Re: [PATCH] PCI and I2C fixes for 2.6.8

Greg KH
2004-08-23T19:34:54Z

ChangeSet 1.1784.41.2, 2004/07/14 13:30:11-07:00, vernux@us.ibm.com

[PATCH] PCI Hotplug: acpiphp extension for 2.6.7 part 2

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.

Signed-off-by: Vernon Mauery <vernux@us.ibm.com>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

drivers/pci/hotplug/Kconfig | 12
drivers/pci/hotplug/Makefile | 1
drivers/pci/hotplug/acpiphp_ibm.c | 474 ++++++++++++++++++++++++++++++++++++++
3 files changed, 487 insertions(+)

diff -Nru a/drivers/pci/hotplug/Kconfig b/drivers/pci/hotplug/Kconfig
--- a/drivers/pci/hotplug/Kconfig 2004-08-23 11:09:07 -07:00
+++ b/drivers/pci/hotplug/Kconfig 2004-08-23 11:09:07 -07:00
@@ -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 -Nru a/drivers/pci/hotplug/Makefile b/drivers/pci/hotplug/Makefile
--- a/drivers/pci/hotplug/Makefile 2004-08-23 11:09:07 -07:00
+++ b/drivers/pci/hotplug/Makefile 2004-08-23 11:09:07 -07:00
@@ -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 -Nru a/drivers/pci/hotplug/acpiphp_ibm.c b/drivers/pci/hotplug/acpiphp_ibm.c
--- /dev/null Wed Dec 31 16:00:00 196900
+++ b/drivers/pci/hotplug/acpiphp_ibm.c 2004-08-23 11:09:07 -07:00
@@ -0,0 +1,474 @@
+/*
+ * 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_param(debug, bool, 644);
+MODULE_PARM_DESC(debug, " Debugging mode enabled or not");
+#define MY_NAME "acpiphp_ibm"
+
+#undef dbg
+#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;
+};
+
+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 acpi_handle ibm_acpi_handle;
+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
+ * @slot: the hotplug_slot to work with
+ * @status: what to set the LED to (0 or 1)
+ *
+ * Description: 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;
+
+ acpi_slot = ((struct slot *)(slot->private))->acpi_slot;
+
+ 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
+ * @slot: the hotplug_slot to work with
+ * @status: returns what the LED is set to (0 or 1)
+ *
+ * Description: 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;
+
+ acpi_slot = ((struct slot *)(slot->private))->acpi_slot;
+
+ 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:
+ kfree(table);
+ return retval;
+}
+
+/**
+ * ibm_handle_events - listens for ACPI events for the IBM37D0 device
+ * @handle: an ACPI handle to the device that caused the event
+ * @event: the event info (device specific)
+ * @context: passed context (our notification struct)
+ *
+ * Description: 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.
+ *
+ * From section 5.6.2.2 of the ACPI 2.0 spec, I understand that the OSPM will
+ * only re-enable the interrupt that causes this event AFTER this method
+ * has returned, thereby enforcing serial access for the notification struct.
+ **/
+static void ibm_handle_events(acpi_handle handle, u32 event, void *context)
+{
+ u8 detail = event & 0x0f;
+ u8 subevent = event & 0xf0;
+ struct notification *note = 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
+ * @bufp: address to pointer to allocate for the table
+ *
+ * Description: 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%p\n",
+ __FUNCTION__, package->package.count, size, 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
+ * @kobj: the kobject this binary attribute is a part of
+ * @buffer: the kernel space buffer to fill
+ * @pos: the offset into the file
+ * @size: the number of bytes requested
+ *
+ * Description: 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);
+ kfree(table);
+ }
+ return bytes_read;
+}
+
+/**
+ * ibm_find_acpi_device - callback to find our ACPI device
+ * @handle: the ACPI handle of the device we are inspecting
+ * @lvl: depth into the namespace tree
+ * @context: a pointer to our handle to fill when we find the device
+ * @rv: a return value to fill if desired
+ *
+ * Description: 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(&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,
+ &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(&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(&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);