Orange Pi5 kernel

// 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);