linux/arch/sh/mm/ioremap_64.c

/*
 * arch/sh/mm/ioremap_64.c
 *
 * Copyright (C) 2000, 2001  Paolo Alberelli
 * Copyright (C) 2003 - 2007  Paul Mundt
 *
 * Mostly derived from arch/sh/mm/ioremap.c which, in turn is mostly
 * derived from arch/i386/mm/ioremap.c .
 *
 *   (C) Copyright 1995 1996 Linus Torvalds
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */
#include <linux/vmalloc.h>
#include <linux/ioport.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/io.h>
#include <linux/bootmem.h>
#include <linux/proc_fs.h>
#include <linux/slab.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/addrspace.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include <asm/mmu.h>

static struct resource shmedia_iomap = {
	.name	= "shmedia_iomap",
	.start	= IOBASE_VADDR + PAGE_SIZE,
	.end	= IOBASE_END - 1,
};

static void shmedia_mapioaddr(unsigned long pa, unsigned long va,
			      unsigned long flags);
static void shmedia_unmapioaddr(unsigned long vaddr);
static void __iomem *shmedia_ioremap(struct resource *res, u32 pa,
				     int sz, unsigned long flags);

/*
 * We have the same problem as the SPARC, so lets have the same comment:
 * Our mini-allocator...
 * Boy this is gross! We need it because we must map I/O for
 * timers and interrupt controller before the kmalloc is available.
 */

#define XNMLN  15
#define XNRES  10

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;
}

static struct resource *shmedia_find_resource(struct resource *root,
					      unsigned long vaddr)
{
	struct resource *res;

	for (res = root->child; res; res = res->sibling)
		if (res->start <= vaddr && res->end >= vaddr)
			return res;

	return NULL;
}

static void __iomem *shmedia_alloc_io(unsigned long phys, unsigned long size,
				      const char *name, unsigned long flags)
{
	struct xresource *xres;
	struct resource *res;
	char *tack;
	int tlen;

	if (name == NULL)
		name = "???";

	xres = xres_alloc();
	if (xres != 0) {
		tack = xres->xname;
		res = &xres->xres;
	} else {
		printk_once(KERN_NOTICE "%s: done with statics, "
			       "switching to kmalloc\n", __func__);
		tlen = strlen(name);
		tack = kmalloc(sizeof(struct resource) + tlen + 1, GFP_KERNEL);
		if (!tack)
			return NULL;
		memset(tack, 0, sizeof(struct resource));
		res = (struct resource *) tack;
		tack += sizeof(struct resource);
	}

	strncpy(tack, name, XNMLN);
	tack[XNMLN] = 0;
	res->name = tack;

	return shmedia_ioremap(res, phys, size, flags);
}

static void __iomem *shmedia_ioremap(struct resource *res, u32 pa, int sz,
				     unsigned long flags)
{
	unsigned long offset = ((unsigned long) pa) & (~PAGE_MASK);
	unsigned long round_sz = (offset + sz + PAGE_SIZE-1) & PAGE_MASK;
	unsigned long va;
	unsigned int psz;

	if (allocate_resource(&shmedia_iomap, res, round_sz,
			      shmedia_iomap.start, shmedia_iomap.end,
			      PAGE_SIZE, NULL, NULL) != 0) {
		panic("alloc_io_res(%s): cannot occupy\n",
		      (res->name != NULL) ? res->name : "???");
	}

	va = res->start;
	pa &= PAGE_MASK;

	psz = (res->end - res->start + (PAGE_SIZE - 1)) / PAGE_SIZE;

	for (psz = res->end - res->start + 1; psz != 0; psz -= PAGE_SIZE) {
		shmedia_mapioaddr(pa, va, flags);
		va += PAGE_SIZE;
		pa += PAGE_SIZE;
	}

	return (void __iomem *)(unsigned long)(res->start + offset);
}

static void shmedia_free_io(struct resource *res)
{
	unsigned long len = res->end - res->start + 1;

	BUG_ON((len & (PAGE_SIZE - 1)) != 0);

	while (len) {
		len -= PAGE_SIZE;
		shmedia_unmapioaddr(res->start + len);
	}

	release_resource(res);
}

static __init_refok void *sh64_get_page(void)
{
	void *page;

	if (slab_is_available())
		page = (void *)get_zeroed_page(GFP_KERNEL);
	else
		page = alloc_bootmem_pages(PAGE_SIZE);

	if (!page || ((unsigned long)page & ~PAGE_MASK))
		panic("sh64_get_page: Out of memory already?\n");

	return page;
}

static void shmedia_mapioaddr(unsigned long pa, unsigned long va,
			      unsigned long flags)
{
	pgd_t *pgdp;
	pud_t *pudp;
	pmd_t *pmdp;
	pte_t *ptep, pte;
	pgprot_t prot;

	pr_debug("shmedia_mapiopage pa %08lx va %08lx\n",  pa, va);

	if (!flags)
		flags = 1; /* 1 = CB0-1 device */

	pgdp = pgd_offset_k(va);
	if (pgd_none(*pgdp) || !pgd_present(*pgdp)) {
		pudp = (pud_t *)sh64_get_page();
		set_pgd(pgdp, __pgd((unsigned long)pudp | _KERNPG_TABLE));
	}

	pudp = pud_offset(pgdp, va);
	if (pud_none(*pudp) || !pud_present(*pudp)) {
		pmdp = (pmd_t *)sh64_get_page();
		set_pud(pudp, __pud((unsigned long)pmdp | _KERNPG_TABLE));
	}

	pmdp = pmd_offset(pudp, va);
	if (pmd_none(*pmdp) || !pmd_present(*pmdp)) {
		ptep = (pte_t *)sh64_get_page();
		set_pmd(pmdp, __pmd((unsigned long)ptep + _PAGE_TABLE));
	}

	prot = __pgprot(_PAGE_PRESENT | _PAGE_READ     | _PAGE_WRITE  |
			_PAGE_DIRTY   | _PAGE_ACCESSED | _PAGE_SHARED | flags);

	pte = pfn_pte(pa >> PAGE_SHIFT, prot);
	ptep = pte_offset_kernel(pmdp, va);

	if (!pte_none(*ptep) &&
	    pte_val(*ptep) != pte_val(pte))
		pte_ERROR(*ptep);

	set_pte(ptep, pte);

	flush_tlb_kernel_range(va, PAGE_SIZE);
}

static void shmedia_unmapioaddr(unsigned long vaddr)
{
	pgd_t *pgdp;
	pud_t *pudp;
	pmd_t *pmdp;
	pte_t *ptep;

	pgdp = pgd_offset_k(vaddr);
	if (pgd_none(*pgdp) || pgd_bad(*pgdp))
		return;

	pudp = pud_offset(pgdp, vaddr);
	if (pud_none(*pudp) || pud_bad(*pudp))
		return;

	pmdp = pmd_offset(pudp, vaddr);
	if (pmd_none(*pmdp) || pmd_bad(*pmdp))
		return;

	ptep = pte_offset_kernel(pmdp, vaddr);

	if (pte_none(*ptep) || !pte_present(*ptep))
		return;

	clear_page((void *)ptep);
	pte_clear(&init_mm, vaddr, ptep);
}

void __iomem *__ioremap(unsigned long offset, unsigned long size,
			unsigned long flags)
{
	char name[14];

	sprintf(name, "phys_%08x", (u32)offset);
	return shmedia_alloc_io(offset, size, name, flags);
}
EXPORT_SYMBOL(__ioremap);

void __iounmap(void __iomem *virtual)
{
	unsigned long vaddr = (unsigned long)virtual & PAGE_MASK;
	struct resource *res;
	unsigned int psz;

	res = shmedia_find_resource(&shmedia_iomap, vaddr);
	if (!res) {
		printk(KERN_ERR "%s: Failed to free 0x%08lx\n",
		       __func__, vaddr);
		return;
	}

	psz = (res->end - res->start + (PAGE_SIZE - 1)) / PAGE_SIZE;

	shmedia_free_io(res);

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

static int
ioremap_proc_info(char *buf, char **start, off_t fpos, int length, int *eof,
		  void *data)
{
	char *p = buf, *e = buf + length;
	struct resource *r;
	const char *nm;

	for (r = ((struct resource *)data)->child; r != NULL; r = r->sibling) {
		if (p + 32 >= e)        /* Better than nothing */
			break;
		nm = r->name;
		if (nm == NULL)
			nm = "???";

		p += sprintf(p, "%08lx-%08lx: %s\n",
			     (unsigned long)r->start,
			     (unsigned long)r->end, nm);
	}

	return p-buf;
}

static int __init register_proc_onchip(void)
{
	create_proc_read_entry("io_map", 0, 0, ioremap_proc_info,
			       &shmedia_iomap);
	return 0;
}
late_initcall(register_proc_onchip);