/*
* 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) 2003, 04, 05 Ralf Baechle (ralf@linux-mips.org)
* Copyright (C) 2007 Maciej W. Rozycki
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/proc_fs.h>
#include <asm/bugs.h>
#include <asm/cacheops.h>
#include <asm/inst.h>
#include <asm/io.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/prefetch.h>
#include <asm/system.h>
#include <asm/bootinfo.h>
#include <asm/mipsregs.h>
#include <asm/mmu_context.h>
#include <asm/cpu.h>
#include <asm/war.h>
#define half_scache_line_size() (cpu_scache_line_size() >> 1)
#define cpu_is_r4600_v1_x() ((read_c0_prid() & 0xfffffff0) == 0x00002010)
#define cpu_is_r4600_v2_x() ((read_c0_prid() & 0xfffffff0) == 0x00002020)
/*
* Maximum sizes:
*
* R4000 128 bytes S-cache: 0x58 bytes
* R4600 v1.7: 0x5c bytes
* R4600 v2.0: 0x60 bytes
* With prefetching, 16 byte strides 0xa0 bytes
*/
static unsigned int clear_page_array[0x130 / 4];
void clear_page(void * page) __attribute__((alias("clear_page_array")));
EXPORT_SYMBOL(clear_page);
/*
* Maximum sizes:
*
* R4000 128 bytes S-cache: 0x11c bytes
* R4600 v1.7: 0x080 bytes
* R4600 v2.0: 0x07c bytes
* With prefetching, 16 byte strides 0x0b8 bytes
*/
static unsigned int copy_page_array[0x148 / 4];
void copy_page(void *to, void *from) __attribute__((alias("copy_page_array")));
EXPORT_SYMBOL(copy_page);
/*
* This is suboptimal for 32-bit kernels; we assume that R10000 is only used
* with 64-bit kernels. The prefetch offsets have been experimentally tuned
* an Origin 200.
*/
static int pref_offset_clear __initdata = 512;
static int pref_offset_copy __initdata = 256;
static unsigned int pref_src_mode __initdata;
static unsigned int pref_dst_mode __initdata;
static int load_offset __initdata;
static int store_offset __initdata;
static unsigned int __initdata *dest, *epc;
static unsigned int instruction_pending;
static union mips_instruction delayed_mi;
static void __init emit_instruction(union mips_instruction mi)
{
if (instruction_pending)
*epc++ = delayed_mi.word;
instruction_pending = 1;
delayed_mi = mi;
}
static inline void flush_delay_slot_or_nop(void)
{
if (instruction_pending) {
*epc++ = delayed_mi.word;
instruction_pending = 0;
return;
}
*epc++ = 0;
}
static inline unsigned int *label(void)
{
if (instruction_pending) {
*epc++ = delayed_mi.word;
instruction_pending = 0;
}
return epc;
}
static inline void build_insn_word(unsigned int word)
{
union mips_instruction mi;
mi.word = word;
emit_instruction(mi);
}
static inline void build_nop(void)
{
build_insn_word(0); /* nop */
}
static inline void build_src_pref(int advance)
{
if (!(load_offset & (cpu_dcache_line_size() - 1)) && advance) {
union mips_instruction mi;
mi.i_format.opcode = pref_op;
mi.i_format.rs = 5; /* $a1 */
mi.i_format.rt = pref_src_mode;
mi.i_format.simmediate = load_offset + advance;
emit_instruction(mi);
}
}
static inline void __build_load_reg(int reg)
{
union mips_instruction mi;
unsigned int width;
if (cpu_has_64bit_gp_regs) {
mi.i_format.opcode = ld_op;
width = 8;
} else {
mi.i_format.opcode = lw_op;
width = 4;
}
mi.i_format.rs = 5; /* $a1 */
mi.i_format.rt = reg; /* $reg */
mi.i_format.simmediate = load_offset;
load_offset += width;
emit_instruction(mi);
}
static inline void build_load_reg(int reg)
{
if (cpu_has_prefetch)
build_src_pref(pref_offset_copy);
__build_load_reg(reg);
}
static inline void build_dst_pref(int advance)
{
if (!(store_offset & (cpu_dcache_line_size() - 1)) && advance) {
union mips_instruction mi;
mi.i_format.opcode = pref_op;
mi.i_format.rs = 4; /* $a0 */
mi.i_format.rt = pref_dst_mode;
mi.i_format.simmediate = store_offset + advance;
emit_instruction(mi);
}
}
static inline void build_cdex_s(void)
{
union mips_instruction mi;
if ((store_offset & (cpu_scache_line_size() - 1)))
return;
mi.c_format.opcode = cache_op;
mi.c_format.rs = 4; /* $a0 */
mi.c_format.c_op = 3; /* Create Dirty Exclusive */
mi.c_format.cache = 3; /* Secondary Data Cache */
mi.c_format.simmediate = store_offset;
emit_instruction(mi);
}
static inline void build_cdex_p(void)
{
union mips_instruction mi;
if (store_offset & (cpu_dcache_line_size() - 1))
return;
if (R4600_V1_HIT_CACHEOP_WAR && cpu_is_r4600_v1_x()) {
build_nop();
build_nop();
build_nop();
build_nop();
}
if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
build_insn_word(0x8c200000); /* lw $zero, ($at) */
mi.c_format.opcode = cache_op;
mi.c_format.rs = 4; /* $a0 */
mi.c_format.c_op = 3; /* Create Dirty Exclusive */
mi.c_format.cache = 1; /* Data Cache */
mi.c_format.simmediate = store_offset;
emit_instruction(mi);
}
static void __init __build_store_reg(int reg)
{
union mips_instruction mi;
unsigned int width;
if (cpu_has_64bit_gp_regs ||
(cpu_has_64bit_zero_reg && reg == 0)) {
mi.i_format.opcode = sd_op;
width = 8;
} else {
mi.i_format.opcode = sw_op;
width = 4;
}
mi.i_format.rs = 4; /* $a0 */
mi.i_format.rt = reg; /* $reg */
mi.i_format.simmediate = store_offset;
store_offset += width;
emit_instruction(mi);
}
static inline void build_store_reg(int reg)
{
int pref_off = cpu_has_prefetch ?
(reg ? pref_offset_copy : pref_offset_clear) : 0;
if (pref_off)
build_dst_pref(pref_off);
else if (cpu_has_cache_cdex_s)
build_cdex_s();
else if (cpu_has_cache_cdex_p)
build_cdex_p();
__build_store_reg(reg);
}
static inline void build_addiu_rt_rs(unsigned int rt, unsigned int rs,
unsigned long offset)
{
union mips_instruction mi;
BUG_ON(offset > 0x7fff);
if (cpu_has_64bit_gp_regs && DADDI_WAR && r4k_daddiu_bug()) {
mi.i_format.opcode = addiu_op;
mi.i_format.rs = 0; /* $zero */
mi.i_format.rt = 25; /* $t9 */
mi.i_format.simmediate = offset;
emit_instruction(mi);
mi.r_format.opcode = spec_op;
mi.r_format.rs = rs;
mi.r_format.rt = 25; /* $t9 */
mi.r_format.rd = rt;
mi.r_format.re = 0;
mi.r_format.func = daddu_op;
} else {
mi.i_format.opcode = cpu_has_64bit_gp_regs ?
daddiu_op : addiu_op;
mi.i_format.rs = rs;
mi.i_format.rt = rt;
mi.i_format.simmediate = offset;
}
emit_instruction(mi);
}
static inline void build_addiu_a2_a0(unsigned long offset)
{
build_addiu_rt_rs(6, 4, offset); /* $a2, $a0, offset */
}
static inline void build_addiu_a2(unsigned long offset)
{
build_addiu_rt_rs(6, 6, offset); /* $a2, $a2, offset */
}
static inline void build_addiu_a1(unsigned long offset)
{
build_addiu_rt_rs(5, 5, offset); /* $a1, $a1, offset */
load_offset -= offset;
}
static inline void build_addiu_a0(unsigned long offset)
{
build_addiu_rt_rs(4, 4, offset); /* $a0, $a0, offset */
store_offset -= offset;
}
static inline void build_bne(unsigned int *dest)
{
union mips_instruction mi;
mi.i_format.opcode = bne_op;
mi.i_format.rs = 6; /* $a2 */
mi.i_format.rt = 4; /* $a0 */
mi.i_format.simmediate = dest - epc - 1;
*epc++ = mi.word;
flush_delay_slot_or_nop();
}
static inline void build_jr_ra(void)
{
union mips_instruction mi;
mi.r_format.opcode = spec_op;
mi.r_format.rs = 31;
mi.r_format.rt = 0;
mi.r_format.rd = 0;
mi.r_format.re = 0;
mi.r_format.func = jr_op;
*epc++ = mi.word;
flush_delay_slot_or_nop();
}
void __init build_clear_page(void)
{
unsigned int loop_start;
unsigned long off;
int i;
epc = (unsigned int *) &clear_page_array;
instruction_pending = 0;
store_offset = 0;
if (cpu_has_prefetch) {
switch (current_cpu_type()) {
case CPU_TX49XX:
/* TX49 supports only Pref_Load */
pref_offset_clear = 0;
pref_offset_copy = 0;
break;
case CPU_RM9000:
/*
* As a workaround for erratum G105 which make the
* PrepareForStore hint unusable we fall back to
* StoreRetained on the RM9000. Once it is known which
* versions of the RM9000 we'll be able to condition-
* alize this.
*/
case CPU_R10000:
case CPU_R12000:
case CPU_R14000:
pref_src_mode = Pref_LoadStreamed;
pref_dst_mode = Pref_StoreStreamed;
break;
default:
pref_src_mode = Pref_LoadStreamed;
pref_dst_mode = Pref_PrepareForStore;
break;
}
}
off = PAGE_SIZE - (cpu_has_prefetch ? pref_offset_clear : 0);
if (off > 0x7fff) {
build_addiu_a2_a0(off >> 1);
build_addiu_a2(off >> 1);
} else
build_addiu_a2_a0(off);
if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
build_insn_word(0x3c01a000); /* lui $at, 0xa000 */
dest = label();
do {
build_store_reg(0);
build_store_reg(0);
build_store_reg(0);
build_store_reg(0);
} while (store_offset < half_scache_line_size());
build_addiu_a0(2 * store_offset);
loop_start = store_offset;
do {
build_store_reg(0);
build_store_reg(0);
build_store_reg(0);
build_store_reg(0);
} while ((store_offset - loop_start) < half_scache_line_size());
build_bne(dest);
if (cpu_has_prefetch && pref_offset_clear) {
build_addiu_a2_a0(pref_offset_clear);
dest = label();
loop_start = store_offset;
do {
__build_store_reg(0);
__build_store_reg(0);
__build_store_reg(0);
__build_store_reg(0);
} while ((store_offset - loop_start) < half_scache_line_size());
build_addiu_a0(2 * store_offset);
loop_start = store_offset;
do {
__build_store_reg(0);
__build_store_reg(0);
__build_store_reg(0);
__build_store_reg(0);
} while ((store_offset - loop_start) < half_scache_line_size());
build_bne(dest);
}
build_jr_ra();
BUG_ON(epc > clear_page_array + ARRAY_SIZE(clear_page_array));
pr_info("Synthesized clear page handler (%u instructions).\n",
(unsigned int)(epc - clear_page_array));
pr_debug("\t.set push\n");
pr_debug("\t.set noreorder\n");
for (i = 0; i < (epc - clear_page_array); i++)
pr_debug("\t.word 0x%08x\n", clear_page_array[i]);
pr_debug("\t.set pop\n");
}
void __init build_copy_page(void)
{
unsigned int loop_start;
unsigned long off;
int i;
epc = (unsigned int *) ©_page_array;
store_offset = load_offset = 0;
instruction_pending = 0;
off = PAGE_SIZE - (cpu_has_prefetch ? pref_offset_copy : 0);
if (off > 0x7fff) {
build_addiu_a2_a0(off >> 1);
build_addiu_a2(off >> 1);
} else
build_addiu_a2_a0(off);
if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
build_insn_word(0x3c01a000); /* lui $at, 0xa000 */
dest = label();
loop_start = store_offset;
do {
build_load_reg( 8);
build_load_reg( 9);
build_load_reg(10);
build_load_reg(11);
build_store_reg( 8);
build_store_reg( 9);
build_store_reg(10);
build_store_reg(11);
} while ((store_offset - loop_start) < half_scache_line_size());
build_addiu_a0(2 * store_offset);
build_addiu_a1(2 * load_offset);
loop_start = store_offset;
do {
build_load_reg( 8);
build_load_reg( 9);
build_load_reg(10);
build_load_reg(11);
build_store_reg( 8);
build_store_reg( 9);
build_store_reg(10);
build_store_reg(11);
} while ((store_offset - loop_start) < half_scache_line_size());
build_bne(dest);
if (cpu_has_prefetch && pref_offset_copy) {
build_addiu_a2_a0(pref_offset_copy);
dest = label();
loop_start = store_offset;
do {
__build_load_reg( 8);
__build_load_reg( 9);
__build_load_reg(10);
__build_load_reg(11);
__build_store_reg( 8);
__build_store_reg( 9);
__build_store_reg(10);
__build_store_reg(11);
} while ((store_offset - loop_start) < half_scache_line_size());
build_addiu_a0(2 * store_offset);
build_addiu_a1(2 * load_offset);
loop_start = store_offset;
do {
__build_load_reg( 8);
__build_load_reg( 9);
__build_load_reg(10);
__build_load_reg(11);
__build_store_reg( 8);
__build_store_reg( 9);
__build_store_reg(10);
__build_store_reg(11);
} while ((store_offset - loop_start) < half_scache_line_size());
build_bne(dest);
}
build_jr_ra();
BUG_ON(epc > copy_page_array + ARRAY_SIZE(copy_page_array));
pr_info("Synthesized copy page handler (%u instructions).\n",
(unsigned int)(epc - copy_page_array));
pr_debug("\t.set push\n");
pr_debug("\t.set noreorder\n");
for (i = 0; i < (epc - copy_page_array); i++)
pr_debug("\t.word 0x%08x\n", copy_page_array[i]);
pr_debug("\t.set pop\n");
}
