From eec43a224cf198c7e3538fca16f689e4d17d4471 Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Thu, 13 Feb 2014 11:27:42 +0000 Subject: MIPS: Save/restore MSA context around signals This patch extends sigcontext in order to hold the most significant 64 bits of each vector register in addition to the MSA control & status register. The least significant 64 bits are already saved as the scalar FP context. This makes things a little awkward since the least & most significant 64 bits of each vector register are not contiguous in memory. Thus the copy_u & insert instructions are used to transfer the values of the most significant 64 bits via GP registers. Signed-off-by: Paul Burton Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/6533/ Signed-off-by: Ralf Baechle --- arch/mips/kernel/signal32.c | 74 ++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 66 insertions(+), 8 deletions(-) (limited to 'arch/mips/kernel/signal32.c') diff --git a/arch/mips/kernel/signal32.c b/arch/mips/kernel/signal32.c index bae2e6ee2109..299f956e4db3 100644 --- a/arch/mips/kernel/signal32.c +++ b/arch/mips/kernel/signal32.c @@ -30,6 +30,7 @@ #include #include #include +#include #include #include #include @@ -42,6 +43,9 @@ static int (*restore_fp_context32)(struct sigcontext32 __user *sc); extern asmlinkage int _save_fp_context32(struct sigcontext32 __user *sc); extern asmlinkage int _restore_fp_context32(struct sigcontext32 __user *sc); +extern asmlinkage int _save_msa_context32(struct sigcontext32 __user *sc); +extern asmlinkage int _restore_msa_context32(struct sigcontext32 __user *sc); + /* * Including would give use the 64-bit syscall numbers ... */ @@ -110,20 +114,60 @@ static int copy_fp_from_sigcontext32(struct sigcontext32 __user *sc) return err; } +/* + * These functions will save only the upper 64 bits of the vector registers, + * since the lower 64 bits have already been saved as the scalar FP context. + */ +static int copy_msa_to_sigcontext32(struct sigcontext32 __user *sc) +{ + int i; + int err = 0; + + for (i = 0; i < NUM_FPU_REGS; i++) { + err |= + __put_user(get_fpr64(¤t->thread.fpu.fpr[i], 1), + &sc->sc_msaregs[i]); + } + err |= __put_user(current->thread.fpu.msacsr, &sc->sc_msa_csr); + + return err; +} + +static int copy_msa_from_sigcontext32(struct sigcontext32 __user *sc) +{ + int i; + int err = 0; + u64 val; + + for (i = 0; i < NUM_FPU_REGS; i++) { + err |= __get_user(val, &sc->sc_msaregs[i]); + set_fpr64(¤t->thread.fpu.fpr[i], 1, val); + } + err |= __get_user(current->thread.fpu.msacsr, &sc->sc_msa_csr); + + return err; +} + /* * sigcontext handlers */ -static int protected_save_fp_context32(struct sigcontext32 __user *sc) +static int protected_save_fp_context32(struct sigcontext32 __user *sc, + unsigned used_math) { int err; + bool save_msa = cpu_has_msa && (used_math & USEDMATH_MSA); while (1) { lock_fpu_owner(); if (is_fpu_owner()) { err = save_fp_context32(sc); + if (save_msa && !err) + err = _save_msa_context32(sc); unlock_fpu_owner(); } else { unlock_fpu_owner(); err = copy_fp_to_sigcontext32(sc); + if (save_msa && !err) + err = copy_msa_to_sigcontext32(sc); } if (likely(!err)) break; @@ -137,17 +181,28 @@ static int protected_save_fp_context32(struct sigcontext32 __user *sc) return err; } -static int protected_restore_fp_context32(struct sigcontext32 __user *sc) +static int protected_restore_fp_context32(struct sigcontext32 __user *sc, + unsigned used_math) { int err, tmp __maybe_unused; + bool restore_msa = cpu_has_msa && (used_math & USEDMATH_MSA); while (1) { lock_fpu_owner(); if (is_fpu_owner()) { err = restore_fp_context32(sc); + if (restore_msa && !err) { + enable_msa(); + err = _restore_msa_context32(sc); + } else { + /* signal handler may have used MSA */ + disable_msa(); + } unlock_fpu_owner(); } else { unlock_fpu_owner(); err = copy_fp_from_sigcontext32(sc); + if (restore_msa && !err) + err = copy_msa_from_sigcontext32(sc); } if (likely(!err)) break; @@ -186,7 +241,8 @@ static int setup_sigcontext32(struct pt_regs *regs, err |= __put_user(mflo3(), &sc->sc_lo3); } - used_math = !!used_math(); + used_math = used_math() ? USEDMATH_FP : 0; + used_math |= thread_msa_context_live() ? USEDMATH_MSA : 0; err |= __put_user(used_math, &sc->sc_used_math); if (used_math) { @@ -194,20 +250,21 @@ static int setup_sigcontext32(struct pt_regs *regs, * Save FPU state to signal context. Signal handler * will "inherit" current FPU state. */ - err |= protected_save_fp_context32(sc); + err |= protected_save_fp_context32(sc, used_math); } return err; } static int -check_and_restore_fp_context32(struct sigcontext32 __user *sc) +check_and_restore_fp_context32(struct sigcontext32 __user *sc, + unsigned used_math) { int err, sig; err = sig = fpcsr_pending(&sc->sc_fpc_csr); if (err > 0) err = 0; - err |= protected_restore_fp_context32(sc); + err |= protected_restore_fp_context32(sc, used_math); return err ?: sig; } @@ -244,9 +301,10 @@ static int restore_sigcontext32(struct pt_regs *regs, if (used_math) { /* restore fpu context if we have used it before */ if (!err) - err = check_and_restore_fp_context32(sc); + err = check_and_restore_fp_context32(sc, used_math); } else { - /* signal handler may have used FPU. Give it up. */ + /* signal handler may have used FPU or MSA. Disable them. */ + disable_msa(); lose_fpu(0); } -- cgit v1.2.2