[patch 37/38] Clean up smp code in preparation for some larger changes.

From: Martin Schwidefsky
Date: Fri Apr 27 2007 - 10:09:00 EST

From: Heiko Carstens <heiko.carstens@xxxxxxxxxx>

Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Signed-off-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
---

arch/s390/kernel/smp.c | 259 ++++++++++++++++++-------------------------------
include/asm-s390/smp.h | 5
2 files changed, 99 insertions(+), 165 deletions(-)

Index: quilt-2.6/arch/s390/kernel/smp.c
===================================================================
--- quilt-2.6.orig/arch/s390/kernel/smp.c 2007-04-27 16:05:00.000000000 +0200
+++ quilt-2.6/arch/s390/kernel/smp.c 2007-04-27 16:05:02.000000000 +0200
@@ -1,12 +1,12 @@
/*
* arch/s390/kernel/smp.c
*
- * Copyright (C) IBM Corp. 1999,2006
+ * Copyright IBM Corp. 1999,2007
* Author(s): Denis Joseph Barrow (djbarrow@xxxxxxxxxx,barrow_dj@xxxxxxxxx),
- * Martin Schwidefsky (schwidefsky@xxxxxxxxxx)
- * Heiko Carstens (heiko.carstens@xxxxxxxxxx)
+ * Martin Schwidefsky (schwidefsky@xxxxxxxxxx)
+ * Heiko Carstens (heiko.carstens@xxxxxxxxxx)
*
- * based on other smp stuff by
+ * based on other smp stuff by
* (c) 1995 Alan Cox, CymruNET Ltd <alan@xxxxxxxxx>
* (c) 1998 Ingo Molnar
*
@@ -43,16 +43,17 @@
#include <asm/timer.h>
#include <asm/lowcore.h>

-extern volatile int __cpu_logical_map[];
-
/*
* An array with a pointer the lowcore of every CPU.
*/
-
struct _lowcore *lowcore_ptr[NR_CPUS];
+EXPORT_SYMBOL(lowcore_ptr);

cpumask_t cpu_online_map = CPU_MASK_NONE;
+EXPORT_SYMBOL(cpu_online_map);
+
cpumask_t cpu_possible_map = CPU_MASK_NONE;
+EXPORT_SYMBOL(cpu_possible_map);

static struct task_struct *current_set[NR_CPUS];

@@ -72,7 +73,7 @@
int wait;
};

-static struct call_data_struct * call_data;
+static struct call_data_struct *call_data;

/*
* 'Call function' interrupt callback
@@ -152,8 +153,8 @@
*
* Run a function on all other CPUs.
*
- * You must not call this function with disabled interrupts or from a
- * hardware interrupt handler. You may call it from a bottom half.
+ * You must not call this function with disabled interrupts, from a
+ * hardware interrupt handler or from a bottom half.
*/
int smp_call_function(void (*func) (void *info), void *info, int nonatomic,
int wait)
@@ -179,11 +180,11 @@
*
* Run a function on one processor.
*
- * You must not call this function with disabled interrupts or from a
- * hardware interrupt handler. You may call it from a bottom half.
+ * You must not call this function with disabled interrupts, from a
+ * hardware interrupt handler or from a bottom half.
*/
int smp_call_function_on(void (*func) (void *info), void *info, int nonatomic,
- int wait, int cpu)
+ int wait, int cpu)
{
cpumask_t map = CPU_MASK_NONE;

@@ -197,9 +198,9 @@

static void do_send_stop(void)
{
- int cpu, rc;
+ int cpu, rc;

- /* stop all processors */
+ /* stop all processors */
for_each_online_cpu(cpu) {
if (cpu == smp_processor_id())
continue;
@@ -211,9 +212,9 @@

static void do_store_status(void)
{
- int cpu, rc;
+ int cpu, rc;

- /* store status of all processors in their lowcores (real 0) */
+ /* store status of all processors in their lowcores (real 0) */
for_each_online_cpu(cpu) {
if (cpu == smp_processor_id())
continue;
@@ -221,8 +222,8 @@
rc = signal_processor_p(
(__u32)(unsigned long) lowcore_ptr[cpu], cpu,
sigp_store_status_at_address);
- } while(rc == sigp_busy);
- }
+ } while (rc == sigp_busy);
+ }
}

static void do_wait_for_stop(void)
@@ -233,7 +234,7 @@
for_each_online_cpu(cpu) {
if (cpu == smp_processor_id())
continue;
- while(!smp_cpu_not_running(cpu))
+ while (!smp_cpu_not_running(cpu))
cpu_relax();
}
}
@@ -247,7 +248,7 @@
/* Disable all interrupts/machine checks */
__load_psw_mask(psw_kernel_bits & ~PSW_MASK_MCHECK);

- /* write magic number to zero page (absolute 0) */
+ /* write magic number to zero page (absolute 0) */
lowcore_ptr[smp_processor_id()]->panic_magic = __PANIC_MAGIC;

/* stop other processors. */
@@ -263,8 +264,7 @@
/*
* Reboot, halt and power_off routines for SMP.
*/
-
-void machine_restart_smp(char * __unused)
+void machine_restart_smp(char *__unused)
{
smp_send_stop();
do_reipl();
@@ -295,17 +295,17 @@

static void do_ext_call_interrupt(__u16 code)
{
- unsigned long bits;
+ unsigned long bits;

- /*
- * handle bit signal external calls
- *
- * For the ec_schedule signal we have to do nothing. All the work
- * is done automatically when we return from the interrupt.
- */
+ /*
+ * handle bit signal external calls
+ *
+ * For the ec_schedule signal we have to do nothing. All the work
+ * is done automatically when we return from the interrupt.
+ */
bits = xchg(&S390_lowcore.ext_call_fast, 0);

- if (test_bit(ec_call_function, &bits))
+ if (test_bit(ec_call_function, &bits))
do_call_function();
}

@@ -315,11 +315,11 @@
*/
static void smp_ext_bitcall(int cpu, ec_bit_sig sig)
{
- /*
- * Set signaling bit in lowcore of target cpu and kick it
- */
+ /*
+ * Set signaling bit in lowcore of target cpu and kick it
+ */
set_bit(sig, (unsigned long *) &lowcore_ptr[cpu]->ext_call_fast);
- while(signal_processor(cpu, sigp_emergency_signal) == sigp_busy)
+ while (signal_processor(cpu, sigp_emergency_signal) == sigp_busy)
udelay(10);
}

@@ -334,7 +334,7 @@

void smp_ptlb_all(void)
{
- on_each_cpu(smp_ptlb_callback, NULL, 0, 1);
+ on_each_cpu(smp_ptlb_callback, NULL, 0, 1);
}
EXPORT_SYMBOL(smp_ptlb_all);
#endif /* ! CONFIG_64BIT */
@@ -346,7 +346,7 @@
*/
void smp_send_reschedule(int cpu)
{
- smp_ext_bitcall(cpu, ec_schedule);
+ smp_ext_bitcall(cpu, ec_schedule);
}

/*
@@ -360,11 +360,12 @@
/*
* callback for setting/clearing control bits
*/
-static void smp_ctl_bit_callback(void *info) {
+static void smp_ctl_bit_callback(void *info)
+{
struct ec_creg_mask_parms *pp = info;
unsigned long cregs[16];
int i;
-
+
__ctl_store(cregs, 0, 15);
for (i = 0; i <= 15; i++)
cregs[i] = (cregs[i] & pp->andvals[i]) | pp->orvals[i];
@@ -383,6 +384,7 @@
parms.orvals[cr] = 1 << bit;
on_each_cpu(smp_ctl_bit_callback, &parms, 0, 1);
}
+EXPORT_SYMBOL(smp_ctl_set_bit);

/*
* Clear a bit in a control register of all cpus
@@ -396,6 +398,7 @@
parms.andvals[cr] = ~(1L << bit);
on_each_cpu(smp_ctl_bit_callback, &parms, 0, 1);
}
+EXPORT_SYMBOL(smp_ctl_clear_bit);

#if defined(CONFIG_ZFCPDUMP) || defined(CONFIG_ZFCPDUMP_MODULE)

@@ -460,8 +463,7 @@
* Lets check how many CPUs we have.
*/

-static unsigned int
-__init smp_count_cpus(void)
+static unsigned int __init smp_count_cpus(void)
{
unsigned int cpu, num_cpus;
__u16 boot_cpu_addr;
@@ -477,31 +479,30 @@
if ((__u16) cpu == boot_cpu_addr)
continue;
__cpu_logical_map[1] = (__u16) cpu;
- if (signal_processor(1, sigp_sense) ==
- sigp_not_operational)
+ if (signal_processor(1, sigp_sense) == sigp_not_operational)
continue;
num_cpus++;
}

- printk("Detected %d CPU's\n",(int) num_cpus);
+ printk("Detected %d CPU's\n", (int) num_cpus);
printk("Boot cpu address %2X\n", boot_cpu_addr);

return num_cpus;
}

/*
- * Activate a secondary processor.
+ * Activate a secondary processor.
*/
int __devinit start_secondary(void *cpuvoid)
{
- /* Setup the cpu */
- cpu_init();
+ /* Setup the cpu */
+ cpu_init();
preempt_disable();
/* Enable TOD clock interrupts on the secondary cpu. */
- init_cpu_timer();
+ init_cpu_timer();
#ifdef CONFIG_VIRT_TIMER
/* Enable cpu timer interrupts on the secondary cpu. */
- init_cpu_vtimer();
+ init_cpu_vtimer();
#endif
/* Enable pfault pseudo page faults on this cpu. */
pfault_init();
@@ -510,11 +511,11 @@
cpu_set(smp_processor_id(), cpu_online_map);
/* Switch on interrupts */
local_irq_enable();
- /* Print info about this processor */
- print_cpu_info(&S390_lowcore.cpu_data);
- /* cpu_idle will call schedule for us */
- cpu_idle();
- return 0;
+ /* Print info about this processor */
+ print_cpu_info(&S390_lowcore.cpu_data);
+ /* cpu_idle will call schedule for us */
+ cpu_idle();
+ return 0;
}

static void __init smp_create_idle(unsigned int cpu)
@@ -531,56 +532,13 @@
current_set[cpu] = p;
}

-/* Reserving and releasing of CPUs */
-
-static DEFINE_SPINLOCK(smp_reserve_lock);
-static int smp_cpu_reserved[NR_CPUS];
-
-int
-smp_get_cpu(cpumask_t cpu_mask)
-{
- unsigned long flags;
- int cpu;
-
- spin_lock_irqsave(&smp_reserve_lock, flags);
- /* Try to find an already reserved cpu. */
- for_each_cpu_mask(cpu, cpu_mask) {
- if (smp_cpu_reserved[cpu] != 0) {
- smp_cpu_reserved[cpu]++;
- /* Found one. */
- goto out;
- }
- }
- /* Reserve a new cpu from cpu_mask. */
- for_each_cpu_mask(cpu, cpu_mask) {
- if (cpu_online(cpu)) {
- smp_cpu_reserved[cpu]++;
- goto out;
- }
- }
- cpu = -ENODEV;
-out:
- spin_unlock_irqrestore(&smp_reserve_lock, flags);
- return cpu;
-}
-
-void
-smp_put_cpu(int cpu)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&smp_reserve_lock, flags);
- smp_cpu_reserved[cpu]--;
- spin_unlock_irqrestore(&smp_reserve_lock, flags);
-}
-
-static int
-cpu_stopped(int cpu)
+static int cpu_stopped(int cpu)
{
__u32 status;

/* Check for stopped state */
- if (signal_processor_ps(&status, 0, cpu, sigp_sense) == sigp_status_stored) {
+ if (signal_processor_ps(&status, 0, cpu, sigp_sense) ==
+ sigp_status_stored) {
if (status & 0x40)
return 1;
}
@@ -589,14 +547,13 @@

/* Upping and downing of CPUs */

-int
-__cpu_up(unsigned int cpu)
+int __cpu_up(unsigned int cpu)
{
struct task_struct *idle;
- struct _lowcore *cpu_lowcore;
+ struct _lowcore *cpu_lowcore;
struct stack_frame *sf;
- sigp_ccode ccode;
- int curr_cpu;
+ sigp_ccode ccode;
+ int curr_cpu;

for (curr_cpu = 0; curr_cpu <= 65535; curr_cpu++) {
__cpu_logical_map[cpu] = (__u16) curr_cpu;
@@ -609,7 +566,7 @@

ccode = signal_processor_p((__u32)(unsigned long)(lowcore_ptr[cpu]),
cpu, sigp_set_prefix);
- if (ccode){
+ if (ccode) {
printk("sigp_set_prefix failed for cpu %d "
"with condition code %d\n",
(int) cpu, (int) ccode);
@@ -617,9 +574,9 @@
}

idle = current_set[cpu];
- cpu_lowcore = lowcore_ptr[cpu];
+ cpu_lowcore = lowcore_ptr[cpu];
cpu_lowcore->kernel_stack = (unsigned long)
- task_stack_page(idle) + (THREAD_SIZE);
+ task_stack_page(idle) + THREAD_SIZE;
sf = (struct stack_frame *) (cpu_lowcore->kernel_stack
- sizeof(struct pt_regs)
- sizeof(struct stack_frame));
@@ -631,11 +588,11 @@
" stam 0,15,0(%0)"
: : "a" (&cpu_lowcore->access_regs_save_area) : "memory");
cpu_lowcore->percpu_offset = __per_cpu_offset[cpu];
- cpu_lowcore->current_task = (unsigned long) idle;
- cpu_lowcore->cpu_data.cpu_nr = cpu;
+ cpu_lowcore->current_task = (unsigned long) idle;
+ cpu_lowcore->cpu_data.cpu_nr = cpu;
eieio();

- while (signal_processor(cpu,sigp_restart) == sigp_busy)
+ while (signal_processor(cpu, sigp_restart) == sigp_busy)
udelay(10);

while (!cpu_online(cpu))
@@ -682,18 +639,11 @@
}
early_param("possible_cpus", setup_possible_cpus);

-int
-__cpu_disable(void)
+int __cpu_disable(void)
{
- unsigned long flags;
struct ec_creg_mask_parms cr_parms;
int cpu = smp_processor_id();

- spin_lock_irqsave(&smp_reserve_lock, flags);
- if (smp_cpu_reserved[cpu] != 0) {
- spin_unlock_irqrestore(&smp_reserve_lock, flags);
- return -EBUSY;
- }
cpu_clear(cpu, cpu_online_map);

/* Disable pfault pseudo page faults on this cpu. */
@@ -704,24 +654,23 @@

/* disable all external interrupts */
cr_parms.orvals[0] = 0;
- cr_parms.andvals[0] = ~(1<<15 | 1<<14 | 1<<13 | 1<<12 |
- 1<<11 | 1<<10 | 1<< 6 | 1<< 4);
+ cr_parms.andvals[0] = ~(1 << 15 | 1 << 14 | 1 << 13 | 1 << 12 |
+ 1 << 11 | 1 << 10 | 1 << 6 | 1 << 4);
/* disable all I/O interrupts */
cr_parms.orvals[6] = 0;
- cr_parms.andvals[6] = ~(1<<31 | 1<<30 | 1<<29 | 1<<28 |
- 1<<27 | 1<<26 | 1<<25 | 1<<24);
+ cr_parms.andvals[6] = ~(1 << 31 | 1 << 30 | 1 << 29 | 1 << 28 |
+ 1 << 27 | 1 << 26 | 1 << 25 | 1 << 24);
/* disable most machine checks */
cr_parms.orvals[14] = 0;
- cr_parms.andvals[14] = ~(1<<28 | 1<<27 | 1<<26 | 1<<25 | 1<<24);
+ cr_parms.andvals[14] = ~(1 << 28 | 1 << 27 | 1 << 26 |
+ 1 << 25 | 1 << 24);

smp_ctl_bit_callback(&cr_parms);

- spin_unlock_irqrestore(&smp_reserve_lock, flags);
return 0;
}

-void
-__cpu_die(unsigned int cpu)
+void __cpu_die(unsigned int cpu)
{
/* Wait until target cpu is down */
while (!smp_cpu_not_running(cpu))
@@ -729,13 +678,12 @@
printk("Processor %d spun down\n", cpu);
}

-void
-cpu_die(void)
+void cpu_die(void)
{
idle_task_exit();
signal_processor(smp_processor_id(), sigp_stop);
BUG();
- for(;;);
+ for (;;);
}

#endif /* CONFIG_HOTPLUG_CPU */
@@ -748,36 +696,36 @@
{
unsigned long stack;
unsigned int cpu;
- int i;
+ int i;

- /* request the 0x1201 emergency signal external interrupt */
- if (register_external_interrupt(0x1201, do_ext_call_interrupt) != 0)
- panic("Couldn't request external interrupt 0x1201");
- memset(lowcore_ptr,0,sizeof(lowcore_ptr));
- /*
- * Initialize prefix pages and stacks for all possible cpus
- */
+ /* request the 0x1201 emergency signal external interrupt */
+ if (register_external_interrupt(0x1201, do_ext_call_interrupt) != 0)
+ panic("Couldn't request external interrupt 0x1201");
+ memset(lowcore_ptr, 0, sizeof(lowcore_ptr));
+ /*
+ * Initialize prefix pages and stacks for all possible cpus
+ */
print_cpu_info(&S390_lowcore.cpu_data);

- for_each_possible_cpu(i) {
+ for_each_possible_cpu(i) {
lowcore_ptr[i] = (struct _lowcore *)
- __get_free_pages(GFP_KERNEL|GFP_DMA,
- sizeof(void*) == 8 ? 1 : 0);
- stack = __get_free_pages(GFP_KERNEL,ASYNC_ORDER);
- if (lowcore_ptr[i] == NULL || stack == 0ULL)
+ __get_free_pages(GFP_KERNEL | GFP_DMA,
+ sizeof(void*) == 8 ? 1 : 0);
+ stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
+ if (!lowcore_ptr[i] || !stack)
panic("smp_boot_cpus failed to allocate memory\n");

*(lowcore_ptr[i]) = S390_lowcore;
- lowcore_ptr[i]->async_stack = stack + (ASYNC_SIZE);
- stack = __get_free_pages(GFP_KERNEL,0);
- if (stack == 0ULL)
+ lowcore_ptr[i]->async_stack = stack + ASYNC_SIZE;
+ stack = __get_free_pages(GFP_KERNEL, 0);
+ if (!stack)
panic("smp_boot_cpus failed to allocate memory\n");
- lowcore_ptr[i]->panic_stack = stack + (PAGE_SIZE);
+ lowcore_ptr[i]->panic_stack = stack + PAGE_SIZE;
#ifndef CONFIG_64BIT
if (MACHINE_HAS_IEEE) {
lowcore_ptr[i]->extended_save_area_addr =
- (__u32) __get_free_pages(GFP_KERNEL,0);
- if (lowcore_ptr[i]->extended_save_area_addr == 0)
+ (__u32) __get_free_pages(GFP_KERNEL, 0);
+ if (!lowcore_ptr[i]->extended_save_area_addr)
panic("smp_boot_cpus failed to "
"allocate memory\n");
}
@@ -816,7 +764,7 @@
*/
int setup_profiling_timer(unsigned int multiplier)
{
- return 0;
+ return 0;
}

static DEFINE_PER_CPU(struct cpu, cpu_devices);
@@ -853,7 +801,7 @@
}

static struct notifier_block __cpuinitdata smp_cpu_nb = {
- .notifier_call = smp_cpu_notify,
+ .notifier_call = smp_cpu_notify,
};

static int __init topology_init(void)
@@ -875,13 +823,4 @@
}
return 0;
}
-
subsys_initcall(topology_init);
-
-EXPORT_SYMBOL(cpu_online_map);
-EXPORT_SYMBOL(cpu_possible_map);
-EXPORT_SYMBOL(lowcore_ptr);
-EXPORT_SYMBOL(smp_ctl_set_bit);
-EXPORT_SYMBOL(smp_ctl_clear_bit);
-EXPORT_SYMBOL(smp_get_cpu);
-EXPORT_SYMBOL(smp_put_cpu);
Index: quilt-2.6/include/asm-s390/smp.h
===================================================================
--- quilt-2.6.orig/include/asm-s390/smp.h 2007-04-27 16:04:59.000000000 +0200
+++ quilt-2.6/include/asm-s390/smp.h 2007-04-27 16:05:02.000000000 +0200
@@ -54,9 +54,6 @@

#define raw_smp_processor_id() (S390_lowcore.cpu_data.cpu_nr)

-extern int smp_get_cpu(cpumask_t cpu_map);
-extern void smp_put_cpu(int cpu);
-
static inline __u16 hard_smp_processor_id(void)
{
__u16 cpu_address;
@@ -114,8 +111,6 @@
}

#define smp_cpu_not_running(cpu) 1
-#define smp_get_cpu(cpu) ({ 0; })
-#define smp_put_cpu(cpu) ({ 0; })
#define smp_setup_cpu_possible_map() do { } while (0)
#endif


--
blue skies,
Martin.

"Reality continues to ruin my life." - Calvin.

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