diff options
Diffstat (limited to 'target/linux/generic/patches-2.6.36/025-mips_disable_fpu.patch')
| -rw-r--r-- | target/linux/generic/patches-2.6.36/025-mips_disable_fpu.patch | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/target/linux/generic/patches-2.6.36/025-mips_disable_fpu.patch b/target/linux/generic/patches-2.6.36/025-mips_disable_fpu.patch new file mode 100644 index 0000000..dd799c5 --- /dev/null +++ b/target/linux/generic/patches-2.6.36/025-mips_disable_fpu.patch @@ -0,0 +1,161 @@ +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 +@@ -841,6 +841,17 @@ 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 +@@ -2,12 +2,14 @@ + # 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 dsemul.o cp1emu.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 + + EXTRA_CFLAGS += -Werror +--- a/arch/mips/math-emu/cp1emu.c ++++ b/arch/mips/math-emu/cp1emu.c +@@ -58,7 +58,11 @@ + #define __mips 4 + + /* Function which emulates a floating point instruction. */ ++#ifdef CONFIG_DEBUG_FS ++DEFINE_PER_CPU(struct mips_fpu_emulator_stats, fpuemustats); ++#endif + ++#ifdef CONFIG_MIPS_FPU_EMU + static int fpu_emu(struct pt_regs *, struct mips_fpu_struct *, + mips_instruction); + +@@ -69,10 +73,6 @@ static int fpux_emu(struct pt_regs *, + + /* Further private data for which no space exists in mips_fpu_struct */ + +-#ifdef CONFIG_DEBUG_FS +-DEFINE_PER_CPU(struct mips_fpu_emulator_stats, fpuemustats); +-#endif +- + /* Control registers */ + + #define FPCREG_RID 0 /* $0 = revision id */ +@@ -1285,7 +1285,6 @@ int fpu_emulator_cop1Handler(struct pt_r + + return sig; + } +- + #ifdef CONFIG_DEBUG_FS + + static int fpuemu_stat_get(void *data, u64 *val) +@@ -1334,4 +1333,11 @@ static int __init debugfs_fpuemu(void) + return 0; + } + __initcall(debugfs_fpuemu); +-#endif ++#endif /* CONFIG_DEBUGFS */ ++#else ++int fpu_emulator_cop1Handler(struct pt_regs *xcp, struct mips_fpu_struct *ctx, ++ int has_fpu) ++{ ++ return 0; ++} ++#endif /* CONFIG_MIPS_FPU_EMU */ +--- a/arch/mips/math-emu/dsemul.c ++++ b/arch/mips/math-emu/dsemul.c +@@ -109,6 +109,7 @@ int mips_dsemul(struct pt_regs *regs, mi + return SIGILL; /* force out of emulation loop */ + } + ++#ifdef CONFIG_MIPS_FPU_EMU + int do_dsemulret(struct pt_regs *xcp) + { + struct emuframe __user *fr; +@@ -165,3 +166,9 @@ int do_dsemulret(struct pt_regs *xcp) + + return 1; + } ++#else ++int do_dsemulret(struct pt_regs *xcp) ++{ ++ return 0; ++} ++#endif /* CONFIG_MIPS_FPU_EMU */ +--- 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; +@@ -112,4 +113,36 @@ int fpu_emulator_restore_context32(struc + + return err; + } +-#endif ++#endif /* CONFIG_64BIT */ ++#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; ++} ++ ++int fpu_emulator_save_context32(struct sigcontext32 __user *sc) ++{ ++ return 0; ++} ++ ++int fpu_emulator_restore_context32(struct sigcontext32 __user *sc) ++{ ++ return 0; ++} ++ ++#ifdef CONFIG_64BIT ++#endif /* CONFIG_64BIT */ ++#endif /* CONFIG_MIPS_FPU_EMU */ |