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Diffstat (limited to 'drivers/acpi/pci_link.c')
-rw-r--r--drivers/acpi/pci_link.c907
1 files changed, 907 insertions, 0 deletions
diff --git a/drivers/acpi/pci_link.c b/drivers/acpi/pci_link.c
new file mode 100644
index 0000000000..aa1038b8ae
--- /dev/null
+++ b/drivers/acpi/pci_link.c
@@ -0,0 +1,907 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * pci_link.c - ACPI PCI Interrupt Link Device Driver ($Revision: 34 $)
+ *
+ * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
+ * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
+ * Copyright (C) 2002 Dominik Brodowski <devel@brodo.de>
+ *
+ * TBD:
+ * 1. Support more than one IRQ resource entry per link device (index).
+ * 2. Implement start/stop mechanism and use ACPI Bus Driver facilities
+ * for IRQ management (e.g. start()->_SRS).
+ */
+
+#define pr_fmt(fmt) "ACPI: PCI: " fmt
+
+#include <linux/syscore_ops.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/spinlock.h>
+#include <linux/pm.h>
+#include <linux/pci.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/acpi.h>
+#include <linux/irq.h>
+
+#include "internal.h"
+
+#define ACPI_PCI_LINK_CLASS "pci_irq_routing"
+#define ACPI_PCI_LINK_DEVICE_NAME "PCI Interrupt Link"
+#define ACPI_PCI_LINK_MAX_POSSIBLE 16
+
+static int acpi_pci_link_add(struct acpi_device *device,
+ const struct acpi_device_id *not_used);
+static void acpi_pci_link_remove(struct acpi_device *device);
+
+static const struct acpi_device_id link_device_ids[] = {
+ {"PNP0C0F", 0},
+ {"", 0},
+};
+
+static struct acpi_scan_handler pci_link_handler = {
+ .ids = link_device_ids,
+ .attach = acpi_pci_link_add,
+ .detach = acpi_pci_link_remove,
+};
+
+/*
+ * If a link is initialized, we never change its active and initialized
+ * later even the link is disable. Instead, we just repick the active irq
+ */
+struct acpi_pci_link_irq {
+ u32 active; /* Current IRQ */
+ u8 triggering; /* All IRQs */
+ u8 polarity; /* All IRQs */
+ u8 resource_type;
+ u8 possible_count;
+ u32 possible[ACPI_PCI_LINK_MAX_POSSIBLE];
+ u8 initialized:1;
+ u8 reserved:7;
+};
+
+struct acpi_pci_link {
+ struct list_head list;
+ struct acpi_device *device;
+ struct acpi_pci_link_irq irq;
+ int refcnt;
+};
+
+static LIST_HEAD(acpi_link_list);
+static DEFINE_MUTEX(acpi_link_lock);
+static int sci_irq = -1, sci_penalty;
+
+/* --------------------------------------------------------------------------
+ PCI Link Device Management
+ -------------------------------------------------------------------------- */
+
+/*
+ * set context (link) possible list from resource list
+ */
+static acpi_status acpi_pci_link_check_possible(struct acpi_resource *resource,
+ void *context)
+{
+ struct acpi_pci_link *link = context;
+ acpi_handle handle = link->device->handle;
+ u32 i;
+
+ switch (resource->type) {
+ case ACPI_RESOURCE_TYPE_START_DEPENDENT:
+ case ACPI_RESOURCE_TYPE_END_TAG:
+ return AE_OK;
+ case ACPI_RESOURCE_TYPE_IRQ:
+ {
+ struct acpi_resource_irq *p = &resource->data.irq;
+ if (!p->interrupt_count) {
+ acpi_handle_debug(handle,
+ "Blank _PRS IRQ resource\n");
+ return AE_OK;
+ }
+ for (i = 0;
+ (i < p->interrupt_count
+ && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
+ if (!p->interrupts[i]) {
+ acpi_handle_debug(handle,
+ "Invalid _PRS IRQ %d\n",
+ p->interrupts[i]);
+ continue;
+ }
+ link->irq.possible[i] = p->interrupts[i];
+ link->irq.possible_count++;
+ }
+ link->irq.triggering = p->triggering;
+ link->irq.polarity = p->polarity;
+ link->irq.resource_type = ACPI_RESOURCE_TYPE_IRQ;
+ break;
+ }
+ case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
+ {
+ struct acpi_resource_extended_irq *p =
+ &resource->data.extended_irq;
+ if (!p->interrupt_count) {
+ acpi_handle_debug(handle,
+ "Blank _PRS EXT IRQ resource\n");
+ return AE_OK;
+ }
+ for (i = 0;
+ (i < p->interrupt_count
+ && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
+ if (!p->interrupts[i]) {
+ acpi_handle_debug(handle,
+ "Invalid _PRS IRQ %d\n",
+ p->interrupts[i]);
+ continue;
+ }
+ link->irq.possible[i] = p->interrupts[i];
+ link->irq.possible_count++;
+ }
+ link->irq.triggering = p->triggering;
+ link->irq.polarity = p->polarity;
+ link->irq.resource_type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
+ break;
+ }
+ default:
+ acpi_handle_debug(handle, "_PRS resource type 0x%x is not IRQ\n",
+ resource->type);
+ return AE_OK;
+ }
+
+ return AE_CTRL_TERMINATE;
+}
+
+static int acpi_pci_link_get_possible(struct acpi_pci_link *link)
+{
+ acpi_handle handle = link->device->handle;
+ acpi_status status;
+
+ status = acpi_walk_resources(handle, METHOD_NAME__PRS,
+ acpi_pci_link_check_possible, link);
+ if (ACPI_FAILURE(status)) {
+ acpi_handle_debug(handle, "_PRS not present or invalid");
+ return 0;
+ }
+
+ acpi_handle_debug(handle, "Found %d possible IRQs\n",
+ link->irq.possible_count);
+
+ return 0;
+}
+
+static acpi_status acpi_pci_link_check_current(struct acpi_resource *resource,
+ void *context)
+{
+ int *irq = context;
+
+ switch (resource->type) {
+ case ACPI_RESOURCE_TYPE_START_DEPENDENT:
+ case ACPI_RESOURCE_TYPE_END_TAG:
+ return AE_OK;
+ case ACPI_RESOURCE_TYPE_IRQ:
+ {
+ struct acpi_resource_irq *p = &resource->data.irq;
+ if (!p->interrupt_count) {
+ /*
+ * IRQ descriptors may have no IRQ# bits set,
+ * particularly those w/ _STA disabled
+ */
+ pr_debug("Blank _CRS IRQ resource\n");
+ return AE_OK;
+ }
+ *irq = p->interrupts[0];
+ break;
+ }
+ case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
+ {
+ struct acpi_resource_extended_irq *p =
+ &resource->data.extended_irq;
+ if (!p->interrupt_count) {
+ /*
+ * extended IRQ descriptors must
+ * return at least 1 IRQ
+ */
+ pr_debug("Blank _CRS EXT IRQ resource\n");
+ return AE_OK;
+ }
+ *irq = p->interrupts[0];
+ break;
+ }
+ break;
+ default:
+ pr_debug("_CRS resource type 0x%x is not IRQ\n",
+ resource->type);
+ return AE_OK;
+ }
+
+ return AE_CTRL_TERMINATE;
+}
+
+/*
+ * Run _CRS and set link->irq.active
+ *
+ * return value:
+ * 0 - success
+ * !0 - failure
+ */
+static int acpi_pci_link_get_current(struct acpi_pci_link *link)
+{
+ acpi_handle handle = link->device->handle;
+ acpi_status status;
+ int result = 0;
+ int irq = 0;
+
+ link->irq.active = 0;
+
+ /* in practice, status disabled is meaningless, ignore it */
+ if (acpi_strict) {
+ /* Query _STA, set link->device->status */
+ result = acpi_bus_get_status(link->device);
+ if (result) {
+ acpi_handle_err(handle, "Unable to read status\n");
+ goto end;
+ }
+
+ if (!link->device->status.enabled) {
+ acpi_handle_debug(handle, "Link disabled\n");
+ return 0;
+ }
+ }
+
+ /*
+ * Query and parse _CRS to get the current IRQ assignment.
+ */
+
+ status = acpi_walk_resources(handle, METHOD_NAME__CRS,
+ acpi_pci_link_check_current, &irq);
+ if (ACPI_FAILURE(status)) {
+ acpi_evaluation_failure_warn(handle, "_CRS", status);
+ result = -ENODEV;
+ goto end;
+ }
+
+ if (acpi_strict && !irq) {
+ acpi_handle_err(handle, "_CRS returned 0\n");
+ result = -ENODEV;
+ }
+
+ link->irq.active = irq;
+
+ acpi_handle_debug(handle, "Link at IRQ %d \n", link->irq.active);
+
+ end:
+ return result;
+}
+
+static int acpi_pci_link_set(struct acpi_pci_link *link, int irq)
+{
+ struct {
+ struct acpi_resource res;
+ struct acpi_resource end;
+ } *resource;
+ struct acpi_buffer buffer = { 0, NULL };
+ acpi_handle handle = link->device->handle;
+ acpi_status status;
+ int result;
+
+ if (!irq)
+ return -EINVAL;
+
+ resource = kzalloc(sizeof(*resource) + 1, irqs_disabled() ? GFP_ATOMIC: GFP_KERNEL);
+ if (!resource)
+ return -ENOMEM;
+
+ buffer.length = sizeof(*resource) + 1;
+ buffer.pointer = resource;
+
+ switch (link->irq.resource_type) {
+ case ACPI_RESOURCE_TYPE_IRQ:
+ resource->res.type = ACPI_RESOURCE_TYPE_IRQ;
+ resource->res.length = sizeof(struct acpi_resource);
+ resource->res.data.irq.triggering = link->irq.triggering;
+ resource->res.data.irq.polarity =
+ link->irq.polarity;
+ if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
+ resource->res.data.irq.shareable =
+ ACPI_EXCLUSIVE;
+ else
+ resource->res.data.irq.shareable = ACPI_SHARED;
+ resource->res.data.irq.interrupt_count = 1;
+ resource->res.data.irq.interrupts[0] = irq;
+ break;
+
+ case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
+ resource->res.type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
+ resource->res.length = sizeof(struct acpi_resource);
+ resource->res.data.extended_irq.producer_consumer =
+ ACPI_CONSUMER;
+ resource->res.data.extended_irq.triggering =
+ link->irq.triggering;
+ resource->res.data.extended_irq.polarity =
+ link->irq.polarity;
+ if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
+ resource->res.data.extended_irq.shareable =
+ ACPI_EXCLUSIVE;
+ else
+ resource->res.data.extended_irq.shareable = ACPI_SHARED;
+ resource->res.data.extended_irq.interrupt_count = 1;
+ resource->res.data.extended_irq.interrupts[0] = irq;
+ /* ignore resource_source, it's optional */
+ break;
+ default:
+ acpi_handle_err(handle, "Invalid resource type %d\n",
+ link->irq.resource_type);
+ result = -EINVAL;
+ goto end;
+
+ }
+ resource->end.type = ACPI_RESOURCE_TYPE_END_TAG;
+ resource->end.length = sizeof(struct acpi_resource);
+
+ /* Attempt to set the resource */
+ status = acpi_set_current_resources(link->device->handle, &buffer);
+
+ /* check for total failure */
+ if (ACPI_FAILURE(status)) {
+ acpi_evaluation_failure_warn(handle, "_SRS", status);
+ result = -ENODEV;
+ goto end;
+ }
+
+ /* Query _STA, set device->status */
+ result = acpi_bus_get_status(link->device);
+ if (result) {
+ acpi_handle_err(handle, "Unable to read status\n");
+ goto end;
+ }
+ if (!link->device->status.enabled)
+ acpi_handle_warn(handle, "Disabled and referenced, BIOS bug\n");
+
+ /* Query _CRS, set link->irq.active */
+ result = acpi_pci_link_get_current(link);
+ if (result) {
+ goto end;
+ }
+
+ /*
+ * Is current setting not what we set?
+ * set link->irq.active
+ */
+ if (link->irq.active != irq) {
+ /*
+ * policy: when _CRS doesn't return what we just _SRS
+ * assume _SRS worked and override _CRS value.
+ */
+ acpi_handle_warn(handle, "BIOS reported IRQ %d, using IRQ %d\n",
+ link->irq.active, irq);
+ link->irq.active = irq;
+ }
+
+ acpi_handle_debug(handle, "Set IRQ %d\n", link->irq.active);
+
+ end:
+ kfree(resource);
+ return result;
+}
+
+/* --------------------------------------------------------------------------
+ PCI Link IRQ Management
+ -------------------------------------------------------------------------- */
+
+/*
+ * "acpi_irq_balance" (default in APIC mode) enables ACPI to use PIC Interrupt
+ * Link Devices to move the PIRQs around to minimize sharing.
+ *
+ * "acpi_irq_nobalance" (default in PIC mode) tells ACPI not to move any PIC IRQs
+ * that the BIOS has already set to active. This is necessary because
+ * ACPI has no automatic means of knowing what ISA IRQs are used. Note that
+ * if the BIOS doesn't set a Link Device active, ACPI needs to program it
+ * even if acpi_irq_nobalance is set.
+ *
+ * A tables of penalties avoids directing PCI interrupts to well known
+ * ISA IRQs. Boot params are available to over-ride the default table:
+ *
+ * List interrupts that are free for PCI use.
+ * acpi_irq_pci=n[,m]
+ *
+ * List interrupts that should not be used for PCI:
+ * acpi_irq_isa=n[,m]
+ *
+ * Note that PCI IRQ routers have a list of possible IRQs,
+ * which may not include the IRQs this table says are available.
+ *
+ * Since this heuristic can't tell the difference between a link
+ * that no device will attach to, vs. a link which may be shared
+ * by multiple active devices -- it is not optimal.
+ *
+ * If interrupt performance is that important, get an IO-APIC system
+ * with a pin dedicated to each device. Or for that matter, an MSI
+ * enabled system.
+ */
+
+#define ACPI_MAX_ISA_IRQS 16
+
+#define PIRQ_PENALTY_PCI_POSSIBLE (16*16)
+#define PIRQ_PENALTY_PCI_USING (16*16*16)
+#define PIRQ_PENALTY_ISA_TYPICAL (16*16*16*16)
+#define PIRQ_PENALTY_ISA_USED (16*16*16*16*16)
+#define PIRQ_PENALTY_ISA_ALWAYS (16*16*16*16*16*16)
+
+static int acpi_isa_irq_penalty[ACPI_MAX_ISA_IRQS] = {
+ PIRQ_PENALTY_ISA_ALWAYS, /* IRQ0 timer */
+ PIRQ_PENALTY_ISA_ALWAYS, /* IRQ1 keyboard */
+ PIRQ_PENALTY_ISA_ALWAYS, /* IRQ2 cascade */
+ PIRQ_PENALTY_ISA_TYPICAL, /* IRQ3 serial */
+ PIRQ_PENALTY_ISA_TYPICAL, /* IRQ4 serial */
+ PIRQ_PENALTY_ISA_TYPICAL, /* IRQ5 sometimes SoundBlaster */
+ PIRQ_PENALTY_ISA_TYPICAL, /* IRQ6 */
+ PIRQ_PENALTY_ISA_TYPICAL, /* IRQ7 parallel, spurious */
+ PIRQ_PENALTY_ISA_TYPICAL, /* IRQ8 rtc, sometimes */
+ 0, /* IRQ9 PCI, often acpi */
+ 0, /* IRQ10 PCI */
+ 0, /* IRQ11 PCI */
+ PIRQ_PENALTY_ISA_USED, /* IRQ12 mouse */
+ PIRQ_PENALTY_ISA_USED, /* IRQ13 fpe, sometimes */
+ PIRQ_PENALTY_ISA_USED, /* IRQ14 ide0 */
+ PIRQ_PENALTY_ISA_USED, /* IRQ15 ide1 */
+ /* >IRQ15 */
+};
+
+static int acpi_irq_pci_sharing_penalty(int irq)
+{
+ struct acpi_pci_link *link;
+ int penalty = 0;
+ int i;
+
+ list_for_each_entry(link, &acpi_link_list, list) {
+ /*
+ * If a link is active, penalize its IRQ heavily
+ * so we try to choose a different IRQ.
+ */
+ if (link->irq.active && link->irq.active == irq)
+ penalty += PIRQ_PENALTY_PCI_USING;
+
+ /*
+ * penalize the IRQs PCI might use, but not as severely.
+ */
+ for (i = 0; i < link->irq.possible_count; i++)
+ if (link->irq.possible[i] == irq)
+ penalty += PIRQ_PENALTY_PCI_POSSIBLE /
+ link->irq.possible_count;
+ }
+
+ return penalty;
+}
+
+static int acpi_irq_get_penalty(int irq)
+{
+ int penalty = 0;
+
+ if (irq == sci_irq)
+ penalty += sci_penalty;
+
+ if (irq < ACPI_MAX_ISA_IRQS)
+ return penalty + acpi_isa_irq_penalty[irq];
+
+ return penalty + acpi_irq_pci_sharing_penalty(irq);
+}
+
+int __init acpi_irq_penalty_init(void)
+{
+ struct acpi_pci_link *link;
+ int i;
+
+ /*
+ * Update penalties to facilitate IRQ balancing.
+ */
+ list_for_each_entry(link, &acpi_link_list, list) {
+
+ /*
+ * reflect the possible and active irqs in the penalty table --
+ * useful for breaking ties.
+ */
+ if (link->irq.possible_count) {
+ int penalty =
+ PIRQ_PENALTY_PCI_POSSIBLE /
+ link->irq.possible_count;
+
+ for (i = 0; i < link->irq.possible_count; i++) {
+ if (link->irq.possible[i] < ACPI_MAX_ISA_IRQS)
+ acpi_isa_irq_penalty[link->irq.
+ possible[i]] +=
+ penalty;
+ }
+
+ } else if (link->irq.active &&
+ (link->irq.active < ACPI_MAX_ISA_IRQS)) {
+ acpi_isa_irq_penalty[link->irq.active] +=
+ PIRQ_PENALTY_PCI_POSSIBLE;
+ }
+ }
+
+ return 0;
+}
+
+static int acpi_irq_balance = -1; /* 0: static, 1: balance */
+
+static int acpi_pci_link_allocate(struct acpi_pci_link *link)
+{
+ acpi_handle handle = link->device->handle;
+ int irq;
+ int i;
+
+ if (link->irq.initialized) {
+ if (link->refcnt == 0)
+ /* This means the link is disabled but initialized */
+ acpi_pci_link_set(link, link->irq.active);
+ return 0;
+ }
+
+ /*
+ * search for active IRQ in list of possible IRQs.
+ */
+ for (i = 0; i < link->irq.possible_count; ++i) {
+ if (link->irq.active == link->irq.possible[i])
+ break;
+ }
+ /*
+ * forget active IRQ that is not in possible list
+ */
+ if (i == link->irq.possible_count) {
+ if (acpi_strict)
+ acpi_handle_warn(handle, "_CRS %d not found in _PRS\n",
+ link->irq.active);
+ link->irq.active = 0;
+ }
+
+ /*
+ * if active found, use it; else pick entry from end of possible list.
+ */
+ if (link->irq.active)
+ irq = link->irq.active;
+ else
+ irq = link->irq.possible[link->irq.possible_count - 1];
+
+ if (acpi_irq_balance || !link->irq.active) {
+ /*
+ * Select the best IRQ. This is done in reverse to promote
+ * the use of IRQs 9, 10, 11, and >15.
+ */
+ for (i = (link->irq.possible_count - 1); i >= 0; i--) {
+ if (acpi_irq_get_penalty(irq) >
+ acpi_irq_get_penalty(link->irq.possible[i]))
+ irq = link->irq.possible[i];
+ }
+ }
+ if (acpi_irq_get_penalty(irq) >= PIRQ_PENALTY_ISA_ALWAYS) {
+ acpi_handle_err(handle,
+ "No IRQ available. Try pci=noacpi or acpi=off\n");
+ return -ENODEV;
+ }
+
+ /* Attempt to enable the link device at this IRQ. */
+ if (acpi_pci_link_set(link, irq)) {
+ acpi_handle_err(handle,
+ "Unable to set IRQ. Try pci=noacpi or acpi=off\n");
+ return -ENODEV;
+ } else {
+ if (link->irq.active < ACPI_MAX_ISA_IRQS)
+ acpi_isa_irq_penalty[link->irq.active] +=
+ PIRQ_PENALTY_PCI_USING;
+
+ acpi_handle_info(handle, "Enabled at IRQ %d\n",
+ link->irq.active);
+ }
+
+ link->irq.initialized = 1;
+ return 0;
+}
+
+/*
+ * acpi_pci_link_allocate_irq
+ * success: return IRQ >= 0
+ * failure: return -1
+ */
+int acpi_pci_link_allocate_irq(acpi_handle handle, int index, int *triggering,
+ int *polarity, char **name)
+{
+ struct acpi_device *device = acpi_fetch_acpi_dev(handle);
+ struct acpi_pci_link *link;
+
+ if (!device) {
+ acpi_handle_err(handle, "Invalid link device\n");
+ return -1;
+ }
+
+ link = acpi_driver_data(device);
+ if (!link) {
+ acpi_handle_err(handle, "Invalid link context\n");
+ return -1;
+ }
+
+ /* TBD: Support multiple index (IRQ) entries per Link Device */
+ if (index) {
+ acpi_handle_err(handle, "Invalid index %d\n", index);
+ return -1;
+ }
+
+ mutex_lock(&acpi_link_lock);
+ if (acpi_pci_link_allocate(link)) {
+ mutex_unlock(&acpi_link_lock);
+ return -1;
+ }
+
+ if (!link->irq.active) {
+ mutex_unlock(&acpi_link_lock);
+ acpi_handle_err(handle, "Link active IRQ is 0!\n");
+ return -1;
+ }
+ link->refcnt++;
+ mutex_unlock(&acpi_link_lock);
+
+ if (triggering)
+ *triggering = link->irq.triggering;
+ if (polarity)
+ *polarity = link->irq.polarity;
+ if (name)
+ *name = acpi_device_bid(link->device);
+ acpi_handle_debug(handle, "Link is referenced\n");
+ return link->irq.active;
+}
+
+/*
+ * We don't change link's irq information here. After it is reenabled, we
+ * continue use the info
+ */
+int acpi_pci_link_free_irq(acpi_handle handle)
+{
+ struct acpi_device *device = acpi_fetch_acpi_dev(handle);
+ struct acpi_pci_link *link;
+
+ if (!device) {
+ acpi_handle_err(handle, "Invalid link device\n");
+ return -1;
+ }
+
+ link = acpi_driver_data(device);
+ if (!link) {
+ acpi_handle_err(handle, "Invalid link context\n");
+ return -1;
+ }
+
+ mutex_lock(&acpi_link_lock);
+ if (!link->irq.initialized) {
+ mutex_unlock(&acpi_link_lock);
+ acpi_handle_err(handle, "Link isn't initialized\n");
+ return -1;
+ }
+#ifdef FUTURE_USE
+ /*
+ * The Link reference count allows us to _DISable an unused link
+ * and suspend time, and set it again on resume.
+ * However, 2.6.12 still has irq_router.resume
+ * which blindly restores the link state.
+ * So we disable the reference count method
+ * to prevent duplicate acpi_pci_link_set()
+ * which would harm some systems
+ */
+ link->refcnt--;
+#endif
+ acpi_handle_debug(handle, "Link is dereferenced\n");
+
+ if (link->refcnt == 0)
+ acpi_evaluate_object(link->device->handle, "_DIS", NULL, NULL);
+
+ mutex_unlock(&acpi_link_lock);
+ return link->irq.active;
+}
+
+/* --------------------------------------------------------------------------
+ Driver Interface
+ -------------------------------------------------------------------------- */
+
+static int acpi_pci_link_add(struct acpi_device *device,
+ const struct acpi_device_id *not_used)
+{
+ acpi_handle handle = device->handle;
+ struct acpi_pci_link *link;
+ int result;
+ int i;
+
+ link = kzalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
+ if (!link)
+ return -ENOMEM;
+
+ link->device = device;
+ strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
+ strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
+ device->driver_data = link;
+
+ mutex_lock(&acpi_link_lock);
+ result = acpi_pci_link_get_possible(link);
+ if (result)
+ goto end;
+
+ /* query and set link->irq.active */
+ acpi_pci_link_get_current(link);
+
+ pr_info("Interrupt link %s configured for IRQ %d\n",
+ acpi_device_bid(device), link->irq.active);
+
+ for (i = 0; i < link->irq.possible_count; i++) {
+ if (link->irq.active != link->irq.possible[i])
+ acpi_handle_debug(handle, "Possible IRQ %d\n",
+ link->irq.possible[i]);
+ }
+
+ if (!link->device->status.enabled)
+ pr_info("Interrupt link %s disabled\n", acpi_device_bid(device));
+
+ list_add_tail(&link->list, &acpi_link_list);
+
+ end:
+ /* disable all links -- to be activated on use */
+ acpi_evaluate_object(handle, "_DIS", NULL, NULL);
+ mutex_unlock(&acpi_link_lock);
+
+ if (result)
+ kfree(link);
+
+ return result < 0 ? result : 1;
+}
+
+static int acpi_pci_link_resume(struct acpi_pci_link *link)
+{
+ if (link->refcnt && link->irq.active && link->irq.initialized)
+ return (acpi_pci_link_set(link, link->irq.active));
+
+ return 0;
+}
+
+static void irqrouter_resume(void)
+{
+ struct acpi_pci_link *link;
+
+ list_for_each_entry(link, &acpi_link_list, list) {
+ acpi_pci_link_resume(link);
+ }
+}
+
+static void acpi_pci_link_remove(struct acpi_device *device)
+{
+ struct acpi_pci_link *link;
+
+ link = acpi_driver_data(device);
+
+ mutex_lock(&acpi_link_lock);
+ list_del(&link->list);
+ mutex_unlock(&acpi_link_lock);
+
+ kfree(link);
+}
+
+/*
+ * modify acpi_isa_irq_penalty[] from cmdline
+ */
+static int __init acpi_irq_penalty_update(char *str, int used)
+{
+ int i;
+
+ for (i = 0; i < 16; i++) {
+ int retval;
+ int irq;
+ int new_penalty;
+
+ retval = get_option(&str, &irq);
+
+ if (!retval)
+ break; /* no number found */
+
+ /* see if this is a ISA IRQ */
+ if ((irq < 0) || (irq >= ACPI_MAX_ISA_IRQS))
+ continue;
+
+ if (used)
+ new_penalty = acpi_isa_irq_penalty[irq] +
+ PIRQ_PENALTY_ISA_USED;
+ else
+ new_penalty = 0;
+
+ acpi_isa_irq_penalty[irq] = new_penalty;
+ if (retval != 2) /* no next number */
+ break;
+ }
+ return 1;
+}
+
+/*
+ * We'd like PNP to call this routine for the
+ * single ISA_USED value for each legacy device.
+ * But instead it calls us with each POSSIBLE setting.
+ * There is no ISA_POSSIBLE weight, so we simply use
+ * the (small) PCI_USING penalty.
+ */
+void acpi_penalize_isa_irq(int irq, int active)
+{
+ if ((irq >= 0) && (irq < ARRAY_SIZE(acpi_isa_irq_penalty)))
+ acpi_isa_irq_penalty[irq] +=
+ (active ? PIRQ_PENALTY_ISA_USED : PIRQ_PENALTY_PCI_USING);
+}
+
+bool acpi_isa_irq_available(int irq)
+{
+ return irq >= 0 && (irq >= ARRAY_SIZE(acpi_isa_irq_penalty) ||
+ acpi_irq_get_penalty(irq) < PIRQ_PENALTY_ISA_ALWAYS);
+}
+
+void acpi_penalize_sci_irq(int irq, int trigger, int polarity)
+{
+ sci_irq = irq;
+
+ if (trigger == ACPI_MADT_TRIGGER_LEVEL &&
+ polarity == ACPI_MADT_POLARITY_ACTIVE_LOW)
+ sci_penalty = PIRQ_PENALTY_PCI_USING;
+ else
+ sci_penalty = PIRQ_PENALTY_ISA_ALWAYS;
+}
+
+/*
+ * Over-ride default table to reserve additional IRQs for use by ISA
+ * e.g. acpi_irq_isa=5
+ * Useful for telling ACPI how not to interfere with your ISA sound card.
+ */
+static int __init acpi_irq_isa(char *str)
+{
+ return acpi_irq_penalty_update(str, 1);
+}
+
+__setup("acpi_irq_isa=", acpi_irq_isa);
+
+/*
+ * Over-ride default table to free additional IRQs for use by PCI
+ * e.g. acpi_irq_pci=7,15
+ * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
+ */
+static int __init acpi_irq_pci(char *str)
+{
+ return acpi_irq_penalty_update(str, 0);
+}
+
+__setup("acpi_irq_pci=", acpi_irq_pci);
+
+static int __init acpi_irq_nobalance_set(char *str)
+{
+ acpi_irq_balance = 0;
+ return 1;
+}
+
+__setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
+
+static int __init acpi_irq_balance_set(char *str)
+{
+ acpi_irq_balance = 1;
+ return 1;
+}
+
+__setup("acpi_irq_balance", acpi_irq_balance_set);
+
+static struct syscore_ops irqrouter_syscore_ops = {
+ .resume = irqrouter_resume,
+};
+
+void __init acpi_pci_link_init(void)
+{
+ if (acpi_noirq)
+ return;
+
+ if (acpi_irq_balance == -1) {
+ /* no command line switch: enable balancing in IOAPIC mode */
+ if (acpi_irq_model == ACPI_IRQ_MODEL_IOAPIC)
+ acpi_irq_balance = 1;
+ else
+ acpi_irq_balance = 0;
+ }
+ register_syscore_ops(&irqrouter_syscore_ops);
+ acpi_scan_add_handler(&pci_link_handler);
+}