From: Ashok Raj ashok.raj@intel.com
This patch is for hotplug test only.
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 yinghai@kernel.org Cc: Len Brown lenb@kernel.org Cc: linux-acpi@vger.kernel.org --- drivers/acpi/Kconfig | 10 ++++ drivers/acpi/Makefile | 1 + drivers/acpi/sci_emu.c | 145 ++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 156 insertions(+) create mode 100644 drivers/acpi/sci_emu.c
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig index 85f774a..0d7f6eb 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -294,6 +294,16 @@ 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 fc0949f..6412cd1 100644 --- a/drivers/acpi/Makefile +++ b/drivers/acpi/Makefile @@ -32,6 +32,7 @@ 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 += resource.o acpi-y += acpi_processor.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);