Hi Marc,
On 2020/2/12 1:49, Marc Zyngier wrote:
> Add a level-hinted TLB invalidation helper that only gets used if
> ARMv8.4-TTL gets detected.
>
> Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
> ---
> arch/arm64/include/asm/tlbflush.h | 30 ++++++++++++++++++++++++++++++
> 1 file changed, 30 insertions(+)
>
> diff --git a/arch/arm64/include/asm/tlbflush.h b/arch/arm64/include/asm/tlbflush.h
> index bc3949064725..a3f70778a325 100644
> --- a/arch/arm64/include/asm/tlbflush.h
> +++ b/arch/arm64/include/asm/tlbflush.h
> @@ -10,6 +10,7 @@
>
> #ifndef __ASSEMBLY__
>
> +#include <linux/bitfield.h>
> #include <linux/mm_types.h>
> #include <linux/sched.h>
> #include <asm/cputype.h>
> @@ -59,6 +60,35 @@
> __ta; \
> })
>
> +#define TLBI_TTL_MASK GENMASK_ULL(47, 44)
> +
> +#define __tlbi_level(op, addr, level) \
> + do { \
> + u64 arg = addr; \
> + \
> + if (cpus_have_const_cap(ARM64_HAS_ARMv8_4_TTL) && \
> + level) { \
> + u64 ttl = level; \
> + \
> + switch (PAGE_SIZE) { \
> + case SZ_4K: \
> + ttl |= 1 << 2; \
> + break; \
> + case SZ_16K: \
> + ttl |= 2 << 2; \
> + break; \
> + case SZ_64K: \
> + ttl |= 3 << 2; \
> + break; \
> + } \
Can we define a macro here to replace the switch? It will be more
clearly and efficient. Such as:
#define __TG ((PAGE_SHIFT - 12) / 2 + 1)
ttl |= __TG << 2;
> + \
> + arg &= ~TLBI_TTL_MASK; \
> + arg |= FIELD_PREP(TLBI_TTL_MASK, ttl); \
> + } \
> + \
> + __tlbi(op, arg); \
> + } while(0)
> +
> /*
> * TLB Invalidation
> * ================
>
Thanks,
Zhenyu
