v4.19.13 snapshot.
diff --git a/lib/ioremap.c b/lib/ioremap.c
new file mode 100644
index 0000000..517f585
--- /dev/null
+++ b/lib/ioremap.c
@@ -0,0 +1,183 @@
+// 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/sched.h>
+#include <linux/io.h>
+#include <linux/export.h>
+#include <asm/cacheflush.h>
+#include <asm/pgtable.h>
+
+#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
+static int __read_mostly ioremap_p4d_capable;
+static int __read_mostly ioremap_pud_capable;
+static int __read_mostly ioremap_pmd_capable;
+static int __read_mostly ioremap_huge_disabled;
+
+static int __init set_nohugeiomap(char *str)
+{
+ ioremap_huge_disabled = 1;
+ return 0;
+}
+early_param("nohugeiomap", set_nohugeiomap);
+
+void __init ioremap_huge_init(void)
+{
+ if (!ioremap_huge_disabled) {
+ if (arch_ioremap_pud_supported())
+ ioremap_pud_capable = 1;
+ if (arch_ioremap_pmd_supported())
+ ioremap_pmd_capable = 1;
+ }
+}
+
+static inline int ioremap_p4d_enabled(void)
+{
+ return ioremap_p4d_capable;
+}
+
+static inline int ioremap_pud_enabled(void)
+{
+ return ioremap_pud_capable;
+}
+
+static inline int ioremap_pmd_enabled(void)
+{
+ return ioremap_pmd_capable;
+}
+
+#else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
+static inline int ioremap_p4d_enabled(void) { return 0; }
+static inline int ioremap_pud_enabled(void) { return 0; }
+static inline int ioremap_pmd_enabled(void) { return 0; }
+#endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
+
+static int ioremap_pte_range(pmd_t *pmd, unsigned long addr,
+ unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
+{
+ pte_t *pte;
+ u64 pfn;
+
+ pfn = phys_addr >> PAGE_SHIFT;
+ pte = pte_alloc_kernel(pmd, addr);
+ if (!pte)
+ return -ENOMEM;
+ do {
+ BUG_ON(!pte_none(*pte));
+ set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot));
+ pfn++;
+ } while (pte++, addr += PAGE_SIZE, addr != end);
+ return 0;
+}
+
+static inline int ioremap_pmd_range(pud_t *pud, unsigned long addr,
+ unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
+{
+ pmd_t *pmd;
+ unsigned long next;
+
+ phys_addr -= addr;
+ pmd = pmd_alloc(&init_mm, pud, addr);
+ if (!pmd)
+ return -ENOMEM;
+ do {
+ next = pmd_addr_end(addr, end);
+
+ if (ioremap_pmd_enabled() &&
+ ((next - addr) == PMD_SIZE) &&
+ IS_ALIGNED(phys_addr + addr, PMD_SIZE) &&
+ pmd_free_pte_page(pmd, addr)) {
+ if (pmd_set_huge(pmd, phys_addr + addr, prot))
+ continue;
+ }
+
+ if (ioremap_pte_range(pmd, addr, next, phys_addr + addr, prot))
+ return -ENOMEM;
+ } while (pmd++, addr = next, addr != end);
+ return 0;
+}
+
+static inline int ioremap_pud_range(p4d_t *p4d, unsigned long addr,
+ unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
+{
+ pud_t *pud;
+ unsigned long next;
+
+ phys_addr -= addr;
+ pud = pud_alloc(&init_mm, p4d, addr);
+ if (!pud)
+ return -ENOMEM;
+ do {
+ next = pud_addr_end(addr, end);
+
+ if (ioremap_pud_enabled() &&
+ ((next - addr) == PUD_SIZE) &&
+ IS_ALIGNED(phys_addr + addr, PUD_SIZE) &&
+ pud_free_pmd_page(pud, addr)) {
+ if (pud_set_huge(pud, phys_addr + addr, prot))
+ continue;
+ }
+
+ if (ioremap_pmd_range(pud, addr, next, phys_addr + addr, prot))
+ return -ENOMEM;
+ } while (pud++, addr = next, addr != end);
+ return 0;
+}
+
+static inline int ioremap_p4d_range(pgd_t *pgd, unsigned long addr,
+ unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
+{
+ p4d_t *p4d;
+ unsigned long next;
+
+ phys_addr -= addr;
+ p4d = p4d_alloc(&init_mm, pgd, addr);
+ if (!p4d)
+ return -ENOMEM;
+ do {
+ next = p4d_addr_end(addr, end);
+
+ if (ioremap_p4d_enabled() &&
+ ((next - addr) == P4D_SIZE) &&
+ IS_ALIGNED(phys_addr + addr, P4D_SIZE)) {
+ if (p4d_set_huge(p4d, phys_addr + addr, prot))
+ continue;
+ }
+
+ if (ioremap_pud_range(p4d, addr, next, phys_addr + addr, prot))
+ return -ENOMEM;
+ } while (p4d++, addr = next, addr != end);
+ return 0;
+}
+
+int ioremap_page_range(unsigned long addr,
+ unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
+{
+ pgd_t *pgd;
+ unsigned long start;
+ unsigned long next;
+ int err;
+
+ might_sleep();
+ BUG_ON(addr >= end);
+
+ start = addr;
+ phys_addr -= addr;
+ pgd = pgd_offset_k(addr);
+ do {
+ next = pgd_addr_end(addr, end);
+ err = ioremap_p4d_range(pgd, addr, next, phys_addr+addr, prot);
+ if (err)
+ break;
+ } while (pgd++, addr = next, addr != end);
+
+ flush_cache_vmap(start, end);
+
+ return err;
+}