diff options
| -rw-r--r-- | arch/arm64/include/asm/fpsimd.h | 64 | ||||
| -rw-r--r-- | arch/arm64/kernel/entry-fpsimd.S | 80 | ||||
| -rw-r--r-- | arch/arm64/kernel/fpsimd.c | 106 |
3 files changed, 250 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/fpsimd.h b/arch/arm64/include/asm/fpsimd.h new file mode 100644 index 0000000..b42fab9 --- /dev/null +++ b/arch/arm64/include/asm/fpsimd.h @@ -0,0 +1,64 @@ +/* + * Copyright (C) 2012 ARM Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ +#ifndef __ASM_FP_H +#define __ASM_FP_H + +#include <asm/ptrace.h> + +#ifndef __ASSEMBLY__ + +/* + * FP/SIMD storage area has: + * - FPSR and FPCR + * - 32 128-bit data registers + * + * Note that user_fp forms a prefix of this structure, which is relied + * upon in the ptrace FP/SIMD accessors. struct user_fpsimd_state must + * form a prefix of struct fpsimd_state. + */ +struct fpsimd_state { + union { + struct user_fpsimd_state user_fpsimd; + struct { + __uint128_t vregs[32]; + u32 fpsr; + u32 fpcr; + }; + }; +}; + +#if defined(__KERNEL__) && defined(CONFIG_COMPAT) +/* Masks for extracting the FPSR and FPCR from the FPSCR */ +#define VFP_FPSCR_STAT_MASK 0xf800009f +#define VFP_FPSCR_CTRL_MASK 0x07f79f00 +/* + * The VFP state has 32x64-bit registers and a single 32-bit + * control/status register. + */ +#define VFP_STATE_SIZE ((32 * 8) + 4) +#endif + +struct task_struct; + +extern void fpsimd_save_state(struct fpsimd_state *state); +extern void fpsimd_load_state(struct fpsimd_state *state); + +extern void fpsimd_thread_switch(struct task_struct *next); +extern void fpsimd_flush_thread(void); + +#endif + +#endif diff --git a/arch/arm64/kernel/entry-fpsimd.S b/arch/arm64/kernel/entry-fpsimd.S new file mode 100644 index 0000000..17988a6 --- /dev/null +++ b/arch/arm64/kernel/entry-fpsimd.S @@ -0,0 +1,80 @@ +/* + * FP/SIMD state saving and restoring + * + * Copyright (C) 2012 ARM Ltd. + * Author: Catalin Marinas <catalin.marinas@arm.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/linkage.h> + +#include <asm/assembler.h> + +/* + * Save the FP registers. + * + * x0 - pointer to struct fpsimd_state + */ +ENTRY(fpsimd_save_state) + stp q0, q1, [x0, #16 * 0] + stp q2, q3, [x0, #16 * 2] + stp q4, q5, [x0, #16 * 4] + stp q6, q7, [x0, #16 * 6] + stp q8, q9, [x0, #16 * 8] + stp q10, q11, [x0, #16 * 10] + stp q12, q13, [x0, #16 * 12] + stp q14, q15, [x0, #16 * 14] + stp q16, q17, [x0, #16 * 16] + stp q18, q19, [x0, #16 * 18] + stp q20, q21, [x0, #16 * 20] + stp q22, q23, [x0, #16 * 22] + stp q24, q25, [x0, #16 * 24] + stp q26, q27, [x0, #16 * 26] + stp q28, q29, [x0, #16 * 28] + stp q30, q31, [x0, #16 * 30]! + mrs x8, fpsr + str w8, [x0, #16 * 2] + mrs x8, fpcr + str w8, [x0, #16 * 2 + 4] + ret +ENDPROC(fpsimd_save_state) + +/* + * Load the FP registers. + * + * x0 - pointer to struct fpsimd_state + */ +ENTRY(fpsimd_load_state) + ldp q0, q1, [x0, #16 * 0] + ldp q2, q3, [x0, #16 * 2] + ldp q4, q5, [x0, #16 * 4] + ldp q6, q7, [x0, #16 * 6] + ldp q8, q9, [x0, #16 * 8] + ldp q10, q11, [x0, #16 * 10] + ldp q12, q13, [x0, #16 * 12] + ldp q14, q15, [x0, #16 * 14] + ldp q16, q17, [x0, #16 * 16] + ldp q18, q19, [x0, #16 * 18] + ldp q20, q21, [x0, #16 * 20] + ldp q22, q23, [x0, #16 * 22] + ldp q24, q25, [x0, #16 * 24] + ldp q26, q27, [x0, #16 * 26] + ldp q28, q29, [x0, #16 * 28] + ldp q30, q31, [x0, #16 * 30]! + ldr w8, [x0, #16 * 2] + ldr w9, [x0, #16 * 2 + 4] + msr fpsr, x8 + msr fpcr, x9 + ret +ENDPROC(fpsimd_load_state) diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c new file mode 100644 index 0000000..e8b8357 --- /dev/null +++ b/arch/arm64/kernel/fpsimd.c @@ -0,0 +1,106 @@ +/* + * FP/SIMD context switching and fault handling + * + * Copyright (C) 2012 ARM Ltd. + * Author: Catalin Marinas <catalin.marinas@arm.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/sched.h> +#include <linux/signal.h> + +#include <asm/fpsimd.h> +#include <asm/cputype.h> + +#define FPEXC_IOF (1 << 0) +#define FPEXC_DZF (1 << 1) +#define FPEXC_OFF (1 << 2) +#define FPEXC_UFF (1 << 3) +#define FPEXC_IXF (1 << 4) +#define FPEXC_IDF (1 << 7) + +/* + * Trapped FP/ASIMD access. + */ +void do_fpsimd_acc(unsigned int esr, struct pt_regs *regs) +{ + /* TODO: implement lazy context saving/restoring */ + WARN_ON(1); +} + +/* + * Raise a SIGFPE for the current process. + */ +void do_fpsimd_exc(unsigned int esr, struct pt_regs *regs) +{ + siginfo_t info; + unsigned int si_code = 0; + + if (esr & FPEXC_IOF) + si_code = FPE_FLTINV; + else if (esr & FPEXC_DZF) + si_code = FPE_FLTDIV; + else if (esr & FPEXC_OFF) + si_code = FPE_FLTOVF; + else if (esr & FPEXC_UFF) + si_code = FPE_FLTUND; + else if (esr & FPEXC_IXF) + si_code = FPE_FLTRES; + + memset(&info, 0, sizeof(info)); + info.si_signo = SIGFPE; + info.si_code = si_code; + info.si_addr = (void __user *)instruction_pointer(regs); + + send_sig_info(SIGFPE, &info, current); +} + +void fpsimd_thread_switch(struct task_struct *next) +{ + /* check if not kernel threads */ + if (current->mm) + fpsimd_save_state(¤t->thread.fpsimd_state); + if (next->mm) + fpsimd_load_state(&next->thread.fpsimd_state); +} + +void fpsimd_flush_thread(void) +{ + memset(¤t->thread.fpsimd_state, 0, sizeof(struct fpsimd_state)); + fpsimd_load_state(¤t->thread.fpsimd_state); +} + +/* + * FP/SIMD support code initialisation. + */ +static int __init fpsimd_init(void) +{ + u64 pfr = read_cpuid(ID_AA64PFR0_EL1); + + if (pfr & (0xf << 16)) { + pr_notice("Floating-point is not implemented\n"); + return 0; + } + elf_hwcap |= HWCAP_FP; + + if (pfr & (0xf << 20)) + pr_notice("Advanced SIMD is not implemented\n"); + else + elf_hwcap |= HWCAP_ASIMD; + + return 0; +} +late_initcall(fpsimd_init); |
