Benjamin Herrenschmidt <b...@kernel.crashing.org> writes:
> We do that because it's used by THP pmd collapsing, so use
> instead a dedicated flush function.
>
> Signed-off-by: Benjamin Herrenschmidt <b...@kernel.crashing.org>
> ---
> .../powerpc/include/asm/book3s/64/tlbflush-radix.h | 1 +
> arch/powerpc/mm/pgtable-radix.c | 5 ++-
> arch/powerpc/mm/tlb-radix.c | 41
> +++++++++++++++++++---
> 3 files changed, 41 insertions(+), 6 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h
> b/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h
> index 7196999..9b433a6 100644
> --- a/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h
> +++ b/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h
> @@ -36,6 +36,7 @@ extern void radix__flush_tlb_page_psize(struct mm_struct
> *mm, unsigned long vmad
> #define radix__flush_tlb_page_psize(mm,addr,p)
> radix__local_flush_tlb_page_psize(mm,addr,p)
> #endif
> extern void radix__flush_tlb_pwc(struct mmu_gather *tlb, unsigned long addr);
> +extern void radix__flush_tlb_collapsed_pmd(struct mm_struct *mm, unsigned
> long addr);
> extern void radix__flush_tlb_lpid_va(unsigned long lpid, unsigned long gpa,
> unsigned long page_size);
> extern void radix__flush_tlb_lpid(unsigned long lpid);
> diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c
> index c28165d..83d70f7 100644
> --- a/arch/powerpc/mm/pgtable-radix.c
> +++ b/arch/powerpc/mm/pgtable-radix.c
> @@ -706,9 +706,12 @@ pmd_t radix__pmdp_collapse_flush(struct vm_area_struct
> *vma, unsigned long addre
> */
> pmd = *pmdp;
> pmd_clear(pmdp);
> +
> /*FIXME!! Verify whether we need this kick below */
> kick_all_cpus_sync();
> - flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
> +
> + radix__flush_tlb_collapsed_pmd(vma->vm_mm, address);
> +
> return pmd;
> }
>
> diff --git a/arch/powerpc/mm/tlb-radix.c b/arch/powerpc/mm/tlb-radix.c
> index f65c928..73d3fbf 100644
> --- a/arch/powerpc/mm/tlb-radix.c
> +++ b/arch/powerpc/mm/tlb-radix.c
> @@ -267,11 +267,7 @@ void radix__flush_tlb_range(struct vm_area_struct *vma,
> unsigned long start,
> {
> struct mm_struct *mm = vma->vm_mm;
>
> - /*
> - * This is currently used when collapsing THPs so we need to
> - * flush the PWC. We should fix this.
> - */
> - radix__flush_all_mm(mm);
> + radix__flush_tlb_mm(mm);
> }
> EXPORT_SYMBOL(radix__flush_tlb_range);
>
> @@ -350,6 +346,41 @@ void radix__flush_tlb_range_psize(struct mm_struct *mm,
> unsigned long start,
> preempt_enable();
> }
>
> +void radix__flush_tlb_collapsed_pmd(struct mm_struct *mm, unsigned long addr)
> +{
> + int local = mm_is_thread_local(mm);
> + unsigned long ap = mmu_get_ap(mmu_virtual_psize);
> + unsigned long pid, end;
> +
> +
> + pid = mm ? mm->context.id : 0;
> + if (unlikely(pid == MMU_NO_CONTEXT))
> + goto no_context;
> +
> + /* 4k page size, just blow the world */
> + if (PAGE_SIZE == 0x1000) {
> + radix__flush_all_mm(mm);
> + return;
> + }
What is special here ? because it is 4096 tlb flushes ?
> +
> + /* Otherwise first do the PWC */
> + if (local)
> + _tlbiel_pid(pid, RIC_FLUSH_PWC);
> + else
> + _tlbie_pid(pid, RIC_FLUSH_PWC);
> +
> + /* Then iterate the pages */
> + end = addr + HPAGE_PMD_SIZE;
> + for (; addr < end; addr += PAGE_SIZE) {
> + if (local)
> + _tlbiel_va(addr, pid, ap, RIC_FLUSH_TLB);
> + else
> + _tlbie_va(addr, pid, ap, RIC_FLUSH_TLB);
> + }
> +no_context:
> + preempt_enable();
> +}
> +
> void radix__flush_tlb_lpid_va(unsigned long lpid, unsigned long gpa,
> unsigned long page_size)
> {
> --
> 2.9.4
