xiaomi-sm8450/android_kernel_xiaomi_sm8450
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Allow to disable FPU support

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FPU codes have been separated from common part in previous patches.
This patch add the CONFIG_FPU option and some stubs, so that a no-FPU
configuration is allowed.

Signed-off-by: Alan Kao <alankao@andestech.com>
Cc: Greentime Hu <greentime@andestech.com>
Cc: Vincent Chen <vincentc@andestech.com>
Cc: Zong Li <zong@andestech.com>
Cc: Nick Hu <nickhu@andestech.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
This commit is contained in:
Alan Kao
2018-10-09 10:18:33 +08:00
committed by Palmer Dabbelt
parent e8be530233
commit 9671f70614
6 changed files with 29 additions and 3 deletions
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2
arch/riscv/kernel/Makefile
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@@ -13,7 +13,6 @@ extra-y += vmlinux.lds
obj-y += cpu.o
obj-y += cpufeature.o
obj-y += entry.o
obj-y += fpu.o
obj-y += irq.o
obj-y += process.o
obj-y += ptrace.o
@@ -32,6 +31,7 @@ obj-y += vdso/
CFLAGS_setup.o := -mcmodel=medany
obj-$(CONFIG_FPU) += fpu.o
obj-$(CONFIG_SMP) += smpboot.o
obj-$(CONFIG_SMP) += smp.o
obj-$(CONFIG_MODULES) += module.o

4
arch/riscv/kernel/process.c
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@@ -76,7 +76,7 @@ void show_regs(struct pt_regs *regs)
void start_thread(struct pt_regs *regs, unsigned long pc,
unsigned long sp)
{
regs->sstatus = SR_SPIE /* User mode, irqs on */ | SR_FS_INITIAL;
regs->sstatus = DEFAULT_SSTATUS;
regs->sepc = pc;
regs->sp = sp;
set_fs(USER_DS);
@@ -84,12 +84,14 @@ void start_thread(struct pt_regs *regs, unsigned long pc,
void flush_thread(void)
{
#ifdef CONFIG_FPU
/*
* Reset FPU context
* frm: round to nearest, ties to even (IEEE default)
* fflags: accrued exceptions cleared
*/
memset(&current->thread.fstate, 0, sizeof(current->thread.fstate));
#endif
}
int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)

5
arch/riscv/kernel/signal.c
View File

@@ -37,6 +37,7 @@ struct rt_sigframe {
struct ucontext uc;
};
#ifdef CONFIG_FPU
static long restore_fp_state(struct pt_regs *regs,
union __riscv_fp_state *sc_fpregs)
{
@@ -85,6 +86,10 @@ static long save_fp_state(struct pt_regs *regs,
return err;
}
#else
#define save_fp_state(task, regs) (0)
#define restore_fp_state(task, regs) (0)
#endif
static long restore_sigcontext(struct pt_regs *regs,
struct sigcontext __user *sc)