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[ARM] Handle HWCAP_VFP in VFP support code 

Don't set HWCAP_VFP in the processor support file; not only does it
depend on the processor features, but it also depends on the support
code being present.  Therefore, only set it if the support code
detects that we have a VFP coprocessor attached.

Also, move the VFP handling of the coprocessor access register into
the VFP support code.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
hifive-unleashed-5.1
Russell King 2006-12-08 15:22:20 +00:00 committed by Russell King
parent c99767974e
commit efe90d273b
5 changed files with 56 additions and 23 deletions
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3
arch/arm/kernel/setup.c
View File

@ -354,9 +354,6 @@ static void __init setup_processor(void)
#ifndef CONFIG_ARM_THUMB
elf_hwcap &= ~HWCAP_THUMB;
#endif
#ifndef CONFIG_VFP
elf_hwcap &= ~HWCAP_VFP;
#endif
cpu_proc_init();
}

2
arch/arm/mm/proc-arm926.S
View File

@ -480,7 +480,7 @@ __arm926_proc_info:
b __arm926_setup
.long cpu_arch_name
.long cpu_elf_name
.long HWCAP_SWP|HWCAP_HALF|HWCAP_THUMB|HWCAP_FAST_MULT|HWCAP_VFP|HWCAP_EDSP|HWCAP_JAVA
.long HWCAP_SWP|HWCAP_HALF|HWCAP_THUMB|HWCAP_FAST_MULT|HWCAP_EDSP|HWCAP_JAVA
.long cpu_arm926_name
.long arm926_processor_functions
.long v4wbi_tlb_fns

7
arch/arm/mm/proc-v6.S
View File

@ -207,11 +207,6 @@ __v6_setup:
#endif
mcr p15, 0, r4, c2, c0, 1 @ load TTB1
#endif /* CONFIG_MMU */
#ifdef CONFIG_VFP
mrc p15, 0, r0, c1, c0, 2
orr r0, r0, #(0xf << 20)
mcr p15, 0, r0, c1, c0, 2 @ Enable full access to VFP
#endif
adr r5, v6_crval
ldmia r5, {r5, r6}
mrc p15, 0, r0, c1, c0, 0 @ read control register
@ -273,7 +268,7 @@ __v6_proc_info:
b __v6_setup
.long cpu_arch_name
.long cpu_elf_name
.long HWCAP_SWP|HWCAP_HALF|HWCAP_THUMB|HWCAP_FAST_MULT|HWCAP_VFP|HWCAP_EDSP|HWCAP_JAVA
.long HWCAP_SWP|HWCAP_HALF|HWCAP_THUMB|HWCAP_FAST_MULT|HWCAP_EDSP|HWCAP_JAVA
.long cpu_v6_name
.long v6_processor_functions
.long v6wbi_tlb_fns

26
arch/arm/vfp/vfpmodule.c
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@ -263,13 +263,24 @@ void VFP9_bounce(u32 trigger, u32 fpexc, struct pt_regs *regs)
if (exceptions)
vfp_raise_exceptions(exceptions, trigger, orig_fpscr, regs);
}
/*
* VFP support code initialisation.
*/
static int __init vfp_init(void)
{
unsigned int vfpsid;
unsigned int cpu_arch = cpu_architecture();
u32 access = 0;
if (cpu_arch >= CPU_ARCH_ARMv6) {
access = get_copro_access();
/*
* Enable full access to VFP (cp10 and cp11)
*/
set_copro_access(access | CPACC_FULL(10) | CPACC_FULL(11));
}
/*
* First check that there is a VFP that we can use.
@ -281,6 +292,12 @@ static int __init vfp_init(void)
printk(KERN_INFO "VFP support v0.3: ");
if (VFP_arch) {
printk("not present\n");
/*
* Restore the copro access register.
*/
if (cpu_arch >= CPU_ARCH_ARMv6)
set_copro_access(access);
} else if (vfpsid & FPSID_NODOUBLE) {
printk("no double precision support\n");
} else {
@ -291,9 +308,16 @@ static int __init vfp_init(void)
(vfpsid & FPSID_PART_MASK) >> FPSID_PART_BIT,
(vfpsid & FPSID_VARIANT_MASK) >> FPSID_VARIANT_BIT,
(vfpsid & FPSID_REV_MASK) >> FPSID_REV_BIT);
vfp_vector = vfp_support_entry;
thread_register_notifier(&vfp_notifier_block);
/*
* We detected VFP, and the support code is
* in place; report VFP support to userspace.
*/
elf_hwcap |= HWCAP_VFP;
}
return 0;
}

41
include/asm-arm/system.h
View File

@ -139,19 +139,36 @@ static inline int cpu_is_xsc3(void)
#define cpu_is_xscale() 1
#endif
#define set_cr(x) \
__asm__ __volatile__( \
"mcr p15, 0, %0, c1, c0, 0 @ set CR" \
: : "r" (x) : "cc")
static inline unsigned int get_cr(void)
{
unsigned int val;
asm("mrc p15, 0, %0, c1, c0, 0 @ get CR" : "=r" (val) : : "cc");
return val;
}
#define get_cr() \
({ \
unsigned int __val; \
__asm__ __volatile__( \
"mrc p15, 0, %0, c1, c0, 0 @ get CR" \
: "=r" (__val) : : "cc"); \
__val; \
})
static inline void set_cr(unsigned int val)
{
asm volatile("mcr p15, 0, %0, c1, c0, 0 @ set CR"
: : "r" (val) : "cc");
}
#define CPACC_FULL(n) (3 << (n * 2))
#define CPACC_SVC(n) (1 << (n * 2))
#define CPACC_DISABLE(n) (0 << (n * 2))
static inline unsigned int get_copro_access(void)
{
unsigned int val;
asm("mrc p15, 0, %0, c1, c0, 2 @ get copro access"
: "=r" (val) : : "cc");
return val;
}
static inline void set_copro_access(unsigned int val)
{
asm volatile("mcr p15, 0, %0, c1, c0, 2 @ set copro access"
: : "r" (val) : "cc");
}
extern unsigned long cr_no_alignment; /* defined in entry-armv.S */
extern unsigned long cr_alignment; /* defined in entry-armv.S */