hexagon: mm: convert to GENERIC_IOREMAP

By taking GENERIC_IOREMAP method, the generic ioremap_prot() and iounmap()
are visible and available to arch. This change will simplify
implementation by removing duplicated code with generic ioremap_prot() and
iounmap(), and has the equivalent functioality.

For hexagon, the current ioremap() and iounmap() are the same as generic
version. After taking GENERIC_IOREMAP way, the old ioremap() and
iounmap() can be completely removed.

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Baoquan He <[e-mail]>
Cc: Brian Cain <[e-mail]>
Cc: Alexander Gordeev <[e-mail]>
Cc: Arnd Bergmann <[e-mail]>
Cc: Catalin Marinas <[e-mail]>
Cc: Christian Borntraeger <[e-mail]>
Cc: Christophe Leroy <[e-mail]>
Cc: Christoph Hellwig <[e-mail]>
Cc: Chris Zankel <[e-mail]>
Cc: David Laight <[e-mail]>
Cc: Geert Uytterhoeven <[e-mail]>
Cc: Gerald Schaefer <[e-mail]>
Cc: Heiko Carstens <[e-mail]>
Cc: Helge Deller <[e-mail]>
Cc: "James E.J. Bottomley" <[e-mail]>
Cc: John Paul Adrian Glaubitz <[e-mail]>
Cc: Jonas Bonn <[e-mail]>
Cc: Kefeng Wang <[e-mail]>
Cc: Matthew Wilcox <[e-mail]>
Cc: Max Filippov <[e-mail]>
Cc: Michael Ellerman <[e-mail]>
Cc: Mike Rapoport (IBM) <[e-mail]>
Cc: Nathan Chancellor <[e-mail]>
Cc: Nicholas Piggin <[e-mail]>
Cc: Niklas Schnelle <[e-mail]>
Cc: Rich Felker <[e-mail]>
Cc: Stafford Horne <[e-mail]>
Cc: Stefan Kristiansson <[e-mail]>
Cc: Sven Schnelle <[e-mail]>
Cc: Vasily Gorbik <[e-mail]>
Cc: Vineet Gupta <[e-mail]>
Cc: Will Deacon <[e-mail]>
Cc: Yoshinori Sato <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>

arch/hexagon/Kconfig

···
 	select NEED_SG_DMA_LENGTH
 	select NO_IOPORT_MAP
 	select GENERIC_IOMAP
+	select GENERIC_IOREMAP
 	select GENERIC_SMP_IDLE_THREAD
 	select STACKTRACE_SUPPORT
 	select GENERIC_CLOCKEVENTS_BROADCAST

arch/hexagon/include/asm/io.h

···
 extern int remap_area_pages(unsigned long start, unsigned long phys_addr,
 				unsigned long end, unsigned long flags);
 
-extern void iounmap(const volatile void __iomem *addr);
-
 /* Defined in lib/io.c, needed for smc91x driver. */
 extern void __raw_readsw(const void __iomem *addr, void *data, int wordlen);
 extern void __raw_writesw(void __iomem *addr, const void *data, int wordlen);
···
 #define writew_relaxed __raw_writew
 #define writel_relaxed __raw_writel
 
-void __iomem *ioremap(unsigned long phys_addr, unsigned long size);
-#define ioremap_uc(X, Y) ioremap((X), (Y))
+/*
+ * I/O memory mapping functions.
+ */
+#define _PAGE_IOREMAP (_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | \
+		       (__HEXAGON_C_DEV << 6))
+
+#define ioremap_uc(addr, size) ioremap((addr), (size))
 
 
 #define __raw_writel writel

arch/hexagon/kernel/hexagon_ksyms.c

···
 EXPORT_SYMBOL(__clear_user_hexagon);
 EXPORT_SYMBOL(raw_copy_from_user);
 EXPORT_SYMBOL(raw_copy_to_user);
-EXPORT_SYMBOL(iounmap);
 EXPORT_SYMBOL(__vmgetie);
 EXPORT_SYMBOL(__vmsetie);
 EXPORT_SYMBOL(__vmyield);
 EXPORT_SYMBOL(empty_zero_page);
-EXPORT_SYMBOL(ioremap);
 EXPORT_SYMBOL(memcpy);
 EXPORT_SYMBOL(memset);
 

arch/hexagon/mm/Makefile

···
 # Makefile for Hexagon memory management subsystem
 #
 
-obj-y := init.o ioremap.o uaccess.o vm_fault.o cache.o
+obj-y := init.o uaccess.o vm_fault.o cache.o
 obj-y += copy_to_user.o copy_from_user.o vm_tlb.o

arch/hexagon/mm/ioremap.c

···
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * I/O remap functions for Hexagon
- *
- * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
- */
-
-#include <linux/io.h>
-#include <linux/vmalloc.h>
-#include <linux/mm.h>
-
-void __iomem *ioremap(unsigned long phys_addr, unsigned long size)
-{
-	unsigned long last_addr, addr;
-	unsigned long offset = phys_addr & ~PAGE_MASK;
-	struct vm_struct *area;
-
-	pgprot_t prot = __pgprot(_PAGE_PRESENT|_PAGE_READ|_PAGE_WRITE
-					|(__HEXAGON_C_DEV << 6));
-
-	last_addr = phys_addr + size - 1;
-
-	/*  Wrapping not allowed  */
-	if (!size || (last_addr < phys_addr))
-		return NULL;
-
-	/*  Rounds up to next page size, including whole-page offset */
-	size = PAGE_ALIGN(offset + size);
-
-	area = get_vm_area(size, VM_IOREMAP);
-	addr = (unsigned long)area->addr;
-
-	if (ioremap_page_range(addr, addr+size, phys_addr, prot)) {
-		vunmap((void *)addr);
-		return NULL;
-	}
-
-	return (void __iomem *) (offset + addr);
-}
-
-void iounmap(const volatile void __iomem *addr)
-{
-	vunmap((void *) ((unsigned long) addr & PAGE_MASK));
-}