On Thu, Jul 27, 2023 at 3:58 AM Marc Zyngier <maz@xxxxxxxxxx> wrote: > > On Sat, 22 Jul 2023 03:22:45 +0100, > Raghavendra Rao Ananta <rananta@xxxxxxxxxx> wrote: > > > > Currently, the core TLB flush functionality of __flush_tlb_range() > > hardcodes vae1is (and variants) for the flush operation. In the > > upcoming patches, the KVM code reuses this core algorithm with > > ipas2e1is for range based TLB invalidations based on the IPA. > > Hence, extract the core flush functionality of __flush_tlb_range() > > into its own macro that accepts an 'op' argument to pass any > > TLBI operation, such that other callers (KVM) can benefit. > > > > No functional changes intended. > > > > Signed-off-by: Raghavendra Rao Ananta <rananta@xxxxxxxxxx> > > Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx> > > Reviewed-by: Gavin Shan <gshan@xxxxxxxxxx> > > Reviewed-by: Shaoqin Huang <shahuang@xxxxxxxxxx> > > --- > > arch/arm64/include/asm/tlbflush.h | 109 +++++++++++++++--------------- > > 1 file changed, 56 insertions(+), 53 deletions(-) > > > > diff --git a/arch/arm64/include/asm/tlbflush.h b/arch/arm64/include/asm/tlbflush.h > > index 412a3b9a3c25..f7fafba25add 100644 > > --- a/arch/arm64/include/asm/tlbflush.h > > +++ b/arch/arm64/include/asm/tlbflush.h > > @@ -278,14 +278,62 @@ static inline void flush_tlb_page(struct vm_area_struct *vma, > > */ > > #define MAX_TLBI_OPS PTRS_PER_PTE > > > > +/* When the CPU does not support TLB range operations, flush the TLB > > + * entries one by one at the granularity of 'stride'. If the TLB > > + * range ops are supported, then: > > Comment format (the original was correct). > Isn't the format the same as original? Or are you referring to the fact that it needs to be placed inside the macro definition? > > + * > > + * 1. If 'pages' is odd, flush the first page through non-range > > + * operations; > > + * > > + * 2. For remaining pages: the minimum range granularity is decided > > + * by 'scale', so multiple range TLBI operations may be required. > > + * Start from scale = 0, flush the corresponding number of pages > > + * ((num+1)*2^(5*scale+1) starting from 'addr'), then increase it > > + * until no pages left. > > + * > > + * Note that certain ranges can be represented by either num = 31 and > > + * scale or num = 0 and scale + 1. The loop below favours the latter > > + * since num is limited to 30 by the __TLBI_RANGE_NUM() macro. > > + */ > > +#define __flush_tlb_range_op(op, start, pages, stride, \ > > + asid, tlb_level, tlbi_user) \ > > If you make this a common macro, please document the parameters, and > what the constraints are. For example, what does tlbi_user mean for an > IPA invalidation? > Sure, I'll document the parameters. That'll be helpful. - Raghavendra > M. > > -- > Without deviation from the norm, progress is not possible.
