[PATCH v6 15/19] mm/ioremap: Consider IOREMAP space in generic ioremap

Baoquan He
2023-06-09T08:00:39Z

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>
---
v5->v6:
Add definition of IOREMAP_START|END in mm/ioremap.c so that
we can call __get_vm_area_caller() for all ARCH-es - Christoph

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