arch/microblaze/kernel/cpu/pvr.c

Source file repositories/reference/linux-study-clean/arch/microblaze/kernel/cpu/pvr.c

File Facts

System
Linux kernel
Corpus path
arch/microblaze/kernel/cpu/pvr.c
Extension
.c
Size
1939 bytes
Lines
82
Domain
Architecture Layer
Bucket
arch/microblaze
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

#include <linux/kernel.h>
#include <linux/compiler.h>
#include <asm/exceptions.h>
#include <asm/pvr.h>
#include <linux/irqflags.h>

/*
 * Until we get an assembler that knows about the pvr registers,
 * this horrible cruft will have to do.
 * That hardcoded opcode is mfs r3, rpvrNN
 */

#define get_single_pvr(pvrid, val)				\
{								\
	register unsigned tmp __asm__("r3");			\
	tmp = 0x0;	/* Prevent warning about unused */	\
	__asm__ __volatile__ (					\
			"mfs	%0, rpvr" #pvrid ";"		\
			: "=r" (tmp) : : "memory");		\
	val = tmp;						\
}

/*
 * Does the CPU support the PVR register?
 * return value:
 * 0: no PVR
 * 1: simple PVR
 * 2: full PVR
 *
 * This must work on all CPU versions, including those before the
 * PVR was even an option.
 */

int cpu_has_pvr(void)
{
	unsigned long flags;
	unsigned pvr0;

	local_save_flags(flags);

	/* PVR bit in MSR tells us if there is any support */
	if (!(flags & PVR_MSR_BIT))
		return 0;

	get_single_pvr(0, pvr0);
	pr_debug("%s: pvr0 is 0x%08x\n", __func__, pvr0);

	if (pvr0 & PVR0_PVR_FULL_MASK)
		return 1;

	/* for partial PVR use static cpuinfo */
	return 2;
}

void get_pvr(struct pvr_s *p)
{
	get_single_pvr(0, p->pvr[0]);
	get_single_pvr(1, p->pvr[1]);
	get_single_pvr(2, p->pvr[2]);
	get_single_pvr(3, p->pvr[3]);
	get_single_pvr(4, p->pvr[4]);
	get_single_pvr(5, p->pvr[5]);
	get_single_pvr(6, p->pvr[6]);
	get_single_pvr(7, p->pvr[7]);
	get_single_pvr(8, p->pvr[8]);
	get_single_pvr(9, p->pvr[9]);
	get_single_pvr(10, p->pvr[10]);
	get_single_pvr(11, p->pvr[11]);
}

Annotation

Implementation Notes