// 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_VMAPstatic 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_p4d_supported())			ioremap_p4d_capable = 1;		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(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(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(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;} #ifdef CONFIG_GENERIC_IOREMAPvoid __iomem *ioremap_prot(phys_addr_t addr, size_t size, unsigned long prot){	unsigned long offset, vaddr;	phys_addr_t last_addr;	struct vm_struct *area; 	/* Disallow wrap-around or zero size */	last_addr = addr + size - 1;	if (!size || last_addr < addr)		return NULL; 	/* Page-align mappings */	offset = addr & (~PAGE_MASK);	addr -= offset;	size = PAGE_ALIGN(size + offset); 	area = get_vm_area_caller(size, VM_IOREMAP,			__builtin_return_address(0));	if (!area)		return NULL;	vaddr = (unsigned long)area->addr; 	if (ioremap_page_range(vaddr, vaddr + size, addr, __pgprot(prot))) {		free_vm_area(area);		return NULL;	} 	return (void __iomem *)(vaddr + offset);}EXPORT_SYMBOL(ioremap_prot); void iounmap(volatile void __iomem *addr){	vunmap((void *)((unsigned long)addr & PAGE_MASK));}EXPORT_SYMBOL(iounmap);#endif /* CONFIG_GENERIC_IOREMAP */