diff options
Diffstat (limited to 'drivers/pci/hotplug/acpiphp_ibm.c')
| -rw-r--r-- | drivers/pci/hotplug/acpiphp_ibm.c | 489 |
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", ¶ms, &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(¬e->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, ¤t_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); |