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 <ard.biesheuvel@linaro.org>
This commit is contained in:
Ard Biesheuvel
2014-02-24 15:26:29 +01:00
parent 005f78cd88
commit 190f1ca85d
5 changed files with 109 additions and 15 deletions

View File

@@ -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