powerpc/64s/radix: ioremap use ioremap_page_range

Radix can use ioremap_page_range for ioremap, after slab is available.
This makes it possible to enable huge ioremap mapping support.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/include/asm/book3s/64/radix.h

@@ -266,6 +266,9 @@ extern void radix__vmemmap_remove_mapping(unsigned long start,
 extern int radix__map_kernel_page(unsigned long ea, unsigned long pa,
 				 pgprot_t flags, unsigned int psz);
 
+extern int radix__ioremap_range(unsigned long ea, phys_addr_t pa,
+				unsigned long size, pgprot_t prot, int nid);
+
 static inline unsigned long radix__get_tree_size(void)
 {
 	unsigned long rts_field;

arch/powerpc/mm/book3s64/pgtable.c

@@ -447,3 +447,24 @@ int pmd_move_must_withdraw(struct spinlock *new_pmd_ptl,
 
 	return true;
 }
+
+int ioremap_range(unsigned long ea, phys_addr_t pa, unsigned long size, pgprot_t prot, int nid)
+{
+	unsigned long i;
+
+	if (radix_enabled())
+		return radix__ioremap_range(ea, pa, size, prot, nid);
+
+	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;
+}

arch/powerpc/mm/book3s64/radix_pgtable.c

@@ -11,6 +11,7 @@
 
 #define pr_fmt(fmt) "radix-mmu: " fmt
 
+#include <linux/io.h>
 #include <linux/kernel.h>
 #include <linux/sched/mm.h>
 #include <linux/memblock.h>
@@ -1122,3 +1123,23 @@ void radix__ptep_modify_prot_commit(struct vm_area_struct *vma,
 
 	set_pte_at(mm, addr, ptep, pte);
 }
+
+int radix__ioremap_range(unsigned long ea, phys_addr_t pa, unsigned long size,
+			pgprot_t prot, int nid)
+{
+	if (likely(slab_is_available())) {
+		int err = ioremap_page_range(ea, ea + size, pa, prot);
+		if (err)
+			unmap_kernel_range(ea, size);
+		return err;
+	} else {
+		unsigned long i;
+
+		for (i = 0; i < size; i += PAGE_SIZE) {
+			int err = map_kernel_page(ea + i, pa + i, prot);
+			if (WARN_ON_ONCE(err)) /* Should clean up */
+				return err;
+		}
+		return 0;
+	}
+}

arch/powerpc/mm/pgtable_64.c

@@ -108,7 +108,7 @@ unsigned long ioremap_bot;
 unsigned long ioremap_bot = IOREMAP_BASE;
 #endif
 
-static int ioremap_range(unsigned long ea, phys_addr_t pa, unsigned long size, pgprot_t prot, int nid)
+int __weak ioremap_range(unsigned long ea, phys_addr_t pa, unsigned long size, pgprot_t prot, int nid)
 {
 	unsigned long i;