[linux.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 int ioremap_try_huge_pmd(pmd_t *pmd, unsigned long addr,
				unsigned long end, phys_addr_t phys_addr,
				pgprot_t prot)
{
	if (!ioremap_pmd_enabled())
		return 0;

	if ((end - addr) != PMD_SIZE)
		return 0;

	if (!IS_ALIGNED(phys_addr, PMD_SIZE))
		return 0;

	if (pmd_present(*pmd) && !pmd_free_pte_page(pmd, addr))
		return 0;

	return pmd_set_huge(pmd, phys_addr, prot);
}

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;

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

		if (ioremap_try_huge_pmd(pmd, addr, next, phys_addr, prot))
			continue;

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

static int ioremap_try_huge_pud(pud_t *pud, unsigned long addr,
				unsigned long end, phys_addr_t phys_addr,
				pgprot_t prot)
{
	if (!ioremap_pud_enabled())
		return 0;

	if ((end - addr) != PUD_SIZE)
		return 0;

	if (!IS_ALIGNED(phys_addr, PUD_SIZE))
		return 0;

	if (pud_present(*pud) && !pud_free_pmd_page(pud, addr))
		return 0;

	return pud_set_huge(pud, phys_addr, prot);
}

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;

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

		if (ioremap_try_huge_pud(pud, addr, next, phys_addr, prot))
			continue;

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

static int ioremap_try_huge_p4d(p4d_t *p4d, unsigned long addr,
				unsigned long end, phys_addr_t phys_addr,
				pgprot_t prot)
{
	if (!ioremap_p4d_enabled())
		return 0;

	if ((end - addr) != P4D_SIZE)
		return 0;

	if (!IS_ALIGNED(phys_addr, P4D_SIZE))
		return 0;

	if (p4d_present(*p4d) && !p4d_free_pud_page(p4d, addr))
		return 0;

	return p4d_set_huge(p4d, phys_addr, prot);
}

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;

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

		if (ioremap_try_huge_p4d(p4d, addr, next, phys_addr, prot))
			continue;

		if (ioremap_pud_range(p4d, addr, next, phys_addr, prot))
			return -ENOMEM;
	} while (p4d++, phys_addr += (next - addr), 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;
	pgd = pgd_offset_k(addr);
	do {
		next = pgd_addr_end(addr, end);
		err = ioremap_p4d_range(pgd, addr, next, phys_addr, prot);
		if (err)
			break;
	} while (pgd++, phys_addr += (next - addr), 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
d239865a WD	79	static int ioremap_try_huge_pmd(pmd_t *pmd, unsigned long addr,
	80	unsigned long end, phys_addr_t phys_addr,
	81	pgprot_t prot)
	82	{
	83	if (!ioremap_pmd_enabled())
	84	return 0;
	85
	86	if ((end - addr) != PMD_SIZE)
	87	return 0;
	88
	89	if (!IS_ALIGNED(phys_addr, PMD_SIZE))
	90	return 0;
	91
	92	if (pmd_present(*pmd) && !pmd_free_pte_page(pmd, addr))
	93	return 0;
	94
	95	return pmd_set_huge(pmd, phys_addr, prot);
	96	}
	97
74588d8b	98	static inline int ioremap_pmd_range(pud_t *pud, unsigned long addr,
ffa71f33	99	unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
74588d8b HS	100	{
	101	pmd_t *pmd;
	102	unsigned long next;
	103
74588d8b HS	104	pmd = pmd_alloc(&init_mm, pud, addr);
	105	if (!pmd)
	106	return -ENOMEM;
	107	do {
	108	next = pmd_addr_end(addr, end);
e61ce6ad	109
36ddc5a7	110	if (ioremap_try_huge_pmd(pmd, addr, next, phys_addr, prot))
d239865a	111	continue;
e61ce6ad	112
36ddc5a7	113	if (ioremap_pte_range(pmd, addr, next, phys_addr, prot))
74588d8b	114	return -ENOMEM;
36ddc5a7	115	} while (pmd++, phys_addr += (next - addr), addr = next, addr != end);
74588d8b HS	116	return 0;
	117	}
	118
d239865a WD	119	static int ioremap_try_huge_pud(pud_t *pud, unsigned long addr,
	120	unsigned long end, phys_addr_t phys_addr,
	121	pgprot_t prot)
	122	{
	123	if (!ioremap_pud_enabled())
	124	return 0;
	125
	126	if ((end - addr) != PUD_SIZE)
	127	return 0;
	128
	129	if (!IS_ALIGNED(phys_addr, PUD_SIZE))
	130	return 0;
	131
	132	if (pud_present(*pud) && !pud_free_pmd_page(pud, addr))
	133	return 0;
	134
	135	return pud_set_huge(pud, phys_addr, prot);
	136	}
	137
c2febafc	138	static inline int ioremap_pud_range(p4d_t *p4d, unsigned long addr,
ffa71f33	139	unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
74588d8b HS	140	{
	141	pud_t *pud;
	142	unsigned long next;
	143
c2febafc	144	pud = pud_alloc(&init_mm, p4d, addr);
74588d8b HS	145	if (!pud)
	146	return -ENOMEM;
	147	do {
	148	next = pud_addr_end(addr, end);
e61ce6ad	149
36ddc5a7	150	if (ioremap_try_huge_pud(pud, addr, next, phys_addr, prot))
d239865a	151	continue;
e61ce6ad	152
36ddc5a7	153	if (ioremap_pmd_range(pud, addr, next, phys_addr, prot))
74588d8b	154	return -ENOMEM;
36ddc5a7	155	} while (pud++, phys_addr += (next - addr), addr = next, addr != end);
74588d8b HS	156	return 0;
	157	}
	158
8e2d4340 WD	159	static int ioremap_try_huge_p4d(p4d_t *p4d, unsigned long addr,
	160	unsigned long end, phys_addr_t phys_addr,
	161	pgprot_t prot)
	162	{
	163	if (!ioremap_p4d_enabled())
	164	return 0;
	165
	166	if ((end - addr) != P4D_SIZE)
	167	return 0;
	168
	169	if (!IS_ALIGNED(phys_addr, P4D_SIZE))
	170	return 0;
	171
	172	if (p4d_present(*p4d) && !p4d_free_pud_page(p4d, addr))
	173	return 0;
	174
	175	return p4d_set_huge(p4d, phys_addr, prot);
	176	}
	177
c2febafc KS	178	static inline int ioremap_p4d_range(pgd_t *pgd, unsigned long addr,
	179	unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
	180	{
	181	p4d_t *p4d;
	182	unsigned long next;
	183
c2febafc KS	184	p4d = p4d_alloc(&init_mm, pgd, addr);
	185	if (!p4d)
	186	return -ENOMEM;
	187	do {
	188	next = p4d_addr_end(addr, end);
	189
8e2d4340 WD	190	if (ioremap_try_huge_p4d(p4d, addr, next, phys_addr, prot))
8e2d4340 WD	191	continue;
c2febafc	192
36ddc5a7	193	if (ioremap_pud_range(p4d, addr, next, phys_addr, prot))
c2febafc	194	return -ENOMEM;
36ddc5a7	195	} while (p4d++, phys_addr += (next - addr), addr = next, addr != end);
c2febafc KS	196	return 0;
	197	}
	198
74588d8b	199	int ioremap_page_range(unsigned long addr,
ffa71f33	200	unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
74588d8b HS	201	{
	202	pgd_t *pgd;
	203	unsigned long start;
	204	unsigned long next;
	205	int err;
	206
b39ab98e	207	might_sleep();
74588d8b HS	208	BUG_ON(addr >= end);
74588d8b HS	209
74588d8b	210	start = addr;
74588d8b HS	211	pgd = pgd_offset_k(addr);
	212	do {
	213	next = pgd_addr_end(addr, end);
36ddc5a7	214	err = ioremap_p4d_range(pgd, addr, next, phys_addr, prot);
74588d8b HS	215	if (err)
74588d8b HS	216	break;
36ddc5a7	217	} while (pgd++, phys_addr += (next - addr), addr = next, addr != end);
74588d8b	218
db71daab	219	flush_cache_vmap(start, end);
74588d8b HS	220
	221	return err;
	222	}