From 27267655c5313ba0f5a3caa9ad35d887d9a12574 Mon Sep 17 00:00:00 2001 From: Stafford Horne Date: Fri, 14 Apr 2023 08:27:51 +0100 Subject: [PATCH] openrisc: Support floating point user api Add support for handling floating point exceptions and forwarding the SIGFPE signal to processes. Also, add fpu state to sigcontext. Signed-off-by: Stafford Horne --- arch/openrisc/include/uapi/asm/elf.h | 3 +-- arch/openrisc/include/uapi/asm/ptrace.h | 4 ++++ arch/openrisc/include/uapi/asm/sigcontext.h | 1 + arch/openrisc/kernel/entry.S | 11 +++++++++-- arch/openrisc/kernel/head.S | 4 ++-- arch/openrisc/kernel/signal.c | 2 ++ arch/openrisc/kernel/traps.c | 22 +++++++++++++++++++++ 7 files changed, 41 insertions(+), 6 deletions(-) diff --git a/arch/openrisc/include/uapi/asm/elf.h b/arch/openrisc/include/uapi/asm/elf.h index e892d506168526..6868f81c281ecb 100644 --- a/arch/openrisc/include/uapi/asm/elf.h +++ b/arch/openrisc/include/uapi/asm/elf.h @@ -53,8 +53,7 @@ typedef unsigned long elf_greg_t; #define ELF_NGREG (sizeof(struct user_regs_struct) / sizeof(elf_greg_t)) typedef elf_greg_t elf_gregset_t[ELF_NGREG]; -/* A placeholder; OR32 does not have fp support yes, so no fp regs for now. */ -typedef unsigned long elf_fpregset_t; +typedef struct __or1k_fpu_state elf_fpregset_t; /* EM_OPENRISC is defined in linux/elf-em.h */ #define EM_OR32 0x8472 diff --git a/arch/openrisc/include/uapi/asm/ptrace.h b/arch/openrisc/include/uapi/asm/ptrace.h index d4fab268f6aa0f..a77cc9915ca8fe 100644 --- a/arch/openrisc/include/uapi/asm/ptrace.h +++ b/arch/openrisc/include/uapi/asm/ptrace.h @@ -30,6 +30,10 @@ struct user_regs_struct { unsigned long pc; unsigned long sr; }; + +struct __or1k_fpu_state { + unsigned long fpcsr; +}; #endif diff --git a/arch/openrisc/include/uapi/asm/sigcontext.h b/arch/openrisc/include/uapi/asm/sigcontext.h index 8ab775fc345067..ca585e4af6b8ea 100644 --- a/arch/openrisc/include/uapi/asm/sigcontext.h +++ b/arch/openrisc/include/uapi/asm/sigcontext.h @@ -28,6 +28,7 @@ struct sigcontext { struct user_regs_struct regs; /* needs to be first */ + struct __or1k_fpu_state fpu; unsigned long oldmask; }; diff --git a/arch/openrisc/kernel/entry.S b/arch/openrisc/kernel/entry.S index c7b47e571220e8..c9f48e750b72b5 100644 --- a/arch/openrisc/kernel/entry.S +++ b/arch/openrisc/kernel/entry.S @@ -848,9 +848,16 @@ _syscall_badsys: /******* END SYSCALL HANDLING *******/ -/* ---[ 0xd00: Trap exception ]------------------------------------------ */ +/* ---[ 0xd00: Floating Point exception ]-------------------------------- */ -UNHANDLED_EXCEPTION(_vector_0xd00,0xd00) +EXCEPTION_ENTRY(_fpe_trap_handler) + CLEAR_LWA_FLAG(r3) + /* r4: EA of fault (set by EXCEPTION_HANDLE) */ + l.jal do_fpe_trap + l.addi r3,r1,0 /* pt_regs */ + + l.j _ret_from_exception + l.nop /* ---[ 0xe00: Trap exception ]------------------------------------------ */ diff --git a/arch/openrisc/kernel/head.S b/arch/openrisc/kernel/head.S index e11699f3d6bdca..439e00f81e5dde 100644 --- a/arch/openrisc/kernel/head.S +++ b/arch/openrisc/kernel/head.S @@ -424,9 +424,9 @@ _dispatch_do_ipage_fault: .org 0xc00 EXCEPTION_HANDLE(_sys_call_handler) -/* ---[ 0xd00: Trap exception ]------------------------------------------ */ +/* ---[ 0xd00: Floating point exception ]--------------------------------- */ .org 0xd00 - UNHANDLED_EXCEPTION(_vector_0xd00) + EXCEPTION_HANDLE(_fpe_trap_handler) /* ---[ 0xe00: Trap exception ]------------------------------------------ */ .org 0xe00 diff --git a/arch/openrisc/kernel/signal.c b/arch/openrisc/kernel/signal.c index 80f69740c731d3..4664a18f0787d4 100644 --- a/arch/openrisc/kernel/signal.c +++ b/arch/openrisc/kernel/signal.c @@ -50,6 +50,7 @@ static int restore_sigcontext(struct pt_regs *regs, err |= __copy_from_user(regs, sc->regs.gpr, 32 * sizeof(unsigned long)); err |= __copy_from_user(®s->pc, &sc->regs.pc, sizeof(unsigned long)); err |= __copy_from_user(®s->sr, &sc->regs.sr, sizeof(unsigned long)); + err |= __copy_from_user(®s->fpcsr, &sc->fpu.fpcsr, sizeof(unsigned long)); /* make sure the SM-bit is cleared so user-mode cannot fool us */ regs->sr &= ~SPR_SR_SM; @@ -112,6 +113,7 @@ static int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) err |= __copy_to_user(sc->regs.gpr, regs, 32 * sizeof(unsigned long)); err |= __copy_to_user(&sc->regs.pc, ®s->pc, sizeof(unsigned long)); err |= __copy_to_user(&sc->regs.sr, ®s->sr, sizeof(unsigned long)); + err |= __copy_to_user(&sc->fpu.fpcsr, ®s->fpcsr, sizeof(unsigned long)); return err; } diff --git a/arch/openrisc/kernel/traps.c b/arch/openrisc/kernel/traps.c index f5bbe6b55849a3..0aa6b07efda1b3 100644 --- a/arch/openrisc/kernel/traps.c +++ b/arch/openrisc/kernel/traps.c @@ -243,6 +243,28 @@ asmlinkage void unhandled_exception(struct pt_regs *regs, int ea, int vector) die("Oops", regs, 9); } +asmlinkage void do_fpe_trap(struct pt_regs *regs, unsigned long address) +{ + int code = FPE_FLTUNK; + unsigned long fpcsr = regs->fpcsr; + + if (fpcsr & SPR_FPCSR_IVF) + code = FPE_FLTINV; + else if (fpcsr & SPR_FPCSR_OVF) + code = FPE_FLTOVF; + else if (fpcsr & SPR_FPCSR_UNF) + code = FPE_FLTUND; + else if (fpcsr & SPR_FPCSR_DZF) + code = FPE_FLTDIV; + else if (fpcsr & SPR_FPCSR_IXF) + code = FPE_FLTRES; + + /* Clear all flags */ + regs->fpcsr &= ~SPR_FPCSR_ALLF; + + force_sig_fault(SIGFPE, code, (void __user *)regs->pc); +} + asmlinkage void do_trap(struct pt_regs *regs, unsigned long address) { force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->pc);