[PATCH v6 13/19] xtensa: mm: Convert to GENERIC_IOREMAP

[Baoquan He <bhe@redhat.com>]

By taking GENERIC_IOREMAP method, the generic generic_ioremap_prot(),
generic_iounmap(), and their generic wrapper ioremap_prot(), ioremap()
and iounmap() are all visible and available to arch. Arch needs to
provide wrapper functions to override the generic versions if there's
arch specific handling in its ioremap_prot(), ioremap() or iounmap().
This change will simplify implementation by removing duplicated codes
with generic_ioremap_prot() and generic_iounmap(), and has the equivalent
functioality as before.

Here, add wrapper functions ioremap_prot(), ioremap() and iounmap() for
xtensa's special operation when ioremap() and iounmap().

Signed-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
---
 arch/xtensa/Kconfig          |  1 +
 arch/xtensa/include/asm/io.h | 32 ++++++++------------
 arch/xtensa/mm/ioremap.c     | 58 +++++++++---------------------------
 3 files changed, 27 insertions(+), 64 deletions(-)

diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index 3c6e5471f025..474cbbff3e6c 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -29,6 +29,7 @@ config XTENSA
 	select GENERIC_LIB_UCMPDI2
 	select GENERIC_PCI_IOMAP
 	select GENERIC_SCHED_CLOCK
+	select GENERIC_IOREMAP if MMU
 	select HAVE_ARCH_AUDITSYSCALL
 	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
 	select HAVE_ARCH_KASAN if MMU && !XIP_KERNEL
diff --git a/arch/xtensa/include/asm/io.h b/arch/xtensa/include/asm/io.h
index a5b707e1c0f4..934e58399c8c 100644
--- a/arch/xtensa/include/asm/io.h
+++ b/arch/xtensa/include/asm/io.h
@@ -16,6 +16,7 @@
 #include <asm/vectors.h>
 #include <linux/bug.h>
 #include <linux/kernel.h>
+#include <linux/pgtable.h>
 
 #include <linux/types.h>
 
@@ -24,22 +25,24 @@
 #define PCI_IOBASE		((void __iomem *)XCHAL_KIO_BYPASS_VADDR)
 
 #ifdef CONFIG_MMU
-
-void __iomem *xtensa_ioremap_nocache(unsigned long addr, unsigned long size);
-void __iomem *xtensa_ioremap_cache(unsigned long addr, unsigned long size);
-void xtensa_iounmap(volatile void __iomem *addr);
-
 /*
- * Return the virtual address for the specified bus memory.
+ * I/O memory mapping functions.
  */
+void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
+			   unsigned long prot);
+#define ioremap_prot ioremap_prot
+#define iounmap iounmap
+
 static inline void __iomem *ioremap(unsigned long offset, unsigned long size)
 {
 	if (offset >= XCHAL_KIO_PADDR
 	    && offset - XCHAL_KIO_PADDR < XCHAL_KIO_SIZE)
 		return (void*)(offset-XCHAL_KIO_PADDR+XCHAL_KIO_BYPASS_VADDR);
 	else
-		return xtensa_ioremap_nocache(offset, size);
+		return ioremap_prot(offset, size,
+			pgprot_val(pgprot_noncached(PAGE_KERNEL)));
 }
+#define ioremap ioremap
 
 static inline void __iomem *ioremap_cache(unsigned long offset,
 		unsigned long size)
@@ -48,21 +51,10 @@ static inline void __iomem *ioremap_cache(unsigned long offset,
 	    && offset - XCHAL_KIO_PADDR < XCHAL_KIO_SIZE)
 		return (void*)(offset-XCHAL_KIO_PADDR+XCHAL_KIO_CACHED_VADDR);
 	else
-		return xtensa_ioremap_cache(offset, size);
-}
-#define ioremap_cache ioremap_cache
+		return ioremap_prot(offset, size, pgprot_val(PAGE_KERNEL));
 
-static inline void iounmap(volatile void __iomem *addr)
-{
-	unsigned long va = (unsigned long) addr;
-
-	if (!(va >= XCHAL_KIO_CACHED_VADDR &&
-	      va - XCHAL_KIO_CACHED_VADDR < XCHAL_KIO_SIZE) &&
-	    !(va >= XCHAL_KIO_BYPASS_VADDR &&
-	      va - XCHAL_KIO_BYPASS_VADDR < XCHAL_KIO_SIZE))
-		xtensa_iounmap(addr);
 }
-
+#define ioremap_cache ioremap_cache
 #endif /* CONFIG_MMU */
 
 #include <asm-generic/io.h>
diff --git a/arch/xtensa/mm/ioremap.c b/arch/xtensa/mm/ioremap.c
index a400188c16b9..8ca660b7ab49 100644
--- a/arch/xtensa/mm/ioremap.c
+++ b/arch/xtensa/mm/ioremap.c
@@ -6,60 +6,30 @@
  */
 
 #include <linux/io.h>
-#include <linux/vmalloc.h>
 #include <linux/pgtable.h>
 #include <asm/cacheflush.h>
 #include <asm/io.h>
 
-static void __iomem *xtensa_ioremap(unsigned long paddr, unsigned long size,
-				    pgprot_t prot)
+void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
+			   unsigned long prot)
 {
-	unsigned long offset = paddr & ~PAGE_MASK;
-	unsigned long pfn = __phys_to_pfn(paddr);
-	struct vm_struct *area;
-	unsigned long vaddr;
-	int err;
-
-	paddr &= PAGE_MASK;
-
+	unsigned long pfn = __phys_to_pfn((phys_addr));
 	WARN_ON(pfn_valid(pfn));
 
-	size = PAGE_ALIGN(offset + size);
-
-	area = get_vm_area(size, VM_IOREMAP);
-	if (!area)
-		return NULL;
-
-	vaddr = (unsigned long)area->addr;
-	area->phys_addr = paddr;
-
-	err = ioremap_page_range(vaddr, vaddr + size, paddr, prot);
-
-	if (err) {
-		vunmap((void *)vaddr);
-		return NULL;
-	}
-
-	flush_cache_vmap(vaddr, vaddr + size);
-	return (void __iomem *)(offset + vaddr);
-}
-
-void __iomem *xtensa_ioremap_nocache(unsigned long addr, unsigned long size)
-{
-	return xtensa_ioremap(addr, size, pgprot_noncached(PAGE_KERNEL));
+	return generic_ioremap_prot(phys_addr, size, __pgprot(prot));
 }
-EXPORT_SYMBOL(xtensa_ioremap_nocache);
+EXPORT_SYMBOL(ioremap_prot);
 
-void __iomem *xtensa_ioremap_cache(unsigned long addr, unsigned long size)
+void iounmap(volatile void __iomem *addr)
 {
-	return xtensa_ioremap(addr, size, PAGE_KERNEL);
-}
-EXPORT_SYMBOL(xtensa_ioremap_cache);
+	unsigned long va = (unsigned long) addr;
 
-void xtensa_iounmap(volatile void __iomem *io_addr)
-{
-	void *addr = (void *)(PAGE_MASK & (unsigned long)io_addr);
+	if ((va >= XCHAL_KIO_CACHED_VADDR &&
+	      va - XCHAL_KIO_CACHED_VADDR < XCHAL_KIO_SIZE) ||
+	    (va >= XCHAL_KIO_BYPASS_VADDR &&
+	      va - XCHAL_KIO_BYPASS_VADDR < XCHAL_KIO_SIZE))
+		return;
 
-	vunmap(addr);
+	generic_iounmap(addr);
 }
-EXPORT_SYMBOL(xtensa_iounmap);
+EXPORT_SYMBOL(iounmap);
-- 
2.34.1