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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /mm/ioremap.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'mm/ioremap.c')
-rw-r--r--mm/ioremap.c61
1 files changed, 61 insertions, 0 deletions
diff --git a/mm/ioremap.c b/mm/ioremap.c
new file mode 100644
index 000000000..865242628
--- /dev/null
+++ b/mm/ioremap.c
@@ -0,0 +1,61 @@
+// 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/io.h>
+#include <linux/export.h>
+
+void __iomem *ioremap_prot(phys_addr_t phys_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 = phys_addr + size - 1;
+ if (!size || last_addr < phys_addr)
+ return NULL;
+
+ /* Page-align mappings */
+ offset = phys_addr & (~PAGE_MASK);
+ phys_addr -= offset;
+ size = PAGE_ALIGN(size + offset);
+
+ if (!ioremap_allowed(phys_addr, size, prot))
+ return NULL;
+
+ area = get_vm_area_caller(size, VM_IOREMAP,
+ __builtin_return_address(0));
+ if (!area)
+ return NULL;
+ vaddr = (unsigned long)area->addr;
+ area->phys_addr = phys_addr;
+
+ if (ioremap_page_range(vaddr, vaddr + size, phys_addr,
+ __pgprot(prot))) {
+ free_vm_area(area);
+ return NULL;
+ }
+
+ return (void __iomem *)(vaddr + offset);
+}
+EXPORT_SYMBOL(ioremap_prot);
+
+void iounmap(volatile void __iomem *addr)
+{
+ void *vaddr = (void *)((unsigned long)addr & PAGE_MASK);
+
+ if (!iounmap_allowed(vaddr))
+ return;
+
+ if (is_vmalloc_addr(vaddr))
+ vunmap(vaddr);
+}
+EXPORT_SYMBOL(iounmap);