aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorHaren Myneni <haren@us.ibm.com>2012-07-11 15:18:44 +1000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2012-07-11 18:22:32 +1000
commite1612de9e4cdf375c3cf1c72434ab8abdcb3927e (patch)
treed2bf73a13ea6e92c9c79d4300294584ef82767c2
parent475d0094293b51353e342d1198377967dbc48169 (diff)
downloadlinaro-lsk-e1612de9e4cdf375c3cf1c72434ab8abdcb3927e.tar.gz
powerpc: Disable /dev/port interface on systems without an ISA bridge
Some power systems do not have legacy ISA devices. So, /dev/port is not a valid interface on these systems. User level tools such as kbdrate is trying to access the device using this interface which is causing the system crash. This patch will fix this issue by not creating this interface on these powerpc systems. Signed-off-by: Haren Myneni <haren@us.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
-rw-r--r--arch/powerpc/include/asm/io.h8
-rw-r--r--drivers/char/mem.c11
-rw-r--r--include/linux/io.h9
3 files changed, 27 insertions, 1 deletions
diff --git a/arch/powerpc/include/asm/io.h b/arch/powerpc/include/asm/io.h
index a3855b81ead..f94ef4213e9 100644
--- a/arch/powerpc/include/asm/io.h
+++ b/arch/powerpc/include/asm/io.h
@@ -20,6 +20,14 @@ extern int check_legacy_ioport(unsigned long base_port);
#define _PNPWRP 0xa79
#define PNPBIOS_BASE 0xf000
+#if defined(CONFIG_PPC64) && defined(CONFIG_PCI)
+extern struct pci_dev *isa_bridge_pcidev;
+/*
+ * has legacy ISA devices ?
+ */
+#define arch_has_dev_port() (isa_bridge_pcidev != NULL)
+#endif
+
#include <linux/device.h>
#include <linux/io.h>
diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 67c3371723c..e5eedfa24c9 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -27,14 +27,16 @@
#include <linux/splice.h>
#include <linux/pfn.h>
#include <linux/export.h>
+#include <linux/io.h>
#include <asm/uaccess.h>
-#include <asm/io.h>
#ifdef CONFIG_IA64
# include <linux/efi.h>
#endif
+#define DEVPORT_MINOR 4
+
static inline unsigned long size_inside_page(unsigned long start,
unsigned long size)
{
@@ -894,6 +896,13 @@ static int __init chr_dev_init(void)
for (minor = 1; minor < ARRAY_SIZE(devlist); minor++) {
if (!devlist[minor].name)
continue;
+
+ /*
+ * Create /dev/port?
+ */
+ if ((minor == DEVPORT_MINOR) && !arch_has_dev_port())
+ continue;
+
device_create(mem_class, NULL, MKDEV(MEM_MAJOR, minor),
NULL, devlist[minor].name);
}
diff --git a/include/linux/io.h b/include/linux/io.h
index 7fd2d2138bf..069e4075f87 100644
--- a/include/linux/io.h
+++ b/include/linux/io.h
@@ -67,4 +67,13 @@ int check_signature(const volatile void __iomem *io_addr,
const unsigned char *signature, int length);
void devm_ioremap_release(struct device *dev, void *res);
+/*
+ * Some systems do not have legacy ISA devices.
+ * /dev/port is not a valid interface on these systems.
+ * So for those archs, <asm/io.h> should define the following symbol.
+ */
+#ifndef arch_has_dev_port
+#define arch_has_dev_port() (1)
+#endif
+
#endif /* _LINUX_IO_H */