@@ -2,6 +2,7 @@
#include <linux/mm.h>
#include <linux/smp.h>
+#include <linux/sched.h>
#include <asm/sbi.h>
void flush_tlb_all(void)
@@ -9,16 +10,30 @@ void flush_tlb_all(void)
sbi_remote_sfence_vma(NULL, 0, -1);
}
+/*
+ * This function must not be called with cmask being null.
+ * Kernel may panic if cmask is NULL.
+ */
static void __sbi_tlb_flush_range(struct cpumask *cmask, unsigned long start,
unsigned long size)
{
struct cpumask hmask;
+ unsigned int cpuid;
if (cpumask_empty(cmask))
return;
- riscv_cpuid_to_hartid_mask(cmask, &hmask);
- sbi_remote_sfence_vma(hmask.bits, start, size);
+ cpuid = get_cpu();
+
+ if (cpumask_any_but(cmask, cpuid) >= nr_cpu_ids) {
+ /* local cpu is the only cpu present in cpumask */
+ local_flush_tlb_all();
+ } else {
+ riscv_cpuid_to_hartid_mask(cmask, &hmask);
+ sbi_remote_sfence_vma(cpumask_bits(&hmask), start, size);
+ }
+
+ put_cpu();
}
void flush_tlb_mm(struct mm_struct *mm)
In RISC-V, tlb flush happens via SBI which is expensive. If the local cpu is the only cpu in cpumask, there is no need to invoke a SBI call. Just do a local flush and return. Signed-off-by: Atish Patra <atish.patra@wdc.com> --- arch/riscv/mm/tlbflush.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-)