forked from Minki/linux
c51f92693c
There are two tacit assumptions in the FPSIMD handling code that will no longer hold after the next patch that optimizes away some FPSIMD state restores: . the FPSIMD registers of this CPU contain the userland FPSIMD state of task 'current'; . when switching to a task, its FPSIMD state will always be restored from memory. This patch adds the following functions to abstract away from straight FPSIMD register file saves and restores: - fpsimd_preserve_current_state -> ensure current's FPSIMD state is saved - fpsimd_update_current_state -> replace current's FPSIMD state Where necessary, the signal handling and fork code are updated to use the above wrappers instead of poking into the FPSIMD registers directly. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
67 lines
1.7 KiB
C
67 lines
1.7 KiB
C
/*
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* Copyright (C) 2012 ARM Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#ifndef __ASM_FP_H
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#define __ASM_FP_H
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#include <asm/ptrace.h>
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#ifndef __ASSEMBLY__
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/*
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* FP/SIMD storage area has:
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* - FPSR and FPCR
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* - 32 128-bit data registers
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*
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* Note that user_fpsimd forms a prefix of this structure, which is
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* relied upon in the ptrace FP/SIMD accessors.
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*/
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struct fpsimd_state {
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union {
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struct user_fpsimd_state user_fpsimd;
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struct {
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__uint128_t vregs[32];
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u32 fpsr;
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u32 fpcr;
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};
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};
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};
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#if defined(__KERNEL__) && defined(CONFIG_COMPAT)
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/* Masks for extracting the FPSR and FPCR from the FPSCR */
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#define VFP_FPSCR_STAT_MASK 0xf800009f
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#define VFP_FPSCR_CTRL_MASK 0x07f79f00
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/*
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* The VFP state has 32x64-bit registers and a single 32-bit
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* control/status register.
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*/
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#define VFP_STATE_SIZE ((32 * 8) + 4)
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#endif
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struct task_struct;
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extern void fpsimd_save_state(struct fpsimd_state *state);
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extern void fpsimd_load_state(struct fpsimd_state *state);
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extern void fpsimd_thread_switch(struct task_struct *next);
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extern void fpsimd_flush_thread(void);
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extern void fpsimd_preserve_current_state(void);
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extern void fpsimd_update_current_state(struct fpsimd_state *state);
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#endif
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#endif
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