kernel: add preliminary support for linux 3.3
[openwrt/svn-archive/archive.git] / target / linux / generic / patches-3.3 / 304-mips_disable_fpu.patch
1 MIPS: allow disabling the kernel FPU emulator
2
3 This patch allows turning off the in-kernel Algorithmics
4 FPU emulator support, which allows one to save a couple of
5 precious blocks on an embedded system.
6
7 Signed-off-by: Florian Fainelli <florian@openwrt.org>
8 --
9 --- a/arch/mips/Kconfig
10 +++ b/arch/mips/Kconfig
11 @@ -961,6 +961,17 @@ config I8259
12 config MIPS_BONITO64
13 bool
14
15 +config MIPS_FPU_EMU
16 + bool "Enable FPU emulation"
17 + default y
18 + help
19 + This option allows building a kernel with or without the Algorithmics
20 + FPU emulator enabled. Turning off this option results in a kernel which
21 + does not catch floating operations exceptions. Make sure that your toolchain
22 + is configured to enable software floating point emulation in that case.
23 +
24 + If unsure say Y here.
25 +
26 config MIPS_MSC
27 bool
28
29 --- a/arch/mips/math-emu/Makefile
30 +++ b/arch/mips/math-emu/Makefile
31 @@ -2,11 +2,13 @@
32 # Makefile for the Linux/MIPS kernel FPU emulation.
33 #
34
35 -obj-y := cp1emu.o ieee754m.o ieee754d.o ieee754dp.o ieee754sp.o ieee754.o \
36 +obj-y := kernel_linkage.o dsemul.o cp1emu.o
37 +
38 +obj-$(CONFIG_MIPS_FPU_EMU) += ieee754m.o ieee754d.o ieee754dp.o ieee754sp.o ieee754.o \
39 ieee754xcpt.o dp_frexp.o dp_modf.o dp_div.o dp_mul.o dp_sub.o \
40 dp_add.o dp_fsp.o dp_cmp.o dp_logb.o dp_scalb.o dp_simple.o \
41 dp_tint.o dp_fint.o dp_tlong.o dp_flong.o sp_frexp.o sp_modf.o \
42 sp_div.o sp_mul.o sp_sub.o sp_add.o sp_fdp.o sp_cmp.o sp_logb.o \
43 sp_scalb.o sp_simple.o sp_tint.o sp_fint.o sp_tlong.o sp_flong.o \
44 - dp_sqrt.o sp_sqrt.o kernel_linkage.o dsemul.o
45 + dp_sqrt.o sp_sqrt.o
46
47 --- a/arch/mips/math-emu/cp1emu.c
48 +++ b/arch/mips/math-emu/cp1emu.c
49 @@ -58,7 +58,11 @@
50 #define __mips 4
51
52 /* Function which emulates a floating point instruction. */
53 +#ifdef CONFIG_DEBUG_FS
54 +DEFINE_PER_CPU(struct mips_fpu_emulator_stats, fpuemustats);
55 +#endif
56
57 +#ifdef CONFIG_MIPS_FPU_EMU
58 static int fpu_emu(struct pt_regs *, struct mips_fpu_struct *,
59 mips_instruction);
60
61 @@ -69,10 +73,6 @@ static int fpux_emu(struct pt_regs *,
62
63 /* Further private data for which no space exists in mips_fpu_struct */
64
65 -#ifdef CONFIG_DEBUG_FS
66 -DEFINE_PER_CPU(struct mips_fpu_emulator_stats, fpuemustats);
67 -#endif
68 -
69 /* Control registers */
70
71 #define FPCREG_RID 0 /* $0 = revision id */
72 @@ -1360,7 +1360,6 @@ int fpu_emulator_cop1Handler(struct pt_r
73
74 return sig;
75 }
76 -
77 #ifdef CONFIG_DEBUG_FS
78
79 static int fpuemu_stat_get(void *data, u64 *val)
80 @@ -1409,4 +1408,11 @@ static int __init debugfs_fpuemu(void)
81 return 0;
82 }
83 __initcall(debugfs_fpuemu);
84 -#endif
85 +#endif /* CONFIG_DEBUGFS */
86 +#else
87 +int fpu_emulator_cop1Handler(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
88 + int has_fpu)
89 +{
90 + return 0;
91 +}
92 +#endif /* CONFIG_MIPS_FPU_EMU */
93 --- a/arch/mips/math-emu/dsemul.c
94 +++ b/arch/mips/math-emu/dsemul.c
95 @@ -109,6 +109,7 @@ int mips_dsemul(struct pt_regs *regs, mi
96 return SIGILL; /* force out of emulation loop */
97 }
98
99 +#ifdef CONFIG_MIPS_FPU_EMU
100 int do_dsemulret(struct pt_regs *xcp)
101 {
102 struct emuframe __user *fr;
103 @@ -165,3 +166,9 @@ int do_dsemulret(struct pt_regs *xcp)
104
105 return 1;
106 }
107 +#else
108 +int do_dsemulret(struct pt_regs *xcp)
109 +{
110 + return 0;
111 +}
112 +#endif /* CONFIG_MIPS_FPU_EMU */
113 --- a/arch/mips/math-emu/kernel_linkage.c
114 +++ b/arch/mips/math-emu/kernel_linkage.c
115 @@ -29,6 +29,7 @@
116
117 #define SIGNALLING_NAN 0x7ff800007ff80000LL
118
119 +#ifdef CONFIG_MIPS_FPU_EMU
120 void fpu_emulator_init_fpu(void)
121 {
122 static int first = 1;
123 @@ -112,4 +113,36 @@ int fpu_emulator_restore_context32(struc
124
125 return err;
126 }
127 -#endif
128 +#endif /* CONFIG_64BIT */
129 +#else
130 +
131 +void fpu_emulator_init_fpu(void)
132 +{
133 + printk(KERN_INFO "FPU emulator disabled, make sure your toolchain"
134 + "was compiled with software floating point support (soft-float)\n");
135 + return;
136 +}
137 +
138 +int fpu_emulator_save_context(struct sigcontext __user *sc)
139 +{
140 + return 0;
141 +}
142 +
143 +int fpu_emulator_restore_context(struct sigcontext __user *sc)
144 +{
145 + return 0;
146 +}
147 +
148 +int fpu_emulator_save_context32(struct sigcontext32 __user *sc)
149 +{
150 + return 0;
151 +}
152 +
153 +int fpu_emulator_restore_context32(struct sigcontext32 __user *sc)
154 +{
155 + return 0;
156 +}
157 +
158 +#ifdef CONFIG_64BIT
159 +#endif /* CONFIG_64BIT */
160 +#endif /* CONFIG_MIPS_FPU_EMU */