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authorAndrew Waterman <andrew@sifive.com>2017-10-26 10:53:40 +0200
committerPalmer Dabbelt <palmer@dabbelt.com>2018-01-31 04:13:33 +0100
commitf1b65f20fb05d1dd94656904848b96cc6df52bc0 (patch)
tree274e7cc83e11045eef2e5883e1e664629f910dce /arch/riscv
parentriscv: disable SUM in the exception handler (diff)
downloadlinux-f1b65f20fb05d1dd94656904848b96cc6df52bc0.tar.xz
linux-f1b65f20fb05d1dd94656904848b96cc6df52bc0.zip
RISC-V: Limit the scope of TLB shootdowns
RISC-V systems perform TLB shootdows via the SBI, which currently performs an IPI to each of the remote harts which then performs a local TLB flush. This process is a bit on the slow side, but we can at least speed it up for some common cases by restricting the set of harts to shoot down to the actual set of harts that are currently participating in the given mm context, as opposed to the entire system. This should provide a measurable performance increase, but we haven't measured it. Regardless, it seems like obviously the right thing to do here. Signed-off-by: Andrew Waterman <andrew@sifive.com> Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
Diffstat (limited to 'arch/riscv')
-rw-r--r--arch/riscv/include/asm/tlbflush.h20
1 files changed, 12 insertions, 8 deletions
diff --git a/arch/riscv/include/asm/tlbflush.h b/arch/riscv/include/asm/tlbflush.h
index 7b9c24ebdf52..7b209aec355d 100644
--- a/arch/riscv/include/asm/tlbflush.h
+++ b/arch/riscv/include/asm/tlbflush.h
@@ -36,7 +36,14 @@ static inline void local_flush_tlb_page(unsigned long addr)
#define flush_tlb_all() local_flush_tlb_all()
#define flush_tlb_page(vma, addr) local_flush_tlb_page(addr)
-#define flush_tlb_range(vma, start, end) local_flush_tlb_all()
+
+static inline void flush_tlb_range(struct vm_area_struct *vma,
+ unsigned long start, unsigned long end)
+{
+ local_flush_tlb_all();
+}
+
+#define flush_tlb_mm(mm) flush_tlb_all()
#else /* CONFIG_SMP */
@@ -45,16 +52,13 @@ static inline void local_flush_tlb_page(unsigned long addr)
#define flush_tlb_all() sbi_remote_sfence_vma(0, 0, -1)
#define flush_tlb_page(vma, addr) flush_tlb_range(vma, addr, 0)
#define flush_tlb_range(vma, start, end) \
- sbi_remote_sfence_vma(0, start, (end) - (start))
+ sbi_remote_sfence_vma(mm_cpumask((vma)->vm_mm)->bits, \
+ start, (end) - (start))
+#define flush_tlb_mm(mm) \
+ sbi_remote_sfence_vma(mm_cpumask(mm)->bits, 0, -1)
#endif /* CONFIG_SMP */
-/* Flush the TLB entries of the specified mm context */
-static inline void flush_tlb_mm(struct mm_struct *mm)
-{
- flush_tlb_all();
-}
-
/* Flush a range of kernel pages */
static inline void flush_tlb_kernel_range(unsigned long start,
unsigned long end)