powerpc/mm: refactor ioremap_range() and use ioremap_page_range()

book3s64's ioremap_range() is almost same as fallback ioremap_range(),
except that it calls radix__ioremap_range() when radix is enabled.

radix__ioremap_range() is also very similar to the other ones, expect
that it calls ioremap_page_range when slab is available.

PPC32 __ioremap_caller() have a loop doing the same thing as
ioremap_range() so use it on PPC32 as well.

Lets keep only one version of ioremap_range() which calls
ioremap_page_range() on all platforms when slab is available.

At the same time, drop the nid parameter which is not used.

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/4b1dca7096b01823b101be7338983578641547f1.1566309263.git.christophe.leroy@c-s.fr

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

@@ -266,9 +266,6 @@ 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/include/asm/io.h

@@ -722,6 +722,8 @@ void __iomem *ioremap_coherent(phys_addr_t address, unsigned long size);
 
 extern void iounmap(volatile void __iomem *addr);
 
+int ioremap_range(unsigned long ea, phys_addr_t pa, unsigned long size, pgprot_t prot);
+
 extern void __iomem *__ioremap_caller(phys_addr_t, unsigned long size,
 				      pgprot_t prot, void *caller);
 

arch/powerpc/mm/book3s64/pgtable.c

@@ -446,24 +446,3 @@ 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

@@ -1218,26 +1218,6 @@ int pmd_free_pte_page(pmd_t *pmd, unsigned long addr)
 	return 1;
 }
 
-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;
-	}
-}
-
 int __init arch_ioremap_p4d_supported(void)
 {
 	return 0;

arch/powerpc/mm/ioremap.c

@@ -1,6 +1,8 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
 #include <asm/io-workarounds.h>
 
 unsigned long ioremap_bot;
@@ -56,3 +58,25 @@ void __iomem *ioremap_prot(phys_addr_t addr, unsigned long size, unsigned long f
 	return __ioremap_caller(addr, size, pte_pgprot(pte), caller);
 }
 EXPORT_SYMBOL(ioremap_prot);
+
+int ioremap_range(unsigned long ea, phys_addr_t pa, unsigned long size, pgprot_t prot)
+{
+	unsigned long i;
+
+	if (slab_is_available()) {
+		int err = ioremap_page_range(ea, ea + size, pa, prot);
+
+		if (err)
+			unmap_kernel_range(ea, size);
+		return err;
+	}
+
+	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/ioremap_32.c

@@ -17,7 +17,7 @@ EXPORT_SYMBOL(ioremap_wt);
 void __iomem *
 __ioremap_caller(phys_addr_t addr, unsigned long size, pgprot_t prot, void *caller)
 {
-	unsigned long v, i;
+	unsigned long v;
 	phys_addr_t p;
 	int err;
 
@@ -76,9 +76,7 @@ __ioremap_caller(phys_addr_t addr, unsigned long size, pgprot_t prot, void *call
 	 * 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);
+	err = ioremap_range((unsigned long)v, p, size, prot);
 	if (err) {
 		if (slab_is_available())
 			vunmap((void *)v);

arch/powerpc/mm/ioremap_64.c

@@ -4,25 +4,6 @@
 #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
  */
@@ -41,7 +22,7 @@ void __iomem *__ioremap_at(phys_addr_t pa, void *ea, unsigned long size, pgprot_
 	WARN_ON(((unsigned long)ea) & ~PAGE_MASK);
 	WARN_ON(size & ~PAGE_MASK);
 
-	if (ioremap_range((unsigned long)ea, pa, size, prot, NUMA_NO_NODE))
+	if (ioremap_range((unsigned long)ea, pa, size, prot))
 		return NULL;
 
 	return (void __iomem *)ea;