s390/smp: remove redundant pcpu::lowcore member

Per-CPU pointer to lowcore is stored in global lowcore_ptr[]
array and duplicated in struct pcpu::lowcore member. This
update removes the redundancy.

Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index eaca08b..e137c84 100644 (file)
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -74,7 +74,6 @@ enum {
 static DEFINE_PER_CPU(struct cpu *, cpu_device);
 
 struct pcpu {
-       struct lowcore *lowcore;        /* lowcore page(s) for the cpu */
        unsigned long ec_mask;          /* bit mask for ec_xxx functions */
        unsigned long ec_clk;           /* sigp timestamp for ec_xxx */
        signed char state;              /* physical cpu state */
@@ -214,7 +213,6 @@ static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu)
        if (nmi_alloc_per_cpu(lc))
                goto out;
        lowcore_ptr[cpu] = lc;
-       pcpu->lowcore = lc;
        pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, (u32)(unsigned long) lc);
        return 0;
 
@@ -230,14 +228,15 @@ static void pcpu_free_lowcore(struct pcpu *pcpu)
 {
        unsigned long async_stack, nodat_stack, mcck_stack;
        struct lowcore *lc;
+       int cpu;
 
-       lc = pcpu->lowcore;
+       cpu = pcpu - pcpu_devices;
+       lc = lowcore_ptr[cpu];
        nodat_stack = lc->nodat_stack - STACK_INIT_OFFSET;
        async_stack = lc->async_stack - STACK_INIT_OFFSET;
        mcck_stack = lc->mcck_stack - STACK_INIT_OFFSET;
        pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, 0);
-       lowcore_ptr[pcpu - pcpu_devices] = NULL;
-       pcpu->lowcore = NULL;
+       lowcore_ptr[cpu] = NULL;
        nmi_free_per_cpu(lc);
        stack_free(async_stack);
        stack_free(mcck_stack);
@@ -247,7 +246,7 @@ static void pcpu_free_lowcore(struct pcpu *pcpu)
 
 static void pcpu_prepare_secondary(struct pcpu *pcpu, int cpu)
 {
-       struct lowcore *lc = pcpu->lowcore;
+       struct lowcore *lc = lowcore_ptr[cpu];
 
        cpumask_set_cpu(cpu, &init_mm.context.cpu_attach_mask);
        cpumask_set_cpu(cpu, mm_cpumask(&init_mm));
@@ -269,8 +268,11 @@ static void pcpu_prepare_secondary(struct pcpu *pcpu, int cpu)
 
 static void pcpu_attach_task(struct pcpu *pcpu, struct task_struct *tsk)
 {
-       struct lowcore *lc = pcpu->lowcore;
+       struct lowcore *lc;
+       int cpu;
 
+       cpu = pcpu - pcpu_devices;
+       lc = lowcore_ptr[cpu];
        lc->kernel_stack = (unsigned long) task_stack_page(tsk)
                + THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
        lc->current_task = (unsigned long) tsk;
@@ -286,8 +288,11 @@ static void pcpu_attach_task(struct pcpu *pcpu, struct task_struct *tsk)
 
 static void pcpu_start_fn(struct pcpu *pcpu, void (*func)(void *), void *data)
 {
-       struct lowcore *lc = pcpu->lowcore;
+       struct lowcore *lc;
+       int cpu;
 
+       cpu = pcpu - pcpu_devices;
+       lc = lowcore_ptr[cpu];
        lc->restart_stack = lc->nodat_stack;
        lc->restart_fn = (unsigned long) func;
        lc->restart_data = (unsigned long) data;
@@ -372,7 +377,7 @@ void smp_call_online_cpu(void (*func)(void *), void *data)
  */
 void smp_call_ipl_cpu(void (*func)(void *), void *data)
 {
-       struct lowcore *lc = pcpu_devices->lowcore;
+       struct lowcore *lc = lowcore_ptr[0];
 
        if (pcpu_devices[0].address == stap())
                lc = &S390_lowcore;
@@ -585,18 +590,21 @@ EXPORT_SYMBOL(smp_ctl_clear_bit);
 
 int smp_store_status(int cpu)
 {
-       struct pcpu *pcpu = pcpu_devices + cpu;
+       struct lowcore *lc;
+       struct pcpu *pcpu;
        unsigned long pa;
 
-       pa = __pa(&pcpu->lowcore->floating_pt_save_area);
+       pcpu = pcpu_devices + cpu;
+       lc = lowcore_ptr[cpu];
+       pa = __pa(&lc->floating_pt_save_area);
        if (__pcpu_sigp_relax(pcpu->address, SIGP_STORE_STATUS_AT_ADDRESS,
                              pa) != SIGP_CC_ORDER_CODE_ACCEPTED)
                return -EIO;
        if (!MACHINE_HAS_VX && !MACHINE_HAS_GS)
                return 0;
-       pa = __pa(pcpu->lowcore->mcesad & MCESA_ORIGIN_MASK);
+       pa = __pa(lc->mcesad & MCESA_ORIGIN_MASK);
        if (MACHINE_HAS_GS)
-               pa |= pcpu->lowcore->mcesad & MCESA_LC_MASK;
+               pa |= lc->mcesad & MCESA_LC_MASK;
        if (__pcpu_sigp_relax(pcpu->address, SIGP_STORE_ADDITIONAL_STATUS,
                              pa) != SIGP_CC_ORDER_CODE_ACCEPTED)
                return -EIO;
@@ -997,7 +1005,6 @@ void __init smp_prepare_boot_cpu(void)
 
        WARN_ON(!cpu_present(0) || !cpu_online(0));
        pcpu->state = CPU_STATE_CONFIGURED;
-       pcpu->lowcore = (struct lowcore *)(unsigned long) store_prefix();
        S390_lowcore.percpu_offset = __per_cpu_offset[0];
        smp_cpu_set_polarization(0, POLARIZATION_UNKNOWN);
 }
@@ -1264,7 +1271,6 @@ static int __init smp_reinit_ipl_cpu(void)
        S390_lowcore.async_stack = async_stack + STACK_INIT_OFFSET;
        S390_lowcore.mcck_stack = mcck_stack + STACK_INIT_OFFSET;
        lowcore_ptr[0] = lc;
-       pcpu_devices[0].lowcore = lc;
        local_mcck_enable();
        local_irq_restore(flags);