[mirror_ubuntu-bionic-kernel.git] / lib / ioremap.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Re-map IO memory to kernel address space so that we can access it.
 * This is needed for high PCI addresses that aren't mapped in the
 * 640k-1MB IO memory area on PC's
 *
 * (C) Copyright 1995 1996 Linus Torvalds
 */
#include <linux/vmalloc.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/io.h>
#include <linux/export.h>
#include <asm/cacheflush.h>
#include <asm/pgtable.h>

#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
static int __read_mostly ioremap_p4d_capable;
static int __read_mostly ioremap_pud_capable;
static int __read_mostly ioremap_pmd_capable;
static int __read_mostly ioremap_huge_disabled;

static int __init set_nohugeiomap(char *str)
{
	ioremap_huge_disabled = 1;
	return 0;
}
early_param("nohugeiomap", set_nohugeiomap);

void __init ioremap_huge_init(void)
{
	if (!ioremap_huge_disabled) {
		if (arch_ioremap_pud_supported())
			ioremap_pud_capable = 1;
		if (arch_ioremap_pmd_supported())
			ioremap_pmd_capable = 1;
	}
}

static inline int ioremap_p4d_enabled(void)
{
	return ioremap_p4d_capable;
}

static inline int ioremap_pud_enabled(void)
{
	return ioremap_pud_capable;
}

static inline int ioremap_pmd_enabled(void)
{
	return ioremap_pmd_capable;
}

#else	/* !CONFIG_HAVE_ARCH_HUGE_VMAP */
static inline int ioremap_p4d_enabled(void) { return 0; }
static inline int ioremap_pud_enabled(void) { return 0; }
static inline int ioremap_pmd_enabled(void) { return 0; }
#endif	/* CONFIG_HAVE_ARCH_HUGE_VMAP */

static int ioremap_pte_range(pmd_t *pmd, unsigned long addr,
		unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
{
	pte_t *pte;
	u64 pfn;

	pfn = phys_addr >> PAGE_SHIFT;
	pte = pte_alloc_kernel(pmd, addr);
	if (!pte)
		return -ENOMEM;
	do {
		BUG_ON(!pte_none(*pte));
		set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot));
		pfn++;
	} while (pte++, addr += PAGE_SIZE, addr != end);
	return 0;
}

static inline int ioremap_pmd_range(pud_t *pud, unsigned long addr,
		unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
{
	pmd_t *pmd;
	unsigned long next;

	phys_addr -= addr;
	pmd = pmd_alloc(&init_mm, pud, addr);
	if (!pmd)
		return -ENOMEM;
	do {
		next = pmd_addr_end(addr, end);

		if (ioremap_pmd_enabled() &&
		    ((next - addr) == PMD_SIZE) &&
		    IS_ALIGNED(phys_addr + addr, PMD_SIZE)) {
			if (pmd_set_huge(pmd, phys_addr + addr, prot))
				continue;
		}

		if (ioremap_pte_range(pmd, addr, next, phys_addr + addr, prot))
			return -ENOMEM;
	} while (pmd++, addr = next, addr != end);
	return 0;
}

static inline int ioremap_pud_range(p4d_t *p4d, unsigned long addr,
		unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
{
	pud_t *pud;
	unsigned long next;

	phys_addr -= addr;
	pud = pud_alloc(&init_mm, p4d, addr);
	if (!pud)
		return -ENOMEM;
	do {
		next = pud_addr_end(addr, end);

		if (ioremap_pud_enabled() &&
		    ((next - addr) == PUD_SIZE) &&
		    IS_ALIGNED(phys_addr + addr, PUD_SIZE)) {
			if (pud_set_huge(pud, phys_addr + addr, prot))
				continue;
		}

		if (ioremap_pmd_range(pud, addr, next, phys_addr + addr, prot))
			return -ENOMEM;
	} while (pud++, addr = next, addr != end);
	return 0;
}

static inline int ioremap_p4d_range(pgd_t *pgd, unsigned long addr,
		unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
{
	p4d_t *p4d;
	unsigned long next;

	phys_addr -= addr;
	p4d = p4d_alloc(&init_mm, pgd, addr);
	if (!p4d)
		return -ENOMEM;
	do {
		next = p4d_addr_end(addr, end);

		if (ioremap_p4d_enabled() &&
		    ((next - addr) == P4D_SIZE) &&
		    IS_ALIGNED(phys_addr + addr, P4D_SIZE)) {
			if (p4d_set_huge(p4d, phys_addr + addr, prot))
				continue;
		}

		if (ioremap_pud_range(p4d, addr, next, phys_addr + addr, prot))
			return -ENOMEM;
	} while (p4d++, addr = next, addr != end);
	return 0;
}

int ioremap_page_range(unsigned long addr,
		       unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
{
	pgd_t *pgd;
	unsigned long start;
	unsigned long next;
	int err;

	might_sleep();
	BUG_ON(addr >= end);

	start = addr;
	phys_addr -= addr;
	pgd = pgd_offset_k(addr);
	do {
		next = pgd_addr_end(addr, end);
		err = ioremap_p4d_range(pgd, addr, next, phys_addr+addr, prot);
		if (err)
			break;
	} while (pgd++, addr = next, addr != end);

	flush_cache_vmap(start, end);

	return err;
}
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
74588d8b HS	2	/*
	3	* Re-map IO memory to kernel address space so that we can access it.
	4	* This is needed for high PCI addresses that aren't mapped in the
	5	* 640k-1MB IO memory area on PC's
	6	*
	7	* (C) Copyright 1995 1996 Linus Torvalds
	8	*/
74588d8b HS	9	#include <linux/vmalloc.h>
74588d8b HS	10	#include <linux/mm.h>
e8edc6e0	11	#include <linux/sched.h>
53fa6645	12	#include <linux/io.h>
8bc3bcc9	13	#include <linux/export.h>
74588d8b HS	14	#include <asm/cacheflush.h>
	15	#include <asm/pgtable.h>
	16
0ddab1d2	17	#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
c2febafc	18	static int __read_mostly ioremap_p4d_capable;
6b637835 TK	19	static int __read_mostly ioremap_pud_capable;
	20	static int __read_mostly ioremap_pmd_capable;
	21	static int __read_mostly ioremap_huge_disabled;
0ddab1d2 TK	22
	23	static int __init set_nohugeiomap(char *str)
	24	{
	25	ioremap_huge_disabled = 1;
	26	return 0;
	27	}
	28	early_param("nohugeiomap", set_nohugeiomap);
	29
	30	void __init ioremap_huge_init(void)
	31	{
	32	if (!ioremap_huge_disabled) {
	33	if (arch_ioremap_pud_supported())
	34	ioremap_pud_capable = 1;
	35	if (arch_ioremap_pmd_supported())
	36	ioremap_pmd_capable = 1;
	37	}
	38	}
	39
c2febafc KS	40	static inline int ioremap_p4d_enabled(void)
	41	{
	42	return ioremap_p4d_capable;
	43	}
	44
0ddab1d2 TK	45	static inline int ioremap_pud_enabled(void)
	46	{
	47	return ioremap_pud_capable;
	48	}
	49
	50	static inline int ioremap_pmd_enabled(void)
	51	{
	52	return ioremap_pmd_capable;
	53	}
	54
	55	#else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
c2febafc	56	static inline int ioremap_p4d_enabled(void) { return 0; }
0ddab1d2 TK	57	static inline int ioremap_pud_enabled(void) { return 0; }
	58	static inline int ioremap_pmd_enabled(void) { return 0; }
	59	#endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
	60
74588d8b	61	static int ioremap_pte_range(pmd_t *pmd, unsigned long addr,
ffa71f33	62	unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
74588d8b HS	63	{
74588d8b HS	64	pte_t *pte;
ffa71f33	65	u64 pfn;
74588d8b HS	66
	67	pfn = phys_addr >> PAGE_SHIFT;
	68	pte = pte_alloc_kernel(pmd, addr);
	69	if (!pte)
	70	return -ENOMEM;
	71	do {
	72	BUG_ON(!pte_none(*pte));
	73	set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot));
	74	pfn++;
	75	} while (pte++, addr += PAGE_SIZE, addr != end);
	76	return 0;
	77	}
	78
	79	static inline int ioremap_pmd_range(pud_t *pud, unsigned long addr,
ffa71f33	80	unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
74588d8b HS	81	{
	82	pmd_t *pmd;
	83	unsigned long next;
	84
	85	phys_addr -= addr;
	86	pmd = pmd_alloc(&init_mm, pud, addr);
	87	if (!pmd)
	88	return -ENOMEM;
	89	do {
	90	next = pmd_addr_end(addr, end);
e61ce6ad TK	91
	92	if (ioremap_pmd_enabled() &&
	93	((next - addr) == PMD_SIZE) &&
	94	IS_ALIGNED(phys_addr + addr, PMD_SIZE)) {
	95	if (pmd_set_huge(pmd, phys_addr + addr, prot))
	96	continue;
	97	}
	98
74588d8b HS	99	if (ioremap_pte_range(pmd, addr, next, phys_addr + addr, prot))
	100	return -ENOMEM;
	101	} while (pmd++, addr = next, addr != end);
	102	return 0;
	103	}
	104
c2febafc	105	static inline int ioremap_pud_range(p4d_t *p4d, unsigned long addr,
ffa71f33	106	unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
74588d8b HS	107	{
	108	pud_t *pud;
	109	unsigned long next;
	110
	111	phys_addr -= addr;
c2febafc	112	pud = pud_alloc(&init_mm, p4d, addr);
74588d8b HS	113	if (!pud)
	114	return -ENOMEM;
	115	do {
	116	next = pud_addr_end(addr, end);
e61ce6ad TK	117
	118	if (ioremap_pud_enabled() &&
	119	((next - addr) == PUD_SIZE) &&
	120	IS_ALIGNED(phys_addr + addr, PUD_SIZE)) {
	121	if (pud_set_huge(pud, phys_addr + addr, prot))
	122	continue;
	123	}
	124
74588d8b HS	125	if (ioremap_pmd_range(pud, addr, next, phys_addr + addr, prot))
	126	return -ENOMEM;
	127	} while (pud++, addr = next, addr != end);
	128	return 0;
	129	}
	130
c2febafc KS	131	static inline int ioremap_p4d_range(pgd_t *pgd, unsigned long addr,
	132	unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
	133	{
	134	p4d_t *p4d;
	135	unsigned long next;
	136
	137	phys_addr -= addr;
	138	p4d = p4d_alloc(&init_mm, pgd, addr);
	139	if (!p4d)
	140	return -ENOMEM;
	141	do {
	142	next = p4d_addr_end(addr, end);
	143
	144	if (ioremap_p4d_enabled() &&
	145	((next - addr) == P4D_SIZE) &&
	146	IS_ALIGNED(phys_addr + addr, P4D_SIZE)) {
	147	if (p4d_set_huge(p4d, phys_addr + addr, prot))
	148	continue;
	149	}
	150
	151	if (ioremap_pud_range(p4d, addr, next, phys_addr + addr, prot))
	152	return -ENOMEM;
	153	} while (p4d++, addr = next, addr != end);
	154	return 0;
	155	}
	156
74588d8b	157	int ioremap_page_range(unsigned long addr,
ffa71f33	158	unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
74588d8b HS	159	{
	160	pgd_t *pgd;
	161	unsigned long start;
	162	unsigned long next;
	163	int err;
	164
b39ab98e	165	might_sleep();
74588d8b HS	166	BUG_ON(addr >= end);
74588d8b HS	167
74588d8b HS	168	start = addr;
	169	phys_addr -= addr;
	170	pgd = pgd_offset_k(addr);
	171	do {
	172	next = pgd_addr_end(addr, end);
c2febafc	173	err = ioremap_p4d_range(pgd, addr, next, phys_addr+addr, prot);
74588d8b HS	174	if (err)
	175	break;
	176	} while (pgd++, addr = next, addr != end);
	177
db71daab	178	flush_cache_vmap(start, end);
74588d8b HS	179
	180	return err;
	181	}