mirror of
https://github.com/openwrt/openwrt.git
synced 2024-12-22 15:02:32 +00:00
76d079204d
Changelogs: * https://www.kernel.org/pub/linux/kernel/v3.x/ChangeLog-3.18.12 * https://www.kernel.org/pub/linux/kernel/v3.x/ChangeLog-3.18.13 * https://www.kernel.org/pub/linux/kernel/v3.x/ChangeLog-3.18.14 Build tested on brcm63xx and ipq806x, runtested on brcm63xx. Signed-off-by: Jonas Gorski <jogo@openwrt.org> SVN-Revision: 45711
106 lines
3.4 KiB
Diff
106 lines
3.4 KiB
Diff
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
|
|
@@ -2495,6 +2495,20 @@ 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
|
|
@@ -275,7 +275,7 @@ 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
|
|
@@ -169,8 +169,10 @@ static inline int init_fpu(void)
|
|
ret = __own_fpu();
|
|
if (!ret)
|
|
_init_fpu();
|
|
- } 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 {
|
|
@@ -65,6 +66,20 @@ extern int do_dsemulret(struct pt_regs *
|
|
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 do_dsemulret(struct pt_regs *xcp)
|
|
+{
|
|
+ return 0; /* 0 means error, should never get here anyway */
|
|
+}
|
|
+
|
|
+static inline int fpu_emulator_cop1Handler(struct pt_regs *xcp,
|
|
+ struct mips_fpu_struct *ctx, int has_fpu,
|
|
+ void *__user *fault_addr)
|
|
+{
|
|
+ return SIGILL; /* we don't speak MIPS FPU */
|
|
+}
|
|
+#endif /* CONFIG_MIPS_FPU_EMULATOR */
|
|
+
|
|
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);
|