From 14001c60939a754717893672209160cec1e2ac18 Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Tue, 7 Nov 2017 18:53:05 +1100 Subject: [PATCH] powerpc/64s/radix: Optimize TLB range flush barriers Short range flushes issue a sequences of tlbie(l) instructions for individual effective addresses. These do not all require individual barrier sequences, only one covering all tlbie(l) instructions. Commit f7327e0ba3 ("powerpc/mm/radix: Remove unnecessary ptesync") made a similar optimization for tlbiel for PID flushing. For tlbie, the ISA says: The tlbsync instruction provides an ordering function for the effects of all tlbie instructions executed by the thread executing the tlbsync instruction, with respect to the memory barrier created by a subsequent ptesync instruction executed by the same thread. Time to munmap 30 pages of memory (after mmap, touch): local global vanilla 10.9us 22.3us patched 3.4us 14.4us Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman --- arch/powerpc/mm/tlb-radix.c | 41 +++++++++++++++++++++++++++++-------- 1 file changed, 32 insertions(+), 9 deletions(-) diff --git a/arch/powerpc/mm/tlb-radix.c b/arch/powerpc/mm/tlb-radix.c index 63e277b6e60c..22b657e4b01a 100644 --- a/arch/powerpc/mm/tlb-radix.c +++ b/arch/powerpc/mm/tlb-radix.c @@ -84,7 +84,7 @@ static inline void _tlbie_pid(unsigned long pid, unsigned long ric) trace_tlbie(0, 0, rb, rs, ric, prs, r); } -static inline void _tlbiel_va(unsigned long va, unsigned long pid, +static inline void __tlbiel_va(unsigned long va, unsigned long pid, unsigned long ap, unsigned long ric) { unsigned long rb,rs,prs,r; @@ -95,14 +95,20 @@ static inline void _tlbiel_va(unsigned long va, unsigned long pid, prs = 1; /* process scoped */ r = 1; /* raidx format */ - asm volatile("ptesync": : :"memory"); asm volatile(PPC_TLBIEL(%0, %4, %3, %2, %1) : : "r"(rb), "i"(r), "i"(prs), "i"(ric), "r"(rs) : "memory"); - asm volatile("ptesync": : :"memory"); trace_tlbie(0, 1, rb, rs, ric, prs, r); } -static inline void _tlbie_va(unsigned long va, unsigned long pid, +static inline void _tlbiel_va(unsigned long va, unsigned long pid, + unsigned long ap, unsigned long ric) +{ + asm volatile("ptesync": : :"memory"); + __tlbiel_va(va, pid, ap, ric); + asm volatile("ptesync": : :"memory"); +} + +static inline void __tlbie_va(unsigned long va, unsigned long pid, unsigned long ap, unsigned long ric) { unsigned long rb,rs,prs,r; @@ -113,13 +119,20 @@ static inline void _tlbie_va(unsigned long va, unsigned long pid, prs = 1; /* process scoped */ r = 1; /* raidx format */ - asm volatile("ptesync": : :"memory"); asm volatile(PPC_TLBIE_5(%0, %4, %3, %2, %1) : : "r"(rb), "i"(r), "i"(prs), "i"(ric), "r"(rs) : "memory"); - asm volatile("eieio; tlbsync; ptesync": : :"memory"); trace_tlbie(0, 0, rb, rs, ric, prs, r); } +static inline void _tlbie_va(unsigned long va, unsigned long pid, + unsigned long ap, unsigned long ric) +{ + asm volatile("ptesync": : :"memory"); + __tlbie_va(va, pid, ap, ric); + asm volatile("eieio; tlbsync; ptesync": : :"memory"); +} + + /* * Base TLB flushing operations: * @@ -341,13 +354,17 @@ void radix__flush_tlb_range_psize(struct mm_struct *mm, unsigned long start, else _tlbie_pid(pid, RIC_FLUSH_TLB); } else { + asm volatile("ptesync": : :"memory"); for (addr = start; addr < end; addr += page_size) { - if (local) - _tlbiel_va(addr, pid, ap, RIC_FLUSH_TLB); + __tlbiel_va(addr, pid, ap, RIC_FLUSH_TLB); else - _tlbie_va(addr, pid, ap, RIC_FLUSH_TLB); + __tlbie_va(addr, pid, ap, RIC_FLUSH_TLB); } + if (local) + asm volatile("ptesync": : :"memory"); + else + asm volatile("eieio; tlbsync; ptesync": : :"memory"); } preempt_enable(); } @@ -378,6 +395,7 @@ void radix__flush_tlb_collapsed_pmd(struct mm_struct *mm, unsigned long addr) _tlbie_pid(pid, RIC_FLUSH_PWC); /* Then iterate the pages */ + asm volatile("ptesync": : :"memory"); end = addr + HPAGE_PMD_SIZE; for (; addr < end; addr += PAGE_SIZE) { if (local) @@ -386,6 +404,11 @@ void radix__flush_tlb_collapsed_pmd(struct mm_struct *mm, unsigned long addr) _tlbie_va(addr, pid, ap, RIC_FLUSH_TLB); } + if (local) + asm volatile("ptesync": : :"memory"); + else + asm volatile("eieio; tlbsync; ptesync": : :"memory"); + preempt_enable(); } #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ -- GitLab