[PATCH] riscv: mm: Fix incorrect ASID argument when flushing TLB

[Dylan Jhong]

Currently, we pass the CONTEXTID instead of the ASID to the TLB flush
function. We should only take the ASID field to prevent from touching
the reserved bit field.

Fixes: 3f1e782998cd ("riscv: add ASID-based tlbflushing methods")
Signed-off-by: Dylan Jhong <dylan@xxxxxxxxxxxxx>
---
 arch/riscv/include/asm/tlbflush.h | 2 ++
 arch/riscv/mm/context.c           | 3 ++-
 arch/riscv/mm/tlbflush.c          | 2 +-
 3 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/include/asm/tlbflush.h b/arch/riscv/include/asm/tlbflush.h
index 907b9efd39a8..597d6d8aec28 100644
--- a/arch/riscv/include/asm/tlbflush.h
+++ b/arch/riscv/include/asm/tlbflush.h
@@ -12,6 +12,8 @@
 #include <asm/errata_list.h>
 
 #ifdef CONFIG_MMU
+extern unsigned long asid_mask;
+
 static inline void local_flush_tlb_all(void)
 {
 	__asm__ __volatile__ ("sfence.vma" : : : "memory");
diff --git a/arch/riscv/mm/context.c b/arch/riscv/mm/context.c
index 80ce9caba8d2..a6b76b33e377 100644
--- a/arch/riscv/mm/context.c
+++ b/arch/riscv/mm/context.c
@@ -22,7 +22,8 @@ DEFINE_STATIC_KEY_FALSE(use_asid_allocator);
 
 static unsigned long asid_bits;
 static unsigned long num_asids;
-static unsigned long asid_mask;
+unsigned long asid_mask;
+EXPORT_SYMBOL(asid_mask);
 
 static atomic_long_t current_version;
 
diff --git a/arch/riscv/mm/tlbflush.c b/arch/riscv/mm/tlbflush.c
index ce7dfc81bb3f..ba4c27187c95 100644
--- a/arch/riscv/mm/tlbflush.c
+++ b/arch/riscv/mm/tlbflush.c
@@ -27,7 +27,7 @@ static void __sbi_tlb_flush_range(struct mm_struct *mm, unsigned long start,
 	/* check if the tlbflush needs to be sent to other CPUs */
 	broadcast = cpumask_any_but(cmask, cpuid) < nr_cpu_ids;
 	if (static_branch_unlikely(&use_asid_allocator)) {
-		unsigned long asid = atomic_long_read(&mm->context.id);
+		unsigned long asid = atomic_long_read(&mm->context.id) & asid_mask;
 
 		/*
 		 * TLB will be immediately flushed on harts concurrently
-- 
2.34.1