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>,
        Jonas Bonn <jonas@southpole.se>,
        Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>,
        openrisc@lists.librecores.org
Subject: [PATCH v4 08/16] openrisc: mm: Convert to GENERIC_IOREMAP
Date:   Thu, 16 Feb 2023 20:34:11 +0800
Message-Id: <20230216123419.461016-9-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 function iounmap() for openrisc's special operation
when iounmap().

Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: openrisc@lists.librecores.org
---
 arch/openrisc/Kconfig          |  1 +
 arch/openrisc/include/asm/io.h | 11 +++++---
 arch/openrisc/mm/ioremap.c     | 46 +---------------------------------
 3 files changed, 9 insertions(+), 49 deletions(-)

diff --git a/arch/openrisc/Kconfig b/arch/openrisc/Kconfig
index c7f282f60f64..fd9bb76a610b 100644
--- a/arch/openrisc/Kconfig
+++ b/arch/openrisc/Kconfig
@@ -21,6 +21,7 @@ config OPENRISC
 	select GENERIC_IRQ_PROBE
 	select GENERIC_IRQ_SHOW
 	select GENERIC_PCI_IOMAP
+	select GENERIC_IOREMAP
 	select GENERIC_CPU_DEVICES
 	select HAVE_PCI
 	select HAVE_UID16
diff --git a/arch/openrisc/include/asm/io.h b/arch/openrisc/include/asm/io.h
index ee6043a03173..e640960c26c2 100644
--- a/arch/openrisc/include/asm/io.h
+++ b/arch/openrisc/include/asm/io.h
@@ -15,6 +15,8 @@
 #define __ASM_OPENRISC_IO_H
 
 #include <linux/types.h>
+#include <asm/pgalloc.h>
+#include <asm/pgtable.h>
 
 /*
  * PCI: We do not use IO ports in OpenRISC
@@ -27,11 +29,12 @@
 #define PIO_OFFSET		0
 #define PIO_MASK		0
 
-#define ioremap ioremap
-void __iomem *ioremap(phys_addr_t offset, unsigned long size);
-
+/*
+ * I/O memory mapping functions.
+ */
 #define iounmap iounmap
-extern void iounmap(volatile void __iomem *addr);
+
+#define _PAGE_IOREMAP (pgprot_val(PAGE_KERNEL) | _PAGE_CI)
 
 #include <asm-generic/io.h>
 
diff --git a/arch/openrisc/mm/ioremap.c b/arch/openrisc/mm/ioremap.c
index 90b59bc53c8c..9f9941df7d4c 100644
--- a/arch/openrisc/mm/ioremap.c
+++ b/arch/openrisc/mm/ioremap.c
@@ -22,49 +22,6 @@
 
 extern int mem_init_done;
 
-/*
- * Remap an arbitrary physical address space into the kernel virtual
- * address space. Needed when the kernel wants to access high addresses
- * directly.
- *
- * NOTE! We need to allow non-page-aligned mappings too: we will obviously
- * have to convert them into an offset in a page-aligned mapping, but the
- * caller shouldn't need to know that small detail.
- */
-void __iomem *__ref ioremap(phys_addr_t addr, unsigned long size)
-{
-	phys_addr_t p;
-	unsigned long v;
-	unsigned long offset, last_addr;
-	struct vm_struct *area = NULL;
-
-	/* Don't allow wraparound or zero size */
-	last_addr = addr + size - 1;
-	if (!size || last_addr < addr)
-		return NULL;
-
-	/*
-	 * Mappings have to be page-aligned
-	 */
-	offset = addr & ~PAGE_MASK;
-	p = addr & PAGE_MASK;
-	size = PAGE_ALIGN(last_addr + 1) - p;
-
-	area = get_vm_area(size, VM_IOREMAP);
-	if (!area)
-		return NULL;
-	v = (unsigned long)area->addr;
-
-	if (ioremap_page_range(v, v + size, p,
-			__pgprot(pgprot_val(PAGE_KERNEL) | _PAGE_CI))) {
-		vfree(area->addr);
-		return NULL;
-	}
-
-	return (void __iomem *)(offset + (char *)v);
-}
-EXPORT_SYMBOL(ioremap);
-
 void iounmap(volatile void __iomem *addr)
 {
 	/* If the page is from the fixmap pool then we just clear out
@@ -88,9 +45,8 @@ void iounmap(volatile void __iomem *addr)
 		return;
 	}
 
-	return vfree((void *)(PAGE_MASK & (unsigned long)addr));
+	generic_iounmap(addr);
 }
-EXPORT_SYMBOL(iounmap);
 
 /**
  * OK, this one's a bit tricky... ioremap can get called before memory is
-- 
2.34.1