mm/ioremap: define generic_ioremap_prot() and generic_iounmap()

Define a generic version of ioremap_prot() and iounmap() that
architectures can call after they have performed the necessary alteration
to parameters and/or necessary verifications.

Link: https://lkml.kernel.org/r/20230706154520.11257-5-bhe@redhat.comSigned-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
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: Matthew Wilcox <willy@infradead.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
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>

include/asm-generic/io.h

@@ -1073,9 +1073,13 @@ static inline bool iounmap_allowed(void *addr)
 }
 #endif
 
+void __iomem *generic_ioremap_prot(phys_addr_t phys_addr, size_t size,
+				   pgprot_t prot);
+
 void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
 			   unsigned long prot);
 void iounmap(volatile void __iomem *addr);
+void generic_iounmap(volatile void __iomem *addr);
 
 static inline void __iomem *ioremap(phys_addr_t addr, size_t size)
 {

mm/ioremap.c

@@ -11,8 +11,8 @@
 #include <linux/io.h>
 #include <linux/export.h>
 
-void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
-			   unsigned long prot)
+void __iomem *generic_ioremap_prot(phys_addr_t phys_addr, size_t size,
+				   pgprot_t prot)
 {
 	unsigned long offset, vaddr;
 	phys_addr_t last_addr;
@@ -28,7 +28,7 @@ void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
 	phys_addr -= offset;
 	size = PAGE_ALIGN(size + offset);
 
-	if (!ioremap_allowed(phys_addr, size, prot))
+	if (!ioremap_allowed(phys_addr, size, pgprot_val(prot)))
 		return NULL;
 
 	area = get_vm_area_caller(size, VM_IOREMAP,
@@ -38,17 +38,22 @@ void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
 	vaddr = (unsigned long)area->addr;
 	area->phys_addr = phys_addr;
 
-	if (ioremap_page_range(vaddr, vaddr + size, phys_addr,
-			       __pgprot(prot))) {
+	if (ioremap_page_range(vaddr, vaddr + size, phys_addr, prot)) {
 		free_vm_area(area);
 		return NULL;
 	}
 
 	return (void __iomem *)(vaddr + offset);
 }
+
+void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
+			   unsigned long prot)
+{
+	return generic_ioremap_prot(phys_addr, size, __pgprot(prot));
+}
 EXPORT_SYMBOL(ioremap_prot);
 
-void iounmap(volatile void __iomem *addr)
+void generic_iounmap(volatile void __iomem *addr)
 {
 	void *vaddr = (void *)((unsigned long)addr & PAGE_MASK);
 
@@ -58,4 +63,9 @@ void iounmap(volatile void __iomem *addr)
 	if (is_vmalloc_addr(vaddr))
 		vunmap(vaddr);
 }
+
+void iounmap(volatile void __iomem *addr)
+{
+	generic_iounmap(addr);
+}
 EXPORT_SYMBOL(iounmap);