arch/sparc/kernel/ioport.c

Source file repositories/reference/linux-study-clean/arch/sparc/kernel/ioport.c

File Facts

System
Linux kernel
Corpus path
arch/sparc/kernel/ioport.c
Extension
.c
Size
8508 bytes
Lines
345
Domain
Architecture Layer
Bucket
arch/sparc
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

struct xresource {
	struct resource xres;	/* Must be first */
	int xflag;		/* 1 == used */
	char xname[XNMLN+1];
};

static struct xresource xresv[XNRES];

static struct xresource *xres_alloc(void) {
	struct xresource *xrp;
	int n;

	xrp = xresv;
	for (n = 0; n < XNRES; n++) {
		if (xrp->xflag == 0) {
			xrp->xflag = 1;
			return xrp;
		}
		xrp++;
	}
	return NULL;
}

static void xres_free(struct xresource *xrp) {
	xrp->xflag = 0;
}

/*
 * These are typically used in PCI drivers
 * which are trying to be cross-platform.
 *
 * Bus type is always zero on IIep.
 */
void __iomem *ioremap(phys_addr_t offset, size_t size)
{
	char name[14];

	sprintf(name, "phys_%08x", (u32)offset);
	return _sparc_alloc_io(0, (unsigned long)offset, size, name);
}
EXPORT_SYMBOL(ioremap);

/*
 * Complementary to ioremap().
 */
void iounmap(volatile void __iomem *virtual)
{
	unsigned long vaddr = (unsigned long) virtual & PAGE_MASK;
	struct resource *res;

	/*
	 * XXX Too slow. Can have 8192 DVMA pages on sun4m in the worst case.
	 * This probably warrants some sort of hashing.
	*/
	if ((res = lookup_resource(&sparc_iomap, vaddr)) == NULL) {
		printk("free_io/iounmap: cannot free %lx\n", vaddr);
		return;
	}
	_sparc_free_io(res);

	if ((char *)res >= (char*)xresv && (char *)res < (char *)&xresv[XNRES]) {
		xres_free((struct xresource *)res);
	} else {
		kfree(res);
	}
}
EXPORT_SYMBOL(iounmap);

void __iomem *of_ioremap(struct resource *res, unsigned long offset,
			 unsigned long size, char *name)
{
	return _sparc_alloc_io(res->flags & 0xF,
			       res->start + offset,
			       size, name);
}
EXPORT_SYMBOL(of_ioremap);

void of_iounmap(struct resource *res, void __iomem *base, unsigned long size)
{
	iounmap(base);
}
EXPORT_SYMBOL(of_iounmap);

/*
 * Meat of mapping
 */
static void __iomem *_sparc_alloc_io(unsigned int busno, unsigned long phys,
    unsigned long size, char *name)
{
	static int printed_full;

Annotation

Implementation Notes