ioport.c

linux-2.6.15.6

/* $Id: ioport.c,v 1.45 2001/10/30 04:54:21 davem Exp $
 * ioport.c:  Simple io mapping allocator.
 *
 * Copyright (C) 1995 David S. Miller ([e-mail])
 * Copyright (C) 1995 Miguel de Icaza ([e-mail])
 *
 * 1996: sparc_free_io, 1999: ioremap()/iounmap() by Pete Zaitcev.
 *
 * 2000/01/29
 * <rth> zait: as long as pci_alloc_consistent produces something addressable, 
 *	things are ok.
 * <zaitcev> rth: no, it is relevant, because get_free_pages returns you a
 *	pointer into the big page mapping
 * <rth> zait: so what?
 * <rth> zait: remap_it_my_way(virt_to_phys(get_free_page()))
 * <zaitcev> Hmm
 * <zaitcev> Suppose I did this remap_it_my_way(virt_to_phys(get_free_page())).
 *	So far so good.
 * <zaitcev> Now, driver calls pci_free_consistent(with result of
 *	remap_it_my_way()).
 * <zaitcev> How do you find the address to pass to free_pages()?
 * <rth> zait: walk the page tables?  It's only two or three level after all.
 * <rth> zait: you have to walk them anyway to remove the mapping.
 * <zaitcev> Hmm
 * <zaitcev> Sounds reasonable
 */

#include <linux/config.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/ioport.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/pci.h>		/* struct pci_dev */
#include <linux/proc_fs.h>

#include <asm/io.h>
#include <asm/vaddrs.h>
#include <asm/oplib.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/dma.h>

#define mmu_inval_dma_area(p, l)	/* Anton pulled it out for 2.4.0-xx */

struct resource *_sparc_find_resource(struct resource *r, unsigned long);

static void __iomem *_sparc_ioremap(struct resource *res, u32 bus, u32 pa, int sz);
static void __iomem *_sparc_alloc_io(unsigned int busno, unsigned long phys,
    unsigned long size, char *name);
static void _sparc_free_io(struct resource *res);

/* This points to the next to use virtual memory for DVMA mappings */
static struct resource _sparc_dvma = {
	.name = "sparc_dvma", .start = DVMA_VADDR, .end = DVMA_END - 1
};
/* This points to the start of I/O mappings, cluable from outside. */
/*ext*/ struct resource sparc_iomap = {
	.name = "sparc_iomap", .start = IOBASE_VADDR, .end = IOBASE_END - 1
};

/*
 * 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	/* SS-10 uses 8 */

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(unsigned long offset, unsigned long size)
{
	char name[14];

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

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

	if ((res = _sparc_find_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);
	}
}

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

/*
 */
void sbus_iounmap(volatile void __iomem *addr, unsigned long size)
{
	iounmap(addr);
}

/*
 * Meat of mapping
 */
static void __iomem *_sparc_alloc_io(unsigned int busno, unsigned long phys,
    unsigned long size, char *name)
{
	static int printed_full;
	struct xresource *xres;
	struct resource *res;
	char *tack;
	int tlen;
	void __iomem *va;	/* P3 diag */

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

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

	strlcpy(tack, name, XNMLN+1);
	res->name = tack;

	va = _sparc_ioremap(res, busno, phys, size);
	/* printk("ioremap(0x%x:%08lx[0x%lx])=%p\n", busno, phys, size, va); */ /* P3 diag */
	return va;
}

/*
 */
static void __iomem *
_sparc_ioremap(struct resource *res, u32 bus, u32 pa, int sz)
{
	unsigned long offset = ((unsigned long) pa) & (~PAGE_MASK);

	if (allocate_resource(&sparc_iomap, res,
	    (offset + sz + PAGE_SIZE-1) & PAGE_MASK,
	    sparc_iomap.start, sparc_iomap.end, PAGE_SIZE, NULL, NULL) != 0) {
		/* Usually we cannot see printks in this case. */
		prom_printf("alloc_io_res(%s): cannot occupy\n",
		    (res->name != NULL)? res->name: "???");
		prom_halt();
	}

	pa &= PAGE_MASK;
	sparc_mapiorange(bus, pa, res->start, res->end - res->start + 1);

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

/*
 * Comlimentary to _sparc_ioremap().
 */
static void _sparc_free_io(struct resource *res)
{
	unsigned long plen;

	plen = res->end - res->start + 1;
	if ((plen & (PAGE_SIZE-1)) != 0) BUG();
	sparc_unmapiorange(res->start, plen);
	release_resource(res);
}

#ifdef CONFIG_SBUS

void sbus_set_sbus64(struct sbus_dev *sdev, int x) {
	printk("sbus_set_sbus64: unsupported\n");
}

/*
 * Allocate a chunk of memory suitable for DMA.
 * Typically devices use them for control blocks.
 * CPU may access them without any explicit flushing.
 *
 * XXX Some clever people know that sdev is not used and supply NULL. Watch.
 */
void *sbus_alloc_consistent(struct sbus_dev *sdev, long len, u32 *dma_addrp)
{
	unsigned long len_total = (len + PAGE_SIZE-1) & PAGE_MASK;
	unsigned long va;
	struct resource *res;
	int order;

	/* XXX why are some lenghts signed, others unsigned? */
	if (len <= 0) {
		return NULL;
	}
	/* XXX So what is maxphys for us and how do drivers know it? */
	if (len > 256*1024) {			/* __get_free_pages() limit */
		return NULL;
	}

	order = get_order(len_total);
	if ((va = __get_free_pages(GFP_KERNEL|__GFP_COMP, order)) == 0)
		goto err_nopages;

	if ((res = kmalloc(sizeof(struct resource), GFP_KERNEL)) == NULL)
		goto err_nomem;
	memset((char*)res, 0, sizeof(struct resource));

	if (allocate_resource(&_sparc_dvma, res, len_total,
	    _sparc_dvma.start, _sparc_dvma.end, PAGE_SIZE, NULL, NULL) != 0) {
		printk("sbus_alloc_consistent: cannot occupy 0x%lx", len_total);
		goto err_nova;
	}
	mmu_inval_dma_area(va, len_total);
	// XXX The mmu_map_dma_area does this for us below, see comments.
	// sparc_mapiorange(0, virt_to_phys(va), res->start, len_total);
	/*
	 * XXX That's where sdev would be used. Currently we load
	 * all iommu tables with the same translations.
	 */
	if (mmu_map_dma_area(dma_addrp, va, res->start, len_total) != 0)
		goto err_noiommu;

	return (void *)res->start;

err_noiommu:
	release_resource(res);
err_nova:
	free_pages(va, order);
err_nomem:
	kfree(res);
err_nopages:
	return NULL;
}

void sbus_free_consistent(struct sbus_dev *sdev, long n, void *p, u32 ba)
{
	struct resource *res;
	struct page *pgv;

	if ((res = _sparc_find_resource(&_sparc_dvma,
	    (unsigned long)p)) == NULL) {
		printk("sbus_free_consistent: cannot free %p\n", p);
		return;
	}

	if (((unsigned long)p & (PAGE_SIZE-1)) != 0) {
		printk("sbus_free_consistent: unaligned va %p\n", p);
		return;
	}

	n = (n + PAGE_SIZE-1) & PAGE_MASK;
	if ((res->end-res->start)+1 != n) {
		printk("sbus_free_consistent: region 0x%lx asked 0x%lx\n",
		    (long)((res->end-res->start)+1), n);
		return;
	}

	release_resource(res);
	kfree(res);

	/* mmu_inval_dma_area(va, n); */ /* it's consistent, isn't it */
	pgv = mmu_translate_dvma(ba);
	mmu_unmap_dma_area(ba, n);

	__free_pages(pgv, get_order(n));
}

/*
 * Map a chunk of memory so that devices can see it.
 * CPU view of this memory may be inconsistent with
 * a device view and explicit flushing is necessary.
 */
dma_addr_t sbus_map_single(struct sbus_dev *sdev, void *va, size_t len, int direction)
{
	/* XXX why are some lenghts signed, others unsigned? */
	if (len <= 0) {
		return 0;
	}
	/* XXX So what is maxphys for us and how do drivers know it? */
	if (len > 256*1024) {			/* __get_free_pages() limit */
		return 0;
	}
	return mmu_get_scsi_one(va, len, sdev->bus);
}

void sbus_unmap_single(struct sbus_dev *sdev, dma_addr_t ba, size_t n, int direction)
{
	mmu_release_scsi_one(ba, n, sdev->bus);
}

int sbus_map_sg(struct sbus_dev *sdev, struct scatterlist *sg, int n, int direction)
{
	mmu_get_scsi_sgl(sg, n, sdev->bus);

	/*
	 * XXX sparc64 can return a partial length here. sun4c should do this
	 * but it currently panics if it can't fulfill the request - Anton
	 */
	return n;
}

void sbus_unmap_sg(struct sbus_dev *sdev, struct scatterlist *sg, int n, int direction)
{
	mmu_release_scsi_sgl(sg, n, sdev->bus);
}

/*
 */
void sbus_dma_sync_single_for_cpu(struct sbus_dev *sdev, dma_addr_t ba, size_t size, int direction)
{
#if 0
	unsigned long va;