
	printk("indy_sc_wback_invalidate[%08lx,%08lx]", addr, size);
#endif

	/* Catch bad driver code */
	BUG_ON(size == 0);

	/* Which lines to flush?  */
	first_line = SC_INDEX(addr);
	last_line = SC_INDEX(addr + size - 1);

	local_irq_save(flags);
	if (first_line <= last_line) {
		indy_sc_wipe(first_line, last_line);

Annotation

Implementation Notes