diff options
Diffstat (limited to 'target/linux/generic/patches-4.9/304-mips_disable_fpu.patch')
-rw-r--r-- | target/linux/generic/patches-4.9/304-mips_disable_fpu.patch | 139 |
1 files changed, 0 insertions, 139 deletions
diff --git a/target/linux/generic/patches-4.9/304-mips_disable_fpu.patch b/target/linux/generic/patches-4.9/304-mips_disable_fpu.patch deleted file mode 100644 index a69ea57678..0000000000 --- a/target/linux/generic/patches-4.9/304-mips_disable_fpu.patch +++ /dev/null @@ -1,139 +0,0 @@ -From: Manuel Lauss <manuel.lauss@gmail.com> -Subject: [RFC PATCH v4 2/2] MIPS: make FPU emulator optional -Date: Mon, 7 Apr 2014 12:57:04 +0200 -Message-Id: <1396868224-252888-2-git-send-email-manuel.lauss@gmail.com> - -This small patch makes the MIPS FPU emulator optional. The kernel -kills float-users on systems without a hardware FPU by sending a SIGILL. - -Disabling the emulator shrinks vmlinux by about 54kBytes (32bit, -optimizing for size). - -Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com> ---- -v4: rediffed because of patch 1/2, should now work with micromips as well -v3: updated patch description with size savings. -v2: incorporated changes suggested by Jonas Gorski - force the fpu emulator on for micromips: relocating the parts - of the mmips code in the emulator to other areas would be a - much larger change; I went the cheap route instead with this. - - arch/mips/Kbuild | 2 +- - arch/mips/Kconfig | 14 ++++++++++++++ - arch/mips/include/asm/fpu.h | 5 +++-- - arch/mips/include/asm/fpu_emulator.h | 15 +++++++++++++++ - 4 files changed, 33 insertions(+), 3 deletions(-) - ---- a/arch/mips/Kconfig -+++ b/arch/mips/Kconfig -@@ -2892,6 +2892,20 @@ config MIPS_O32_FP64_SUPPORT - - If unsure, say N. - -+config MIPS_FPU_EMULATOR -+ bool "MIPS FPU Emulator" -+ default y -+ help -+ This option lets you disable the built-in MIPS FPU (Coprocessor 1) -+ emulator, which handles floating-point instructions on processors -+ without a hardware FPU. It is generally a good idea to keep the -+ emulator built-in, unless you are perfectly sure you have a -+ complete soft-float environment. With the emulator disabled, all -+ users of float operations will be killed with an illegal instr- -+ uction exception. -+ -+ Say Y, please. -+ - config USE_OF - bool - select OF ---- a/arch/mips/Makefile -+++ b/arch/mips/Makefile -@@ -287,7 +287,7 @@ OBJCOPYFLAGS += --remove-section=.regin - head-y := arch/mips/kernel/head.o - - libs-y += arch/mips/lib/ --libs-y += arch/mips/math-emu/ -+libs-$(CONFIG_MIPS_FPU_EMULATOR) += arch/mips/math-emu/ - - # See arch/mips/Kbuild for content of core part of the kernel - core-y += arch/mips/ ---- a/arch/mips/include/asm/fpu.h -+++ b/arch/mips/include/asm/fpu.h -@@ -227,8 +227,10 @@ static inline int init_fpu(void) - /* Restore FRE */ - write_c0_config5(config5); - enable_fpu_hazard(); -- } else -+ } else if (IS_ENABLED(CONFIG_MIPS_FPU_EMULATOR)) - fpu_emulator_init_fpu(); -+ else -+ ret = SIGILL; - - return ret; - } ---- a/arch/mips/include/asm/fpu_emulator.h -+++ b/arch/mips/include/asm/fpu_emulator.h -@@ -30,6 +30,7 @@ - #include <asm/local.h> - #include <asm/processor.h> - -+#ifdef CONFIG_MIPS_FPU_EMULATOR - #ifdef CONFIG_DEBUG_FS - - struct mips_fpu_emulator_stats { -@@ -63,6 +64,16 @@ do { \ - extern int fpu_emulator_cop1Handler(struct pt_regs *xcp, - struct mips_fpu_struct *ctx, int has_fpu, - void *__user *fault_addr); -+#else /* no CONFIG_MIPS_FPU_EMULATOR */ -+static inline int fpu_emulator_cop1Handler(struct pt_regs *xcp, -+ struct mips_fpu_struct *ctx, int has_fpu, -+ void *__user *fault_addr) -+{ -+ *fault_addr = NULL; -+ return SIGILL; /* we don't speak MIPS FPU */ -+} -+#endif /* CONFIG_MIPS_FPU_EMULATOR */ -+ - void force_fcr31_sig(unsigned long fcr31, void __user *fault_addr, - struct task_struct *tsk); - int process_fpemu_return(int sig, void __user *fault_addr, ---- a/arch/mips/include/asm/dsemul.h -+++ b/arch/mips/include/asm/dsemul.h -@@ -41,6 +41,7 @@ struct task_struct; - extern int mips_dsemul(struct pt_regs *regs, mips_instruction ir, - unsigned long branch_pc, unsigned long cont_pc); - -+#ifdef CONFIG_MIPS_FPU_EMULATOR - /** - * do_dsemulret() - Return from a delay slot 'emulation' frame - * @xcp: User thread register context. -@@ -88,5 +89,27 @@ extern bool dsemul_thread_rollback(struc - * before @mm is freed in order to avoid memory leaks. - */ - extern void dsemul_mm_cleanup(struct mm_struct *mm); -+#else -+static inline bool do_dsemulret(struct pt_regs *xcp) -+{ -+ return false; -+} -+ -+static inline bool dsemul_thread_cleanup(struct task_struct *tsk) -+{ -+ return false; -+} -+ -+static inline bool dsemul_thread_rollback(struct pt_regs *regs) -+{ -+ return false; -+} -+ -+static inline void dsemul_mm_cleanup(struct mm_struct *mm) -+{ -+ -+} -+ -+#endif - - #endif /* __MIPS_ASM_DSEMUL_H__ */ |