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, 123 insertions, 0 deletions

diff --git a/arch/powerpc/mm/ioremap_64.c b/arch/powerpc/mm/ioremap_64.c
new file mode 100644
index 000000000000..57f3b096143c
--- /dev/null
+++ b/arch/powerpc/mm/ioremap_64.c
@@ -0,0 +1,123 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+
+int __weak ioremap_range(unsigned long ea, phys_addr_t pa, unsigned long size,
+			 pgprot_t prot, int nid)
+{
+	unsigned long i;
+
+	for (i = 0; i < size; i += PAGE_SIZE) {
+		int err = map_kernel_page(ea + i, pa + i, prot);
+		if (err) {
+			if (slab_is_available())
+				unmap_kernel_range(ea, size);
+			else
+				WARN_ON_ONCE(1); /* Should clean up */
+			return err;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * Low level function to establish the page tables for an IO mapping
+ */
+void __iomem *__ioremap_at(phys_addr_t pa, void *ea, unsigned long size, pgprot_t prot)
+{
+	/* We don't support the 4K PFN hack with ioremap */
+	if (pgprot_val(prot) & H_PAGE_4K_PFN)
+		return NULL;
+
+	if ((ea + size) >= (void *)IOREMAP_END) {
+		pr_warn("Outside the supported range\n");
+		return NULL;
+	}
+
+	WARN_ON(pa & ~PAGE_MASK);
+	WARN_ON(((unsigned long)ea) & ~PAGE_MASK);
+	WARN_ON(size & ~PAGE_MASK);
+
+	if (ioremap_range((unsigned long)ea, pa, size, prot, NUMA_NO_NODE))
+		return NULL;
+
+	return (void __iomem *)ea;
+}
+EXPORT_SYMBOL(__ioremap_at);
+
+/**
+ * Low level function to tear down the page tables for an IO mapping. This is
+ * used for mappings that are manipulated manually, like partial unmapping of
+ * PCI IOs or ISA space.
+ */
+void __iounmap_at(void *ea, unsigned long size)
+{
+	WARN_ON(((unsigned long)ea) & ~PAGE_MASK);
+	WARN_ON(size & ~PAGE_MASK);
+
+	unmap_kernel_range((unsigned long)ea, size);
+}
+EXPORT_SYMBOL(__iounmap_at);
+
+void __iomem *__ioremap_caller(phys_addr_t addr, unsigned long size,
+			       pgprot_t prot, void *caller)
+{
+	phys_addr_t paligned;
+	void __iomem *ret;
+
+	/*
+	 * Choose an address to map it to. Once the vmalloc system is running,
+	 * we use it. Before that, we map using addresses going up from
+	 * ioremap_bot.  vmalloc will use the addresses from IOREMAP_BASE
+	 * through ioremap_bot.
+	 */
+	paligned = addr & PAGE_MASK;
+	size = PAGE_ALIGN(addr + size) - paligned;
+
+	if (size == 0 || paligned == 0)
+		return NULL;
+
+	if (slab_is_available()) {
+		struct vm_struct *area;
+
+		area = __get_vm_area_caller(size, VM_IOREMAP, ioremap_bot,
+					    IOREMAP_END, caller);
+		if (area == NULL)
+			return NULL;
+
+		area->phys_addr = paligned;
+		ret = __ioremap_at(paligned, area->addr, size, prot);
+	} else {
+		ret = __ioremap_at(paligned, (void *)ioremap_bot, size, prot);
+		if (ret)
+			ioremap_bot += size;
+	}
+
+	if (ret)
+		ret += addr & ~PAGE_MASK;
+	return ret;
+}
+
+/*
+ * Unmap an IO region and remove it from vmalloc'd list.
+ * Access to IO memory should be serialized by driver.
+ */
+void iounmap(volatile void __iomem *token)
+{
+	void *addr;
+
+	if (!slab_is_available())
+		return;
+
+	addr = (void *)((unsigned long __force)PCI_FIX_ADDR(token) & PAGE_MASK);
+
+	if ((unsigned long)addr < ioremap_bot) {
+		pr_warn("Attempt to iounmap early bolted mapping at 0x%p\n", addr);
+		return;
+	}
+	vunmap(addr);
+}
+EXPORT_SYMBOL(iounmap);