mm/ioremap: consider IOREMAP space in generic ioremap

Architectures like powerpc have a dedicated space for IOREMAP mappings.

If so, use it in generic_ioremap_prot().

Link: https://lkml.kernel.org/r/20230706154520.11257-16-bhe@redhat.com
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Brian Cain <bcain@quicinc.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
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>

mm/ioremap.c

@@ -11,6 +11,15 @@
 #include <linux/io.h>
 #include <linux/export.h>
 
+/*
+ * Ioremap often, but not always uses the generic vmalloc area. E.g on
+ * Power ARCH, it could have different ioremap space.
+ */
+#ifndef IOREMAP_START
+#define IOREMAP_START   VMALLOC_START
+#define IOREMAP_END     VMALLOC_END
+#endif
+
 void __iomem *generic_ioremap_prot(phys_addr_t phys_addr, size_t size,
 				   pgprot_t prot)
 {
@@ -35,8 +44,8 @@ void __iomem *generic_ioremap_prot(phys_addr_t phys_addr, size_t size,
 	if (!ioremap_allowed(phys_addr, size, pgprot_val(prot)))
 		return NULL;
 
-	area = get_vm_area_caller(size, VM_IOREMAP,
-			__builtin_return_address(0));
+	area = __get_vm_area_caller(size, VM_IOREMAP, IOREMAP_START,
+				    IOREMAP_END, __builtin_return_address(0));
 	if (!area)
 		return NULL;
 	vaddr = (unsigned long)area->addr;
@@ -66,7 +75,7 @@ void generic_iounmap(volatile void __iomem *addr)
 	if (!iounmap_allowed(vaddr))
 		return;
 
-	if (is_vmalloc_addr(vaddr))
+	if (is_ioremap_addr(vaddr))
 		vunmap(vaddr);
 }