kernel-ark/arch/mips/kernel/cpu-probe.c
Ralf Baechle 441ee341ad [MIPS] Fix RM9000 wait instruction detection.
Only revisions < 4.0 don't have a functional wait instruction.

From Thomas Koeller (Thomas.Koeller@baslerweb.com).

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-10-09 23:20:45 +01:00

778 lines
18 KiB
C

/*
* Processor capabilities determination functions.
*
* Copyright (C) xxxx the Anonymous
* Copyright (C) 1994 - 2006 Ralf Baechle
* Copyright (C) 2003, 2004 Maciej W. Rozycki
* Copyright (C) 2001, 2004 MIPS Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/ptrace.h>
#include <linux/stddef.h>
#include <asm/cpu.h>
#include <asm/fpu.h>
#include <asm/mipsregs.h>
#include <asm/system.h>
/*
* Not all of the MIPS CPUs have the "wait" instruction available. Moreover,
* the implementation of the "wait" feature differs between CPU families. This
* points to the function that implements CPU specific wait.
* The wait instruction stops the pipeline and reduces the power consumption of
* the CPU very much.
*/
void (*cpu_wait)(void) = NULL;
static void r3081_wait(void)
{
unsigned long cfg = read_c0_conf();
write_c0_conf(cfg | R30XX_CONF_HALT);
}
static void r39xx_wait(void)
{
local_irq_disable();
if (!need_resched())
write_c0_conf(read_c0_conf() | TX39_CONF_HALT);
local_irq_enable();
}
/*
* There is a race when WAIT instruction executed with interrupt
* enabled.
* But it is implementation-dependent wheter the pipelie restarts when
* a non-enabled interrupt is requested.
*/
static void r4k_wait(void)
{
__asm__(" .set mips3 \n"
" wait \n"
" .set mips0 \n");
}
/*
* This variant is preferable as it allows testing need_resched and going to
* sleep depending on the outcome atomically. Unfortunately the "It is
* implementation-dependent whether the pipeline restarts when a non-enabled
* interrupt is requested" restriction in the MIPS32/MIPS64 architecture makes
* using this version a gamble.
*/
static void r4k_wait_irqoff(void)
{
local_irq_disable();
if (!need_resched())
__asm__(" .set mips3 \n"
" wait \n"
" .set mips0 \n");
local_irq_enable();
}
/* The Au1xxx wait is available only if using 32khz counter or
* external timer source, but specifically not CP0 Counter. */
int allow_au1k_wait;
static void au1k_wait(void)
{
/* using the wait instruction makes CP0 counter unusable */
__asm__(" .set mips3 \n"
" cache 0x14, 0(%0) \n"
" cache 0x14, 32(%0) \n"
" sync \n"
" nop \n"
" wait \n"
" nop \n"
" nop \n"
" nop \n"
" nop \n"
" .set mips0 \n"
: : "r" (au1k_wait));
}
static int __initdata nowait = 0;
int __init wait_disable(char *s)
{
nowait = 1;
return 1;
}
__setup("nowait", wait_disable);
static inline void check_wait(void)
{
struct cpuinfo_mips *c = &current_cpu_data;
printk("Checking for 'wait' instruction... ");
if (nowait) {
printk (" disabled.\n");
return;
}
switch (c->cputype) {
case CPU_R3081:
case CPU_R3081E:
cpu_wait = r3081_wait;
printk(" available.\n");
break;
case CPU_TX3927:
cpu_wait = r39xx_wait;
printk(" available.\n");
break;
case CPU_R4200:
/* case CPU_R4300: */
case CPU_R4600:
case CPU_R4640:
case CPU_R4650:
case CPU_R4700:
case CPU_R5000:
case CPU_NEVADA:
case CPU_RM7000:
case CPU_4KC:
case CPU_4KEC:
case CPU_4KSC:
case CPU_5KC:
/* case CPU_20KC:*/
case CPU_24K:
case CPU_25KF:
case CPU_34K:
case CPU_74K:
case CPU_PR4450:
cpu_wait = r4k_wait;
printk(" available.\n");
break;
case CPU_TX49XX:
cpu_wait = r4k_wait_irqoff;
printk(" available.\n");
break;
case CPU_AU1000:
case CPU_AU1100:
case CPU_AU1500:
case CPU_AU1550:
case CPU_AU1200:
if (allow_au1k_wait) {
cpu_wait = au1k_wait;
printk(" available.\n");
} else
printk(" unavailable.\n");
break;
case CPU_RM9000:
if ((c->processor_id & 0x00ff) >= 0x40) {
cpu_wait = r4k_wait;
printk(" available.\n");
} else {
printk(" unavailable.\n");
}
break;
default:
printk(" unavailable.\n");
break;
}
}
void __init check_bugs32(void)
{
check_wait();
}
/*
* Probe whether cpu has config register by trying to play with
* alternate cache bit and see whether it matters.
* It's used by cpu_probe to distinguish between R3000A and R3081.
*/
static inline int cpu_has_confreg(void)
{
#ifdef CONFIG_CPU_R3000
extern unsigned long r3k_cache_size(unsigned long);
unsigned long size1, size2;
unsigned long cfg = read_c0_conf();
size1 = r3k_cache_size(ST0_ISC);
write_c0_conf(cfg ^ R30XX_CONF_AC);
size2 = r3k_cache_size(ST0_ISC);
write_c0_conf(cfg);
return size1 != size2;
#else
return 0;
#endif
}
/*
* Get the FPU Implementation/Revision.
*/
static inline unsigned long cpu_get_fpu_id(void)
{
unsigned long tmp, fpu_id;
tmp = read_c0_status();
__enable_fpu();
fpu_id = read_32bit_cp1_register(CP1_REVISION);
write_c0_status(tmp);
return fpu_id;
}
/*
* Check the CPU has an FPU the official way.
*/
static inline int __cpu_has_fpu(void)
{
return ((cpu_get_fpu_id() & 0xff00) != FPIR_IMP_NONE);
}
#define R4K_OPTS (MIPS_CPU_TLB | MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE \
| MIPS_CPU_COUNTER)
static inline void cpu_probe_legacy(struct cpuinfo_mips *c)
{
switch (c->processor_id & 0xff00) {
case PRID_IMP_R2000:
c->cputype = CPU_R2000;
c->isa_level = MIPS_CPU_ISA_I;
c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
MIPS_CPU_NOFPUEX;
if (__cpu_has_fpu())
c->options |= MIPS_CPU_FPU;
c->tlbsize = 64;
break;
case PRID_IMP_R3000:
if ((c->processor_id & 0xff) == PRID_REV_R3000A)
if (cpu_has_confreg())
c->cputype = CPU_R3081E;
else
c->cputype = CPU_R3000A;
else
c->cputype = CPU_R3000;
c->isa_level = MIPS_CPU_ISA_I;
c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE |
MIPS_CPU_NOFPUEX;
if (__cpu_has_fpu())
c->options |= MIPS_CPU_FPU;
c->tlbsize = 64;
break;
case PRID_IMP_R4000:
if (read_c0_config() & CONF_SC) {
if ((c->processor_id & 0xff) >= PRID_REV_R4400)
c->cputype = CPU_R4400PC;
else
c->cputype = CPU_R4000PC;
} else {
if ((c->processor_id & 0xff) >= PRID_REV_R4400)
c->cputype = CPU_R4400SC;
else
c->cputype = CPU_R4000SC;
}
c->isa_level = MIPS_CPU_ISA_III;
c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
MIPS_CPU_WATCH | MIPS_CPU_VCE |
MIPS_CPU_LLSC;
c->tlbsize = 48;
break;
case PRID_IMP_VR41XX:
switch (c->processor_id & 0xf0) {
case PRID_REV_VR4111:
c->cputype = CPU_VR4111;
break;
case PRID_REV_VR4121:
c->cputype = CPU_VR4121;
break;
case PRID_REV_VR4122:
if ((c->processor_id & 0xf) < 0x3)
c->cputype = CPU_VR4122;
else
c->cputype = CPU_VR4181A;
break;
case PRID_REV_VR4130:
if ((c->processor_id & 0xf) < 0x4)
c->cputype = CPU_VR4131;
else
c->cputype = CPU_VR4133;
break;
default:
printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
c->cputype = CPU_VR41XX;
break;
}
c->isa_level = MIPS_CPU_ISA_III;
c->options = R4K_OPTS;
c->tlbsize = 32;
break;
case PRID_IMP_R4300:
c->cputype = CPU_R4300;
c->isa_level = MIPS_CPU_ISA_III;
c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
MIPS_CPU_LLSC;
c->tlbsize = 32;
break;
case PRID_IMP_R4600:
c->cputype = CPU_R4600;
c->isa_level = MIPS_CPU_ISA_III;
c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
MIPS_CPU_LLSC;
c->tlbsize = 48;
break;
#if 0
case PRID_IMP_R4650:
/*
* This processor doesn't have an MMU, so it's not
* "real easy" to run Linux on it. It is left purely
* for documentation. Commented out because it shares
* it's c0_prid id number with the TX3900.
*/
c->cputype = CPU_R4650;
c->isa_level = MIPS_CPU_ISA_III;
c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC;
c->tlbsize = 48;
break;
#endif
case PRID_IMP_TX39:
c->isa_level = MIPS_CPU_ISA_I;
c->options = MIPS_CPU_TLB | MIPS_CPU_TX39_CACHE;
if ((c->processor_id & 0xf0) == (PRID_REV_TX3927 & 0xf0)) {
c->cputype = CPU_TX3927;
c->tlbsize = 64;
} else {
switch (c->processor_id & 0xff) {
case PRID_REV_TX3912:
c->cputype = CPU_TX3912;
c->tlbsize = 32;
break;
case PRID_REV_TX3922:
c->cputype = CPU_TX3922;
c->tlbsize = 64;
break;
default:
c->cputype = CPU_UNKNOWN;
break;
}
}
break;
case PRID_IMP_R4700:
c->cputype = CPU_R4700;
c->isa_level = MIPS_CPU_ISA_III;
c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
MIPS_CPU_LLSC;
c->tlbsize = 48;
break;
case PRID_IMP_TX49:
c->cputype = CPU_TX49XX;
c->isa_level = MIPS_CPU_ISA_III;
c->options = R4K_OPTS | MIPS_CPU_LLSC;
if (!(c->processor_id & 0x08))
c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR;
c->tlbsize = 48;
break;
case PRID_IMP_R5000:
c->cputype = CPU_R5000;
c->isa_level = MIPS_CPU_ISA_IV;
c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
MIPS_CPU_LLSC;
c->tlbsize = 48;
break;
case PRID_IMP_R5432:
c->cputype = CPU_R5432;
c->isa_level = MIPS_CPU_ISA_IV;
c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
MIPS_CPU_WATCH | MIPS_CPU_LLSC;
c->tlbsize = 48;
break;
case PRID_IMP_R5500:
c->cputype = CPU_R5500;
c->isa_level = MIPS_CPU_ISA_IV;
c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
MIPS_CPU_WATCH | MIPS_CPU_LLSC;
c->tlbsize = 48;
break;
case PRID_IMP_NEVADA:
c->cputype = CPU_NEVADA;
c->isa_level = MIPS_CPU_ISA_IV;
c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
MIPS_CPU_DIVEC | MIPS_CPU_LLSC;
c->tlbsize = 48;
break;
case PRID_IMP_R6000:
c->cputype = CPU_R6000;
c->isa_level = MIPS_CPU_ISA_II;
c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
MIPS_CPU_LLSC;
c->tlbsize = 32;
break;
case PRID_IMP_R6000A:
c->cputype = CPU_R6000A;
c->isa_level = MIPS_CPU_ISA_II;
c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
MIPS_CPU_LLSC;
c->tlbsize = 32;
break;
case PRID_IMP_RM7000:
c->cputype = CPU_RM7000;
c->isa_level = MIPS_CPU_ISA_IV;
c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
MIPS_CPU_LLSC;
/*
* Undocumented RM7000: Bit 29 in the info register of
* the RM7000 v2.0 indicates if the TLB has 48 or 64
* entries.
*
* 29 1 => 64 entry JTLB
* 0 => 48 entry JTLB
*/
c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
break;
case PRID_IMP_RM9000:
c->cputype = CPU_RM9000;
c->isa_level = MIPS_CPU_ISA_IV;
c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
MIPS_CPU_LLSC;
/*
* Bit 29 in the info register of the RM9000
* indicates if the TLB has 48 or 64 entries.
*
* 29 1 => 64 entry JTLB
* 0 => 48 entry JTLB
*/
c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
break;
case PRID_IMP_R8000:
c->cputype = CPU_R8000;
c->isa_level = MIPS_CPU_ISA_IV;
c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
MIPS_CPU_FPU | MIPS_CPU_32FPR |
MIPS_CPU_LLSC;
c->tlbsize = 384; /* has weird TLB: 3-way x 128 */
break;
case PRID_IMP_R10000:
c->cputype = CPU_R10000;
c->isa_level = MIPS_CPU_ISA_IV;
c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
MIPS_CPU_FPU | MIPS_CPU_32FPR |
MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
MIPS_CPU_LLSC;
c->tlbsize = 64;
break;
case PRID_IMP_R12000:
c->cputype = CPU_R12000;
c->isa_level = MIPS_CPU_ISA_IV;
c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
MIPS_CPU_FPU | MIPS_CPU_32FPR |
MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
MIPS_CPU_LLSC;
c->tlbsize = 64;
break;
case PRID_IMP_R14000:
c->cputype = CPU_R14000;
c->isa_level = MIPS_CPU_ISA_IV;
c->options = MIPS_CPU_TLB | MIPS_CPU_4K_CACHE | MIPS_CPU_4KEX |
MIPS_CPU_FPU | MIPS_CPU_32FPR |
MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
MIPS_CPU_LLSC;
c->tlbsize = 64;
break;
}
}
static char unknown_isa[] __initdata = KERN_ERR \
"Unsupported ISA type, c0.config0: %d.";
static inline unsigned int decode_config0(struct cpuinfo_mips *c)
{
unsigned int config0;
int isa;
config0 = read_c0_config();
if (((config0 & MIPS_CONF_MT) >> 7) == 1)
c->options |= MIPS_CPU_TLB;
isa = (config0 & MIPS_CONF_AT) >> 13;
switch (isa) {
case 0:
switch ((config0 & MIPS_CONF_AR) >> 10) {
case 0:
c->isa_level = MIPS_CPU_ISA_M32R1;
break;
case 1:
c->isa_level = MIPS_CPU_ISA_M32R2;
break;
default:
goto unknown;
}
break;
case 2:
switch ((config0 & MIPS_CONF_AR) >> 10) {
case 0:
c->isa_level = MIPS_CPU_ISA_M64R1;
break;
case 1:
c->isa_level = MIPS_CPU_ISA_M64R2;
break;
default:
goto unknown;
}
break;
default:
goto unknown;
}
return config0 & MIPS_CONF_M;
unknown:
panic(unknown_isa, config0);
}
static inline unsigned int decode_config1(struct cpuinfo_mips *c)
{
unsigned int config1;
config1 = read_c0_config1();
if (config1 & MIPS_CONF1_MD)
c->ases |= MIPS_ASE_MDMX;
if (config1 & MIPS_CONF1_WR)
c->options |= MIPS_CPU_WATCH;
if (config1 & MIPS_CONF1_CA)
c->ases |= MIPS_ASE_MIPS16;
if (config1 & MIPS_CONF1_EP)
c->options |= MIPS_CPU_EJTAG;
if (config1 & MIPS_CONF1_FP) {
c->options |= MIPS_CPU_FPU;
c->options |= MIPS_CPU_32FPR;
}
if (cpu_has_tlb)
c->tlbsize = ((config1 & MIPS_CONF1_TLBS) >> 25) + 1;
return config1 & MIPS_CONF_M;
}
static inline unsigned int decode_config2(struct cpuinfo_mips *c)
{
unsigned int config2;
config2 = read_c0_config2();
if (config2 & MIPS_CONF2_SL)
c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
return config2 & MIPS_CONF_M;
}
static inline unsigned int decode_config3(struct cpuinfo_mips *c)
{
unsigned int config3;
config3 = read_c0_config3();
if (config3 & MIPS_CONF3_SM)
c->ases |= MIPS_ASE_SMARTMIPS;
if (config3 & MIPS_CONF3_DSP)
c->ases |= MIPS_ASE_DSP;
if (config3 & MIPS_CONF3_VINT)
c->options |= MIPS_CPU_VINT;
if (config3 & MIPS_CONF3_VEIC)
c->options |= MIPS_CPU_VEIC;
if (config3 & MIPS_CONF3_MT)
c->ases |= MIPS_ASE_MIPSMT;
return config3 & MIPS_CONF_M;
}
static void __init decode_configs(struct cpuinfo_mips *c)
{
/* MIPS32 or MIPS64 compliant CPU. */
c->options = MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE | MIPS_CPU_COUNTER |
MIPS_CPU_DIVEC | MIPS_CPU_LLSC | MIPS_CPU_MCHECK;
c->scache.flags = MIPS_CACHE_NOT_PRESENT;
/* Read Config registers. */
if (!decode_config0(c))
return; /* actually worth a panic() */
if (!decode_config1(c))
return;
if (!decode_config2(c))
return;
if (!decode_config3(c))
return;
}
static inline void cpu_probe_mips(struct cpuinfo_mips *c)
{
decode_configs(c);
switch (c->processor_id & 0xff00) {
case PRID_IMP_4KC:
c->cputype = CPU_4KC;
break;
case PRID_IMP_4KEC:
c->cputype = CPU_4KEC;
break;
case PRID_IMP_4KECR2:
c->cputype = CPU_4KEC;
break;
case PRID_IMP_4KSC:
case PRID_IMP_4KSD:
c->cputype = CPU_4KSC;
break;
case PRID_IMP_5KC:
c->cputype = CPU_5KC;
break;
case PRID_IMP_20KC:
c->cputype = CPU_20KC;
break;
case PRID_IMP_24K:
case PRID_IMP_24KE:
c->cputype = CPU_24K;
break;
case PRID_IMP_25KF:
c->cputype = CPU_25KF;
break;
case PRID_IMP_34K:
c->cputype = CPU_34K;
break;
case PRID_IMP_74K:
c->cputype = CPU_74K;
break;
}
}
static inline void cpu_probe_alchemy(struct cpuinfo_mips *c)
{
decode_configs(c);
switch (c->processor_id & 0xff00) {
case PRID_IMP_AU1_REV1:
case PRID_IMP_AU1_REV2:
switch ((c->processor_id >> 24) & 0xff) {
case 0:
c->cputype = CPU_AU1000;
break;
case 1:
c->cputype = CPU_AU1500;
break;
case 2:
c->cputype = CPU_AU1100;
break;
case 3:
c->cputype = CPU_AU1550;
break;
case 4:
c->cputype = CPU_AU1200;
break;
default:
panic("Unknown Au Core!");
break;
}
break;
}
}
static inline void cpu_probe_sibyte(struct cpuinfo_mips *c)
{
decode_configs(c);
/*
* For historical reasons the SB1 comes with it's own variant of
* cache code which eventually will be folded into c-r4k.c. Until
* then we pretend it's got it's own cache architecture.
*/
c->options &= ~MIPS_CPU_4K_CACHE;
c->options |= MIPS_CPU_SB1_CACHE;
switch (c->processor_id & 0xff00) {
case PRID_IMP_SB1:
c->cputype = CPU_SB1;
/* FPU in pass1 is known to have issues. */
if ((c->processor_id & 0xff) < 0x02)
c->options &= ~(MIPS_CPU_FPU | MIPS_CPU_32FPR);
break;
case PRID_IMP_SB1A:
c->cputype = CPU_SB1A;
break;
}
}
static inline void cpu_probe_sandcraft(struct cpuinfo_mips *c)
{
decode_configs(c);
switch (c->processor_id & 0xff00) {
case PRID_IMP_SR71000:
c->cputype = CPU_SR71000;
c->scache.ways = 8;
c->tlbsize = 64;
break;
}
}
static inline void cpu_probe_philips(struct cpuinfo_mips *c)
{
decode_configs(c);
switch (c->processor_id & 0xff00) {
case PRID_IMP_PR4450:
c->cputype = CPU_PR4450;
c->isa_level = MIPS_CPU_ISA_M32R1;
break;
default:
panic("Unknown Philips Core!"); /* REVISIT: die? */
break;
}
}
__init void cpu_probe(void)
{
struct cpuinfo_mips *c = &current_cpu_data;
c->processor_id = PRID_IMP_UNKNOWN;
c->fpu_id = FPIR_IMP_NONE;
c->cputype = CPU_UNKNOWN;
c->processor_id = read_c0_prid();
switch (c->processor_id & 0xff0000) {
case PRID_COMP_LEGACY:
cpu_probe_legacy(c);
break;
case PRID_COMP_MIPS:
cpu_probe_mips(c);
break;
case PRID_COMP_ALCHEMY:
cpu_probe_alchemy(c);
break;
case PRID_COMP_SIBYTE:
cpu_probe_sibyte(c);
break;
case PRID_COMP_SANDCRAFT:
cpu_probe_sandcraft(c);
break;
case PRID_COMP_PHILIPS:
cpu_probe_philips(c);
break;
default:
c->cputype = CPU_UNKNOWN;
}
if (c->options & MIPS_CPU_FPU) {
c->fpu_id = cpu_get_fpu_id();
if (c->isa_level == MIPS_CPU_ISA_M32R1 ||
c->isa_level == MIPS_CPU_ISA_M32R2 ||
c->isa_level == MIPS_CPU_ISA_M64R1 ||
c->isa_level == MIPS_CPU_ISA_M64R2) {
if (c->fpu_id & MIPS_FPIR_3D)
c->ases |= MIPS_ASE_MIPS3D;
}
}
}
__init void cpu_report(void)
{
struct cpuinfo_mips *c = &current_cpu_data;
printk("CPU revision is: %08x\n", c->processor_id);
if (c->options & MIPS_CPU_FPU)
printk("FPU revision is: %08x\n", c->fpu_id);
}