From 1e530f1352a2709d7bcacdb8b6d42c8900ba2c80 Mon Sep 17 00:00:00 2001 From: Julien Grall Date: Fri, 28 Aug 2020 19:11:52 +0100 Subject: arm64/sve: Implement a helper to flush SVE registers Introduce a new helper that will zero all SVE registers but the first 128-bits of each vector. This will be used by subsequent patches to avoid costly store/maipulate/reload sequences in places like do_sve_acc(). Signed-off-by: Julien Grall Signed-off-by: Mark Brown Reviewed-by: Dave Martin Link: https://lore.kernel.org/r/20200828181155.17745-6-broonie@kernel.org Signed-off-by: Will Deacon --- arch/arm64/include/asm/fpsimd.h | 1 + arch/arm64/include/asm/fpsimdmacros.h | 19 +++++++++++++++++++ 2 files changed, 20 insertions(+) (limited to 'arch/arm64/include') diff --git a/arch/arm64/include/asm/fpsimd.h b/arch/arm64/include/asm/fpsimd.h index 59f10dd13f12..958f642e930d 100644 --- a/arch/arm64/include/asm/fpsimd.h +++ b/arch/arm64/include/asm/fpsimd.h @@ -69,6 +69,7 @@ static inline void *sve_pffr(struct thread_struct *thread) extern void sve_save_state(void *state, u32 *pfpsr); extern void sve_load_state(void const *state, u32 const *pfpsr, unsigned long vq_minus_1); +extern void sve_flush_live(void); extern unsigned int sve_get_vl(void); struct arm64_cpu_capabilities; diff --git a/arch/arm64/include/asm/fpsimdmacros.h b/arch/arm64/include/asm/fpsimdmacros.h index feef5b371fba..af43367534c7 100644 --- a/arch/arm64/include/asm/fpsimdmacros.h +++ b/arch/arm64/include/asm/fpsimdmacros.h @@ -164,6 +164,13 @@ | ((\np) << 5) .endm +/* PFALSE P\np.B */ +.macro _sve_pfalse np + _sve_check_preg \np + .inst 0x2518e400 \ + | (\np) +.endm + .macro __for from:req, to:req .if (\from) == (\to) _for__body %\from @@ -198,6 +205,18 @@ 921: .endm +/* Preserve the first 128-bits of Znz and zero the rest. */ +.macro _sve_flush_z nz + _sve_check_zreg \nz + mov v\nz\().16b, v\nz\().16b +.endm + +.macro sve_flush + _for n, 0, 31, _sve_flush_z \n + _for n, 0, 15, _sve_pfalse \n + _sve_wrffr 0 +.endm + .macro sve_save nxbase, xpfpsr, nxtmp _for n, 0, 31, _sve_str_v \n, \nxbase, \n - 34 _for n, 0, 15, _sve_str_p \n, \nxbase, \n - 16 -- cgit