mm/early_ioremap.c - arm/linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Provide common bits of early_ioremap() support for architectures needing
  * temporary mappings during boot before ioremap() is available.
  *
  * This is mostly a direct copy of the x86 early_ioremap implementation.
  *
  * (C) Copyright 1995 1996, 2014 Linus Torvalds
  *
  */
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/mm.h>
 #include <linux/vmalloc.h>
 #include <asm/fixmap.h>
 #include <asm/early_ioremap.h>

 #ifdef CONFIG_MMU
 static int early_ioremap_debug __initdata;

 static int __init early_ioremap_debug_setup(char *str)
 {
 	early_ioremap_debug = 1;

 	return 0;
 }
 early_param("early_ioremap_debug", early_ioremap_debug_setup);

 static int after_paging_init __initdata;

 pgprot_t __init __weak early_memremap_pgprot_adjust(resource_size_t phys_addr,
 						    unsigned long size,
 						    pgprot_t prot)
 {
 	return prot;
 }

 void __init __weak early_ioremap_shutdown(void)
 {
 }

 void __init early_ioremap_reset(void)
 {
 	early_ioremap_shutdown();
 	after_paging_init = 1;
 }

 /*
  * Generally, ioremap() is available after paging_init() has been called.
  * Architectures wanting to allow early_ioremap after paging_init() can
  * define __late_set_fixmap and __late_clear_fixmap to do the right thing.
  */
 #ifndef __late_set_fixmap
 static inline void __init __late_set_fixmap(enum fixed_addresses idx,
 					    phys_addr_t phys, pgprot_t prot)
 {
 	BUG();
 }
 #endif

 #ifndef __late_clear_fixmap
 static inline void __init __late_clear_fixmap(enum fixed_addresses idx)
 {
 	BUG();
 }
 #endif

 static void __iomem *prev_map[FIX_BTMAPS_SLOTS] __initdata;
 static unsigned long prev_size[FIX_BTMAPS_SLOTS] __initdata;
 static unsigned long slot_virt[FIX_BTMAPS_SLOTS] __initdata;

 void __init early_ioremap_setup(void)
 {
 	int i;

 	for (i = 0; i < FIX_BTMAPS_SLOTS; i++)
 		if (WARN_ON(prev_map[i]))
 			break;

 	for (i = 0; i < FIX_BTMAPS_SLOTS; i++)
 		slot_virt[i] = __fix_to_virt(FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*i);
 }

 static int __init check_early_ioremap_leak(void)
 {
 	int count = 0;
 	int i;

 	for (i = 0; i < FIX_BTMAPS_SLOTS; i++)
 		if (prev_map[i])
 			count++;

 	if (WARN(count, KERN_WARNING
 		 "Debug warning: early ioremap leak of %d areas detected.\n"
 		 "please boot with early_ioremap_debug and report the dmesg.\n",
 		 count))
 		return 1;
 	return 0;
 }
 late_initcall(check_early_ioremap_leak);

 static void __init __iomem *
 __early_ioremap(resource_size_t phys_addr, unsigned long size, pgprot_t prot)
 {
 	unsigned long offset;
 	resource_size_t last_addr;
 	unsigned int nrpages;
 	enum fixed_addresses idx;
 	int i, slot;

 	WARN_ON(system_state != SYSTEM_BOOTING);

 	slot = -1;
 	for (i = 0; i < FIX_BTMAPS_SLOTS; i++) {
 		if (!prev_map[i]) {
 			slot = i;
 			break;
 		}
 	}

 	if (WARN(slot < 0, "%s(%08llx, %08lx) not found slot\n",
 		 __func__, (u64)phys_addr, size))
 		return NULL;

 	/* Don't allow wraparound or zero size */
 	last_addr = phys_addr + size - 1;
 	if (WARN_ON(!size || last_addr < phys_addr))
 		return NULL;

 	prev_size[slot] = size;
 	/*
 	 * Mappings have to be page-aligned
 	 */
 	offset = offset_in_page(phys_addr);
 	phys_addr &= PAGE_MASK;
 	size = PAGE_ALIGN(last_addr + 1) - phys_addr;

 	/*
 	 * Mappings have to fit in the FIX_BTMAP area.
 	 */
 	nrpages = size >> PAGE_SHIFT;
 	if (WARN_ON(nrpages > NR_FIX_BTMAPS))
 		return NULL;

 	/*
 	 * Ok, go for it..
 	 */
 	idx = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*slot;
 	while (nrpages > 0) {
 		if (after_paging_init)
 			__late_set_fixmap(idx, phys_addr, prot);
 		else
 			__early_set_fixmap(idx, phys_addr, prot);
 		phys_addr += PAGE_SIZE;
 		--idx;
 		--nrpages;
 	}
 	WARN(early_ioremap_debug, "%s(%08llx, %08lx) [%d] => %08lx + %08lx\n",
 	     __func__, (u64)phys_addr, size, slot, offset, slot_virt[slot]);

 	prev_map[slot] = (void __iomem *)(offset + slot_virt[slot]);
 	return prev_map[slot];
 }

 void __init early_iounmap(void __iomem *addr, unsigned long size)
 {
 	unsigned long virt_addr;
 	unsigned long offset;
 	unsigned int nrpages;
 	enum fixed_addresses idx;
 	int i, slot;

 	slot = -1;
 	for (i = 0; i < FIX_BTMAPS_SLOTS; i++) {
 		if (prev_map[i] == addr) {
 			slot = i;
 			break;
 		}
 	}

 	if (WARN(slot < 0, "early_iounmap(%p, %08lx) not found slot\n",
 		 addr, size))
 		return;

 	if (WARN(prev_size[slot] != size,
 		 "early_iounmap(%p, %08lx) [%d] size not consistent %08lx\n",
 		 addr, size, slot, prev_size[slot]))
 		return;

 	WARN(early_ioremap_debug, "early_iounmap(%p, %08lx) [%d]\n",
 	     addr, size, slot);

 	virt_addr = (unsigned long)addr;
 	if (WARN_ON(virt_addr < fix_to_virt(FIX_BTMAP_BEGIN)))
 		return;

 	offset = offset_in_page(virt_addr);
 	nrpages = PAGE_ALIGN(offset + size) >> PAGE_SHIFT;

 	idx = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*slot;
 	while (nrpages > 0) {
 		if (after_paging_init)
 			__late_clear_fixmap(idx);
 		else
 			__early_set_fixmap(idx, 0, FIXMAP_PAGE_CLEAR);
 		--idx;
 		--nrpages;
 	}
 	prev_map[slot] = NULL;
 }

 /* Remap an IO device */
 void __init __iomem *
 early_ioremap(resource_size_t phys_addr, unsigned long size)
 {
 	return __early_ioremap(phys_addr, size, FIXMAP_PAGE_IO);
 }

 /* Remap memory */
 void __init *
 early_memremap(resource_size_t phys_addr, unsigned long size)
 {
 	pgprot_t prot = early_memremap_pgprot_adjust(phys_addr, size,
 						     FIXMAP_PAGE_NORMAL);

 	return (__force void *)__early_ioremap(phys_addr, size, prot);
 }
 #ifdef FIXMAP_PAGE_RO
 void __init *
 early_memremap_ro(resource_size_t phys_addr, unsigned long size)
 {
 	pgprot_t prot = early_memremap_pgprot_adjust(phys_addr, size,
 						     FIXMAP_PAGE_RO);

 	return (__force void *)__early_ioremap(phys_addr, size, prot);
 }
 #endif

 #ifdef CONFIG_ARCH_USE_MEMREMAP_PROT
 void __init *
 early_memremap_prot(resource_size_t phys_addr, unsigned long size,
 		    unsigned long prot_val)
 {
 	return (__force void *)__early_ioremap(phys_addr, size,
 					       __pgprot(prot_val));
 }
 #endif

 #define MAX_MAP_CHUNK	(NR_FIX_BTMAPS << PAGE_SHIFT)

 void __init copy_from_early_mem(void *dest, phys_addr_t src, unsigned long size)
 {
 	unsigned long slop, clen;
 	char *p;

 	while (size) {
 		slop = offset_in_page(src);
 		clen = size;
 		if (clen > MAX_MAP_CHUNK - slop)
 			clen = MAX_MAP_CHUNK - slop;
 		p = early_memremap(src & PAGE_MASK, clen + slop);
 		memcpy(dest, p + slop, clen);
 		early_memunmap(p, clen + slop);
 		dest += clen;
 		src += clen;
 		size -= clen;
 	}
 }

 #else /* CONFIG_MMU */

 void __init __iomem *
 early_ioremap(resource_size_t phys_addr, unsigned long size)
 {
 	return (__force void __iomem *)phys_addr;
 }

 /* Remap memory */
 void __init *
 early_memremap(resource_size_t phys_addr, unsigned long size)
 {
 	return (void *)phys_addr;
 }
 void __init *
 early_memremap_ro(resource_size_t phys_addr, unsigned long size)
 {
 	return (void *)phys_addr;
 }

 void __init early_iounmap(void __iomem *addr, unsigned long size)
 {
 }

 #endif /* CONFIG_MMU */


 void __init early_memunmap(void *addr, unsigned long size)
 {
 	early_iounmap((__force void __iomem *)addr, size);
 }
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Provide common bits of early_ioremap() support for architectures needing
	* temporary mappings during boot before ioremap() is available.
	*
	* This is mostly a direct copy of the x86 early_ioremap implementation.
	*
	* (C) Copyright 1995 1996, 2014 Linus Torvalds
	*
	*/
	#include <linux/kernel.h>
	#include <linux/init.h>
	#include <linux/io.h>
	#include <linux/module.h>
	#include <linux/slab.h>
	#include <linux/mm.h>
	#include <linux/vmalloc.h>
	#include <asm/fixmap.h>
	#include <asm/early_ioremap.h>

	#ifdef CONFIG_MMU
	static int early_ioremap_debug __initdata;

	static int __init early_ioremap_debug_setup(char *str)
	{
	early_ioremap_debug = 1;

	return 0;
	}
	early_param("early_ioremap_debug", early_ioremap_debug_setup);

	static int after_paging_init __initdata;

	pgprot_t __init __weak early_memremap_pgprot_adjust(resource_size_t phys_addr,
	unsigned long size,
	pgprot_t prot)
	{
	return prot;
	}

	void __init __weak early_ioremap_shutdown(void)
	{
	}

	void __init early_ioremap_reset(void)
	{
	early_ioremap_shutdown();
	after_paging_init = 1;
	}

	/*
	* Generally, ioremap() is available after paging_init() has been called.
	* Architectures wanting to allow early_ioremap after paging_init() can
	* define __late_set_fixmap and __late_clear_fixmap to do the right thing.
	*/
	#ifndef __late_set_fixmap
	static inline void __init __late_set_fixmap(enum fixed_addresses idx,
	phys_addr_t phys, pgprot_t prot)
	{
	BUG();
	}
	#endif

	#ifndef __late_clear_fixmap
	static inline void __init __late_clear_fixmap(enum fixed_addresses idx)
	{
	BUG();
	}
	#endif

	static void __iomem *prev_map[FIX_BTMAPS_SLOTS] __initdata;
	static unsigned long prev_size[FIX_BTMAPS_SLOTS] __initdata;
	static unsigned long slot_virt[FIX_BTMAPS_SLOTS] __initdata;

	void __init early_ioremap_setup(void)
	{
	int i;

	for (i = 0; i < FIX_BTMAPS_SLOTS; i++)
	if (WARN_ON(prev_map[i]))
	break;

	for (i = 0; i < FIX_BTMAPS_SLOTS; i++)
	slot_virt[i] = __fix_to_virt(FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*i);
	}

	static int __init check_early_ioremap_leak(void)
	{
	int count = 0;
	int i;

	for (i = 0; i < FIX_BTMAPS_SLOTS; i++)
	if (prev_map[i])
	count++;

	if (WARN(count, KERN_WARNING
	"Debug warning: early ioremap leak of %d areas detected.\n"
	"please boot with early_ioremap_debug and report the dmesg.\n",
	count))
	return 1;
	return 0;
	}
	late_initcall(check_early_ioremap_leak);

	static void __init __iomem *
	__early_ioremap(resource_size_t phys_addr, unsigned long size, pgprot_t prot)
	{
	unsigned long offset;
	resource_size_t last_addr;
	unsigned int nrpages;
	enum fixed_addresses idx;
	int i, slot;

	WARN_ON(system_state != SYSTEM_BOOTING);

	slot = -1;
	for (i = 0; i < FIX_BTMAPS_SLOTS; i++) {
	if (!prev_map[i]) {
	slot = i;
	break;
	}
	}

	if (WARN(slot < 0, "%s(%08llx, %08lx) not found slot\n",
	__func__, (u64)phys_addr, size))
	return NULL;

	/* Don't allow wraparound or zero size */
	last_addr = phys_addr + size - 1;
	if (WARN_ON(!size \|\| last_addr < phys_addr))
	return NULL;

	prev_size[slot] = size;
	/*
	* Mappings have to be page-aligned
	*/
	offset = offset_in_page(phys_addr);
	phys_addr &= PAGE_MASK;
	size = PAGE_ALIGN(last_addr + 1) - phys_addr;

	/*
	* Mappings have to fit in the FIX_BTMAP area.
	*/
	nrpages = size >> PAGE_SHIFT;
	if (WARN_ON(nrpages > NR_FIX_BTMAPS))
	return NULL;

	/*
	* Ok, go for it..
	*/
	idx = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*slot;
	while (nrpages > 0) {
	if (after_paging_init)
	__late_set_fixmap(idx, phys_addr, prot);
	else
	__early_set_fixmap(idx, phys_addr, prot);
	phys_addr += PAGE_SIZE;
	--idx;
	--nrpages;
	}
	WARN(early_ioremap_debug, "%s(%08llx, %08lx) [%d] => %08lx + %08lx\n",
	__func__, (u64)phys_addr, size, slot, offset, slot_virt[slot]);

	prev_map[slot] = (void __iomem *)(offset + slot_virt[slot]);
	return prev_map[slot];
	}

	void __init early_iounmap(void __iomem *addr, unsigned long size)
	{
	unsigned long virt_addr;
	unsigned long offset;
	unsigned int nrpages;
	enum fixed_addresses idx;
	int i, slot;

	slot = -1;
	for (i = 0; i < FIX_BTMAPS_SLOTS; i++) {
	if (prev_map[i] == addr) {
	slot = i;
	break;
	}
	}

	if (WARN(slot < 0, "early_iounmap(%p, %08lx) not found slot\n",
	addr, size))
	return;

	if (WARN(prev_size[slot] != size,
	"early_iounmap(%p, %08lx) [%d] size not consistent %08lx\n",
	addr, size, slot, prev_size[slot]))
	return;

	WARN(early_ioremap_debug, "early_iounmap(%p, %08lx) [%d]\n",
	addr, size, slot);

	virt_addr = (unsigned long)addr;
	if (WARN_ON(virt_addr < fix_to_virt(FIX_BTMAP_BEGIN)))
	return;

	offset = offset_in_page(virt_addr);
	nrpages = PAGE_ALIGN(offset + size) >> PAGE_SHIFT;

	idx = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*slot;
	while (nrpages > 0) {
	if (after_paging_init)
	__late_clear_fixmap(idx);
	else
	__early_set_fixmap(idx, 0, FIXMAP_PAGE_CLEAR);
	--idx;
	--nrpages;
	}
	prev_map[slot] = NULL;
	}

	/* Remap an IO device */
	void __init __iomem *
	early_ioremap(resource_size_t phys_addr, unsigned long size)
	{
	return __early_ioremap(phys_addr, size, FIXMAP_PAGE_IO);
	}

	/* Remap memory */
	void __init *
	early_memremap(resource_size_t phys_addr, unsigned long size)
	{
	pgprot_t prot = early_memremap_pgprot_adjust(phys_addr, size,
	FIXMAP_PAGE_NORMAL);

	return (__force void *)__early_ioremap(phys_addr, size, prot);
	}
	#ifdef FIXMAP_PAGE_RO
	void __init *
	early_memremap_ro(resource_size_t phys_addr, unsigned long size)
	{
	pgprot_t prot = early_memremap_pgprot_adjust(phys_addr, size,
	FIXMAP_PAGE_RO);

	return (__force void *)__early_ioremap(phys_addr, size, prot);
	}
	#endif

	#ifdef CONFIG_ARCH_USE_MEMREMAP_PROT
	void __init *
	early_memremap_prot(resource_size_t phys_addr, unsigned long size,
	unsigned long prot_val)
	{
	return (__force void *)__early_ioremap(phys_addr, size,
	__pgprot(prot_val));
	}
	#endif

	#define MAX_MAP_CHUNK (NR_FIX_BTMAPS << PAGE_SHIFT)

	void __init copy_from_early_mem(void *dest, phys_addr_t src, unsigned long size)
	{
	unsigned long slop, clen;
	char *p;

	while (size) {
	slop = offset_in_page(src);
	clen = size;
	if (clen > MAX_MAP_CHUNK - slop)
	clen = MAX_MAP_CHUNK - slop;
	p = early_memremap(src & PAGE_MASK, clen + slop);
	memcpy(dest, p + slop, clen);
	early_memunmap(p, clen + slop);
	dest += clen;
	src += clen;
	size -= clen;
	}
	}

	#else /* CONFIG_MMU */

	void __init __iomem *
	early_ioremap(resource_size_t phys_addr, unsigned long size)
	{
	return (__force void __iomem *)phys_addr;
	}

	/* Remap memory */
	void __init *
	early_memremap(resource_size_t phys_addr, unsigned long size)
	{
	return (void *)phys_addr;
	}
	void __init *
	early_memremap_ro(resource_size_t phys_addr, unsigned long size)
	{
	return (void *)phys_addr;
	}

	void __init early_iounmap(void __iomem *addr, unsigned long size)
	{
	}

	#endif /* CONFIG_MMU */


	void __init early_memunmap(void *addr, unsigned long size)
	{
	early_iounmap((__force void __iomem *)addr, size);
	}