Re: [PATCH v3 2/3] arm64: tlb: Improve __TLBI_VADDR_RANGE()

From: Anshuman Khandual
Date: Wed Apr 10 2024 - 03:58:09 EST




On 4/5/24 09:28, Gavin Shan wrote:
> The macro returns the operand of TLBI RANGE instruction. A mask needs
> to be applied to each individual field upon producing the operand, to
> avoid the adjacent fields can interfere with each other when invalid
> arguments have been provided. The code looks more tidy at least with
> a mask and FIELD_PREP().
>
> Suggested-by: Marc Zyngier <maz@xxxxxxxxxx>
> Signed-off-by: Gavin Shan <gshan@xxxxxxxxxx>

This looks much better.

Reviewed-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>

> ---
> arch/arm64/include/asm/tlbflush.h | 29 ++++++++++++++++++-----------
> 1 file changed, 18 insertions(+), 11 deletions(-)
>
> diff --git a/arch/arm64/include/asm/tlbflush.h b/arch/arm64/include/asm/tlbflush.h
> index a75de2665d84..243d71f7bc1f 100644
> --- a/arch/arm64/include/asm/tlbflush.h
> +++ b/arch/arm64/include/asm/tlbflush.h
> @@ -142,17 +142,24 @@ static inline unsigned long get_trans_granule(void)
> * EL1, Inner Shareable".
> *
> */
> -#define __TLBI_VADDR_RANGE(baddr, asid, scale, num, ttl) \
> - ({ \
> - unsigned long __ta = (baddr); \
> - unsigned long __ttl = (ttl >= 1 && ttl <= 3) ? ttl : 0; \
> - __ta &= GENMASK_ULL(36, 0); \
> - __ta |= __ttl << 37; \
> - __ta |= (unsigned long)(num) << 39; \
> - __ta |= (unsigned long)(scale) << 44; \
> - __ta |= get_trans_granule() << 46; \
> - __ta |= (unsigned long)(asid) << 48; \
> - __ta; \
> +#define TLBIR_ASID_MASK GENMASK_ULL(63, 48)
> +#define TLBIR_TG_MASK GENMASK_ULL(47, 46)
> +#define TLBIR_SCALE_MASK GENMASK_ULL(45, 44)
> +#define TLBIR_NUM_MASK GENMASK_ULL(43, 39)
> +#define TLBIR_TTL_MASK GENMASK_ULL(38, 37)
> +#define TLBIR_BADDR_MASK GENMASK_ULL(36, 0)
> +
> +#define __TLBI_VADDR_RANGE(baddr, asid, scale, num, ttl) \
> + ({ \
> + unsigned long __ta = 0; \
> + unsigned long __ttl = (ttl >= 1 && ttl <= 3) ? ttl : 0; \
> + __ta |= FIELD_PREP(TLBIR_BADDR_MASK, baddr); \
> + __ta |= FIELD_PREP(TLBIR_TTL_MASK, __ttl); \
> + __ta |= FIELD_PREP(TLBIR_NUM_MASK, num); \
> + __ta |= FIELD_PREP(TLBIR_SCALE_MASK, scale); \
> + __ta |= FIELD_PREP(TLBIR_TG_MASK, get_trans_granule()); \
> + __ta |= FIELD_PREP(TLBIR_ASID_MASK, asid); \
> + __ta; \
> })
>
> /* These macros are used by the TLBI RANGE feature. */