diff options
Diffstat (limited to 'target/linux/generic/patches-3.12/304-mips_disable_fpu.patch')
| -rw-r--r-- | target/linux/generic/patches-3.12/304-mips_disable_fpu.patch | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/target/linux/generic/patches-3.12/304-mips_disable_fpu.patch b/target/linux/generic/patches-3.12/304-mips_disable_fpu.patch new file mode 100644 index 0000000..b524e79 --- /dev/null +++ b/target/linux/generic/patches-3.12/304-mips_disable_fpu.patch @@ -0,0 +1,160 @@ +MIPS: allow disabling the kernel FPU emulator + +This patch allows turning off the in-kernel Algorithmics +FPU emulator support, which allows one to save a couple of +precious blocks on an embedded system. + +Signed-off-by: Florian Fainelli <florian@openwrt.org> +-- +--- a/arch/mips/Kconfig ++++ b/arch/mips/Kconfig +@@ -945,6 +945,17 @@ config I8259 + config MIPS_BONITO64 + bool + ++config MIPS_FPU_EMU ++ bool "Enable FPU emulation" ++ default y ++ help ++ This option allows building a kernel with or without the Algorithmics ++ FPU emulator enabled. Turning off this option results in a kernel which ++ does not catch floating operations exceptions. Make sure that your toolchain ++ is configured to enable software floating point emulation in that case. ++ ++ If unsure say Y here. ++ + config MIPS_MSC + bool + +--- a/arch/mips/math-emu/Makefile ++++ b/arch/mips/math-emu/Makefile +@@ -2,10 +2,12 @@ + # Makefile for the Linux/MIPS kernel FPU emulation. + # + +-obj-y := cp1emu.o ieee754m.o ieee754d.o ieee754dp.o ieee754sp.o ieee754.o \ ++obj-y := kernel_linkage.o ++ ++obj-$(CONFIG_MIPS_FPU_EMU) += ieee754m.o ieee754d.o ieee754dp.o ieee754sp.o ieee754.o \ + ieee754xcpt.o dp_frexp.o dp_modf.o dp_div.o dp_mul.o dp_sub.o \ + dp_add.o dp_fsp.o dp_cmp.o dp_logb.o dp_scalb.o dp_simple.o \ + dp_tint.o dp_fint.o dp_tlong.o dp_flong.o sp_frexp.o sp_modf.o \ + sp_div.o sp_mul.o sp_sub.o sp_add.o sp_fdp.o sp_cmp.o sp_logb.o \ + sp_scalb.o sp_simple.o sp_tint.o sp_fint.o sp_tlong.o sp_flong.o \ +- dp_sqrt.o sp_sqrt.o kernel_linkage.o dsemul.o ++ dp_sqrt.o sp_sqrt.o dsemul.o cp1emu.o +--- a/arch/mips/math-emu/kernel_linkage.c ++++ b/arch/mips/math-emu/kernel_linkage.c +@@ -29,6 +29,7 @@ + + #define SIGNALLING_NAN 0x7ff800007ff80000LL + ++#ifdef CONFIG_MIPS_FPU_EMU + void fpu_emulator_init_fpu(void) + { + static int first = 1; +@@ -113,3 +114,36 @@ int fpu_emulator_restore_context32(struc + return err; + } + #endif ++ ++#else ++ ++void fpu_emulator_init_fpu(void) ++{ ++ printk(KERN_INFO "FPU emulator disabled, make sure your toolchain" ++ "was compiled with software floating point support (soft-float)\n"); ++ return; ++} ++ ++int fpu_emulator_save_context(struct sigcontext __user *sc) ++{ ++ return 0; ++} ++ ++int fpu_emulator_restore_context(struct sigcontext __user *sc) ++{ ++ return 0; ++} ++ ++#ifdef CONFIG_64BIT ++int fpu_emulator_save_context32(struct sigcontext32 __user *sc) ++{ ++ return 0; ++} ++ ++int fpu_emulator_restore_context32(struct sigcontext32 __user *sc) ++{ ++ return 0; ++} ++#endif /* CONFIG_64BIT */ ++ ++#endif /* CONFIG_MIPS_FPU_EMU */ +--- a/arch/mips/include/asm/fpu_emulator.h ++++ b/arch/mips/include/asm/fpu_emulator.h +@@ -27,6 +27,8 @@ + #include <asm/inst.h> + #include <asm/local.h> + ++#ifdef CONFIG_MIPS_FPU_EMU ++ + #ifdef CONFIG_DEBUG_FS + + struct mips_fpu_emulator_stats { +@@ -60,6 +62,38 @@ extern int fpu_emulator_cop1Handler(stru + int process_fpemu_return(int sig, void __user *fault_addr); + int mm_isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn, + unsigned long *contpc); ++#else ++static inline int mips_dsemul(struct pt_regs *regs, mips_instruction ir, ++ unsigned long cpc) ++{ ++ return 0; ++} ++ ++static inline int do_dsemulret(struct pt_regs *xcp) ++{ ++ return 0; ++} ++ ++static inline int fpu_emulator_cop1Handler(struct pt_regs *xcp, ++ struct mips_fpu_struct *ctx, ++ int has_fpu, ++ void *__user *fault_addr) ++{ ++ return 0; ++} ++ ++static inline int process_fpemu_return(int sig, void __user *fault_addr) ++{ ++ return -EINVAL; ++} ++ ++static inline int mm_isBranchInstr(struct pt_regs *regs, ++ struct mm_decoded_insn dec_insn, ++ unsigned long *contpc) ++{ ++ return 0; ++} ++#endif /* CONFIG_MIPS_FPU_EMU */ + + /* + * Instruction inserted following the badinst to further tag the sequence +--- a/arch/mips/kernel/traps.c ++++ b/arch/mips/kernel/traps.c +@@ -694,6 +694,7 @@ asmlinkage void do_ov(struct pt_regs *re + exception_exit(prev_state); + } + ++#ifdef CONFIG_MIPS_FPU_EMU + int process_fpemu_return(int sig, void __user *fault_addr) + { + if (sig == SIGSEGV || sig == SIGBUS) { +@@ -717,6 +718,7 @@ int process_fpemu_return(int sig, void _ + return 0; + } + } ++#endif /* CONFIG_MIPS_FPU_EMU */ + + /* + * XXX Delayed fp exceptions when doing a lazy ctx switch XXX |