x86: unify ioremap

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 295 insertions, 22 deletions

diff --git a/arch/x86/mm/ioremap_64.c b/arch/x86/mm/ioremap_64.c
index e79d2b353de..f4a2082568c 100644
--- a/arch/x86/mm/ioremap_64.c
+++ b/arch/x86/mm/ioremap_64.c
@@ -6,6 +6,7 @@
  * (C) Copyright 1995 1996 Linus Torvalds
  */
 
+#include <linux/bootmem.h>
 #include <linux/init.h>
 #include <linux/io.h>
 #include <linux/module.h>
@@ -18,6 +19,8 @@
 #include <asm/pgtable.h>
 #include <asm/tlbflush.h>
 
+#ifdef CONFIG_X86_64
+
 unsigned long __phys_addr(unsigned long x)
 {
 	if (x >= __START_KERNEL_map)
@@ -26,6 +29,8 @@ unsigned long __phys_addr(unsigned long x)
 }
 EXPORT_SYMBOL(__phys_addr);
 
+#endif
+
 /*
  * Fix up the linear direct mapping of the kernel to avoid cache attribute
  * conflicts.
@@ -33,28 +38,33 @@ EXPORT_SYMBOL(__phys_addr);
 static int ioremap_change_attr(unsigned long phys_addr, unsigned long size,
 			       pgprot_t prot)
 {
-	int err = 0;
-	if (phys_addr + size - 1 < (end_pfn_map << PAGE_SHIFT)) {
-		unsigned long npages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
-		unsigned long vaddr = (unsigned long) __va(phys_addr);
-		int level;
-
-		/*
-		 * If there is no identity map for this address,
-		 * change_page_attr_addr is unnecessary
-		 */
-		if (!lookup_address(vaddr, &level))
-			return err;
-		/*
-		 * Must use a address here and not struct page because
-		 * the phys addr can be a in hole between nodes and
-		 * not have an memmap entry.
-		 */
-		err = change_page_attr_addr(vaddr, npages, prot);
-
-		if (!err)
-			global_flush_tlb();
-	}
+	unsigned long npages, vaddr, last_addr = phys_addr + size - 1;
+	int err, level;
+
+	/* No change for pages after the last mapping */
+	if (last_addr >= (max_pfn_mapped << PAGE_SHIFT))
+		return 0;
+
+	npages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
+	vaddr = (unsigned long) __va(phys_addr);
+
+	/*
+	 * If there is no identity map for this address,
+	 * change_page_attr_addr is unnecessary
+	 */
+	if (!lookup_address(vaddr, &level))
+		return 0;
+
+	/*
+	 * Must use an address here and not struct page because the
+	 * phys addr can be a in hole between nodes and not have a
+	 * memmap entry.
+	 */
+	err = change_page_attr_addr(vaddr, npages, prot);
+
+	if (!err)
+		global_flush_tlb();
+
 	return err;
 }
 
@@ -86,7 +96,26 @@ void __iomem *__ioremap(unsigned long phys_addr, unsigned long size,
 	if (phys_addr >= ISA_START_ADDRESS && last_addr < ISA_END_ADDRESS)
 		return (__force void __iomem *)phys_to_virt(phys_addr);
 
+#ifdef CONFIG_X86_32
+	/*
+	 * Don't allow anybody to remap normal RAM that we're using..
+	 */
+	if (phys_addr <= virt_to_phys(high_memory - 1)) {
+		char *t_addr, *t_end;
+		struct page *page;
+
+		t_addr = __va(phys_addr);
+		t_end = t_addr + (size - 1);
+
+		for (page = virt_to_page(t_addr);
+		     page <= virt_to_page(t_end); page++)
+			if (!PageReserved(page))
+				return NULL;
+	}
+#endif
+
 	pgprot = MAKE_GLOBAL(__PAGE_KERNEL | flags);
+
 	/*
 	 * Mappings have to be page-aligned
 	 */
@@ -107,10 +136,12 @@ void __iomem *__ioremap(unsigned long phys_addr, unsigned long size,
 		remove_vm_area((void *)(PAGE_MASK & (unsigned long) addr));
 		return NULL;
 	}
+
 	if (ioremap_change_attr(phys_addr, size, pgprot) < 0) {
 		vunmap(addr);
 		return NULL;
 	}
+
 	return (void __iomem *) (offset + (char __iomem *)addr);
 }
 EXPORT_SYMBOL(__ioremap);
@@ -154,12 +185,19 @@ void iounmap(volatile void __iomem *addr)
 
 	if ((void __force *)addr <= high_memory)
 		return;
+
+	/*
+	 * __ioremap special-cases the PCI/ISA range by not instantiating a
+	 * vm_area and by simply returning an address into the kernel mapping
+	 * of ISA space.   So handle that here.
+	 */
 	if (addr >= phys_to_virt(ISA_START_ADDRESS) &&
 	    addr < phys_to_virt(ISA_END_ADDRESS))
 		return;
 
 	addr = (volatile void __iomem *)
 		(PAGE_MASK & (unsigned long __force)addr);
+
 	/* Use the vm area unlocked, assuming the caller
 	   ensures there isn't another iounmap for the same address
 	   in parallel. Reuse of the virtual address is prevented by
@@ -188,3 +226,238 @@ void iounmap(volatile void __iomem *addr)
 }
 EXPORT_SYMBOL(iounmap);
 
+#ifdef CONFIG_X86_32
+
+int __initdata early_ioremap_debug;
+
+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 __initdata int after_paging_init;
+static __initdata unsigned long bm_pte[1024]
+				__attribute__((aligned(PAGE_SIZE)));
+
+static inline unsigned long * __init early_ioremap_pgd(unsigned long addr)
+{
+	return (unsigned long *)swapper_pg_dir + ((addr >> 22) & 1023);
+}
+
+static inline unsigned long * __init early_ioremap_pte(unsigned long addr)
+{
+	return bm_pte + ((addr >> PAGE_SHIFT) & 1023);
+}
+
+void __init early_ioremap_init(void)
+{
+	unsigned long *pgd;
+
+	if (early_ioremap_debug)
+		printk(KERN_DEBUG "early_ioremap_init()\n");
+
+	pgd = early_ioremap_pgd(fix_to_virt(FIX_BTMAP_BEGIN));
+	*pgd = __pa(bm_pte) | _PAGE_TABLE;
+	memset(bm_pte, 0, sizeof(bm_pte));
+	/*
+	 * The boot-ioremap range spans multiple pgds, for which
+	 * we are not prepared:
+	 */
+	if (pgd != early_ioremap_pgd(fix_to_virt(FIX_BTMAP_END))) {
+		WARN_ON(1);
+		printk(KERN_WARNING "pgd %p != %p\n",
+		       pgd, early_ioremap_pgd(fix_to_virt(FIX_BTMAP_END)));
+		printk(KERN_WARNING "fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
+		       fix_to_virt(FIX_BTMAP_BEGIN));
+		printk(KERN_WARNING "fix_to_virt(FIX_BTMAP_END):   %08lx\n",
+		       fix_to_virt(FIX_BTMAP_END));
+
+		printk(KERN_WARNING "FIX_BTMAP_END:       %d\n", FIX_BTMAP_END);
+		printk(KERN_WARNING "FIX_BTMAP_BEGIN:     %d\n",
+		       FIX_BTMAP_BEGIN);
+	}
+}
+
+void __init early_ioremap_clear(void)
+{
+	unsigned long *pgd;
+
+	if (early_ioremap_debug)
+		printk(KERN_DEBUG "early_ioremap_clear()\n");
+
+	pgd = early_ioremap_pgd(fix_to_virt(FIX_BTMAP_BEGIN));
+	*pgd = 0;
+	__flush_tlb_all();
+}
+
+void __init early_ioremap_reset(void)
+{
+	enum fixed_addresses idx;
+	unsigned long *pte, phys, addr;
+
+	after_paging_init = 1;
+	for (idx = FIX_BTMAP_BEGIN; idx >= FIX_BTMAP_END; idx--) {
+		addr = fix_to_virt(idx);
+		pte = early_ioremap_pte(addr);
+		if (!*pte & _PAGE_PRESENT) {
+			phys = *pte & PAGE_MASK;
+			set_fixmap(idx, phys);
+		}
+	}
+}
+
+static void __init __early_set_fixmap(enum fixed_addresses idx,
+				   unsigned long phys, pgprot_t flags)
+{
+	unsigned long *pte, addr = __fix_to_virt(idx);
+
+	if (idx >= __end_of_fixed_addresses) {
+		BUG();
+		return;
+	}
+	pte = early_ioremap_pte(addr);
+	if (pgprot_val(flags))
+		*pte = (phys & PAGE_MASK) | pgprot_val(flags);
+	else
+		*pte = 0;
+	__flush_tlb_one(addr);
+}
+
+static inline void __init early_set_fixmap(enum fixed_addresses idx,
+					unsigned long phys)
+{
+	if (after_paging_init)
+		set_fixmap(idx, phys);
+	else
+		__early_set_fixmap(idx, phys, PAGE_KERNEL);
+}
+
+static inline void __init early_clear_fixmap(enum fixed_addresses idx)
+{
+	if (after_paging_init)
+		clear_fixmap(idx);
+	else
+		__early_set_fixmap(idx, 0, __pgprot(0));
+}
+
+
+int __initdata early_ioremap_nested;
+
+static int __init check_early_ioremap_leak(void)
+{
+	if (!early_ioremap_nested)
+		return 0;
+
+	printk(KERN_WARNING
+	       "Debug warning: early ioremap leak of %d areas detected.\n",
+	       early_ioremap_nested);
+	printk(KERN_WARNING
+	       "please boot with early_ioremap_debug and report the dmesg.\n");
+	WARN_ON(1);
+
+	return 1;
+}
+late_initcall(check_early_ioremap_leak);
+
+void __init *early_ioremap(unsigned long phys_addr, unsigned long size)
+{
+	unsigned long offset, last_addr;
+	unsigned int nrpages, nesting;
+	enum fixed_addresses idx0, idx;
+
+	WARN_ON(system_state != SYSTEM_BOOTING);
+
+	nesting = early_ioremap_nested;
+	if (early_ioremap_debug) {
+		printk(KERN_DEBUG "early_ioremap(%08lx, %08lx) [%d] => ",
+		       phys_addr, size, nesting);
+		dump_stack();
+	}
+
+	/* Don't allow wraparound or zero size */
+	last_addr = phys_addr + size - 1;
+	if (!size || last_addr < phys_addr) {
+		WARN_ON(1);
+		return NULL;
+	}
+
+	if (nesting >= FIX_BTMAPS_NESTING) {
+		WARN_ON(1);
+		return NULL;
+	}
+	early_ioremap_nested++;
+	/*
+	 * Mappings have to be page-aligned
+	 */
+	offset = phys_addr & ~PAGE_MASK;
+	phys_addr &= PAGE_MASK;
+	size = PAGE_ALIGN(last_addr) - phys_addr;
+
+	/*
+	 * Mappings have to fit in the FIX_BTMAP area.
+	 */
+	nrpages = size >> PAGE_SHIFT;
+	if (nrpages > NR_FIX_BTMAPS) {
+		WARN_ON(1);
+		return NULL;
+	}
+
+	/*
+	 * Ok, go for it..
+	 */
+	idx0 = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*nesting;
+	idx = idx0;
+	while (nrpages > 0) {
+		early_set_fixmap(idx, phys_addr);
+		phys_addr += PAGE_SIZE;
+		--idx;
+		--nrpages;
+	}
+	if (early_ioremap_debug)
+		printk(KERN_CONT "%08lx + %08lx\n", offset, fix_to_virt(idx0));
+
+	return (void *) (offset + fix_to_virt(idx0));
+}
+
+void __init early_iounmap(void *addr, unsigned long size)
+{
+	unsigned long virt_addr;
+	unsigned long offset;
+	unsigned int nrpages;
+	enum fixed_addresses idx;
+	unsigned int nesting;
+
+	nesting = --early_ioremap_nested;
+	WARN_ON(nesting < 0);
+
+	if (early_ioremap_debug) {
+		printk(KERN_DEBUG "early_iounmap(%p, %08lx) [%d]\n", addr,
+		       size, nesting);
+		dump_stack();
+	}
+
+	virt_addr = (unsigned long)addr;
+	if (virt_addr < fix_to_virt(FIX_BTMAP_BEGIN)) {
+		WARN_ON(1);
+		return;
+	}
+	offset = virt_addr & ~PAGE_MASK;
+	nrpages = PAGE_ALIGN(offset + size - 1) >> PAGE_SHIFT;
+
+	idx = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*nesting;
+	while (nrpages > 0) {
+		early_clear_fixmap(idx);
+		--idx;
+		--nrpages;
+	}
+}
+
+void __this_fixmap_does_not_exist(void)
+{
+	WARN_ON(1);
+}
+
+#endif /* CONFIG_X86_32 */