powerpc/mm: Move ioremap functions out of pgtable_32/64.c

Create ioremap_32.c and ioremap_64.c and move respective ioremap
functions out of pgtable_32.c and pgtable_64.c

In the meantime, fix a few comments and changes a printk() to
pr_warn(). Also fix a few oversplitted lines.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b5c8b02ccefd4ede64c61b53cf64fb5dacb35740.1566309263.git.christophe.leroy@c-s.fr

1 files changed, 104 insertions, 0 deletions

diff --git a/arch/powerpc/mm/ioremap_32.c b/arch/powerpc/mm/ioremap_32.c
new file mode 100644
index 000000000000..fb43ba71aa54
--- /dev/null
+++ b/arch/powerpc/mm/ioremap_32.c
@@ -0,0 +1,104 @@
+// 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, i;
+	phys_addr_t p;
+	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;
+	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)
+		goto out;
+
+	if (slab_is_available()) {
+		struct vm_struct *area;
+		area = get_vm_area_caller(size, VM_IOREMAP, caller);
+		if (area == 0)
+			return NULL;
+		area->phys_addr = p;
+		v = (unsigned long)area->addr;
+	} else {
+		v = (ioremap_bot -= size);
+	}
+
+	/*
+	 * Should check if it is a candidate for a BAT mapping
+	 */
+
+	err = 0;
+	for (i = 0; i < size && err == 0; i += PAGE_SIZE)
+		err = map_kernel_page(v + i, p + i, prot);
+	if (err) {
+		if (slab_is_available())
+			vunmap((void *)v);
+		return NULL;
+	}
+
+out:
+	return (void __iomem *)(v + ((unsigned long)addr & ~PAGE_MASK));
+}
+
+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);