1 files changed, 93 insertions, 0 deletions
diff --git a/arch/powerpc/mm/ioremap_32.c b/arch/powerpc/mm/ioremap_32.c
new file mode 100644
index 000000000..9d13143b8
--- /dev/null
+++ b/arch/powerpc/mm/ioremap_32.c
@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+
+#include <mm/mmu_decl.h>
+
+void __iomem *ioremap_wt(phys_addr_t addr, unsigned long size)
+{
+	pgprot_t prot = pgprot_cached_wthru(PAGE_KERNEL);
+
+	return __ioremap_caller(addr, size, prot, __builtin_return_address(0));
+}
+EXPORT_SYMBOL(ioremap_wt);
+
+void __iomem *
+__ioremap_caller(phys_addr_t addr, unsigned long size, pgprot_t prot, void *caller)
+{
+	unsigned long v;
+	phys_addr_t p, offset;
+	int err;
+
+	/*
+	 * Choose an address to map it to.
+	 * Once the vmalloc system is running, we use it.
+	 * Before then, we use space going down from IOREMAP_TOP
+	 * (ioremap_bot records where we're up to).
+	 */
+	p = addr & PAGE_MASK;
+	offset = addr & ~PAGE_MASK;
+	size = PAGE_ALIGN(addr + size) - p;
+
+	/*
+	 * If the address lies within the first 16 MB, assume it's in ISA
+	 * memory space
+	 */
+	if (p < 16 * 1024 * 1024)
+		p += _ISA_MEM_BASE;
+
+#ifndef CONFIG_CRASH_DUMP
+	/*
+	 * Don't allow anybody to remap normal RAM that we're using.
+	 * mem_init() sets high_memory so only do the check after that.
+	 */
+	if (slab_is_available() && p <= virt_to_phys(high_memory - 1) &&
+	    page_is_ram(__phys_to_pfn(p))) {
+		pr_warn("%s(): phys addr 0x%llx is RAM lr %ps\n", __func__,
+			(unsigned long long)p, __builtin_return_address(0));
+		return NULL;
+	}
+#endif
+
+	if (size == 0)
+		return NULL;
+
+	/*
+	 * Is it already mapped?  Perhaps overlapped by a previous
+	 * mapping.
+	 */
+	v = p_block_mapped(p);
+	if (v)
+		return (void __iomem *)v + offset;
+
+	if (slab_is_available())
+		return do_ioremap(p, offset, size, prot, caller);
+
+	/*
+	 * Should check if it is a candidate for a BAT mapping
+	 */
+	pr_warn("ioremap() called early from %pS. Use early_ioremap() instead\n", caller);
+
+	err = early_ioremap_range(ioremap_bot - size - PAGE_SIZE, p, size, prot);
+	if (err)
+		return NULL;
+	ioremap_bot -= size + PAGE_SIZE;
+
+	return (void __iomem *)ioremap_bot + offset;
+}
+
+void iounmap(volatile void __iomem *addr)
+{
+	/*
+	 * If mapped by BATs then there is nothing to do.
+	 * Calling vfree() generates a benign warning.
+	 */
+	if (v_block_mapped((unsigned long)addr))
+		return;
+
+	if (addr > high_memory && (unsigned long)addr < ioremap_bot)
+		vunmap((void *)(PAGE_MASK & (unsigned long)addr));
+}
+EXPORT_SYMBOL(iounmap);