From: Ashok Raj <ashok....@intel.com>
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 /sys/kernel/debug/acpi/sci_notify when new kernel is
booted.
echo "\_SB.PCIB 1" > /sys/kernel/debug/acpi/sci_notify to trigger a hot-add
of root bus that is corresponding to PCIB.
echo "\_SB.PCIB 3" > /sys/kernel/debug/acpi/sci_notify to trigger a hot-remove
of root bus that is corresponding to PCIB.
-v2: Update to current upstream, and remove not related stuff.
-v3: According to Len's request, update it to use debugfs. - Yinghai Lu
Signed-off-by: Yinghai Lu <ying...@kernel.org>
Cc: Len Brown <l...@kernel.org>
Cc: linux-a...@vger.kernel.org
===================================================================
---
drivers/acpi/Kconfig | 10 +++
drivers/acpi/Makefile | 1 +
drivers/acpi/sci_emu.c | 145 ++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 156 insertions(+), 0 deletions(-)
create mode 100644 drivers/acpi/sci_emu.c
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 8099895..227f7ee 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 DEBUG_FS
+ 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" > /sys/kernel/debug/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 c9abd4c..40b3021 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/sci_emu.c b/drivers/acpi/sci_emu.c
new file mode 100644
index 0000000..2f13ca1
--- /dev/null
+++ b/drivers/acpi/sci_emu.c
@@ -0,0 +1,145 @@
+/*
+ * Code to emulate SCI interrupt for Hotplug node insertion/removal
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/uaccess.h>
+#include <linux/debugfs.h>
+#include <acpi/acpi_drivers.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");
+MODULE_LICENSE("GPL");
+
+static struct dentry *sci_notify_dentry;
+
+static void 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)) {
+ pr_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)) {
+ pr_err(PREFIX "Acquiring acpi namespace mutext failed\n");
+ return;
+ }
+
+ node = acpi_ns_validate_handle(hlsb);
+ if (!node) {
+ acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
+ pr_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.notify_list[0]) {
+ /*
+ * 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))
+ pr_err(PREFIX "acpi_ev_queue_notify_request
failed\n");
+ else
+ pr_info(PREFIX "Notify event is queued\n");
+ return;
+ }
+ } else {
+ pr_info(PREFIX "Notify handler not registered for this
device\n");
+ }
+
+ acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
+ return;
+}
+
+static ssize_t sci_notify_write(struct file *file, const char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ u32 event;
+ char *name1 = NULL;
+ char *name2 = NULL;
+ const char *delim = " ";
+ char *temp_buf = NULL;
+ char *temp_buf_addr = NULL;
+
+ temp_buf = kmalloc(count+1, GFP_ATOMIC);
+ if (!temp_buf) {
+ pr_warn(PREFIX "sci_notify_wire: Memory allocation failed\n");
+ return count;
+ }
+ temp_buf[count] = '\0';
+ temp_buf_addr = temp_buf;
+ if (copy_from_user(temp_buf, user_buf, count))
+ goto out;
+
+ name1 = strsep(&temp_buf, delim);
+ name2 = strsep(&temp_buf, delim);
+
+ if (name1 && name2) {
+ ssize_t ret;
+ unsigned long val;
+
+ ret = kstrtoul(name2, 10, &val);
+ if (ret) {
+ pr_warn(PREFIX "unknown event\n");
+ goto out;
+ }
+
+ event = (u32)val;
+ } else {
+ pr_warn(PREFIX "unknown device\n");
+ goto out;
+ }
+
+ pr_info(PREFIX "ACPI device name is <%s>, event code is <%d>\n",
+ name1, event);
+
+ sci_notify_client(name1, event);
+
+out:
+ kfree(temp_buf_addr);
+ return count;
+}
+
+static const struct file_operations sci_notify_fops = {
+ .write = sci_notify_write,
+};
+
+static int __init acpi_sci_notify_init(void)
+{
+ if (acpi_debugfs_dir == NULL)
+ return -ENOENT;
+
+ sci_notify_dentry = debugfs_create_file("sci_notify", S_IWUSR,
+ acpi_debugfs_dir, NULL, &sci_notify_fops);
+ if (sci_notify_dentry == NULL)
+ return -ENODEV;
+
+ return 0;
+}
+
+device_initcall(acpi_sci_notify_init);
--
1.7.7
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