From 190f1ca85d071114930dd7abe6b5d103e9d5572f Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Mon, 24 Feb 2014 15:26:29 +0100 Subject: arm64: add support for kernel mode NEON in interrupt context This patch modifies kernel_neon_begin() and kernel_neon_end(), so they may be called from any context. To address the case where only a couple of registers are needed, kernel_neon_begin_partial(u32) is introduced which takes as a parameter the number of bottom 'n' NEON q-registers required. To mark the end of such a partial section, the regular kernel_neon_end() should be used. Signed-off-by: Ard Biesheuvel --- arch/arm64/include/asm/fpsimd.h | 15 +++++++++++++++ arch/arm64/include/asm/fpsimdmacros.h | 35 +++++++++++++++++++++++++++++++++++ arch/arm64/include/asm/neon.h | 6 +++++- 3 files changed, 55 insertions(+), 1 deletion(-) (limited to 'arch/arm64/include/asm') diff --git a/arch/arm64/include/asm/fpsimd.h b/arch/arm64/include/asm/fpsimd.h index 7a900142dbc8..50f559f574fe 100644 --- a/arch/arm64/include/asm/fpsimd.h +++ b/arch/arm64/include/asm/fpsimd.h @@ -41,6 +41,17 @@ struct fpsimd_state { unsigned int cpu; }; +/* + * Struct for stacking the bottom 'n' FP/SIMD registers. + */ +struct fpsimd_partial_state { + u32 fpsr; + u32 fpcr; + u32 num_regs; + __uint128_t vregs[32]; +}; + + #if defined(__KERNEL__) && defined(CONFIG_COMPAT) /* Masks for extracting the FPSR and FPCR from the FPSCR */ #define VFP_FPSCR_STAT_MASK 0xf800009f @@ -66,6 +77,10 @@ extern void fpsimd_update_current_state(struct fpsimd_state *state); extern void fpsimd_flush_task_state(struct task_struct *target); +extern void fpsimd_save_partial_state(struct fpsimd_partial_state *state, + u32 num_regs); +extern void fpsimd_load_partial_state(struct fpsimd_partial_state *state); + #endif #endif diff --git a/arch/arm64/include/asm/fpsimdmacros.h b/arch/arm64/include/asm/fpsimdmacros.h index bbec599c96bd..768414d55e64 100644 --- a/arch/arm64/include/asm/fpsimdmacros.h +++ b/arch/arm64/include/asm/fpsimdmacros.h @@ -62,3 +62,38 @@ ldr w\tmpnr, [\state, #16 * 2 + 4] msr fpcr, x\tmpnr .endm + +.altmacro +.macro fpsimd_save_partial state, numnr, tmpnr1, tmpnr2 + mrs x\tmpnr1, fpsr + str w\numnr, [\state, #8] + mrs x\tmpnr2, fpcr + stp w\tmpnr1, w\tmpnr2, [\state] + adr x\tmpnr1, 0f + add \state, \state, x\numnr, lsl #4 + sub x\tmpnr1, x\tmpnr1, x\numnr, lsl #1 + br x\tmpnr1 + .irp qa, 30, 28, 26, 24, 22, 20, 18, 16, 14, 12, 10, 8, 6, 4, 2, 0 + .irp qb, %(qa + 1) + stp q\qa, q\qb, [\state, # -16 * \qa - 16] + .endr + .endr +0: +.endm + +.macro fpsimd_restore_partial state, tmpnr1, tmpnr2 + ldp w\tmpnr1, w\tmpnr2, [\state] + msr fpsr, x\tmpnr1 + msr fpcr, x\tmpnr2 + adr x\tmpnr1, 0f + ldr w\tmpnr2, [\state, #8] + add \state, \state, x\tmpnr2, lsl #4 + sub x\tmpnr1, x\tmpnr1, x\tmpnr2, lsl #1 + br x\tmpnr1 + .irp qa, 30, 28, 26, 24, 22, 20, 18, 16, 14, 12, 10, 8, 6, 4, 2, 0 + .irp qb, %(qa + 1) + ldp q\qa, q\qb, [\state, # -16 * \qa - 16] + .endr + .endr +0: +.endm diff --git a/arch/arm64/include/asm/neon.h b/arch/arm64/include/asm/neon.h index b0cc58a97780..13ce4cc18e26 100644 --- a/arch/arm64/include/asm/neon.h +++ b/arch/arm64/include/asm/neon.h @@ -8,7 +8,11 @@ * published by the Free Software Foundation. */ +#include + #define cpu_has_neon() (1) -void kernel_neon_begin(void); +#define kernel_neon_begin() kernel_neon_begin_partial(32) + +void kernel_neon_begin_partial(u32 num_regs); void kernel_neon_end(void); -- cgit v1.2.3