arch/mips/cavium-octeon/csrc-octeon.c

Source file repositories/reference/linux-study-clean/arch/mips/cavium-octeon/csrc-octeon.c

File Facts

System
Linux kernel
Corpus path
arch/mips/cavium-octeon/csrc-octeon.c
Extension
.c
Size
4983 bytes
Lines
215
Domain
Architecture Layer
Bucket
arch/mips
Inferred role
Architecture Layer: exported/initcall integration point
Status
integration 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

if (rdiv != 0) {
			clk_count *= rdiv;
			if (f != 0) {
				asm("dmultu\t%[cnt],%[f]\n\t"
				    "mfhi\t%[cnt]"
				    : [cnt] "+r" (clk_count)
				    : [f] "r" (f)
				    : "hi", "lo");
			}
		}
		write_c0_cvmcount(clk_count);
	}
	local_irq_restore(flags);
}

static u64 octeon_cvmcount_read(struct clocksource *cs)
{
	return read_c0_cvmcount();
}

static struct clocksource clocksource_mips = {
	.name		= "OCTEON_CVMCOUNT",
	.read		= octeon_cvmcount_read,
	.mask		= CLOCKSOURCE_MASK(64),
	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
};

unsigned long long notrace sched_clock(void)
{
	/* 64-bit arithmetic can overflow, so use 128-bit.  */
	u64 t1, t2, t3;
	unsigned long long rv;
	u64 mult = clocksource_mips.mult;
	u64 shift = clocksource_mips.shift;
	u64 cnt = read_c0_cvmcount();

	asm (
		"dmultu\t%[cnt],%[mult]\n\t"
		"nor\t%[t1],$0,%[shift]\n\t"
		"mfhi\t%[t2]\n\t"
		"mflo\t%[t3]\n\t"
		"dsll\t%[t2],%[t2],1\n\t"
		"dsrlv\t%[rv],%[t3],%[shift]\n\t"
		"dsllv\t%[t1],%[t2],%[t1]\n\t"
		"or\t%[rv],%[t1],%[rv]\n\t"
		: [rv] "=&r" (rv), [t1] "=&r" (t1), [t2] "=&r" (t2), [t3] "=&r" (t3)
		: [cnt] "r" (cnt), [mult] "r" (mult), [shift] "r" (shift)
		: "hi", "lo");
	return rv;
}

void __init plat_time_init(void)
{
	clocksource_mips.rating = 300;
	clocksource_register_hz(&clocksource_mips, octeon_get_clock_rate());
}

void __udelay(unsigned long us)
{
	u64 cur, end, inc;

	cur = read_c0_cvmcount();

	inc = us * octeon_udelay_factor;
	end = cur + inc;

	while (end > cur)
		cur = read_c0_cvmcount();
}
EXPORT_SYMBOL(__udelay);

void __ndelay(unsigned long ns)
{
	u64 cur, end, inc;

	cur = read_c0_cvmcount();

	inc = ((ns * octeon_ndelay_factor) >> 16);
	end = cur + inc;

	while (end > cur)
		cur = read_c0_cvmcount();
}
EXPORT_SYMBOL(__ndelay);

void __delay(unsigned long loops)
{
	u64 cur, end;

	cur = read_c0_cvmcount();

Annotation

Implementation Notes