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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>
Subject: [PATCH v8 15/19] mm/ioremap: Consider IOREMAP space in generic ioremap
Date:   Thu,  6 Jul 2023 23:45:16 +0800
Message-Id: <20230706154520.11257-16-bhe@redhat.com>
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References: <20230706154520.11257-1-bhe@redhat.com>
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From: Christophe Leroy <christophe.leroy@csgroup.eu>

Architectures like powerpc have a dedicated space for IOREMAP mappings.

If so, use it in generic_ioremap_prot().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 mm/ioremap.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/mm/ioremap.c b/mm/ioremap.c
index 86b82ec27d2b..68d9895144ad 100644
--- a/mm/ioremap.c
+++ b/mm/ioremap.c
@@ -11,6 +11,15 @@
 #include <linux/io.h>
 #include <linux/export.h>
 
+/*
+ * Ioremap often, but not always uses the generic vmalloc area. E.g on
+ * Power ARCH, it could have different ioremap space.
+ */
+#ifndef IOREMAP_START
+#define IOREMAP_START   VMALLOC_START
+#define IOREMAP_END     VMALLOC_END
+#endif
+
 void __iomem *generic_ioremap_prot(phys_addr_t phys_addr, size_t size,
 				   pgprot_t prot)
 {
@@ -35,8 +44,8 @@ void __iomem *generic_ioremap_prot(phys_addr_t phys_addr, size_t size,
 	if (!ioremap_allowed(phys_addr, size, pgprot_val(prot)))
 		return NULL;
 
-	area = get_vm_area_caller(size, VM_IOREMAP,
-			__builtin_return_address(0));
+	area = __get_vm_area_caller(size, VM_IOREMAP, IOREMAP_START,
+				    IOREMAP_END, __builtin_return_address(0));
 	if (!area)
 		return NULL;
 	vaddr = (unsigned long)area->addr;
@@ -66,7 +75,7 @@ void generic_iounmap(volatile void __iomem *addr)
 	if (!iounmap_allowed(vaddr))
 		return;
 
-	if (is_vmalloc_addr(vaddr))
+	if (is_ioremap_addr(vaddr))
 		vunmap(vaddr);
 }
 
-- 
2.34.1