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From:   Baoquan He <bhe@redhat.com>
To:     linux-kernel@vger.kernel.org
Cc:     linux-mm@kvack.org, akpm@linux-foundation.org, hch@infradead.org,
        agordeev@linux.ibm.com, wangkefeng.wang@huawei.com,
        linux-arm-kernel@lists.infradead.org, Baoquan He <bhe@redhat.com>,
        Vineet Gupta <vgupta@kernel.org>,
        linux-snps-arc@lists.infradead.org
Subject: [PATCH v2 04/11] arc: mm: Convert to GENERIC_IOREMAP
Date:   Sat, 20 Aug 2022 08:31:18 +0800
Message-Id: <20220820003125.353570-5-bhe@redhat.com>
In-Reply-To: <20220820003125.353570-1-bhe@redhat.com>
References: <20220820003125.353570-1-bhe@redhat.com>
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Add hooks arch_ioremap() and arch_iounmap() for arc's special
operation when ioremap_prot() and iounmap(). Meanwhile define and
implement arc's own ioremap() because arc has some special handling
in ioremap() than standard ioremap().

Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: linux-snps-arc@lists.infradead.org
---
 arch/arc/Kconfig          |  1 +
 arch/arc/include/asm/io.h | 19 +++++++++----
 arch/arc/mm/ioremap.c     | 60 ++++++---------------------------------
 3 files changed, 23 insertions(+), 57 deletions(-)

diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index 9e3653253ef2..a08d2abfaf61 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 8f777d6441a5..af88a2c5550e 100644
--- a/arch/arc/include/asm/io.h
+++ b/arch/arc/include/asm/io.h
@@ -20,9 +20,20 @@
 #define __iowmb()		do { } while (0)
 #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);
+/*
+ * I/O memory mapping functions.
+ */
+
+void __iomem *
+arch_ioremap(phys_addr_t *paddr, size_t size, unsigned long *prot_val);
+#define arch_ioremap arch_ioremap
+
+int arch_iounmap(void __iomem *addr);
+#define arch_iounmap arch_iounmap
+
+void __iomem *ioremap(phys_addr_t paddr, unsigned long size);
+#define ioremap ioremap
+
 static inline void __iomem *ioport_map(unsigned long port, unsigned int nr)
 {
 	return (void __iomem *)port;
@@ -32,8 +43,6 @@ static inline void ioport_unmap(void __iomem *addr)
 {
 }
 
-extern void iounmap(const 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 0ee75aca6e10..72b01da31ea1 100644
--- a/arch/arc/mm/ioremap.c
+++ b/arch/arc/mm/ioremap.c
@@ -25,13 +25,6 @@ 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
@@ -44,62 +37,25 @@ void __iomem *ioremap(phys_addr_t paddr, unsigned long size)
 }
 EXPORT_SYMBOL(ioremap);
 
-/*
- * ioremap with access flags
- * Cache semantics wise it is same as ioremap - "forced" uncached.
- * However unlike vanilla ioremap which bypasses ARC MMU for addresses in
- * 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,
-			   unsigned long flags)
+void __iomem *
+arch_ioremap(phys_addr_t *paddr, size_t size, unsigned long *prot_val)
 {
-	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;
+		return IOMEM_ERR_PTR(-EINVAL);
 
 	/* force uncached */
-	prot = pgprot_noncached(prot);
+	*prot_val = pgprot_val(pgprot_noncached(__pgprot(*prot_val)));
 
-	/* Mappings have to be page-aligned */
-	off = paddr & ~PAGE_MASK;
-	paddr &= PAGE_MASK_PHYS;
-	size = PAGE_ALIGN(end + 1) - paddr;
+	return NULL;
 
-	/*
-	 * 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);
 }
-EXPORT_SYMBOL(ioremap_prot);
-
 
-void iounmap(const void __iomem *addr)
+int arch_iounmap(void __iomem *addr)
 {
 	/* weird double cast to handle phys_addr_t > 32 bits */
 	if (arc_uncached_addr_space((phys_addr_t)(u32)addr))
-		return;
+		return -EINVAL;
 
-	vfree((void *)(PAGE_MASK & (unsigned long __force)addr));
+	return 0;
 }
-EXPORT_SYMBOL(iounmap);
-- 
2.34.1