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authorJulien Grall <julien.grall@arm.com>2020-08-28 19:11:52 +0100
committerWill Deacon <will@kernel.org>2020-09-21 18:06:33 +0100
commit1e530f1352a2709d7bcacdb8b6d42c8900ba2c80 (patch)
tree704ec716cc72a2cdce2ef8dd0d2a3fb8c1c43868 /arch/arm64/include
parent6d40f05fad0babfb3e991edb2d0bd28a30a2f10c (diff)
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 <julien.grall@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Link: https://lore.kernel.org/r/20200828181155.17745-6-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch/arm64/include')
-rw-r--r--arch/arm64/include/asm/fpsimd.h1
-rw-r--r--arch/arm64/include/asm/fpsimdmacros.h19
2 files changed, 20 insertions, 0 deletions
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