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From:   Baoquan He <bhe@redhat.com>
To:     linux-kernel@vger.kernel.org
Cc:     akpm@linux-foundation.org, linux-mm@kvack.org, arnd@arndb.de,
        hch@lst.de, christophe.leroy@csgroup.eu, rppt@kernel.org,
        willy@infradead.org, agordeev@linux.ibm.com,
        wangkefeng.wang@huawei.com, schnelle@linux.ibm.com,
        shorne@gmail.com, David.Laight@ACULAB.COM, deller@gmx.de,
        nathan@kernel.org, glaubitz@physik.fu-berlin.de,
        Baoquan He <bhe@redhat.com>, Jonas Bonn <jonas@southpole.se>,
        Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>,
        openrisc@lists.librecores.org
Subject: [PATCH v8 09/19] openrisc: mm: Convert to GENERIC_IOREMAP
Date:   Thu,  6 Jul 2023 23:45:10 +0800
Message-Id: <20230706154520.11257-10-bhe@redhat.com>
In-Reply-To: <20230706154520.11257-1-bhe@redhat.com>
References: <20230706154520.11257-1-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 code
with generic_ioremap_prot() and generic_iounmap(), and has the equivalent
functioality as before.

For openrisc, the current ioremap() and iounmap() are the same as
generic version. After taking GENERIC_IOREMAP way, the old ioremap()
and iounmap() can be completely removed.

Signed-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
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     | 49 ----------------------------------
 3 files changed, 7 insertions(+), 54 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..5a6f0f16a5ce 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 +29,10 @@
 #define PIO_OFFSET		0
 #define PIO_MASK		0
 
-#define ioremap ioremap
-void __iomem *ioremap(phys_addr_t offset, unsigned long size);
-
-#define iounmap iounmap
-extern void iounmap(volatile void __iomem *addr);
+/*
+ * I/O memory mapping functions.
+ */
+#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 cdbcc7e73684..91c8259d4b7e 100644
--- a/arch/openrisc/mm/ioremap.c
+++ b/arch/openrisc/mm/ioremap.c
@@ -22,55 +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)
-{
-	return vfree((void *)(PAGE_MASK & (unsigned long)addr));
-}
-EXPORT_SYMBOL(iounmap);
-
 /**
  * OK, this one's a bit tricky... ioremap can get called before memory is
  * initialized (early serial console does this) and will want to alloc a page
-- 
2.34.1