[PATCH] [2/2] acpiphp extension for 2.6.7

[Vernon Mauery <vernux@us.ibm.com>]

02 - acpiphp_ibm-v1.0.1c.patch

        This patch adds the first driver that actually uses the callback
        function for attention LEDs that the acpiphp-attention patch
        adds.  It searches the ACPI namespace for IBM hardware, sets up
        the callbacks and sets up a handler to read ACPI events and
        forward them on to /proc/acpi/event.  It also exports an ACPI
        table that shows current hotplug status to userland.


 Kconfig       |   12 +
 Makefile      |    1
 acpiphp_ibm.c |  476 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 489 insertions(+)


Signed-off-by: Vernon Mauery <vernux@us.ibm.com>


=====================================================================


diff -ruN -X dontdiff linux-2.6.7.orig/drivers/pci/hotplug/Kconfig linux-2.6.7-apci/drivers/pci/hotplug/Kconfig
--- linux-2.6.7.orig/drivers/pci/hotplug/Kconfig	2004-06-15 22:19:17.000000000 -0700
+++ linux-2.6.7-apci/drivers/pci/hotplug/Kconfig	2004-06-22 11:49:38.000000000 -0700
@@ -88,6 +88,18 @@
 
 	  When in doubt, say N.
 
+config HOTPLUG_PCI_ACPI_IBM
+	tristate "ACPI PCI Hotplug driver IBM extensions"
+	depends on HOTPLUG_PCI_ACPI
+	help
+	  Say Y here if you have an IBM system that supports PCI Hotplug using
+	  ACPI.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called acpiphp_ibm.
+
+	  When in doubt, say N.
+
 config HOTPLUG_PCI_CPCI
 	bool "CompactPCI Hotplug driver"
 	depends on HOTPLUG_PCI
diff -ruN -X dontdiff linux-2.6.7.orig/drivers/pci/hotplug/Makefile linux-2.6.7-apci/drivers/pci/hotplug/Makefile
--- linux-2.6.7.orig/drivers/pci/hotplug/Makefile	2004-06-15 22:19:43.000000000 -0700
+++ linux-2.6.7-apci/drivers/pci/hotplug/Makefile	2004-06-22 11:49:38.000000000 -0700
@@ -7,6 +7,7 @@
 obj-$(CONFIG_HOTPLUG_PCI_COMPAQ)	+= cpqphp.o
 obj-$(CONFIG_HOTPLUG_PCI_IBM)		+= ibmphp.o
 obj-$(CONFIG_HOTPLUG_PCI_ACPI)		+= acpiphp.o
+obj-$(CONFIG_HOTPLUG_PCI_ACPI_IBM)	+= acpiphp_ibm.o
 obj-$(CONFIG_HOTPLUG_PCI_CPCI_ZT5550)	+= cpcihp_zt5550.o
 obj-$(CONFIG_HOTPLUG_PCI_CPCI_GENERIC)	+= cpcihp_generic.o
 obj-$(CONFIG_HOTPLUG_PCI_PCIE)		+= pciehp.o
diff -ruN -X dontdiff linux-2.6.7.orig/drivers/pci/hotplug/acpiphp_ibm.c linux-2.6.7-apci/drivers/pci/hotplug/acpiphp_ibm.c
--- linux-2.6.7.orig/drivers/pci/hotplug/acpiphp_ibm.c	1969-12-31 16:00:00.000000000 -0800
+++ linux-2.6.7-apci/drivers/pci/hotplug/acpiphp_ibm.c	2004-06-29 16:06:59.877502816 -0700
@@ -0,0 +1,476 @@
+/*
+ * ACPI PCI Hot Plug IBM Extension
+ *
+ * Copyright (C) 2004 Vernon Mauery <vernux@us.ibm.com>
+ * Copyright (C) 2004 IBM Corp.
+ *
+ * All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT.  See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * Send feedback to <vernux@us.ibm.com>
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <acpi/acpi_bus.h>
+#include <linux/sysfs.h>
+#include <linux/kobject.h>
+#include <asm/uaccess.h>
+//#include <linux/moduleparam.h>
+
+#include "acpiphp.h"
+#include "pci_hotplug.h"
+
+#define DRIVER_VERSION	"1.0.1"
+#define DRIVER_AUTHOR	"Irene Zubarev <zubarev@us.ibm.com>, Vernon Mauery <vernux@us.ibm.com>"
+#define DRIVER_DESC	"ACPI Hot Plug PCI Controller Driver IBM extension"
+
+static int debug;
+
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRIVER_VERSION);
+MODULE_PARM(debug, "i");
+MODULE_PARM_DESC(debug, " Debugging mode enabled or not");
+#define MY_NAME "acpiphp_ibm"
+
+#ifdef dbg
+#undef dbg
+#endif
+#define dbg(format, arg...)				\
+do {							\
+	if (debug)					\
+		printk(KERN_DEBUG "%s: " format,	\
+				MY_NAME , ## arg);	\
+} while (0)
+
+#define FOUND_APCI 0x61504349
+/* these are the names for the IBM ACPI pseudo-device */
+#define IBM_HARDWARE_ID1 "IBM37D0"
+#define IBM_HARDWARE_ID2 "IBM37D4"
+
+/* union apci_descriptor - allows access to the
+ * various device descriptors that are embedded in the
+ * aPCI table
+ */
+union apci_descriptor {
+	struct {
+		char sig[4];
+		u8   len;
+	} header;
+	struct {
+		u8  type;
+		u8  len;
+		u16 slot_id;
+		u8  bus_id;
+		u8  dev_num;
+		u8  slot_num;
+		u8  slot_attr[2];
+		u8  attn;
+		u8  status[2];
+		u8  sun;
+	} slot;
+	struct {
+		u8 type;
+		u8 len;
+	} generic;
+};
+
+/* struct notification - keeps info about the device
+ * that cause the ACPI notification event
+ */
+struct notification {
+	struct acpi_device *device;
+	u8                  event;
+};
+
+/* forward declarations of functions for this module
+ */
+static int ibm_set_attention_status (struct hotplug_slot *slot, u8 status);
+static int ibm_get_attention_status (struct hotplug_slot *slot, u8 *status);
+static void ibm_handle_events(acpi_handle handle, u32 event, void *context);
+static int ibm_get_table_from_acpi(char **bufp);
+static ssize_t ibm_read_apci_table(struct kobject *kobj,
+		char *buffer, loff_t pos, size_t size);
+static acpi_status __init ibm_find_acpi_device(acpi_handle handle,
+		u32 lvl, void *context, void **rv);
+static int __init ibm_acpiphp_init(void);
+static void __exit ibm_acpiphp_exit(void);
+
+/* static global variables
+ */
+static acpi_handle ibm_acpi_handle = NULL;
+static struct notification ibm_note;
+static struct bin_attribute ibm_apci_table_attr = {
+	    .attr = {
+		    .name = "apci_table",
+		    .owner = THIS_MODULE,
+		    .mode = S_IRUGO,
+	    },
+	    .read = ibm_read_apci_table,
+	    .write = NULL,
+};
+static struct acpiphp_attention_info ibm_attention_info = 
+{
+	.set_attn = ibm_set_attention_status,
+	.get_attn = ibm_get_attention_status,
+	.owner = THIS_MODULE,
+};
+
+
+/*
+ * ibm_set_attention_status - callback method to set the attention LED
+ *
+ * this method is registered with the acpiphp module as a callback
+ * to do the device specific task of setting the LED status
+ *
+ */
+static int ibm_set_attention_status (struct hotplug_slot *slot, u8 status)
+{
+	int retval = 0;
+	union acpi_object args[2]; 
+	struct acpi_object_list params = { .pointer = args, .count = 2 };
+	acpi_status stat; 
+	unsigned long rc = 0;
+	struct acpiphp_slot *acpi_slot;
+
+	if (!slot || !slot->private)
+		return -EINVAL;
+	acpi_slot = ((struct slot *)(slot->private))->acpi_slot;
+	if (!acpi_slot)
+		return -EINVAL;
+
+	dbg("%s: set slot %d attention status to %d\n", __FUNCTION__,
+			acpi_slot->sun, (status ? 1 : 0));
+
+	args[0].type = ACPI_TYPE_INTEGER;
+	args[0].integer.value = acpi_slot->sun;
+	args[1].type = ACPI_TYPE_INTEGER;
+	args[1].integer.value = (status) ? 1 : 0;
+
+	stat = acpi_evaluate_integer(ibm_acpi_handle, "APLS", &params, &rc);
+	if (ACPI_FAILURE(stat)) {
+		retval = -ENODEV;
+		err("APLS evaluation failed:  0x%08x\n", stat);
+	} else if (!rc) {
+		retval = -ERANGE;
+		err("APLS method failed:  0x%08lx\n", rc);
+	}
+	return retval;
+}
+
+/*
+ * ibm_get_attention_status - callback method to get attention LED status
+ *
+ * this method is registered with the acpiphp module as a callback
+ * to do the device specific task of getting the LED status
+ * 
+ * Because there is no direct method of getting the LED status directly
+ * from an ACPI call, we read the aPCI table and parse out our
+ * slot descriptor to read the status from that.
+ *
+ */
+static int ibm_get_attention_status (struct hotplug_slot *slot, u8 *status)
+{
+	int retval = -EINVAL, ind = 0, size;
+	char *table = NULL;
+	struct acpiphp_slot *acpi_slot;
+	union apci_descriptor *des;
+
+	if (!slot || !slot->private)
+		goto get_attn_done;
+	acpi_slot = ((struct slot *)(slot->private))->acpi_slot;
+	if (!acpi_slot)
+		goto get_attn_done;
+
+	size = ibm_get_table_from_acpi(&table);
+	if (size <= 0 || !table)
+		goto get_attn_done;
+	// read the header
+	des = (union apci_descriptor *)&table[ind];
+	if (memcmp(des->header.sig, "aPCI", 4) != 0)
+		goto get_attn_done;
+	des = (union apci_descriptor *)&table[ind += des->header.len];
+	while (ind < size && (des->generic.type != 0x82 ||
+			des->slot.slot_id != acpi_slot->sun))
+		des = (union apci_descriptor *)&table[ind += des->generic.len];
+	if (ind < size && des->slot.slot_id == acpi_slot->sun) {
+		retval = 0;
+		if (des->slot.attn & 0xa0 || des->slot.status[1] & 0x08)
+			*status = 1;
+		else
+			*status = 0;
+	}
+
+	dbg("%s: get slot %d attention status is %d retval=%x\n",
+			__FUNCTION__, acpi_slot->sun, *status, retval);
+
+get_attn_done:
+	if (table)
+		kfree(table);
+	return retval;
+}
+
+/*
+ * ibm_handle_events - listens for ACPI events for the IBM37D0 device
+ *
+ * this method is registered as a callback with the ACPI subsystem
+ * it is called when this device has an event to notify the OS of
+ *
+ * the events actually come from the device as two events that get
+ * synthesized into one event with data by this function.  The event
+ * ID comes first and then the slot number that caused it.  We report
+ * this as one event to the OS.
+ *
+ */
+static void ibm_handle_events(acpi_handle handle, u32 event, void *context)
+{
+	// FIXME: this may have re-entrancy errors with event being static...
+	u8 detail = event & 0x0f;
+	u8 subevent = event & 0xf0;
+
+	struct notification *note = (struct notification *)context;
+
+	dbg("%s: Received notification %02x\n", __FUNCTION__, event);
+
+	if (subevent == 0x80) {
+		dbg("%s: generationg bus event\n", __FUNCTION__);
+		acpi_bus_generate_event(note->device, note->event, detail);
+	} else
+		note->event = event;
+}
+
+/*
+ * ibm_get_table_from_acpi - reads the APLS buffer from ACPI
+ * 
+ * this method reads the APLS buffer in from ACPI and
+ * stores the "stripped" table into a single buffer
+ * it allocates and passes the address back in bufp
+ *
+ * if NULL is passed in as buffer, this method only calculates
+ * the size of the table and returns that without filling
+ * in the buffer
+ *
+ * returns < 0 on error or the size of the table on success
+ */
+static int ibm_get_table_from_acpi(char **bufp)
+{
+	union acpi_object *package;
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	acpi_status status;
+	char *lbuf = NULL;
+	int i, size = -EIO;
+
+	status = acpi_evaluate_object(ibm_acpi_handle, "APCI", NULL, &buffer);
+	if (ACPI_FAILURE(status)) {
+		err("%s:  APCI evaluation failed\n", __FUNCTION__);
+		return -ENODEV;
+	}
+
+	package = (union acpi_object *) buffer.pointer;
+	if(!(package) ||
+			(package->type != ACPI_TYPE_PACKAGE) ||
+			!(package->package.elements)) {
+		err("%s:  Invalid APCI object\n", __FUNCTION__);
+		goto read_table_done;
+	}
+
+	for(size = 0, i = 0; i < package->package.count; i++) {
+		if (package->package.elements[i].type != ACPI_TYPE_BUFFER) {
+			err("%s:  Invalid APCI element %d\n", __FUNCTION__, i);
+			goto read_table_done;
+		}
+		size += package->package.elements[i].buffer.length;
+	}
+
+	if (bufp == NULL)
+		goto read_table_done;
+
+	lbuf = kmalloc(size, GFP_KERNEL);
+	dbg("%s: element count: %i, ASL table size: %i, &table = 0x%x\n",
+			__FUNCTION__, package->package.count, size, (int)lbuf);
+
+	if (lbuf) {
+		*bufp = lbuf;
+		memset(lbuf, 0, size);
+	} else {
+		size = -ENOMEM;
+		goto read_table_done;
+	}
+
+	size = 0;
+	for (i=0; i<package->package.count; i++) {
+		memcpy(&lbuf[size],
+				package->package.elements[i].buffer.pointer,
+				package->package.elements[i].buffer.length);
+		size += package->package.elements[i].buffer.length;
+	}
+
+read_table_done:
+	kfree(buffer.pointer);
+	return size;
+}
+
+/* ibm_read_apci_table - callback for the sysfs apci_table file
+ *
+ * gets registered with sysfs as the reader callback
+ * to be executed when /sys/bus/pci/slots/apci_table gets read
+ *
+ * since we don't get notified on open and close for this file,
+ * things get really tricky here...
+ * our solution is to only allow reading the table in all at once
+ */
+static ssize_t ibm_read_apci_table(struct kobject *kobj,
+		char *buffer, loff_t pos, size_t size)
+{
+	int bytes_read = -EINVAL;
+	char *table = NULL;
+	
+	dbg("%s: pos = %d, size = %d\n", __FUNCTION__, (int)pos, size);
+
+	if (pos == 0) {
+		bytes_read = ibm_get_table_from_acpi(&table);
+		if (bytes_read > 0 && bytes_read <= size)
+			memcpy(buffer, table, bytes_read);
+		if (table)
+			kfree(table);
+	}
+	return bytes_read;
+}
+
+/* ibm_find_acpi_device - callback to find our ACPI device
+ *
+ * used as a callback when calling acpi_walk_namespace
+ * to find our device.  When this method returns non-zero
+ * acpi_walk_namespace quits its search and returns our value
+ */
+static acpi_status __init ibm_find_acpi_device(acpi_handle handle,
+		u32 lvl, void *context, void **rv)
+{
+	acpi_handle *phandle = (acpi_handle *)context;
+	acpi_status status; 
+	struct acpi_device_info info; 
+	struct acpi_buffer info_buffer = {
+		.length = sizeof(struct acpi_device_info),
+		.pointer = &info,
+	};
+
+	status = acpi_get_object_info(handle, &info_buffer);
+	if (ACPI_FAILURE(status)) {
+		err("%s:  Failed to get device information", __FUNCTION__);
+		return 0;
+	}
+	info.hardware_id.value[sizeof(info.hardware_id.value) - 1] = '\0';
+
+	if(info.current_status && (info.valid & ACPI_VALID_HID) &&
+			(!strcmp(info.hardware_id.value, IBM_HARDWARE_ID1) ||
+			!strcmp(info.hardware_id.value, IBM_HARDWARE_ID2))) {
+		dbg("found hardware: %s, handle: %x\n", info.hardware_id.value,
+				(unsigned int)handle);
+		*phandle = handle;
+		/* returning non-zero causes the search to stop
+		 * and returns this value to the caller of 
+		 * acpi_walk_namespace, but it also causes some warnings
+		 * in the acpi debug code to print...
+		 */
+		return FOUND_APCI;
+	}
+	return 0;
+}
+
+static int __init ibm_acpiphp_init(void)
+{
+	int retval = 0;
+	acpi_status status;
+	struct acpi_device *device;
+	struct kobject *sysdir = &pci_hotplug_slots_subsys.kset.kobj;
+
+	dbg("%s\n", __FUNCTION__);
+
+	if (acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
+			ACPI_UINT32_MAX, ibm_find_acpi_device,
+			&ibm_acpi_handle, NULL) != FOUND_APCI) {
+		err("%s: acpi_walk_namespace failed\n", __FUNCTION__);
+		retval = -ENODEV;
+		goto init_return;
+	}
+	dbg("%s: found IBM aPCI device\n", __FUNCTION__);
+	if (acpi_bus_get_device(ibm_acpi_handle, &device)) {
+		err("%s: acpi_bus_get_device failed\n", __FUNCTION__);
+		retval = -ENODEV;
+		goto init_return;
+	}
+	if (acpiphp_register_attention_info(&ibm_attention_info)) {
+		retval = -ENODEV;
+		goto init_return;
+	}
+
+	ibm_note.device = device;
+	status = acpi_install_notify_handler(
+			ibm_acpi_handle,
+			ACPI_DEVICE_NOTIFY,
+			ibm_handle_events,
+			(void *)&ibm_note);
+	if (ACPI_FAILURE(status))
+	{
+		err("%s:  Failed to register notification handler\n",
+				__FUNCTION__);
+		retval = -EBUSY;
+		goto init_cleanup;
+	}
+
+	ibm_apci_table_attr.size = ibm_get_table_from_acpi(NULL);
+	retval = sysfs_create_bin_file(sysdir, &ibm_apci_table_attr);
+
+	return retval;
+
+init_cleanup:
+	acpiphp_unregister_attention_info(&ibm_attention_info);
+init_return:
+	return retval;
+}
+
+static void __exit ibm_acpiphp_exit(void)
+{
+	acpi_status status;
+	struct kobject *sysdir = &pci_hotplug_slots_subsys.kset.kobj;
+
+	dbg("%s\n", __FUNCTION__);
+
+	if (acpiphp_unregister_attention_info(&ibm_attention_info))
+		err("%s: attention info deregistration failed", __FUNCTION__);
+
+	   status = acpi_remove_notify_handler(
+			   ibm_acpi_handle,
+			   ACPI_DEVICE_NOTIFY,
+			   ibm_handle_events);
+	   if (ACPI_FAILURE(status))
+		   err("%s:  Notification handler removal failed\n",
+				   __FUNCTION__);
+	// remove the /sys entries
+	if (sysfs_remove_bin_file(sysdir, &ibm_apci_table_attr))
+		err("%s: removal of sysfs file apci_table failed\n",
+				__FUNCTION__);
+}
+
+module_init(ibm_acpiphp_init);
+module_exit(ibm_acpiphp_exit);
+
+