[PATCH v2 36/37] ACPI: Enable SCI_EMULATE to manually simulate physical hotplug testing.

From: Yinghai Lu
Date: Sat Mar 10 2012 - 02:04:41 EST


From: Ashok Raj <ashok.raj@xxxxxxxxx>

Emulate an ACPI SCI interrupt to emulate a hot-plug event. Useful
for testing ACPI based hot-plug on systems that don't have the
necessary firmware support.

Enable CONFIG_ACPI_SCI_EMULATE on kernel compile.

Now you will notice /proc/acpi/sci/notify when new kernel is booted.

echo "\_SB.CPU4 1" > /proc/acpi/sci/notify to trigger a hot-add of CPU4.
You will now notice an entry /sys/firmware/acpi/namespace/ACPI/_SB/CPU4
if the namespace had an entry CPU4 under _SB scope. If the entry had a
_EJ0 method, you will also notice a file "eject" under the CPU4 directory.

-v2: Update to current upstream, and remove not related stuff.

Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
Cc: Len Brown <lenb@xxxxxxxxxx>
Cc: linux-acpi@xxxxxxxxxxxxxxx

===================================================================
---
drivers/acpi/Kconfig | 10 +++
drivers/acpi/Makefile | 1 +
drivers/acpi/bus.c | 2 +
drivers/acpi/internal.h | 6 ++
drivers/acpi/sci_emu.c | 141 +++++++++++++++++++++++++++++++++++++++++++++++
5 files changed, 160 insertions(+), 0 deletions(-)
create mode 100644 drivers/acpi/sci_emu.c

diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 7556913..b7b8541 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -272,6 +272,16 @@ config ACPI_BLACKLIST_YEAR
Enter 0 to disable this mechanism and allow ACPI to
run by default no matter what the year. (default)

+config ACPI_SCI_EMULATE
+ bool "ACPI SCI Event Emulation Support"
+ depends on ACPI
+ default n
+ help
+ This will enable your system to emulate sci hotplug event
+ notification through proc file system. For example user needs to
+ echo "XXX 0" > /proc/acpi/sci/notify (where, XXX is a target ACPI
+ device object name present under \_SB scope).
+
config ACPI_DEBUG
bool "Debug Statements"
default n
diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index bc6e53f..3580f04 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -31,6 +31,7 @@ acpi-$(CONFIG_ACPI_SLEEP) += proc.o
# ACPI Bus and Device Drivers
#
acpi-y += bus.o glue.o
+acpi-$(CONFIG_ACPI_SCI_EMULATE) += sci_emu.o
acpi-y += scan.o
acpi-y += processor_core.o
acpi-y += ec.o
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 9ecec98..512235e 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -1001,6 +1001,8 @@ static int __init acpi_bus_init(void)
*/
acpi_root_dir = proc_mkdir(ACPI_BUS_FILE_ROOT, NULL);

+ acpi_init_sci_emulate();
+
return 0;

/* Mimic structured exception handling */
diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
index ca75b9c..5b22cd2 100644
--- a/drivers/acpi/internal.h
+++ b/drivers/acpi/internal.h
@@ -34,6 +34,12 @@ int acpi_debugfs_init(void);
static inline void acpi_debugfs_init(void) { return; }
#endif

+#ifdef CONFIG_ACPI_SCI_EMULATE
+int acpi_init_sci_emulate(void);
+#else
+static inline int acpi_init_sci_emulate(void) { return 0; }
+#endif
+
/* --------------------------------------------------------------------------
Power Resource
-------------------------------------------------------------------------- */
diff --git a/drivers/acpi/sci_emu.c b/drivers/acpi/sci_emu.c
new file mode 100644
index 0000000..d972436
--- /dev/null
+++ b/drivers/acpi/sci_emu.c
@@ -0,0 +1,141 @@
+/*
+ * Code to emulate SCI interrupt for Hotplug node insertion/removal
+ */
+#include <linux/kernel.h>
+#include <linux/proc_fs.h>
+#include <linux/acpi.h>
+
+#include "internal.h"
+
+#include "acpica/accommon.h"
+#include "acpica/acnamesp.h"
+#include "acpica/acevents.h"
+
+#define _COMPONENT ACPI_SYSTEM_COMPONENT
+ACPI_MODULE_NAME("sci_emu");
+
+static void acpi_sci_notify_client(char *acpi_name, u32 event);
+static int acpi_sci_notify_write_proc(struct file *file, const char *buffer, \
+ unsigned long count, void *data);
+struct proc_dir_entry *acpi_sci_dir;
+
+static int acpi_sci_notify_write_proc(struct file *file, const char *buffer,
+ unsigned long count, void *data)
+{
+ u32 event;
+ char *name1 = NULL;
+ char *name2 = NULL;
+ char *end_name = NULL;
+ const char *delim = " ";
+ char *temp_buf = NULL;
+ char *temp_buf_addr = NULL;
+
+ temp_buf = kmalloc(count+1, GFP_ATOMIC);
+ if (!temp_buf) {
+ printk(KERN_WARNING PREFIX
+ "acpi_sci_notify_wire_proc: Memory allocation failed\n");
+ return count;
+ }
+ temp_buf[count] = '\0';
+ temp_buf_addr = temp_buf;
+ memcpy(temp_buf, buffer, count);
+ name1 = strsep(&temp_buf, delim);
+ name2 = strsep(&temp_buf, delim);
+
+ if (name1 && name2)
+ event = simple_strtoul(name2, &end_name, 10);
+ else {
+ printk(KERN_WARNING PREFIX "unknown device\n");
+ kfree(temp_buf_addr);
+ return count;
+ }
+
+ printk(KERN_INFO PREFIX
+ "ACPI device name is <%s>, event code is <%d>\n",
+ name1, event);
+
+ acpi_sci_notify_client(name1, event);
+
+ kfree(temp_buf_addr);
+
+ return count;
+}
+
+static void acpi_sci_notify_client(char *acpi_name, u32 event)
+{
+ struct acpi_namespace_node *node;
+ acpi_status status, status1;
+ acpi_handle hlsb, hsb;
+ union acpi_operand_object *obj_desc;
+
+ status = acpi_get_handle(NULL, "\\_SB", &hsb);
+ status1 = acpi_get_handle(hsb, acpi_name, &hlsb);
+ if (ACPI_FAILURE(status) || ACPI_FAILURE(status1)) {
+ printk(KERN_ERR PREFIX
+ "acpi getting handle to <\\_SB.%s> failed inside notify_client\n",
+ acpi_name);
+ return;
+ }
+
+ status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
+ if (ACPI_FAILURE(status)) {
+ printk(KERN_ERR PREFIX "Acquiring acpi namespace mutext failed\n");
+ return;
+ }
+
+ node = acpi_ns_validate_handle(hlsb);
+ if (!node) {
+ acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
+ printk(KERN_ERR PREFIX "Mapping handle to node failed\n");
+ return;
+ }
+
+ /*
+ * Check for internal object and make sure there is a handler
+ * registered for this object
+ */
+ obj_desc = acpi_ns_get_attached_object(node);
+ if (obj_desc) {
+ if (obj_desc->common_notify.system_notify) {
+ /*
+ * Release the lock and queue the item for later
+ * exectuion
+ */
+ acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
+ status = acpi_ev_queue_notify_request(node, event);
+ if (ACPI_FAILURE(status))
+ printk(KERN_ERR PREFIX "acpi_ev_queue_notify_request failed\n");
+ else
+ printk(KERN_INFO PREFIX "Notify event is queued\n");
+ return;
+ }
+ } else {
+ printk(KERN_INFO PREFIX "Notify handler not registered for this device\n");
+ }
+
+ acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
+ return;
+}
+
+int __init acpi_init_sci_emulate(void)
+{
+ struct proc_dir_entry *notify_entry = NULL;
+
+ ACPI_FUNCTION_TRACE("acpi_init_sci_emulate");
+
+ acpi_sci_dir = proc_mkdir("sci", acpi_root_dir);
+ if (!acpi_sci_dir)
+ return_VALUE(-ENODEV);
+
+ notify_entry = create_proc_entry("notify", \
+ S_IWUGO|S_IRUGO, acpi_sci_dir);
+ if (!notify_entry) {
+ ACPI_DEBUG_PRINT((ACPI_DB_INIT,
+ "Unable to create '%s' fs entry\n", "notify"));
+ } else {
+ notify_entry->write_proc = acpi_sci_notify_write_proc;
+ notify_entry->data = NULL;
+ }
+
+ return_VALUE(0);
+}
--
1.7.7

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