mm/ioremap.c - virt/kvm/kvm - Git at Google

 // 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 "pgalloc-track.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_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,
 		pgtbl_mod_mask *mask)
 {
 	pte_t *pte;
 	u64 pfn;

 	pfn = phys_addr >> PAGE_SHIFT;
 	pte = pte_alloc_kernel_track(pmd, addr, mask);
 	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);
 	*mask |= PGTBL_PTE_MODIFIED;
 	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,
 		pgtbl_mod_mask *mask)
 {
 	pmd_t *pmd;
 	unsigned long next;

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

 		if (ioremap_try_huge_pmd(pmd, addr, next, phys_addr, prot)) {
 			*mask |= PGTBL_PMD_MODIFIED;
 			continue;
 		}

 		if (ioremap_pte_range(pmd, addr, next, phys_addr, prot, mask))
 			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,
 		pgtbl_mod_mask *mask)
 {
 	pud_t *pud;
 	unsigned long next;

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

 		if (ioremap_try_huge_pud(pud, addr, next, phys_addr, prot)) {
 			*mask |= PGTBL_PUD_MODIFIED;
 			continue;
 		}

 		if (ioremap_pmd_range(pud, addr, next, phys_addr, prot, mask))
 			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,
 		pgtbl_mod_mask *mask)
 {
 	p4d_t *p4d;
 	unsigned long next;

 	p4d = p4d_alloc_track(&init_mm, pgd, addr, mask);
 	if (!p4d)
 		return -ENOMEM;
 	do {
 		next = p4d_addr_end(addr, end);

 		if (ioremap_try_huge_p4d(p4d, addr, next, phys_addr, prot)) {
 			*mask |= PGTBL_P4D_MODIFIED;
 			continue;
 		}

 		if (ioremap_pud_range(p4d, addr, next, phys_addr, prot, mask))
 			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;
 	pgtbl_mod_mask mask = 0;

 	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,
 					&mask);
 		if (err)
 			break;
 	} while (pgd++, phys_addr += (next - addr), addr = next, addr != end);

 	flush_cache_vmap(start, end);

 	if (mask & ARCH_PAGE_TABLE_SYNC_MASK)
 		arch_sync_kernel_mappings(start, end);

 	return err;
 }

 #ifdef CONFIG_GENERIC_IOREMAP
 void __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 */
	// 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 "pgalloc-track.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_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,
	pgtbl_mod_mask *mask)
	{
	pte_t *pte;
	u64 pfn;

	pfn = phys_addr >> PAGE_SHIFT;
	pte = pte_alloc_kernel_track(pmd, addr, mask);
	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);
	*mask \|= PGTBL_PTE_MODIFIED;
	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,
	pgtbl_mod_mask *mask)
	{
	pmd_t *pmd;
	unsigned long next;

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

	if (ioremap_try_huge_pmd(pmd, addr, next, phys_addr, prot)) {
	*mask \|= PGTBL_PMD_MODIFIED;
	continue;
	}

	if (ioremap_pte_range(pmd, addr, next, phys_addr, prot, mask))
	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,
	pgtbl_mod_mask *mask)
	{
	pud_t *pud;
	unsigned long next;

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

	if (ioremap_try_huge_pud(pud, addr, next, phys_addr, prot)) {
	*mask \|= PGTBL_PUD_MODIFIED;
	continue;
	}

	if (ioremap_pmd_range(pud, addr, next, phys_addr, prot, mask))
	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,
	pgtbl_mod_mask *mask)
	{
	p4d_t *p4d;
	unsigned long next;

	p4d = p4d_alloc_track(&init_mm, pgd, addr, mask);
	if (!p4d)
	return -ENOMEM;
	do {
	next = p4d_addr_end(addr, end);

	if (ioremap_try_huge_p4d(p4d, addr, next, phys_addr, prot)) {
	*mask \|= PGTBL_P4D_MODIFIED;
	continue;
	}

	if (ioremap_pud_range(p4d, addr, next, phys_addr, prot, mask))
	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;
	pgtbl_mod_mask mask = 0;

	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,
	&mask);
	if (err)
	break;
	} while (pgd++, phys_addr += (next - addr), addr = next, addr != end);

	flush_cache_vmap(start, end);

	if (mask & ARCH_PAGE_TABLE_SYNC_MASK)
	arch_sync_kernel_mappings(start, end);

	return err;
	}

	#ifdef CONFIG_GENERIC_IOREMAP
	void __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 */