From:   Baoquan He <bhe@redhat.com>
To:     linux-kernel@vger.kernel.org
Cc:     linux-mm@kvack.org, akpm@linux-foundation.org,
        christophe.leroy@csgroup.eu, hch@infradead.org,
        agordeev@linux.ibm.com, wangkefeng.wang@huawei.com,
        schnelle@linux.ibm.com, David.Laight@ACULAB.COM, shorne@gmail.com,
        arnd@arndb.de, Baoquan He <bhe@redhat.com>,
        Vineet Gupta <vgupta@kernel.org>,
        linux-snps-arc@lists.infradead.org
Subject: [PATCH v4 06/16] arc: mm: Convert to GENERIC_IOREMAP
Date:   Thu, 16 Feb 2023 20:34:09 +0800
Message-Id: <20230216123419.461016-7-bhe@redhat.com>
In-Reply-To: <20230216123419.461016-1-bhe@redhat.com>
References: <20230216123419.461016-1-bhe@redhat.com>
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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() and iounmap() for arc's
special operation when ioremap_prot() and iounmap().

Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: linux-snps-arc@lists.infradead.org
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/arc/Kconfig          |  1 +
 arch/arc/include/asm/io.h |  7 +++---
 arch/arc/mm/ioremap.c     | 49 ++++-----------------------------------
 3 files changed, 8 insertions(+), 49 deletions(-)

diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index d9a13ccf89a3..37da34ac7abf 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -26,6 +26,7 @@ config ARC
 	select GENERIC_PENDING_IRQ if SMP
 	select GENERIC_SCHED_CLOCK
 	select GENERIC_SMP_IDLE_THREAD
+	select GENERIC_IOREMAP
 	select HAVE_ARCH_KGDB
 	select HAVE_ARCH_TRACEHOOK
 	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if ARC_MMU_V4
diff --git a/arch/arc/include/asm/io.h b/arch/arc/include/asm/io.h
index 80347382a380..4fdb7350636c 100644
--- a/arch/arc/include/asm/io.h
+++ b/arch/arc/include/asm/io.h
@@ -21,8 +21,9 @@
 #endif
 
 extern void __iomem *ioremap(phys_addr_t paddr, unsigned long size);
-extern void __iomem *ioremap_prot(phys_addr_t paddr, unsigned long size,
-				  unsigned long flags);
+#define ioremap ioremap
+#define ioremap_prot ioremap_prot
+#define iounmap iounmap
 static inline void __iomem *ioport_map(unsigned long port, unsigned int nr)
 {
 	return (void __iomem *)port;
@@ -32,8 +33,6 @@ static inline void ioport_unmap(void __iomem *addr)
 {
 }
 
-extern void iounmap(const volatile void __iomem *addr);
-
 /*
  * io{read,write}{16,32}be() macros
  */
diff --git a/arch/arc/mm/ioremap.c b/arch/arc/mm/ioremap.c
index 712c2311daef..b07004d53267 100644
--- a/arch/arc/mm/ioremap.c
+++ b/arch/arc/mm/ioremap.c
@@ -8,7 +8,6 @@
 #include <linux/module.h>
 #include <linux/io.h>
 #include <linux/mm.h>
-#include <linux/slab.h>
 #include <linux/cache.h>
 
 static inline bool arc_uncached_addr_space(phys_addr_t paddr)
@@ -25,13 +24,6 @@ static inline bool arc_uncached_addr_space(phys_addr_t paddr)
 
 void __iomem *ioremap(phys_addr_t paddr, unsigned long size)
 {
-	phys_addr_t end;
-
-	/* Don't allow wraparound or zero size */
-	end = paddr + size - 1;
-	if (!size || (end < paddr))
-		return NULL;
-
 	/*
 	 * If the region is h/w uncached, MMU mapping can be elided as optim
 	 * The cast to u32 is fine as this region can only be inside 4GB
@@ -51,55 +43,22 @@ EXPORT_SYMBOL(ioremap);
  * ARC hardware uncached region, this one still goes thru the MMU as caller
  * might need finer access control (R/W/X)
  */
-void __iomem *ioremap_prot(phys_addr_t paddr, unsigned long size,
+void __iomem *ioremap_prot(phys_addr_t paddr, size_t size,
 			   unsigned long flags)
 {
-	unsigned int off;
-	unsigned long vaddr;
-	struct vm_struct *area;
-	phys_addr_t end;
 	pgprot_t prot = __pgprot(flags);
 
-	/* Don't allow wraparound, zero size */
-	end = paddr + size - 1;
-	if ((!size) || (end < paddr))
-		return NULL;
-
-	/* An early platform driver might end up here */
-	if (!slab_is_available())
-		return NULL;
-
 	/* force uncached */
-	prot = pgprot_noncached(prot);
-
-	/* Mappings have to be page-aligned */
-	off = paddr & ~PAGE_MASK;
-	paddr &= PAGE_MASK_PHYS;
-	size = PAGE_ALIGN(end + 1) - paddr;
-
-	/*
-	 * Ok, go for it..
-	 */
-	area = get_vm_area(size, VM_IOREMAP);
-	if (!area)
-		return NULL;
-	area->phys_addr = paddr;
-	vaddr = (unsigned long)area->addr;
-	if (ioremap_page_range(vaddr, vaddr + size, paddr, prot)) {
-		vunmap((void __force *)vaddr);
-		return NULL;
-	}
-	return (void __iomem *)(off + (char __iomem *)vaddr);
+	return generic_ioremap_prot(paddr, size, pgprot_noncached(prot));
 }
 EXPORT_SYMBOL(ioremap_prot);
 
-
-void iounmap(const volatile void __iomem *addr)
+void iounmap(volatile void __iomem *addr)
 {
 	/* weird double cast to handle phys_addr_t > 32 bits */
 	if (arc_uncached_addr_space((phys_addr_t)(u32)addr))
 		return;
 
-	vfree((void *)(PAGE_MASK & (unsigned long __force)addr));
+	generic_iounmap(addr);
 }
 EXPORT_SYMBOL(iounmap);
-- 
2.34.1