android_kernel_xiaomi_sm7250/arch/m32r/kernel/smpboot.c
Nick Piggin 5bfb5d690f [PATCH] sched: disable preempt in idle tasks
Run idle threads with preempt disabled.

Also corrected a bugs in arm26's cpu_idle (make it actually call schedule()).
How did it ever work before?

Might fix the CPU hotplugging hang which Nigel Cunningham noted.

We think the bug hits if the idle thread is preempted after checking
need_resched() and before going to sleep, then the CPU offlined.

After calling stop_machine_run, the CPU eventually returns from preemption and
into the idle thread and goes to sleep.  The CPU will continue executing
previous idle and have no chance to call play_dead.

By disabling preemption until we are ready to explicitly schedule, this bug is
fixed and the idle threads generally become more robust.

From: alexs <ashepard@u.washington.edu>

  PPC build fix

From: Yoichi Yuasa <yuasa@hh.iij4u.or.jp>

  MIPS build fix

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Yoichi Yuasa <yuasa@hh.iij4u.or.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:33 -08:00

633 lines
16 KiB
C

/*
* linux/arch/m32r/kernel/smpboot.c
* orig : i386 2.4.10
*
* M32R SMP booting functions
*
* Copyright (c) 2001, 2002, 2003 Hitoshi Yamamoto
*
* Taken from i386 version.
* (c) 1995 Alan Cox, Building #3 <alan@redhat.com>
* (c) 1998, 1999, 2000 Ingo Molnar <mingo@redhat.com>
*
* Much of the core SMP work is based on previous work by Thomas Radke, to
* whom a great many thanks are extended.
*
* Thanks to Intel for making available several different Pentium,
* Pentium Pro and Pentium-II/Xeon MP machines.
* Original development of Linux SMP code supported by Caldera.
*
* This code is released under the GNU General Public License version 2 or
* later.
*
* Fixes
* Felix Koop : NR_CPUS used properly
* Jose Renau : Handle single CPU case.
* Alan Cox : By repeated request
* 8) - Total BogoMIP report.
* Greg Wright : Fix for kernel stacks panic.
* Erich Boleyn : MP v1.4 and additional changes.
* Matthias Sattler : Changes for 2.1 kernel map.
* Michel Lespinasse : Changes for 2.1 kernel map.
* Michael Chastain : Change trampoline.S to gnu as.
* Alan Cox : Dumb bug: 'B' step PPro's are fine
* Ingo Molnar : Added APIC timers, based on code
* from Jose Renau
* Ingo Molnar : various cleanups and rewrites
* Tigran Aivazian : fixed "0.00 in /proc/uptime on SMP" bug.
* Maciej W. Rozycki : Bits for genuine 82489DX APICs
* Martin J. Bligh : Added support for multi-quad systems
*/
#include <linux/config.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/smp_lock.h>
#include <linux/irq.h>
#include <linux/bootmem.h>
#include <linux/delay.h>
#include <asm/io.h>
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
#define DEBUG_SMP
#ifdef DEBUG_SMP
#define Dprintk(x...) printk(x)
#else
#define Dprintk(x...)
#endif
extern cpumask_t cpu_initialized;
/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
/* Data structures and variables */
/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
/* Processor that is doing the boot up */
static unsigned int bsp_phys_id = -1;
/* Bitmask of physically existing CPUs */
physid_mask_t phys_cpu_present_map;
/* Bitmask of currently online CPUs */
cpumask_t cpu_online_map;
cpumask_t cpu_bootout_map;
cpumask_t cpu_bootin_map;
cpumask_t cpu_callout_map;
static cpumask_t cpu_callin_map;
/* Per CPU bogomips and other parameters */
struct cpuinfo_m32r cpu_data[NR_CPUS] __cacheline_aligned;
static int cpucount;
static cpumask_t smp_commenced_mask;
extern struct {
void * spi;
unsigned short ss;
} stack_start;
/* which physical physical ID maps to which logical CPU number */
static volatile int physid_2_cpu[NR_CPUS];
#define physid_to_cpu(physid) physid_2_cpu[physid]
/* which logical CPU number maps to which physical ID */
volatile int cpu_2_physid[NR_CPUS];
DEFINE_PER_CPU(int, prof_multiplier) = 1;
DEFINE_PER_CPU(int, prof_old_multiplier) = 1;
DEFINE_PER_CPU(int, prof_counter) = 1;
spinlock_t ipi_lock[NR_IPIS];
static unsigned int calibration_result;
/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
/* Function Prototypes */
/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
void smp_prepare_boot_cpu(void);
void smp_prepare_cpus(unsigned int);
static void smp_tune_scheduling(void);
static void init_ipi_lock(void);
static void do_boot_cpu(int);
int __cpu_up(unsigned int);
void smp_cpus_done(unsigned int);
int start_secondary(void *);
static void smp_callin(void);
static void smp_online(void);
static void show_mp_info(int);
static void smp_store_cpu_info(int);
static void show_cpu_info(int);
int setup_profiling_timer(unsigned int);
static void init_cpu_to_physid(void);
static void map_cpu_to_physid(int, int);
static void unmap_cpu_to_physid(int, int);
/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
/* Boot up APs Routins : BSP */
/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
void __devinit smp_prepare_boot_cpu(void)
{
bsp_phys_id = hard_smp_processor_id();
physid_set(bsp_phys_id, phys_cpu_present_map);
cpu_set(0, cpu_online_map); /* BSP's cpu_id == 0 */
cpu_set(0, cpu_callout_map);
cpu_set(0, cpu_callin_map);
/*
* Initialize the logical to physical CPU number mapping
*/
init_cpu_to_physid();
map_cpu_to_physid(0, bsp_phys_id);
current_thread_info()->cpu = 0;
}
/*==========================================================================*
* Name: smp_prepare_cpus (old smp_boot_cpus)
*
* Description: This routine boot up APs.
*
* Born on Date: 2002.02.05
*
* Arguments: NONE
*
* Returns: void (cannot fail)
*
* Modification log:
* Date Who Description
* ---------- --- --------------------------------------------------------
* 2003-06-24 hy modify for linux-2.5.69
*
*==========================================================================*/
void __init smp_prepare_cpus(unsigned int max_cpus)
{
int phys_id;
unsigned long nr_cpu;
nr_cpu = inl(M32R_FPGA_NUM_OF_CPUS_PORTL);
if (nr_cpu > NR_CPUS) {
printk(KERN_INFO "NUM_OF_CPUS reg. value [%ld] > NR_CPU [%d]",
nr_cpu, NR_CPUS);
goto smp_done;
}
for (phys_id = 0 ; phys_id < nr_cpu ; phys_id++)
physid_set(phys_id, phys_cpu_present_map);
show_mp_info(nr_cpu);
init_ipi_lock();
/*
* Setup boot CPU information
*/
smp_store_cpu_info(0); /* Final full version of the data */
smp_tune_scheduling();
/*
* If SMP should be disabled, then really disable it!
*/
if (!max_cpus) {
printk(KERN_INFO "SMP mode deactivated by commandline.\n");
goto smp_done;
}
/*
* Now scan the CPU present map and fire up the other CPUs.
*/
Dprintk("CPU present map : %lx\n", physids_coerce(phys_cpu_present_map));
for (phys_id = 0 ; phys_id < NR_CPUS ; phys_id++) {
/*
* Don't even attempt to start the boot CPU!
*/
if (phys_id == bsp_phys_id)
continue;
if (!physid_isset(phys_id, phys_cpu_present_map))
continue;
if ((max_cpus >= 0) && (max_cpus <= cpucount + 1))
continue;
do_boot_cpu(phys_id);
/*
* Make sure we unmap all failed CPUs
*/
if (physid_to_cpu(phys_id) == -1) {
physid_clear(phys_id, phys_cpu_present_map);
printk("phys CPU#%d not responding - " \
"cannot use it.\n", phys_id);
}
}
smp_done:
Dprintk("Boot done.\n");
}
static void __init smp_tune_scheduling(void)
{
/* Nothing to do. */
}
/*
* init_ipi_lock : Initialize IPI locks.
*/
static void __init init_ipi_lock(void)
{
int ipi;
for (ipi = 0 ; ipi < NR_IPIS ; ipi++)
spin_lock_init(&ipi_lock[ipi]);
}
/*==========================================================================*
* Name: do_boot_cpu
*
* Description: This routine boot up one AP.
*
* Born on Date: 2002.02.05
*
* Arguments: phys_id - Target CPU physical ID
*
* Returns: void (cannot fail)
*
* Modification log:
* Date Who Description
* ---------- --- --------------------------------------------------------
* 2003-06-24 hy modify for linux-2.5.69
*
*==========================================================================*/
static void __init do_boot_cpu(int phys_id)
{
struct task_struct *idle;
unsigned long send_status, boot_status;
int timeout, cpu_id;
cpu_id = ++cpucount;
/*
* We can't use kernel_thread since we must avoid to
* reschedule the child.
*/
idle = fork_idle(cpu_id);
if (IS_ERR(idle))
panic("failed fork for CPU#%d.", cpu_id);
idle->thread.lr = (unsigned long)start_secondary;
map_cpu_to_physid(cpu_id, phys_id);
/* So we see what's up */
printk("Booting processor %d/%d\n", phys_id, cpu_id);
stack_start.spi = (void *)idle->thread.sp;
idle->thread_info->cpu = cpu_id;
/*
* Send Startup IPI
* 1.IPI received by CPU#(phys_id).
* 2.CPU#(phys_id) enter startup_AP (arch/m32r/kernel/head.S)
* 3.CPU#(phys_id) enter start_secondary()
*/
send_status = 0;
boot_status = 0;
cpu_set(phys_id, cpu_bootout_map);
/* Send Startup IPI */
send_IPI_mask_phys(cpumask_of_cpu(phys_id), CPU_BOOT_IPI, 0);
Dprintk("Waiting for send to finish...\n");
timeout = 0;
/* Wait 100[ms] */
do {
Dprintk("+");
udelay(1000);
send_status = !cpu_isset(phys_id, cpu_bootin_map);
} while (send_status && (timeout++ < 100));
Dprintk("After Startup.\n");
if (!send_status) {
/*
* allow APs to start initializing.
*/
Dprintk("Before Callout %d.\n", cpu_id);
cpu_set(cpu_id, cpu_callout_map);
Dprintk("After Callout %d.\n", cpu_id);
/*
* Wait 5s total for a response
*/
for (timeout = 0; timeout < 5000; timeout++) {
if (cpu_isset(cpu_id, cpu_callin_map))
break; /* It has booted */
udelay(1000);
}
if (cpu_isset(cpu_id, cpu_callin_map)) {
/* number CPUs logically, starting from 1 (BSP is 0) */
Dprintk("OK.\n");
} else {
boot_status = 1;
printk("Not responding.\n");
}
} else
printk("IPI never delivered???\n");
if (send_status || boot_status) {
unmap_cpu_to_physid(cpu_id, phys_id);
cpu_clear(cpu_id, cpu_callout_map);
cpu_clear(cpu_id, cpu_callin_map);
cpu_clear(cpu_id, cpu_initialized);
cpucount--;
}
}
int __devinit __cpu_up(unsigned int cpu_id)
{
int timeout;
cpu_set(cpu_id, smp_commenced_mask);
/*
* Wait 5s total for a response
*/
for (timeout = 0; timeout < 5000; timeout++) {
if (cpu_isset(cpu_id, cpu_online_map))
break;
udelay(1000);
}
if (!cpu_isset(cpu_id, cpu_online_map))
BUG();
return 0;
}
void __init smp_cpus_done(unsigned int max_cpus)
{
int cpu_id, timeout;
unsigned long bogosum = 0;
for (timeout = 0; timeout < 5000; timeout++) {
if (cpus_equal(cpu_callin_map, cpu_online_map))
break;
udelay(1000);
}
if (!cpus_equal(cpu_callin_map, cpu_online_map))
BUG();
for (cpu_id = 0 ; cpu_id < num_online_cpus() ; cpu_id++)
show_cpu_info(cpu_id);
/*
* Allow the user to impress friends.
*/
Dprintk("Before bogomips.\n");
if (cpucount) {
for_each_cpu_mask(cpu_id, cpu_online_map)
bogosum += cpu_data[cpu_id].loops_per_jiffy;
printk(KERN_INFO "Total of %d processors activated " \
"(%lu.%02lu BogoMIPS).\n", cpucount + 1,
bogosum / (500000 / HZ),
(bogosum / (5000 / HZ)) % 100);
Dprintk("Before bogocount - setting activated=1.\n");
}
}
/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
/* Activate a secondary processor Routins */
/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
/*==========================================================================*
* Name: start_secondary
*
* Description: This routine activate a secondary processor.
*
* Born on Date: 2002.02.05
*
* Arguments: *unused - currently unused.
*
* Returns: void (cannot fail)
*
* Modification log:
* Date Who Description
* ---------- --- --------------------------------------------------------
* 2003-06-24 hy modify for linux-2.5.69
*
*==========================================================================*/
int __init start_secondary(void *unused)
{
cpu_init();
preempt_disable();
smp_callin();
while (!cpu_isset(smp_processor_id(), smp_commenced_mask))
cpu_relax();
smp_online();
/*
* low-memory mappings have been cleared, flush them from
* the local TLBs too.
*/
local_flush_tlb_all();
cpu_idle();
return 0;
}
/*==========================================================================*
* Name: smp_callin
*
* Description: This routine activate a secondary processor.
*
* Born on Date: 2002.02.05
*
* Arguments: NONE
*
* Returns: void (cannot fail)
*
* Modification log:
* Date Who Description
* ---------- --- --------------------------------------------------------
* 2003-06-24 hy modify for linux-2.5.69
*
*==========================================================================*/
static void __init smp_callin(void)
{
int phys_id = hard_smp_processor_id();
int cpu_id = smp_processor_id();
unsigned long timeout;
if (cpu_isset(cpu_id, cpu_callin_map)) {
printk("huh, phys CPU#%d, CPU#%d already present??\n",
phys_id, cpu_id);
BUG();
}
Dprintk("CPU#%d (phys ID: %d) waiting for CALLOUT\n", cpu_id, phys_id);
/* Waiting 2s total for startup (udelay is not yet working) */
timeout = jiffies + (2 * HZ);
while (time_before(jiffies, timeout)) {
/* Has the boot CPU finished it's STARTUP sequence ? */
if (cpu_isset(cpu_id, cpu_callout_map))
break;
cpu_relax();
}
if (!time_before(jiffies, timeout)) {
printk("BUG: CPU#%d started up but did not get a callout!\n",
cpu_id);
BUG();
}
/* Allow the master to continue. */
cpu_set(cpu_id, cpu_callin_map);
}
static void __init smp_online(void)
{
int cpu_id = smp_processor_id();
local_irq_enable();
/* Get our bogomips. */
calibrate_delay();
/* Save our processor parameters */
smp_store_cpu_info(cpu_id);
cpu_set(cpu_id, cpu_online_map);
}
/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
/* Boot up CPUs common Routins */
/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
static void __init show_mp_info(int nr_cpu)
{
int i;
char cpu_model0[17], cpu_model1[17], cpu_ver[9];
strncpy(cpu_model0, (char *)M32R_FPGA_CPU_NAME_ADDR, 16);
strncpy(cpu_model1, (char *)M32R_FPGA_MODEL_ID_ADDR, 16);
strncpy(cpu_ver, (char *)M32R_FPGA_VERSION_ADDR, 8);
cpu_model0[16] = '\0';
for (i = 15 ; i >= 0 ; i--) {
if (cpu_model0[i] != ' ')
break;
cpu_model0[i] = '\0';
}
cpu_model1[16] = '\0';
for (i = 15 ; i >= 0 ; i--) {
if (cpu_model1[i] != ' ')
break;
cpu_model1[i] = '\0';
}
cpu_ver[8] = '\0';
for (i = 7 ; i >= 0 ; i--) {
if (cpu_ver[i] != ' ')
break;
cpu_ver[i] = '\0';
}
printk(KERN_INFO "M32R-mp information\n");
printk(KERN_INFO " On-chip CPUs : %d\n", nr_cpu);
printk(KERN_INFO " CPU model : %s/%s(%s)\n", cpu_model0,
cpu_model1, cpu_ver);
}
/*
* The bootstrap kernel entry code has set these up. Save them for
* a given CPU
*/
static void __init smp_store_cpu_info(int cpu_id)
{
struct cpuinfo_m32r *ci = cpu_data + cpu_id;
*ci = boot_cpu_data;
ci->loops_per_jiffy = loops_per_jiffy;
}
static void __init show_cpu_info(int cpu_id)
{
struct cpuinfo_m32r *ci = &cpu_data[cpu_id];
printk("CPU#%d : ", cpu_id);
#define PRINT_CLOCK(name, value) \
printk(name " clock %d.%02dMHz", \
((value) / 1000000), ((value) % 1000000) / 10000)
PRINT_CLOCK("CPU", (int)ci->cpu_clock);
PRINT_CLOCK(", Bus", (int)ci->bus_clock);
printk(", loops_per_jiffy[%ld]\n", ci->loops_per_jiffy);
}
/*
* the frequency of the profiling timer can be changed
* by writing a multiplier value into /proc/profile.
*/
int setup_profiling_timer(unsigned int multiplier)
{
int i;
/*
* Sanity check. [at least 500 APIC cycles should be
* between APIC interrupts as a rule of thumb, to avoid
* irqs flooding us]
*/
if ( (!multiplier) || (calibration_result / multiplier < 500))
return -EINVAL;
/*
* Set the new multiplier for each CPU. CPUs don't start using the
* new values until the next timer interrupt in which they do process
* accounting. At that time they also adjust their APIC timers
* accordingly.
*/
for (i = 0; i < NR_CPUS; ++i)
per_cpu(prof_multiplier, i) = multiplier;
return 0;
}
/* Initialize all maps between cpu number and apicids */
static void __init init_cpu_to_physid(void)
{
int i;
for (i = 0 ; i < NR_CPUS ; i++) {
cpu_2_physid[i] = -1;
physid_2_cpu[i] = -1;
}
}
/*
* set up a mapping between cpu and apicid. Uses logical apicids for multiquad,
* else physical apic ids
*/
static void __init map_cpu_to_physid(int cpu_id, int phys_id)
{
physid_2_cpu[phys_id] = cpu_id;
cpu_2_physid[cpu_id] = phys_id;
}
/*
* undo a mapping between cpu and apicid. Uses logical apicids for multiquad,
* else physical apic ids
*/
static void __init unmap_cpu_to_physid(int cpu_id, int phys_id)
{
physid_2_cpu[phys_id] = -1;
cpu_2_physid[cpu_id] = -1;
}