mm: create generic early_ioremap() support (9e5c33d7) · Commits · e / devices / android_kernel_oneplus_sm7250

include/asm-generic/early_ioremap.h

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		#ifndef _ASM_EARLY_IOREMAP_H_
		#define _ASM_EARLY_IOREMAP_H_

		#include <linux/types.h>

		/*
		* early_ioremap() and early_iounmap() are for temporary early boot-time
		* mappings, before the real ioremap() is functional.
		*/
		extern void __iomem *early_ioremap(resource_size_t phys_addr,
		unsigned long size);
		extern void *early_memremap(resource_size_t phys_addr,
		unsigned long size);
		extern void early_iounmap(void __iomem *addr, unsigned long size);
		extern void early_memunmap(void *addr, unsigned long size);

		/*
		* Weak function called by early_ioremap_reset(). It does nothing, but
		* architectures may provide their own version to do any needed cleanups.
		*/
		extern void early_ioremap_shutdown(void);

		#if defined(CONFIG_GENERIC_EARLY_IOREMAP) && defined(CONFIG_MMU)
		/* Arch-specific initialization */
		extern void early_ioremap_init(void);

		/* Generic initialization called by architecture code */
		extern void early_ioremap_setup(void);

		/*
		* Called as last step in paging_init() so library can act
		* accordingly for subsequent map/unmap requests.
		*/
		extern void early_ioremap_reset(void);

		#else
		static inline void early_ioremap_init(void) { }
		static inline void early_ioremap_setup(void) { }
		static inline void early_ioremap_reset(void) { }
		#endif

		#endif /* _ASM_EARLY_IOREMAP_H_ */

mm/Kconfig

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		@@ -578,3 +578,6 @@ config PGTABLE_MAPPING

		You can check speed with zsmalloc benchmark:
		https://github.com/spartacus06/zsmapbench

		config GENERIC_EARLY_IOREMAP
		bool

mm/Makefile

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		@@ -61,3 +61,4 @@ obj-$(CONFIG_CLEANCACHE) += cleancache.o
		obj-$(CONFIG_MEMORY_ISOLATION) += page_isolation.o
		obj-$(CONFIG_ZBUD) += zbud.o
		obj-$(CONFIG_ZSMALLOC) += zsmalloc.o
		obj-$(CONFIG_GENERIC_EARLY_IOREMAP) += early_ioremap.o

mm/early_ioremap.c

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		/*
		* 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>

		#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;

		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 = phys_addr & ~PAGE_MASK;
		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 = virt_addr & ~PAGE_MASK;
		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)
		{
		return (__force void *)__early_ioremap(phys_addr, size,
		FIXMAP_PAGE_NORMAL);
		}
		#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_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);
		}