[deliverable/linux.git] / arch / ia64 / mm / ioremap.c

/*
 * (c) Copyright 2006, 2007 Hewlett-Packard Development Company, L.P.
 *	Bjorn Helgaas <bjorn.helgaas@hp.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/compiler.h>
#include <linux/module.h>
#include <linux/efi.h>
#include <linux/io.h>
#include <linux/vmalloc.h>
#include <asm/io.h>
#include <asm/meminit.h>

static inline void __iomem *
__ioremap (unsigned long phys_addr)
{
	return (void __iomem *) (__IA64_UNCACHED_OFFSET | phys_addr);
}

void __iomem *
ioremap (unsigned long phys_addr, unsigned long size)
{
	void __iomem *addr;
	struct vm_struct *area;
	unsigned long offset;
	pgprot_t prot;
	u64 attr;
	unsigned long gran_base, gran_size;
	unsigned long page_base;

	/*
	 * For things in kern_memmap, we must use the same attribute
	 * as the rest of the kernel.  For more details, see
	 * Documentation/ia64/aliasing.txt.
	 */
	attr = kern_mem_attribute(phys_addr, size);
	if (attr & EFI_MEMORY_WB)
		return (void __iomem *) phys_to_virt(phys_addr);
	else if (attr & EFI_MEMORY_UC)
		return __ioremap(phys_addr);

	/*
	 * Some chipsets don't support UC access to memory.  If
	 * WB is supported for the whole granule, we prefer that.
	 */
	gran_base = GRANULEROUNDDOWN(phys_addr);
	gran_size = GRANULEROUNDUP(phys_addr + size) - gran_base;
	if (efi_mem_attribute(gran_base, gran_size) & EFI_MEMORY_WB)
		return (void __iomem *) phys_to_virt(phys_addr);

	/*
	 * WB is not supported for the whole granule, so we can't use
	 * the region 7 identity mapping.  If we can safely cover the
	 * area with kernel page table mappings, we can use those
	 * instead.
	 */
	page_base = phys_addr & PAGE_MASK;
	size = PAGE_ALIGN(phys_addr + size) - page_base;
	if (efi_mem_attribute(page_base, size) & EFI_MEMORY_WB) {
		prot = PAGE_KERNEL;

		/*
		 * Mappings have to be page-aligned
		 */
		offset = phys_addr & ~PAGE_MASK;
		phys_addr &= PAGE_MASK;

		/*
		 * Ok, go for it..
		 */
		area = get_vm_area(size, VM_IOREMAP);
		if (!area)
			return NULL;

		area->phys_addr = phys_addr;
		addr = (void __iomem *) area->addr;
		if (ioremap_page_range((unsigned long) addr,
				(unsigned long) addr + size, phys_addr, prot)) {
			vunmap((void __force *) addr);
			return NULL;
		}

		return (void __iomem *) (offset + (char __iomem *)addr);
	}

	return __ioremap(phys_addr);
}
EXPORT_SYMBOL(ioremap);

void __iomem *
ioremap_nocache (unsigned long phys_addr, unsigned long size)
{
	if (kern_mem_attribute(phys_addr, size) & EFI_MEMORY_WB)
		return NULL;

	return __ioremap(phys_addr);
}
EXPORT_SYMBOL(ioremap_nocache);

void
iounmap (volatile void __iomem *addr)
{
	if (REGION_NUMBER(addr) == RGN_GATE)
		vunmap((void *) ((unsigned long) addr & PAGE_MASK));
}
EXPORT_SYMBOL(iounmap);
Commit	Line	Data
e9b0a071	1	/*
9b50ffb0	2	* (c) Copyright 2006, 2007 Hewlett-Packard Development Company, L.P.
e9b0a071 BH	3	* Bjorn Helgaas <bjorn.helgaas@hp.com>
	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License version 2 as
	7	* published by the Free Software Foundation.
	8	*/
	9
	10	#include <linux/compiler.h>
	11	#include <linux/module.h>
	12	#include <linux/efi.h>
9b50ffb0 BH	13	#include <linux/io.h>
9b50ffb0 BH	14	#include <linux/vmalloc.h>
e9b0a071	15	#include <asm/io.h>
32e62c63	16	#include <asm/meminit.h>
e9b0a071 BH	17
e9b0a071 BH	18	static inline void __iomem *
9b50ffb0	19	__ioremap (unsigned long phys_addr)
e9b0a071	20	{
c4add2e5	21	return (void __iomem *) (__IA64_UNCACHED_OFFSET \| phys_addr);
e9b0a071 BH	22	}
	23
	24	void __iomem *
c4add2e5	25	ioremap (unsigned long phys_addr, unsigned long size)
e9b0a071	26	{
9b50ffb0 BH	27	void __iomem *addr;
	28	struct vm_struct *area;
	29	unsigned long offset;
	30	pgprot_t prot;
32e62c63 BH	31	u64 attr;
32e62c63 BH	32	unsigned long gran_base, gran_size;
9b50ffb0	33	unsigned long page_base;
e9b0a071	34
32e62c63 BH	35	/*
	36	* For things in kern_memmap, we must use the same attribute
	37	* as the rest of the kernel. For more details, see
	38	* Documentation/ia64/aliasing.txt.
	39	*/
c4add2e5	40	attr = kern_mem_attribute(phys_addr, size);
32e62c63	41	if (attr & EFI_MEMORY_WB)
c4add2e5	42	return (void __iomem *) phys_to_virt(phys_addr);
32e62c63	43	else if (attr & EFI_MEMORY_UC)
9b50ffb0	44	return __ioremap(phys_addr);
c1c57d76	45
e9b0a071	46	/*
32e62c63 BH	47	* Some chipsets don't support UC access to memory. If
32e62c63 BH	48	* WB is supported for the whole granule, we prefer that.
e9b0a071	49	*/
c4add2e5 BH	50	gran_base = GRANULEROUNDDOWN(phys_addr);
c4add2e5 BH	51	gran_size = GRANULEROUNDUP(phys_addr + size) - gran_base;
32e62c63	52	if (efi_mem_attribute(gran_base, gran_size) & EFI_MEMORY_WB)
c4add2e5	53	return (void __iomem *) phys_to_virt(phys_addr);
32e62c63	54
9b50ffb0 BH	55	/*
	56	* WB is not supported for the whole granule, so we can't use
	57	* the region 7 identity mapping. If we can safely cover the
	58	* area with kernel page table mappings, we can use those
	59	* instead.
	60	*/
	61	page_base = phys_addr & PAGE_MASK;
	62	size = PAGE_ALIGN(phys_addr + size) - page_base;
	63	if (efi_mem_attribute(page_base, size) & EFI_MEMORY_WB) {
	64	prot = PAGE_KERNEL;
	65
	66	/*
	67	* Mappings have to be page-aligned
	68	*/
	69	offset = phys_addr & ~PAGE_MASK;
	70	phys_addr &= PAGE_MASK;
	71
	72	/*
	73	* Ok, go for it..
	74	*/
	75	area = get_vm_area(size, VM_IOREMAP);
	76	if (!area)
	77	return NULL;
	78
	79	area->phys_addr = phys_addr;
	80	addr = (void __iomem *) area->addr;
	81	if (ioremap_page_range((unsigned long) addr,
	82	(unsigned long) addr + size, phys_addr, prot)) {
	83	vunmap((void __force *) addr);
	84	return NULL;
	85	}
	86
	87	return (void __iomem ) (offset + (char __iomem )addr);
	88	}
	89
	90	return __ioremap(phys_addr);
e9b0a071 BH	91	}
	92	EXPORT_SYMBOL(ioremap);
	93
	94	void __iomem *
c4add2e5	95	ioremap_nocache (unsigned long phys_addr, unsigned long size)
e9b0a071	96	{
c4add2e5	97	if (kern_mem_attribute(phys_addr, size) & EFI_MEMORY_WB)
e037cda5	98	return NULL;
32e62c63	99
9b50ffb0	100	return __ioremap(phys_addr);
e9b0a071 BH	101	}
e9b0a071 BH	102	EXPORT_SYMBOL(ioremap_nocache);
9b50ffb0 BH	103
	104	void
	105	iounmap (volatile void __iomem *addr)
	106	{
	107	if (REGION_NUMBER(addr) == RGN_GATE)
	108	vunmap((void *) ((unsigned long) addr & PAGE_MASK));
	109	}
	110	EXPORT_SYMBOL(iounmap);