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/20230706154520.11257-3-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Brian Cain <bcain@quicinc.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chris Zankel <chris@zankel.net>
Cc: David Laight <David.Laight@ACULAB.COM>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Niklas Schnelle <schnelle@linux.ibm.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

arch/hexagon/Kconfig

@@ -25,6 +25,7 @@ config HEXAGON
 	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

@@ -27,8 +27,6 @@
 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);
@@ -170,8 +168,13 @@ static inline void writel(u32 data, volatile void __iomem *addr)
 #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

@@ -14,12 +14,10 @@
 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

@@ -3,5 +3,5 @@
 # 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