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-rw-r--r--drivers/pci/hotplug/acpiphp_ibm.c489
1 files changed, 489 insertions, 0 deletions
diff --git a/drivers/pci/hotplug/acpiphp_ibm.c b/drivers/pci/hotplug/acpiphp_ibm.c
new file mode 100644
index 000000000..df48b3b03
--- /dev/null
+++ b/drivers/pci/hotplug/acpiphp_ibm.c
@@ -0,0 +1,489 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * ACPI PCI Hot Plug IBM Extension
+ *
+ * Copyright (C) 2004 Vernon Mauery <vernux@us.ibm.com>
+ * Copyright (C) 2004 IBM Corp.
+ *
+ * All rights reserved.
+ *
+ * Send feedback to <vernux@us.ibm.com>
+ *
+ */
+
+#define pr_fmt(fmt) "acpiphp_ibm: " fmt
+
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/sysfs.h>
+#include <linux/kobject.h>
+#include <linux/moduleparam.h>
+#include <linux/pci.h>
+#include <linux/uaccess.h>
+
+#include "acpiphp.h"
+#include "../pci.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"
+
+
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRIVER_VERSION);
+
+#define FOUND_APCI 0x61504349
+/* these are the names for the IBM ACPI pseudo-device */
+#define IBM_HARDWARE_ID1 "IBM37D0"
+#define IBM_HARDWARE_ID2 "IBM37D4"
+
+#define hpslot_to_sun(A) (to_slot(A)->sun)
+
+/* 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;
+ u8 res[3];
+ } 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 file *filp, struct kobject *kobj,
+ struct bin_attribute *bin_attr,
+ 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 __ro_after_init = {
+ .attr = {
+ .name = "apci_table",
+ .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_slot_from_id - workaround for bad ibm hardware
+ * @id: the slot number that linux refers to the slot by
+ *
+ * Description: This method returns the aCPI slot descriptor
+ * corresponding to the Linux slot number. This descriptor
+ * has info about the aPCI slot id and attention status.
+ * This descriptor must be freed using kfree when done.
+ */
+static union apci_descriptor *ibm_slot_from_id(int id)
+{
+ int ind = 0, size;
+ union apci_descriptor *ret = NULL, *des;
+ char *table;
+
+ size = ibm_get_table_from_acpi(&table);
+ if (size < 0)
+ return NULL;
+ des = (union apci_descriptor *)table;
+ if (memcmp(des->header.sig, "aPCI", 4) != 0)
+ goto ibm_slot_done;
+
+ des = (union apci_descriptor *)&table[ind += des->header.len];
+ while (ind < size && (des->generic.type != 0x82 ||
+ des->slot.slot_num != id)) {
+ des = (union apci_descriptor *)&table[ind += des->generic.len];
+ }
+
+ if (ind < size && des->slot.slot_num == id)
+ ret = des;
+
+ibm_slot_done:
+ if (ret) {
+ ret = kmalloc(sizeof(union apci_descriptor), GFP_KERNEL);
+ if (ret)
+ memcpy(ret, des, sizeof(union apci_descriptor));
+ }
+ kfree(table);
+ return ret;
+}
+
+/**
+ * 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)
+{
+ union acpi_object args[2];
+ struct acpi_object_list params = { .pointer = args, .count = 2 };
+ acpi_status stat;
+ unsigned long long rc;
+ union apci_descriptor *ibm_slot;
+ int id = hpslot_to_sun(slot);
+
+ ibm_slot = ibm_slot_from_id(id);
+ if (!ibm_slot) {
+ pr_err("APLS null ACPI descriptor for slot %d\n", id);
+ return -ENODEV;
+ }
+
+ pr_debug("%s: set slot %d (%d) attention status to %d\n", __func__,
+ ibm_slot->slot.slot_num, ibm_slot->slot.slot_id,
+ (status ? 1 : 0));
+
+ args[0].type = ACPI_TYPE_INTEGER;
+ args[0].integer.value = ibm_slot->slot.slot_id;
+ args[1].type = ACPI_TYPE_INTEGER;
+ args[1].integer.value = (status) ? 1 : 0;
+
+ kfree(ibm_slot);
+
+ stat = acpi_evaluate_integer(ibm_acpi_handle, "APLS", &params, &rc);
+ if (ACPI_FAILURE(stat)) {
+ pr_err("APLS evaluation failed: 0x%08x\n", stat);
+ return -ENODEV;
+ } else if (!rc) {
+ pr_err("APLS method failed: 0x%08llx\n", rc);
+ return -ERANGE;
+ }
+ return 0;
+}
+
+/**
+ * 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)
+{
+ union apci_descriptor *ibm_slot;
+ int id = hpslot_to_sun(slot);
+
+ ibm_slot = ibm_slot_from_id(id);
+ if (!ibm_slot) {
+ pr_err("APLS null ACPI descriptor for slot %d\n", id);
+ return -ENODEV;
+ }
+
+ if (ibm_slot->slot.attn & 0xa0 || ibm_slot->slot.status[1] & 0x08)
+ *status = 1;
+ else
+ *status = 0;
+
+ pr_debug("%s: get slot %d (%d) attention status is %d\n", __func__,
+ ibm_slot->slot.slot_num, ibm_slot->slot.slot_id,
+ *status);
+
+ kfree(ibm_slot);
+ return 0;
+}
+
+/**
+ * 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;
+
+ pr_debug("%s: Received notification %02x\n", __func__, event);
+
+ if (subevent == 0x80) {
+ pr_debug("%s: generating bus event\n", __func__);
+ acpi_bus_generate_netlink_event(note->device->pnp.device_class,
+ dev_name(&note->device->dev),
+ 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)) {
+ pr_err("%s: APCI evaluation failed\n", __func__);
+ return -ENODEV;
+ }
+
+ package = (union acpi_object *) buffer.pointer;
+ if (!(package) ||
+ (package->type != ACPI_TYPE_PACKAGE) ||
+ !(package->package.elements)) {
+ pr_err("%s: Invalid APCI object\n", __func__);
+ goto read_table_done;
+ }
+
+ for (size = 0, i = 0; i < package->package.count; i++) {
+ if (package->package.elements[i].type != ACPI_TYPE_BUFFER) {
+ pr_err("%s: Invalid APCI element %d\n", __func__, i);
+ goto read_table_done;
+ }
+ size += package->package.elements[i].buffer.length;
+ }
+
+ if (bufp == NULL)
+ goto read_table_done;
+
+ lbuf = kzalloc(size, GFP_KERNEL);
+ pr_debug("%s: element count: %i, ASL table size: %i, &table = 0x%p\n",
+ __func__, package->package.count, size, lbuf);
+
+ if (lbuf) {
+ *bufp = lbuf;
+ } 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
+ * @filp: the open sysfs file
+ * @kobj: the kobject this binary attribute is a part of
+ * @bin_attr: struct bin_attribute for this file
+ * @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 file *filp, struct kobject *kobj,
+ struct bin_attribute *bin_attr,
+ char *buffer, loff_t pos, size_t size)
+{
+ int bytes_read = -EINVAL;
+ char *table = NULL;
+
+ pr_debug("%s: pos = %d, size = %zd\n", __func__, (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;
+ unsigned long long current_status = 0;
+ acpi_status status;
+ struct acpi_device_info *info;
+ int retval = 0;
+
+ status = acpi_get_object_info(handle, &info);
+ if (ACPI_FAILURE(status)) {
+ pr_err("%s: Failed to get device information status=0x%x\n",
+ __func__, status);
+ return retval;
+ }
+
+ acpi_bus_get_status_handle(handle, &current_status);
+
+ if (current_status && (info->valid & ACPI_VALID_HID) &&
+ (!strcmp(info->hardware_id.string, IBM_HARDWARE_ID1) ||
+ !strcmp(info->hardware_id.string, IBM_HARDWARE_ID2))) {
+ pr_debug("found hardware: %s, handle: %p\n",
+ info->hardware_id.string, 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...
+ */
+ retval = FOUND_APCI;
+ }
+ kfree(info);
+ return retval;
+}
+
+static int __init ibm_acpiphp_init(void)
+{
+ int retval = 0;
+ acpi_status status;
+ struct acpi_device *device;
+ struct kobject *sysdir = &pci_slots_kset->kobj;
+
+ pr_debug("%s\n", __func__);
+
+ if (acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
+ ACPI_UINT32_MAX, ibm_find_acpi_device, NULL,
+ &ibm_acpi_handle, NULL) != FOUND_APCI) {
+ pr_err("%s: acpi_walk_namespace failed\n", __func__);
+ retval = -ENODEV;
+ goto init_return;
+ }
+ pr_debug("%s: found IBM aPCI device\n", __func__);
+ if (acpi_bus_get_device(ibm_acpi_handle, &device)) {
+ pr_err("%s: acpi_bus_get_device failed\n", __func__);
+ 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)) {
+ pr_err("%s: Failed to register notification handler\n",
+ __func__);
+ 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_slots_kset->kobj;
+
+ pr_debug("%s\n", __func__);
+
+ if (acpiphp_unregister_attention(&ibm_attention_info))
+ pr_err("%s: attention info deregistration failed", __func__);
+
+ status = acpi_remove_notify_handler(
+ ibm_acpi_handle,
+ ACPI_DEVICE_NOTIFY,
+ ibm_handle_events);
+ if (ACPI_FAILURE(status))
+ pr_err("%s: Notification handler removal failed\n", __func__);
+ /* remove the /sys entries */
+ sysfs_remove_bin_file(sysdir, &ibm_apci_table_attr);
+}
+
+module_init(ibm_acpiphp_init);
+module_exit(ibm_acpiphp_exit);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-04 15:03:39 +0000