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	* properly format/comment all patches * merge debloat patches * merge Kconfig patches * merge swconfig patches * merge hotplug patches * drop 200-fix_localversion.patch - upstream * drop 222-arm_zimage_none.patch - unused * drop 252-mv_cesa_depends.patch - no longer required * drop 410-mtd-move-forward-declaration-of-struct-mtd_info.patch - unused * drop 661-fq_codel_keep_dropped_stats.patch - outdated * drop 702-phy_add_aneg_done_function.patch - upstream * drop 840-rtc7301.patch - unused * drop 841-rtc_pt7c4338.patch - upstream * drop 921-use_preinit_as_init.patch - unused * drop spio-gpio-old and gpio-mmc - unused Signed-off-by: John Crispin <john@phrozen.org>
		
			
				
	
	
		
			106 lines
		
	
	
		
			3.4 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
			
		
		
	
	
			106 lines
		
	
	
		
			3.4 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
| From:   Manuel Lauss <manuel.lauss@gmail.com>
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| Subject: [RFC PATCH v4 2/2] MIPS: make FPU emulator optional
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| Date:   Mon,  7 Apr 2014 12:57:04 +0200
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| Message-Id: <1396868224-252888-2-git-send-email-manuel.lauss@gmail.com>
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| 
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| This small patch makes the MIPS FPU emulator optional. The kernel
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| kills float-users on systems without a hardware FPU by sending a SIGILL.
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| 
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| Disabling the emulator shrinks vmlinux by about 54kBytes (32bit,
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| optimizing for size).
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| 
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| Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com>
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| ---
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| v4: rediffed because of patch 1/2, should now work with micromips as well
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| v3: updated patch description with size savings.
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| v2: incorporated changes suggested by Jonas Gorski
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|     force the fpu emulator on for micromips: relocating the parts
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|     of the mmips code in the emulator to other areas would be a
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|     much larger change; I went the cheap route instead with this.
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| 
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|  arch/mips/Kbuild                     |  2 +-
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|  arch/mips/Kconfig                    | 14 ++++++++++++++
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|  arch/mips/include/asm/fpu.h          |  5 +++--
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|  arch/mips/include/asm/fpu_emulator.h | 15 +++++++++++++++
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|  4 files changed, 33 insertions(+), 3 deletions(-)
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| 
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| --- a/arch/mips/Kconfig
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| +++ b/arch/mips/Kconfig
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| @@ -2495,6 +2495,20 @@ config MIPS_O32_FP64_SUPPORT
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|  
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|  	  If unsure, say N.
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|  
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| +config MIPS_FPU_EMULATOR
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| +	bool "MIPS FPU Emulator"
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| +	default y
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| +	help
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| +	  This option lets you disable the built-in MIPS FPU (Coprocessor 1)
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| +	  emulator, which handles floating-point instructions on processors
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| +	  without a hardware FPU.  It is generally a good idea to keep the
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| +	  emulator built-in, unless you are perfectly sure you have a
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| +	  complete soft-float environment.  With the emulator disabled, all
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| +	  users of float operations will be killed with an illegal instr-
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| +	  uction exception.
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| +
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| +	  Say Y, please.
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| +
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|  config USE_OF
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|  	bool
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|  	select OF
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| --- a/arch/mips/Makefile
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| +++ b/arch/mips/Makefile
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| @@ -275,7 +275,7 @@ OBJCOPYFLAGS		+= --remove-section=.regin
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|  head-y := arch/mips/kernel/head.o
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|  
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|  libs-y			+= arch/mips/lib/
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| -libs-y			+= arch/mips/math-emu/
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| +libs-$(CONFIG_MIPS_FPU_EMULATOR)	+= arch/mips/math-emu/
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|  
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|  # See arch/mips/Kbuild for content of core part of the kernel
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|  core-y += arch/mips/
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| --- a/arch/mips/include/asm/fpu.h
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| +++ b/arch/mips/include/asm/fpu.h
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| @@ -169,8 +169,10 @@ static inline int init_fpu(void)
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|  		ret = __own_fpu();
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|  		if (!ret)
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|  			_init_fpu();
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| -	} else
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| +	} else if (IS_ENABLED(CONFIG_MIPS_FPU_EMULATOR))
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|  		fpu_emulator_init_fpu();
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| +	else
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| +		ret = SIGILL;
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|  
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|  	return ret;
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|  }
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| --- a/arch/mips/include/asm/fpu_emulator.h
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| +++ b/arch/mips/include/asm/fpu_emulator.h
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| @@ -30,6 +30,7 @@
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|  #include <asm/local.h>
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|  #include <asm/processor.h>
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|  
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| +#ifdef CONFIG_MIPS_FPU_EMULATOR
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|  #ifdef CONFIG_DEBUG_FS
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|  
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|  struct mips_fpu_emulator_stats {
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| @@ -65,6 +66,20 @@ extern int do_dsemulret(struct pt_regs *
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|  extern int fpu_emulator_cop1Handler(struct pt_regs *xcp,
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|  				    struct mips_fpu_struct *ctx, int has_fpu,
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|  				    void *__user *fault_addr);
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| +#else	/* no CONFIG_MIPS_FPU_EMULATOR */
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| +static inline int do_dsemulret(struct pt_regs *xcp)
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| +{
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| +	return 0;	/* 0 means error, should never get here anyway */
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| +}
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| +
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| +static inline int fpu_emulator_cop1Handler(struct pt_regs *xcp,
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| +				struct mips_fpu_struct *ctx, int has_fpu,
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| +				void *__user *fault_addr)
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| +{
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| +	return SIGILL;	/* we don't speak MIPS FPU */
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| +}
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| +#endif	/* CONFIG_MIPS_FPU_EMULATOR */
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| +
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|  int process_fpemu_return(int sig, void __user *fault_addr);
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|  int mm_isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
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|  		     unsigned long *contpc);
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