Ever since the PCI hotplug core was introduced in 2002, drivers had to allocate and register a struct hotplug_slot_info for every slot: https://git.kernel.org/tglx/history/c/a8a2069f432c Apparently the idea was that drivers furnish the hotplug core with an up-to-date card presence status, power status, latch status and attention indicator status as well as notify the hotplug core of changes thereof. However only 4 out of 12 hotplug drivers bother to notify the hotplug core with pci_hp_change_slot_info() and the hotplug core never made any use of the information: There is just a single macro in pci_hotplug_core.c, GET_STATUS(), which uses the hotplug_slot_info if the driver lacks the corresponding callback in hotplug_slot_ops. The macro is called when the user reads the attribute via sysfs. Now, if the callback isn't defined, the attribute isn't exposed in sysfs in the first place (see e.g. has_power_file()). There are only two situations when the hotplug_slot_info would actually be accessed: * If the driver defines ->enable_slot or ->disable_slot but not ->get_power_status. * If the driver defines ->set_attention_status but not ->get_attention_status. There is no driver doing the former and just a single driver doing the latter, namely pnv_php.c. Amend it with a ->get_attention_status callback. With that, the hotplug_slot_info becomes completely unused by the PCI hotplug core. But a few drivers use it internally as a cache: cpcihp uses it to cache the latch_status and adapter_status. cpqhp uses it to cache the adapter_status. pnv_php and rpaphp use it to cache the attention_status. shpchp uses it to cache all four values. Amend these drivers to cache the information in their private slot struct. shpchp's slot struct already contains members to cache the power_status and adapter_status, so additional members are only needed for the other two values. In the case of cpqphp, the cached value is only accessed in a single place, so instead of caching it, read the current value from the hardware. Caution: acpiphp, cpci, cpqhp, shpchp, asus-wmi and eeepc-laptop populate the hotplug_slot_info with initial values on probe. That code is herewith removed. There is a theoretical chance that the code has side effects without which the driver fails to function, e.g. if the ACPI method to read the adapter status needs to be executed at least once on probe. That seems unlikely to me, still maintainers should review the changes carefully for this possibility. Rafael adds: "I'm not aware of any case in which it will break anything, [...] but if that happens, it may be necessary to add the execution of the control methods in question directly to the initialization part." Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com> # drivers/pci/hotplug/rpa* Acked-by: Sebastian Ott <sebott@linux.ibm.com> # drivers/pci/hotplug/s390* Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com> # drivers/platform/x86 Cc: Len Brown <lenb@kernel.org> Cc: Scott Murray <scott@spiteful.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Oliver OHalloran <oliveroh@au1.ibm.com> Cc: Gavin Shan <gwshan@linux.vnet.ibm.com> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Cc: Corentin Chary <corentin.chary@gmail.com> Cc: Darren Hart <dvhart@infradead.org>
491 lines
11 KiB
C
491 lines
11 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* PCI Hot Plug Controller Driver for RPA-compliant PPC64 platform.
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* Copyright (C) 2003 Linda Xie <lxie@us.ibm.com>
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*
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* All rights reserved.
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*
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* Send feedback to <lxie@us.ibm.com>
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*
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/pci.h>
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#include <linux/pci_hotplug.h>
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#include <linux/smp.h>
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#include <linux/init.h>
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#include <linux/vmalloc.h>
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#include <asm/firmware.h>
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#include <asm/eeh.h> /* for eeh_add_device() */
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#include <asm/rtas.h> /* rtas_call */
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#include <asm/pci-bridge.h> /* for pci_controller */
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#include "../pci.h" /* for pci_add_new_bus */
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/* and pci_do_scan_bus */
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#include "rpaphp.h"
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bool rpaphp_debug;
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LIST_HEAD(rpaphp_slot_head);
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EXPORT_SYMBOL_GPL(rpaphp_slot_head);
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#define DRIVER_VERSION "0.1"
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#define DRIVER_AUTHOR "Linda Xie <lxie@us.ibm.com>"
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#define DRIVER_DESC "RPA HOT Plug PCI Controller Driver"
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#define MAX_LOC_CODE 128
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MODULE_AUTHOR(DRIVER_AUTHOR);
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MODULE_DESCRIPTION(DRIVER_DESC);
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MODULE_LICENSE("GPL");
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module_param_named(debug, rpaphp_debug, bool, 0644);
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/**
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* set_attention_status - set attention LED
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* @hotplug_slot: target &hotplug_slot
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* @value: LED control value
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*
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* echo 0 > attention -- set LED OFF
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* echo 1 > attention -- set LED ON
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* echo 2 > attention -- set LED ID(identify, light is blinking)
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*/
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static int set_attention_status(struct hotplug_slot *hotplug_slot, u8 value)
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{
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int rc;
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struct slot *slot = (struct slot *)hotplug_slot->private;
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switch (value) {
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case 0:
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case 1:
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case 2:
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break;
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default:
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value = 1;
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break;
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}
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rc = rtas_set_indicator(DR_INDICATOR, slot->index, value);
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if (!rc)
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slot->attention_status = value;
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return rc;
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}
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/**
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* get_power_status - get power status of a slot
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* @hotplug_slot: slot to get status
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* @value: pointer to store status
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*/
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static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
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{
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int retval, level;
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struct slot *slot = (struct slot *)hotplug_slot->private;
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retval = rtas_get_power_level(slot->power_domain, &level);
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if (!retval)
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*value = level;
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return retval;
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}
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/**
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* get_attention_status - get attention LED status
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* @hotplug_slot: slot to get status
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* @value: pointer to store status
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*/
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static int get_attention_status(struct hotplug_slot *hotplug_slot, u8 *value)
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{
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struct slot *slot = (struct slot *)hotplug_slot->private;
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*value = slot->attention_status;
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return 0;
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}
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static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
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{
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struct slot *slot = (struct slot *)hotplug_slot->private;
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int rc, state;
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rc = rpaphp_get_sensor_state(slot, &state);
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*value = NOT_VALID;
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if (rc)
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return rc;
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if (state == EMPTY)
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*value = EMPTY;
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else if (state == PRESENT)
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*value = slot->state;
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return 0;
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}
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static enum pci_bus_speed get_max_bus_speed(struct slot *slot)
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{
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enum pci_bus_speed speed;
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switch (slot->type) {
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case 1:
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case 2:
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case 3:
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case 4:
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case 5:
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case 6:
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speed = PCI_SPEED_33MHz; /* speed for case 1-6 */
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break;
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case 7:
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case 8:
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speed = PCI_SPEED_66MHz;
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break;
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case 11:
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case 14:
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speed = PCI_SPEED_66MHz_PCIX;
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break;
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case 12:
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case 15:
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speed = PCI_SPEED_100MHz_PCIX;
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break;
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case 13:
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case 16:
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speed = PCI_SPEED_133MHz_PCIX;
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break;
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default:
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speed = PCI_SPEED_UNKNOWN;
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break;
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}
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return speed;
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}
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static int get_children_props(struct device_node *dn, const int **drc_indexes,
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const int **drc_names, const int **drc_types,
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const int **drc_power_domains)
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{
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const int *indexes, *names, *types, *domains;
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indexes = of_get_property(dn, "ibm,drc-indexes", NULL);
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names = of_get_property(dn, "ibm,drc-names", NULL);
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types = of_get_property(dn, "ibm,drc-types", NULL);
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domains = of_get_property(dn, "ibm,drc-power-domains", NULL);
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if (!indexes || !names || !types || !domains) {
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/* Slot does not have dynamically-removable children */
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return -EINVAL;
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}
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if (drc_indexes)
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*drc_indexes = indexes;
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if (drc_names)
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/* &drc_names[1] contains NULL terminated slot names */
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*drc_names = names;
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if (drc_types)
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/* &drc_types[1] contains NULL terminated slot types */
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*drc_types = types;
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if (drc_power_domains)
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*drc_power_domains = domains;
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return 0;
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}
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/* Verify the existence of 'drc_name' and/or 'drc_type' within the
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* current node. First obtain it's my-drc-index property. Next,
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* obtain the DRC info from it's parent. Use the my-drc-index for
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* correlation, and obtain/validate the requested properties.
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*/
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static int rpaphp_check_drc_props_v1(struct device_node *dn, char *drc_name,
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char *drc_type, unsigned int my_index)
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{
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char *name_tmp, *type_tmp;
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const int *indexes, *names;
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const int *types, *domains;
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int i, rc;
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rc = get_children_props(dn->parent, &indexes, &names, &types, &domains);
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if (rc < 0) {
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return -EINVAL;
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}
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name_tmp = (char *) &names[1];
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type_tmp = (char *) &types[1];
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/* Iterate through parent properties, looking for my-drc-index */
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for (i = 0; i < be32_to_cpu(indexes[0]); i++) {
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if ((unsigned int) indexes[i + 1] == my_index)
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break;
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name_tmp += (strlen(name_tmp) + 1);
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type_tmp += (strlen(type_tmp) + 1);
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}
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if (((drc_name == NULL) || (drc_name && !strcmp(drc_name, name_tmp))) &&
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((drc_type == NULL) || (drc_type && !strcmp(drc_type, type_tmp))))
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return 0;
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return -EINVAL;
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}
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static int rpaphp_check_drc_props_v2(struct device_node *dn, char *drc_name,
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char *drc_type, unsigned int my_index)
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{
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struct property *info;
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unsigned int entries;
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struct of_drc_info drc;
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const __be32 *value;
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char cell_drc_name[MAX_DRC_NAME_LEN];
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int j, fndit;
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info = of_find_property(dn->parent, "ibm,drc-info", NULL);
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if (info == NULL)
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return -EINVAL;
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value = of_prop_next_u32(info, NULL, &entries);
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if (!value)
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return -EINVAL;
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for (j = 0; j < entries; j++) {
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of_read_drc_info_cell(&info, &value, &drc);
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/* Should now know end of current entry */
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if (my_index > drc.last_drc_index)
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continue;
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fndit = 1;
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break;
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}
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/* Found it */
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if (fndit)
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sprintf(cell_drc_name, "%s%d", drc.drc_name_prefix,
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my_index);
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if (((drc_name == NULL) ||
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(drc_name && !strcmp(drc_name, cell_drc_name))) &&
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((drc_type == NULL) ||
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(drc_type && !strcmp(drc_type, drc.drc_type))))
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return 0;
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return -EINVAL;
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}
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int rpaphp_check_drc_props(struct device_node *dn, char *drc_name,
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char *drc_type)
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{
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const unsigned int *my_index;
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my_index = of_get_property(dn, "ibm,my-drc-index", NULL);
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if (!my_index) {
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/* Node isn't DLPAR/hotplug capable */
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return -EINVAL;
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}
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if (firmware_has_feature(FW_FEATURE_DRC_INFO))
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return rpaphp_check_drc_props_v2(dn, drc_name, drc_type,
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*my_index);
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else
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return rpaphp_check_drc_props_v1(dn, drc_name, drc_type,
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*my_index);
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}
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EXPORT_SYMBOL_GPL(rpaphp_check_drc_props);
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static int is_php_type(char *drc_type)
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{
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unsigned long value;
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char *endptr;
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/* PCI Hotplug nodes have an integer for drc_type */
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value = simple_strtoul(drc_type, &endptr, 10);
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if (endptr == drc_type)
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return 0;
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return 1;
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}
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/**
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* is_php_dn() - return 1 if this is a hotpluggable pci slot, else 0
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* @dn: target &device_node
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* @indexes: passed to get_children_props()
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* @names: passed to get_children_props()
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* @types: returned from get_children_props()
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* @power_domains:
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*
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* This routine will return true only if the device node is
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* a hotpluggable slot. This routine will return false
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* for built-in pci slots (even when the built-in slots are
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* dlparable.)
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*/
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static int is_php_dn(struct device_node *dn, const int **indexes,
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const int **names, const int **types, const int **power_domains)
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{
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const int *drc_types;
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int rc;
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rc = get_children_props(dn, indexes, names, &drc_types, power_domains);
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if (rc < 0)
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return 0;
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if (!is_php_type((char *) &drc_types[1]))
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return 0;
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*types = drc_types;
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return 1;
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}
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/**
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* rpaphp_add_slot -- declare a hotplug slot to the hotplug subsystem.
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* @dn: device node of slot
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*
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* This subroutine will register a hotpluggable slot with the
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* PCI hotplug infrastructure. This routine is typically called
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* during boot time, if the hotplug slots are present at boot time,
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* or is called later, by the dlpar add code, if the slot is
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* being dynamically added during runtime.
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*
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* If the device node points at an embedded (built-in) slot, this
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* routine will just return without doing anything, since embedded
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* slots cannot be hotplugged.
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*
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* To remove a slot, it suffices to call rpaphp_deregister_slot().
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*/
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int rpaphp_add_slot(struct device_node *dn)
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{
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struct slot *slot;
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int retval = 0;
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int i;
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const int *indexes, *names, *types, *power_domains;
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char *name, *type;
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if (!dn->name || strcmp(dn->name, "pci"))
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return 0;
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/* If this is not a hotplug slot, return without doing anything. */
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if (!is_php_dn(dn, &indexes, &names, &types, &power_domains))
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return 0;
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dbg("Entry %s: dn=%pOF\n", __func__, dn);
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/* register PCI devices */
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name = (char *) &names[1];
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type = (char *) &types[1];
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for (i = 0; i < be32_to_cpu(indexes[0]); i++) {
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int index;
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index = be32_to_cpu(indexes[i + 1]);
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slot = alloc_slot_struct(dn, index, name,
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be32_to_cpu(power_domains[i + 1]));
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if (!slot)
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return -ENOMEM;
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slot->type = simple_strtoul(type, NULL, 10);
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dbg("Found drc-index:0x%x drc-name:%s drc-type:%s\n",
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index, name, type);
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retval = rpaphp_enable_slot(slot);
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if (!retval)
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retval = rpaphp_register_slot(slot);
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if (retval)
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dealloc_slot_struct(slot);
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name += strlen(name) + 1;
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type += strlen(type) + 1;
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}
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dbg("%s - Exit: rc[%d]\n", __func__, retval);
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/* XXX FIXME: reports a failure only if last entry in loop failed */
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return retval;
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}
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EXPORT_SYMBOL_GPL(rpaphp_add_slot);
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static void __exit cleanup_slots(void)
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{
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struct slot *slot, *next;
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/*
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* Unregister all of our slots with the pci_hotplug subsystem,
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* and free up all memory that we had allocated.
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*/
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list_for_each_entry_safe(slot, next, &rpaphp_slot_head,
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rpaphp_slot_list) {
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list_del(&slot->rpaphp_slot_list);
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pci_hp_deregister(slot->hotplug_slot);
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dealloc_slot_struct(slot);
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}
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return;
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}
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static int __init rpaphp_init(void)
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{
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struct device_node *dn;
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info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
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for_each_node_by_name(dn, "pci")
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rpaphp_add_slot(dn);
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return 0;
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}
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static void __exit rpaphp_exit(void)
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{
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cleanup_slots();
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}
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static int enable_slot(struct hotplug_slot *hotplug_slot)
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{
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struct slot *slot = (struct slot *)hotplug_slot->private;
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int state;
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int retval;
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if (slot->state == CONFIGURED)
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return 0;
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retval = rpaphp_get_sensor_state(slot, &state);
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if (retval)
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return retval;
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if (state == PRESENT) {
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pci_lock_rescan_remove();
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pci_hp_add_devices(slot->bus);
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pci_unlock_rescan_remove();
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slot->state = CONFIGURED;
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} else if (state == EMPTY) {
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slot->state = EMPTY;
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} else {
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err("%s: slot[%s] is in invalid state\n", __func__, slot->name);
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slot->state = NOT_VALID;
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return -EINVAL;
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}
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slot->bus->max_bus_speed = get_max_bus_speed(slot);
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return 0;
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}
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static int disable_slot(struct hotplug_slot *hotplug_slot)
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{
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struct slot *slot = (struct slot *)hotplug_slot->private;
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if (slot->state == NOT_CONFIGURED)
|
|
return -EINVAL;
|
|
|
|
pci_lock_rescan_remove();
|
|
pci_hp_remove_devices(slot->bus);
|
|
pci_unlock_rescan_remove();
|
|
vm_unmap_aliases();
|
|
|
|
slot->state = NOT_CONFIGURED;
|
|
return 0;
|
|
}
|
|
|
|
const struct hotplug_slot_ops rpaphp_hotplug_slot_ops = {
|
|
.enable_slot = enable_slot,
|
|
.disable_slot = disable_slot,
|
|
.set_attention_status = set_attention_status,
|
|
.get_power_status = get_power_status,
|
|
.get_attention_status = get_attention_status,
|
|
.get_adapter_status = get_adapter_status,
|
|
};
|
|
|
|
module_init(rpaphp_init);
|
|
module_exit(rpaphp_exit);
|