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Diffstat (limited to 'arch/x86/mm/ioremap.c')
-rw-r--r--arch/x86/mm/ioremap.c152
1 files changed, 114 insertions, 38 deletions
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index 794895c6dcc9..c590fd200e29 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -19,11 +19,7 @@
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
#include <asm/pgalloc.h>
-
-enum ioremap_mode {
- IOR_MODE_UNCACHED,
- IOR_MODE_CACHED,
-};
+#include <asm/pat.h>
#ifdef CONFIG_X86_64
@@ -35,11 +31,23 @@ unsigned long __phys_addr(unsigned long x)
}
EXPORT_SYMBOL(__phys_addr);
+static inline int phys_addr_valid(unsigned long addr)
+{
+ return addr < (1UL << boot_cpu_data.x86_phys_bits);
+}
+
+#else
+
+static inline int phys_addr_valid(unsigned long addr)
+{
+ return 1;
+}
+
#endif
int page_is_ram(unsigned long pagenr)
{
- unsigned long addr, end;
+ resource_size_t addr, end;
int i;
/*
@@ -78,19 +86,22 @@ int page_is_ram(unsigned long pagenr)
* Fix up the linear direct mapping of the kernel to avoid cache attribute
* conflicts.
*/
-static int ioremap_change_attr(unsigned long vaddr, unsigned long size,
- enum ioremap_mode mode)
+int ioremap_change_attr(unsigned long vaddr, unsigned long size,
+ unsigned long prot_val)
{
unsigned long nrpages = size >> PAGE_SHIFT;
int err;
- switch (mode) {
- case IOR_MODE_UNCACHED:
+ switch (prot_val) {
+ case _PAGE_CACHE_UC:
default:
- err = set_memory_uc(vaddr, nrpages);
+ err = _set_memory_uc(vaddr, nrpages);
+ break;
+ case _PAGE_CACHE_WC:
+ err = _set_memory_wc(vaddr, nrpages);
break;
- case IOR_MODE_CACHED:
- err = set_memory_wb(vaddr, nrpages);
+ case _PAGE_CACHE_WB:
+ err = _set_memory_wb(vaddr, nrpages);
break;
}
@@ -107,17 +118,27 @@ static int ioremap_change_attr(unsigned long vaddr, unsigned long size,
* caller shouldn't need to know that small detail.
*/
static void __iomem *__ioremap(resource_size_t phys_addr, unsigned long size,
- enum ioremap_mode mode)
+ unsigned long prot_val)
{
- unsigned long pfn, offset, last_addr, vaddr;
+ unsigned long pfn, offset, vaddr;
+ resource_size_t last_addr;
struct vm_struct *area;
+ unsigned long new_prot_val;
pgprot_t prot;
+ int retval;
/* Don't allow wraparound or zero size */
last_addr = phys_addr + size - 1;
if (!size || last_addr < phys_addr)
return NULL;
+ if (!phys_addr_valid(phys_addr)) {
+ printk(KERN_WARNING "ioremap: invalid physical address %llx\n",
+ phys_addr);
+ WARN_ON_ONCE(1);
+ return NULL;
+ }
+
/*
* Don't remap the low PCI/ISA area, it's always mapped..
*/
@@ -127,25 +148,14 @@ static void __iomem *__ioremap(resource_size_t phys_addr, unsigned long size,
/*
* Don't allow anybody to remap normal RAM that we're using..
*/
- for (pfn = phys_addr >> PAGE_SHIFT; pfn < max_pfn_mapped &&
- (pfn << PAGE_SHIFT) < last_addr; pfn++) {
- if (page_is_ram(pfn) && pfn_valid(pfn) &&
- !PageReserved(pfn_to_page(pfn)))
- return NULL;
- }
+ for (pfn = phys_addr >> PAGE_SHIFT;
+ (pfn << PAGE_SHIFT) < last_addr; pfn++) {
- switch (mode) {
- case IOR_MODE_UNCACHED:
- default:
- /*
- * FIXME: we will use UC MINUS for now, as video fb drivers
- * depend on it. Upcoming ioremap_wc() will fix this behavior.
- */
- prot = PAGE_KERNEL_UC_MINUS;
- break;
- case IOR_MODE_CACHED:
- prot = PAGE_KERNEL;
- break;
+ int is_ram = page_is_ram(pfn);
+
+ if (is_ram && pfn_valid(pfn) && !PageReserved(pfn_to_page(pfn)))
+ return NULL;
+ WARN_ON_ONCE(is_ram);
}
/*
@@ -155,6 +165,49 @@ static void __iomem *__ioremap(resource_size_t phys_addr, unsigned long size,
phys_addr &= PAGE_MASK;
size = PAGE_ALIGN(last_addr+1) - phys_addr;
+ retval = reserve_memtype(phys_addr, phys_addr + size,
+ prot_val, &new_prot_val);
+ if (retval) {
+ pr_debug("Warning: reserve_memtype returned %d\n", retval);
+ return NULL;
+ }
+
+ if (prot_val != new_prot_val) {
+ /*
+ * Do not fallback to certain memory types with certain
+ * requested type:
+ * - request is uncached, return cannot be write-back
+ * - request is uncached, return cannot be write-combine
+ * - request is write-combine, return cannot be write-back
+ */
+ if ((prot_val == _PAGE_CACHE_UC &&
+ (new_prot_val == _PAGE_CACHE_WB ||
+ new_prot_val == _PAGE_CACHE_WC)) ||
+ (prot_val == _PAGE_CACHE_WC &&
+ new_prot_val == _PAGE_CACHE_WB)) {
+ pr_debug(
+ "ioremap error for 0x%llx-0x%llx, requested 0x%lx, got 0x%lx\n",
+ phys_addr, phys_addr + size,
+ prot_val, new_prot_val);
+ free_memtype(phys_addr, phys_addr + size);
+ return NULL;
+ }
+ prot_val = new_prot_val;
+ }
+
+ switch (prot_val) {
+ case _PAGE_CACHE_UC:
+ default:
+ prot = PAGE_KERNEL_NOCACHE;
+ break;
+ case _PAGE_CACHE_WC:
+ prot = PAGE_KERNEL_WC;
+ break;
+ case _PAGE_CACHE_WB:
+ prot = PAGE_KERNEL;
+ break;
+ }
+
/*
* Ok, go for it..
*/
@@ -164,11 +217,13 @@ static void __iomem *__ioremap(resource_size_t phys_addr, unsigned long size,
area->phys_addr = phys_addr;
vaddr = (unsigned long) area->addr;
if (ioremap_page_range(vaddr, vaddr + size, phys_addr, prot)) {
+ free_memtype(phys_addr, phys_addr + size);
free_vm_area(area);
return NULL;
}
- if (ioremap_change_attr(vaddr, size, mode) < 0) {
+ if (ioremap_change_attr(vaddr, size, prot_val) < 0) {
+ free_memtype(phys_addr, phys_addr + size);
vunmap(area->addr);
return NULL;
}
@@ -199,13 +254,32 @@ static void __iomem *__ioremap(resource_size_t phys_addr, unsigned long size,
*/
void __iomem *ioremap_nocache(resource_size_t phys_addr, unsigned long size)
{
- return __ioremap(phys_addr, size, IOR_MODE_UNCACHED);
+ return __ioremap(phys_addr, size, _PAGE_CACHE_UC);
}
EXPORT_SYMBOL(ioremap_nocache);
+/**
+ * ioremap_wc - map memory into CPU space write combined
+ * @offset: bus address of the memory
+ * @size: size of the resource to map
+ *
+ * This version of ioremap ensures that the memory is marked write combining.
+ * Write combining allows faster writes to some hardware devices.
+ *
+ * Must be freed with iounmap.
+ */
+void __iomem *ioremap_wc(unsigned long phys_addr, unsigned long size)
+{
+ if (pat_wc_enabled)
+ return __ioremap(phys_addr, size, _PAGE_CACHE_WC);
+ else
+ return ioremap_nocache(phys_addr, size);
+}
+EXPORT_SYMBOL(ioremap_wc);
+
void __iomem *ioremap_cache(resource_size_t phys_addr, unsigned long size)
{
- return __ioremap(phys_addr, size, IOR_MODE_CACHED);
+ return __ioremap(phys_addr, size, _PAGE_CACHE_WB);
}
EXPORT_SYMBOL(ioremap_cache);
@@ -252,6 +326,8 @@ void iounmap(volatile void __iomem *addr)
return;
}
+ free_memtype(p->phys_addr, p->phys_addr + get_vm_area_size(p));
+
/* Finally remove it */
o = remove_vm_area((void *)addr);
BUG_ON(p != o || o == NULL);
@@ -272,8 +348,8 @@ static int __init early_ioremap_debug_setup(char *str)
early_param("early_ioremap_debug", early_ioremap_debug_setup);
static __initdata int after_paging_init;
-static __initdata pte_t bm_pte[PAGE_SIZE/sizeof(pte_t)]
- __attribute__((aligned(PAGE_SIZE)));
+static pte_t bm_pte[PAGE_SIZE/sizeof(pte_t)]
+ __section(.bss.page_aligned);
static inline pmd_t * __init early_ioremap_pmd(unsigned long addr)
{
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.