satip-axe/kernel/arch/m32r/kernel/smp.c
2015-03-26 17:24:57 +01:00

848 lines
24 KiB
C

/*
* linux/arch/m32r/kernel/smp.c
*
* M32R SMP support routines.
*
* Copyright (c) 2001, 2002 Hitoshi Yamamoto
*
* Taken from i386 version.
* (c) 1995 Alan Cox, Building #3 <alan@redhat.com>
* (c) 1998-99, 2000 Ingo Molnar <mingo@redhat.com>
*
* This code is released under the GNU General Public License version 2 or
* later.
*/
#undef DEBUG_SMP
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/profile.h>
#include <linux/cpu.h>
#include <asm/cacheflush.h>
#include <asm/pgalloc.h>
#include <asm/atomic.h>
#include <asm/io.h>
#include <asm/mmu_context.h>
#include <asm/m32r.h>
/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
/* Data structures and variables */
/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
/*
* For flush_cache_all()
*/
static DEFINE_SPINLOCK(flushcache_lock);
static volatile unsigned long flushcache_cpumask = 0;
/*
* For flush_tlb_others()
*/
static volatile cpumask_t flush_cpumask;
static struct mm_struct *flush_mm;
static struct vm_area_struct *flush_vma;
static volatile unsigned long flush_va;
static DEFINE_SPINLOCK(tlbstate_lock);
#define FLUSH_ALL 0xffffffff
DECLARE_PER_CPU(int, prof_multiplier);
DECLARE_PER_CPU(int, prof_old_multiplier);
DECLARE_PER_CPU(int, prof_counter);
extern spinlock_t ipi_lock[];
/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
/* Function Prototypes */
/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
void smp_send_reschedule(int);
void smp_reschedule_interrupt(void);
void smp_flush_cache_all(void);
void smp_flush_cache_all_interrupt(void);
void smp_flush_tlb_all(void);
static void flush_tlb_all_ipi(void *);
void smp_flush_tlb_mm(struct mm_struct *);
void smp_flush_tlb_range(struct vm_area_struct *, unsigned long, \
unsigned long);
void smp_flush_tlb_page(struct vm_area_struct *, unsigned long);
static void flush_tlb_others(cpumask_t, struct mm_struct *,
struct vm_area_struct *, unsigned long);
void smp_invalidate_interrupt(void);
void smp_send_stop(void);
static void stop_this_cpu(void *);
void smp_send_timer(void);
void smp_ipi_timer_interrupt(struct pt_regs *);
void smp_local_timer_interrupt(void);
static void send_IPI_allbutself(int, int);
static void send_IPI_mask(const struct cpumask *, int, int);
unsigned long send_IPI_mask_phys(cpumask_t, int, int);
/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
/* Rescheduling request Routines */
/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
/*==========================================================================*
* Name: smp_send_reschedule
*
* Description: This routine requests other CPU to execute rescheduling.
* 1.Send 'RESCHEDULE_IPI' to other CPU.
* Request other CPU to execute 'smp_reschedule_interrupt()'.
*
* Born on Date: 2002.02.05
*
* Arguments: cpu_id - Target CPU ID
*
* Returns: void (cannot fail)
*
* Modification log:
* Date Who Description
* ---------- --- --------------------------------------------------------
*
*==========================================================================*/
void smp_send_reschedule(int cpu_id)
{
WARN_ON(cpu_is_offline(cpu_id));
send_IPI_mask(cpumask_of(cpu_id), RESCHEDULE_IPI, 1);
}
/*==========================================================================*
* Name: smp_reschedule_interrupt
*
* Description: This routine executes on CPU which received
* 'RESCHEDULE_IPI'.
* Rescheduling is processed at the exit of interrupt
* operation.
*
* Born on Date: 2002.02.05
*
* Arguments: NONE
*
* Returns: void (cannot fail)
*
* Modification log:
* Date Who Description
* ---------- --- --------------------------------------------------------
*
*==========================================================================*/
void smp_reschedule_interrupt(void)
{
/* nothing to do */
}
/*==========================================================================*
* Name: smp_flush_cache_all
*
* Description: This routine sends a 'INVALIDATE_CACHE_IPI' to all other
* CPUs in the system.
*
* Born on Date: 2003-05-28
*
* Arguments: NONE
*
* Returns: void (cannot fail)
*
* Modification log:
* Date Who Description
* ---------- --- --------------------------------------------------------
*
*==========================================================================*/
void smp_flush_cache_all(void)
{
cpumask_t cpumask;
unsigned long *mask;
preempt_disable();
cpumask = cpu_online_map;
cpu_clear(smp_processor_id(), cpumask);
spin_lock(&flushcache_lock);
mask=cpus_addr(cpumask);
atomic_set_mask(*mask, (atomic_t *)&flushcache_cpumask);
send_IPI_mask(&cpumask, INVALIDATE_CACHE_IPI, 0);
_flush_cache_copyback_all();
while (flushcache_cpumask)
mb();
spin_unlock(&flushcache_lock);
preempt_enable();
}
void smp_flush_cache_all_interrupt(void)
{
_flush_cache_copyback_all();
clear_bit(smp_processor_id(), &flushcache_cpumask);
}
/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
/* TLB flush request Routines */
/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
/*==========================================================================*
* Name: smp_flush_tlb_all
*
* Description: This routine flushes all processes TLBs.
* 1.Request other CPU to execute 'flush_tlb_all_ipi()'.
* 2.Execute 'do_flush_tlb_all_local()'.
*
* Born on Date: 2002.02.05
*
* Arguments: NONE
*
* Returns: void (cannot fail)
*
* Modification log:
* Date Who Description
* ---------- --- --------------------------------------------------------
*
*==========================================================================*/
void smp_flush_tlb_all(void)
{
unsigned long flags;
preempt_disable();
local_irq_save(flags);
__flush_tlb_all();
local_irq_restore(flags);
smp_call_function(flush_tlb_all_ipi, NULL, 1);
preempt_enable();
}
/*==========================================================================*
* Name: flush_tlb_all_ipi
*
* Description: This routine flushes all local TLBs.
* 1.Execute 'do_flush_tlb_all_local()'.
*
* Born on Date: 2002.02.05
*
* Arguments: *info - not used
*
* Returns: void (cannot fail)
*
* Modification log:
* Date Who Description
* ---------- --- --------------------------------------------------------
*
*==========================================================================*/
static void flush_tlb_all_ipi(void *info)
{
__flush_tlb_all();
}
/*==========================================================================*
* Name: smp_flush_tlb_mm
*
* Description: This routine flushes the specified mm context TLB's.
*
* Born on Date: 2002.02.05
*
* Arguments: *mm - a pointer to the mm struct for flush TLB
*
* Returns: void (cannot fail)
*
* Modification log:
* Date Who Description
* ---------- --- --------------------------------------------------------
*
*==========================================================================*/
void smp_flush_tlb_mm(struct mm_struct *mm)
{
int cpu_id;
cpumask_t cpu_mask;
unsigned long *mmc;
unsigned long flags;
preempt_disable();
cpu_id = smp_processor_id();
mmc = &mm->context[cpu_id];
cpu_mask = *mm_cpumask(mm);
cpu_clear(cpu_id, cpu_mask);
if (*mmc != NO_CONTEXT) {
local_irq_save(flags);
*mmc = NO_CONTEXT;
if (mm == current->mm)
activate_context(mm);
else
cpumask_clear_cpu(cpu_id, mm_cpumask(mm));
local_irq_restore(flags);
}
if (!cpus_empty(cpu_mask))
flush_tlb_others(cpu_mask, mm, NULL, FLUSH_ALL);
preempt_enable();
}
/*==========================================================================*
* Name: smp_flush_tlb_range
*
* Description: This routine flushes a range of pages.
*
* Born on Date: 2002.02.05
*
* Arguments: *mm - a pointer to the mm struct for flush TLB
* start - not used
* end - not used
*
* Returns: void (cannot fail)
*
* Modification log:
* Date Who Description
* ---------- --- --------------------------------------------------------
*
*==========================================================================*/
void smp_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
unsigned long end)
{
smp_flush_tlb_mm(vma->vm_mm);
}
/*==========================================================================*
* Name: smp_flush_tlb_page
*
* Description: This routine flushes one page.
*
* Born on Date: 2002.02.05
*
* Arguments: *vma - a pointer to the vma struct include va
* va - virtual address for flush TLB
*
* Returns: void (cannot fail)
*
* Modification log:
* Date Who Description
* ---------- --- --------------------------------------------------------
*
*==========================================================================*/
void smp_flush_tlb_page(struct vm_area_struct *vma, unsigned long va)
{
struct mm_struct *mm = vma->vm_mm;
int cpu_id;
cpumask_t cpu_mask;
unsigned long *mmc;
unsigned long flags;
preempt_disable();
cpu_id = smp_processor_id();
mmc = &mm->context[cpu_id];
cpu_mask = *mm_cpumask(mm);
cpu_clear(cpu_id, cpu_mask);
#ifdef DEBUG_SMP
if (!mm)
BUG();
#endif
if (*mmc != NO_CONTEXT) {
local_irq_save(flags);
va &= PAGE_MASK;
va |= (*mmc & MMU_CONTEXT_ASID_MASK);
__flush_tlb_page(va);
local_irq_restore(flags);
}
if (!cpus_empty(cpu_mask))
flush_tlb_others(cpu_mask, mm, vma, va);
preempt_enable();
}
/*==========================================================================*
* Name: flush_tlb_others
*
* Description: This routine requests other CPU to execute flush TLB.
* 1.Setup parameters.
* 2.Send 'INVALIDATE_TLB_IPI' to other CPU.
* Request other CPU to execute 'smp_invalidate_interrupt()'.
* 3.Wait for other CPUs operation finished.
*
* Born on Date: 2002.02.05
*
* Arguments: cpumask - bitmap of target CPUs
* *mm - a pointer to the mm struct for flush TLB
* *vma - a pointer to the vma struct include va
* va - virtual address for flush TLB
*
* Returns: void (cannot fail)
*
* Modification log:
* Date Who Description
* ---------- --- --------------------------------------------------------
*
*==========================================================================*/
static void flush_tlb_others(cpumask_t cpumask, struct mm_struct *mm,
struct vm_area_struct *vma, unsigned long va)
{
unsigned long *mask;
#ifdef DEBUG_SMP
unsigned long flags;
__save_flags(flags);
if (!(flags & 0x0040)) /* Interrupt Disable NONONO */
BUG();
#endif /* DEBUG_SMP */
/*
* A couple of (to be removed) sanity checks:
*
* - we do not send IPIs to not-yet booted CPUs.
* - current CPU must not be in mask
* - mask must exist :)
*/
BUG_ON(cpus_empty(cpumask));
BUG_ON(cpu_isset(smp_processor_id(), cpumask));
BUG_ON(!mm);
/* If a CPU which we ran on has gone down, OK. */
cpus_and(cpumask, cpumask, cpu_online_map);
if (cpus_empty(cpumask))
return;
/*
* i'm not happy about this global shared spinlock in the
* MM hot path, but we'll see how contended it is.
* Temporarily this turns IRQs off, so that lockups are
* detected by the NMI watchdog.
*/
spin_lock(&tlbstate_lock);
flush_mm = mm;
flush_vma = vma;
flush_va = va;
mask=cpus_addr(cpumask);
atomic_set_mask(*mask, (atomic_t *)&flush_cpumask);
/*
* We have to send the IPI only to
* CPUs affected.
*/
send_IPI_mask(&cpumask, INVALIDATE_TLB_IPI, 0);
while (!cpus_empty(flush_cpumask)) {
/* nothing. lockup detection does not belong here */
mb();
}
flush_mm = NULL;
flush_vma = NULL;
flush_va = 0;
spin_unlock(&tlbstate_lock);
}
/*==========================================================================*
* Name: smp_invalidate_interrupt
*
* Description: This routine executes on CPU which received
* 'INVALIDATE_TLB_IPI'.
* 1.Flush local TLB.
* 2.Report flush TLB process was finished.
*
* Born on Date: 2002.02.05
*
* Arguments: NONE
*
* Returns: void (cannot fail)
*
* Modification log:
* Date Who Description
* ---------- --- --------------------------------------------------------
*
*==========================================================================*/
void smp_invalidate_interrupt(void)
{
int cpu_id = smp_processor_id();
unsigned long *mmc = &flush_mm->context[cpu_id];
if (!cpu_isset(cpu_id, flush_cpumask))
return;
if (flush_va == FLUSH_ALL) {
*mmc = NO_CONTEXT;
if (flush_mm == current->active_mm)
activate_context(flush_mm);
else
cpumask_clear_cpu(cpu_id, mm_cpumask(flush_mm));
} else {
unsigned long va = flush_va;
if (*mmc != NO_CONTEXT) {
va &= PAGE_MASK;
va |= (*mmc & MMU_CONTEXT_ASID_MASK);
__flush_tlb_page(va);
}
}
cpu_clear(cpu_id, flush_cpumask);
}
/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
/* Stop CPU request Routines */
/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
/*==========================================================================*
* Name: smp_send_stop
*
* Description: This routine requests stop all CPUs.
* 1.Request other CPU to execute 'stop_this_cpu()'.
*
* Born on Date: 2002.02.05
*
* Arguments: NONE
*
* Returns: void (cannot fail)
*
* Modification log:
* Date Who Description
* ---------- --- --------------------------------------------------------
*
*==========================================================================*/
void smp_send_stop(void)
{
smp_call_function(stop_this_cpu, NULL, 0);
}
/*==========================================================================*
* Name: stop_this_cpu
*
* Description: This routine halt CPU.
*
* Born on Date: 2002.02.05
*
* Arguments: NONE
*
* Returns: void (cannot fail)
*
* Modification log:
* Date Who Description
* ---------- --- --------------------------------------------------------
*
*==========================================================================*/
static void stop_this_cpu(void *dummy)
{
int cpu_id = smp_processor_id();
/*
* Remove this CPU:
*/
cpu_clear(cpu_id, cpu_online_map);
/*
* PSW IE = 1;
* IMASK = 0;
* goto SLEEP
*/
local_irq_disable();
outl(0, M32R_ICU_IMASK_PORTL);
inl(M32R_ICU_IMASK_PORTL); /* dummy read */
local_irq_enable();
for ( ; ; );
}
void arch_send_call_function_ipi_mask(const struct cpumask *mask)
{
send_IPI_mask(mask, CALL_FUNCTION_IPI, 0);
}
void arch_send_call_function_single_ipi(int cpu)
{
send_IPI_mask(cpumask_of(cpu), CALL_FUNC_SINGLE_IPI, 0);
}
/*==========================================================================*
* Name: smp_call_function_interrupt
*
* Description: This routine executes on CPU which received
* 'CALL_FUNCTION_IPI'.
*
* Born on Date: 2002.02.05
*
* Arguments: NONE
*
* Returns: void (cannot fail)
*
* Modification log:
* Date Who Description
* ---------- --- --------------------------------------------------------
*
*==========================================================================*/
void smp_call_function_interrupt(void)
{
irq_enter();
generic_smp_call_function_interrupt();
irq_exit();
}
void smp_call_function_single_interrupt(void)
{
irq_enter();
generic_smp_call_function_single_interrupt();
irq_exit();
}
/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
/* Timer Routines */
/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
/*==========================================================================*
* Name: smp_send_timer
*
* Description: This routine sends a 'LOCAL_TIMER_IPI' to all other CPUs
* in the system.
*
* Born on Date: 2002.02.05
*
* Arguments: NONE
*
* Returns: void (cannot fail)
*
* Modification log:
* Date Who Description
* ---------- --- --------------------------------------------------------
*
*==========================================================================*/
void smp_send_timer(void)
{
send_IPI_allbutself(LOCAL_TIMER_IPI, 1);
}
/*==========================================================================*
* Name: smp_send_timer
*
* Description: This routine executes on CPU which received
* 'LOCAL_TIMER_IPI'.
*
* Born on Date: 2002.02.05
*
* Arguments: *regs - a pointer to the saved regster info
*
* Returns: void (cannot fail)
*
* Modification log:
* Date Who Description
* ---------- --- --------------------------------------------------------
*
*==========================================================================*/
void smp_ipi_timer_interrupt(struct pt_regs *regs)
{
struct pt_regs *old_regs;
old_regs = set_irq_regs(regs);
irq_enter();
smp_local_timer_interrupt();
irq_exit();
set_irq_regs(old_regs);
}
/*==========================================================================*
* Name: smp_local_timer_interrupt
*
* Description: Local timer interrupt handler. It does both profiling and
* process statistics/rescheduling.
* We do profiling in every local tick, statistics/rescheduling
* happen only every 'profiling multiplier' ticks. The default
* multiplier is 1 and it can be changed by writing the new
* multiplier value into /proc/profile.
*
* Born on Date: 2002.02.05
*
* Arguments: *regs - a pointer to the saved regster info
*
* Returns: void (cannot fail)
*
* Original: arch/i386/kernel/apic.c
*
* Modification log:
* Date Who Description
* ---------- --- --------------------------------------------------------
* 2003-06-24 hy use per_cpu structure.
*==========================================================================*/
void smp_local_timer_interrupt(void)
{
int user = user_mode(get_irq_regs());
int cpu_id = smp_processor_id();
/*
* The profiling function is SMP safe. (nothing can mess
* around with "current", and the profiling counters are
* updated with atomic operations). This is especially
* useful with a profiling multiplier != 1
*/
profile_tick(CPU_PROFILING);
if (--per_cpu(prof_counter, cpu_id) <= 0) {
/*
* The multiplier may have changed since the last time we got
* to this point as a result of the user writing to
* /proc/profile. In this case we need to adjust the APIC
* timer accordingly.
*
* Interrupts are already masked off at this point.
*/
per_cpu(prof_counter, cpu_id)
= per_cpu(prof_multiplier, cpu_id);
if (per_cpu(prof_counter, cpu_id)
!= per_cpu(prof_old_multiplier, cpu_id))
{
per_cpu(prof_old_multiplier, cpu_id)
= per_cpu(prof_counter, cpu_id);
}
update_process_times(user);
}
}
/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
/* Send IPI Routines */
/*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
/*==========================================================================*
* Name: send_IPI_allbutself
*
* Description: This routine sends a IPI to all other CPUs in the system.
*
* Born on Date: 2002.02.05
*
* Arguments: ipi_num - Number of IPI
* try - 0 : Send IPI certainly.
* !0 : The following IPI is not sent when Target CPU
* has not received the before IPI.
*
* Returns: void (cannot fail)
*
* Modification log:
* Date Who Description
* ---------- --- --------------------------------------------------------
*
*==========================================================================*/
static void send_IPI_allbutself(int ipi_num, int try)
{
cpumask_t cpumask;
cpumask = cpu_online_map;
cpu_clear(smp_processor_id(), cpumask);
send_IPI_mask(&cpumask, ipi_num, try);
}
/*==========================================================================*
* Name: send_IPI_mask
*
* Description: This routine sends a IPI to CPUs in the system.
*
* Born on Date: 2002.02.05
*
* Arguments: cpu_mask - Bitmap of target CPUs logical ID
* ipi_num - Number of IPI
* try - 0 : Send IPI certainly.
* !0 : The following IPI is not sent when Target CPU
* has not received the before IPI.
*
* Returns: void (cannot fail)
*
* Modification log:
* Date Who Description
* ---------- --- --------------------------------------------------------
*
*==========================================================================*/
static void send_IPI_mask(const struct cpumask *cpumask, int ipi_num, int try)
{
cpumask_t physid_mask, tmp;
int cpu_id, phys_id;
int num_cpus = num_online_cpus();
if (num_cpus <= 1) /* NO MP */
return;
cpumask_and(&tmp, cpumask, cpu_online_mask);
BUG_ON(!cpumask_equal(cpumask, &tmp));
physid_mask = CPU_MASK_NONE;
for_each_cpu(cpu_id, cpumask) {
if ((phys_id = cpu_to_physid(cpu_id)) != -1)
cpu_set(phys_id, physid_mask);
}
send_IPI_mask_phys(physid_mask, ipi_num, try);
}
/*==========================================================================*
* Name: send_IPI_mask_phys
*
* Description: This routine sends a IPI to other CPUs in the system.
*
* Born on Date: 2002.02.05
*
* Arguments: cpu_mask - Bitmap of target CPUs physical ID
* ipi_num - Number of IPI
* try - 0 : Send IPI certainly.
* !0 : The following IPI is not sent when Target CPU
* has not received the before IPI.
*
* Returns: IPICRi regster value.
*
* Modification log:
* Date Who Description
* ---------- --- --------------------------------------------------------
*
*==========================================================================*/
unsigned long send_IPI_mask_phys(cpumask_t physid_mask, int ipi_num,
int try)
{
spinlock_t *ipilock;
volatile unsigned long *ipicr_addr;
unsigned long ipicr_val;
unsigned long my_physid_mask;
unsigned long mask = cpus_addr(physid_mask)[0];
if (mask & ~physids_coerce(phys_cpu_present_map))
BUG();
if (ipi_num >= NR_IPIS || ipi_num < 0)
BUG();
mask <<= IPI_SHIFT;
ipilock = &ipi_lock[ipi_num];
ipicr_addr = (volatile unsigned long *)(M32R_ICU_IPICR_ADDR
+ (ipi_num << 2));
my_physid_mask = ~(1 << smp_processor_id());
/*
* lock ipi_lock[i]
* check IPICRi == 0
* write IPICRi (send IPIi)
* unlock ipi_lock[i]
*/
spin_lock(ipilock);
__asm__ __volatile__ (
";; CHECK IPICRi == 0 \n\t"
".fillinsn \n"
"1: \n\t"
"ld %0, @%1 \n\t"
"and %0, %4 \n\t"
"beqz %0, 2f \n\t"
"bnez %3, 3f \n\t"
"bra 1b \n\t"
";; WRITE IPICRi (send IPIi) \n\t"
".fillinsn \n"
"2: \n\t"
"st %2, @%1 \n\t"
".fillinsn \n"
"3: \n\t"
: "=&r"(ipicr_val)
: "r"(ipicr_addr), "r"(mask), "r"(try), "r"(my_physid_mask)
: "memory"
);
spin_unlock(ipilock);
return ipicr_val;
}