sparc/srmmu: Remove on-stack cpumask var

In general it's preferable to avoid placing cpumasks on the stack, as
for large values of NR_CPUS these can consume significant amounts of
stack space and make stack overflows more likely.

Use cpumask_any_but() to avoid the need for a temporary cpumask on
the stack and simplify code.

Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Dawei Li <dawei.li@shingroup.cn>
Reviewed-by: Andreas Larsson <andreas@gaisler.com>
Link: https://lore.kernel.org/r/20240424025548.3765250-2-dawei.li@shingroup.cn
Signed-off-by: Andreas Larsson <andreas@gaisler.com>

diff --git a/arch/sparc/mm/srmmu.c b/arch/sparc/mm/srmmu.c
index 852085ada3689d9e09f948c01f6d4e3d76d6340c..9df51a62333d68c49f058d55dd40cf0439232efa 100644 (file)
--- a/arch/sparc/mm/srmmu.c
+++ b/arch/sparc/mm/srmmu.c
@@ -1653,13 +1653,15 @@ static void smp_flush_tlb_all(void)
        local_ops->tlb_all();
 }
 
+static bool any_other_mm_cpus(struct mm_struct *mm)
+{
+       return cpumask_any_but(mm_cpumask(mm), smp_processor_id()) < nr_cpu_ids;
+}
+
 static void smp_flush_cache_mm(struct mm_struct *mm)
 {
        if (mm->context != NO_CONTEXT) {
-               cpumask_t cpu_mask;
-               cpumask_copy(&cpu_mask, mm_cpumask(mm));
-               cpumask_clear_cpu(smp_processor_id(), &cpu_mask);
-               if (!cpumask_empty(&cpu_mask))
+               if (any_other_mm_cpus(mm))
                        xc1(local_ops->cache_mm, (unsigned long)mm);
                local_ops->cache_mm(mm);
        }
@@ -1668,10 +1670,7 @@ static void smp_flush_cache_mm(struct mm_struct *mm)
 static void smp_flush_tlb_mm(struct mm_struct *mm)
 {
        if (mm->context != NO_CONTEXT) {
-               cpumask_t cpu_mask;
-               cpumask_copy(&cpu_mask, mm_cpumask(mm));
-               cpumask_clear_cpu(smp_processor_id(), &cpu_mask);
-               if (!cpumask_empty(&cpu_mask)) {
+               if (any_other_mm_cpus(mm)) {
                        xc1(local_ops->tlb_mm, (unsigned long)mm);
                        if (atomic_read(&mm->mm_users) == 1 && current->active_mm == mm)
                                cpumask_copy(mm_cpumask(mm),
@@ -1688,10 +1687,7 @@ static void smp_flush_cache_range(struct vm_area_struct *vma,
        struct mm_struct *mm = vma->vm_mm;
 
        if (mm->context != NO_CONTEXT) {
-               cpumask_t cpu_mask;
-               cpumask_copy(&cpu_mask, mm_cpumask(mm));
-               cpumask_clear_cpu(smp_processor_id(), &cpu_mask);
-               if (!cpumask_empty(&cpu_mask))
+               if (any_other_mm_cpus(mm))
                        xc3(local_ops->cache_range, (unsigned long)vma, start,
                            end);
                local_ops->cache_range(vma, start, end);
@@ -1705,10 +1701,7 @@ static void smp_flush_tlb_range(struct vm_area_struct *vma,
        struct mm_struct *mm = vma->vm_mm;
 
        if (mm->context != NO_CONTEXT) {
-               cpumask_t cpu_mask;
-               cpumask_copy(&cpu_mask, mm_cpumask(mm));
-               cpumask_clear_cpu(smp_processor_id(), &cpu_mask);
-               if (!cpumask_empty(&cpu_mask))
+               if (any_other_mm_cpus(mm))
                        xc3(local_ops->tlb_range, (unsigned long)vma, start,
                            end);
                local_ops->tlb_range(vma, start, end);
@@ -1720,10 +1713,7 @@ static void smp_flush_cache_page(struct vm_area_struct *vma, unsigned long page)
        struct mm_struct *mm = vma->vm_mm;
 
        if (mm->context != NO_CONTEXT) {
-               cpumask_t cpu_mask;
-               cpumask_copy(&cpu_mask, mm_cpumask(mm));
-               cpumask_clear_cpu(smp_processor_id(), &cpu_mask);
-               if (!cpumask_empty(&cpu_mask))
+               if (any_other_mm_cpus(mm))
                        xc2(local_ops->cache_page, (unsigned long)vma, page);
                local_ops->cache_page(vma, page);
        }
@@ -1734,10 +1724,7 @@ static void smp_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
        struct mm_struct *mm = vma->vm_mm;
 
        if (mm->context != NO_CONTEXT) {
-               cpumask_t cpu_mask;
-               cpumask_copy(&cpu_mask, mm_cpumask(mm));
-               cpumask_clear_cpu(smp_processor_id(), &cpu_mask);
-               if (!cpumask_empty(&cpu_mask))
+               if (any_other_mm_cpus(mm))
                        xc2(local_ops->tlb_page, (unsigned long)vma, page);
                local_ops->tlb_page(vma, page);
        }
@@ -1759,10 +1746,7 @@ static void smp_flush_page_to_ram(unsigned long page)
 
 static void smp_flush_sig_insns(struct mm_struct *mm, unsigned long insn_addr)
 {
-       cpumask_t cpu_mask;
-       cpumask_copy(&cpu_mask, mm_cpumask(mm));
-       cpumask_clear_cpu(smp_processor_id(), &cpu_mask);
-       if (!cpumask_empty(&cpu_mask))
+       if (any_other_mm_cpus(mm))
                xc2(local_ops->sig_insns, (unsigned long)mm, insn_addr);
        local_ops->sig_insns(mm, insn_addr);
 }