ACPI,PCI,IRQ: reduce resource requirements
authorSinan Kaya <okaya@codeaurora.org>
Sun, 17 Apr 2016 17:36:53 +0000 (13:36 -0400)
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>
Wed, 4 May 2016 23:10:31 +0000 (01:10 +0200)
Code has been redesigned to calculate penalty requirements on the fly. This
significantly simplifies the implementation and removes some of the init
calls from x86 architecture.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
drivers/acpi/pci_link.c

index ededa909df2fc02eb2b77fb495e43f8e850c5469..cc0ba1651db11323df5c128e88f7fd4a831e1f34 100644 (file)
@@ -36,6 +36,7 @@
 #include <linux/mutex.h>
 #include <linux/slab.h>
 #include <linux/acpi.h>
+#include <linux/irq.h>
 
 #include "internal.h"
 
@@ -440,7 +441,6 @@ static int acpi_pci_link_set(struct acpi_pci_link *link, int irq)
 #define ACPI_MAX_IRQS          256
 #define ACPI_MAX_ISA_IRQ       16
 
-#define PIRQ_PENALTY_PCI_AVAILABLE     (0)
 #define PIRQ_PENALTY_PCI_POSSIBLE      (16*16)
 #define PIRQ_PENALTY_PCI_USING         (16*16*16)
 #define PIRQ_PENALTY_ISA_TYPICAL       (16*16*16*16)
@@ -457,9 +457,9 @@ static int acpi_irq_penalty[ACPI_MAX_IRQS] = {
        PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ6 */
        PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ7 parallel, spurious */
        PIRQ_PENALTY_ISA_TYPICAL,       /* IRQ8 rtc, sometimes */
-       PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ9  PCI, often acpi */
-       PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ10 PCI */
-       PIRQ_PENALTY_PCI_AVAILABLE,     /* IRQ11 PCI */
+       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 */
@@ -467,6 +467,60 @@ static int acpi_irq_penalty[ACPI_MAX_IRQS] = {
        /* >IRQ15 */
 };
 
+static int acpi_irq_pci_sharing_penalty(int irq)
+{
+       struct acpi_pci_link *link;
+       int penalty = 0;
+
+       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;
+               else {
+                       int i;
+
+                       /*
+                        * If a link is inactive, penalize the IRQs it
+                        * 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 < ACPI_MAX_ISA_IRQ)
+               penalty += acpi_irq_penalty[irq];
+
+       /*
+       * Penalize IRQ used by ACPI SCI. If ACPI SCI pin attributes conflict
+       * with PCI IRQ attributes, mark ACPI SCI as ISA_ALWAYS so it won't be
+       * use for PCI IRQs.
+       */
+       if (irq == acpi_gbl_FADT.sci_interrupt) {
+               u32 type = irq_get_trigger_type(irq) & IRQ_TYPE_SENSE_MASK;
+
+               if (type != IRQ_TYPE_LEVEL_LOW)
+                       penalty += PIRQ_PENALTY_ISA_ALWAYS;
+               else
+                       penalty += PIRQ_PENALTY_PCI_USING;
+       }
+
+       penalty += acpi_irq_pci_sharing_penalty(irq);
+       return penalty;
+}
+
 int __init acpi_irq_penalty_init(void)
 {
        struct acpi_pci_link *link;
@@ -547,12 +601,12 @@ static int acpi_pci_link_allocate(struct acpi_pci_link *link)
                 * the use of IRQs 9, 10, 11, and >15.
                 */
                for (i = (link->irq.possible_count - 1); i >= 0; i--) {
-                       if (acpi_irq_penalty[irq] >
-                           acpi_irq_penalty[link->irq.possible[i]])
+                       if (acpi_irq_get_penalty(irq) >
+                           acpi_irq_get_penalty(link->irq.possible[i]))
                                irq = link->irq.possible[i];
                }
        }
-       if (acpi_irq_penalty[irq] >= PIRQ_PENALTY_ISA_ALWAYS) {
+       if (acpi_irq_get_penalty(irq) >= PIRQ_PENALTY_ISA_ALWAYS) {
                printk(KERN_ERR PREFIX "No IRQ available for %s [%s]. "
                            "Try pci=noacpi or acpi=off\n",
                            acpi_device_name(link->device),
@@ -568,7 +622,6 @@ static int acpi_pci_link_allocate(struct acpi_pci_link *link)
                            acpi_device_bid(link->device));
                return -ENODEV;
        } else {
-               acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_USING;
                printk(KERN_WARNING PREFIX "%s [%s] enabled at IRQ %d\n",
                       acpi_device_name(link->device),
                       acpi_device_bid(link->device), link->irq.active);
@@ -800,9 +853,10 @@ static int __init acpi_irq_penalty_update(char *str, int used)
                        continue;
 
                if (used)
-                       acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
+                       acpi_irq_penalty[irq] = acpi_irq_get_penalty(irq) +
+                               PIRQ_PENALTY_ISA_USED;
                else
-                       acpi_irq_penalty[irq] = PIRQ_PENALTY_PCI_AVAILABLE;
+                       acpi_irq_penalty[irq] = 0;
 
                if (retval != 2)        /* no next number */
                        break;
@@ -819,34 +873,19 @@ static int __init acpi_irq_penalty_update(char *str, int used)
  */
 void acpi_penalize_isa_irq(int irq, int active)
 {
-       if (irq >= 0 && irq < ARRAY_SIZE(acpi_irq_penalty)) {
-               if (active)
-                       acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
-               else
-                       acpi_irq_penalty[irq] += PIRQ_PENALTY_PCI_USING;
-       }
+       if (irq >= 0 && irq < ARRAY_SIZE(acpi_irq_penalty))
+               acpi_irq_penalty[irq] = acpi_irq_get_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_irq_penalty) ||
-                           acpi_irq_penalty[irq] < PIRQ_PENALTY_ISA_ALWAYS);
+                   acpi_irq_get_penalty(irq) < PIRQ_PENALTY_ISA_ALWAYS);
 }
 
-/*
- * Penalize IRQ used by ACPI SCI. If ACPI SCI pin attributes conflict with
- * PCI IRQ attributes, mark ACPI SCI as ISA_ALWAYS so it won't be use for
- * PCI IRQs.
- */
 void acpi_penalize_sci_irq(int irq, int trigger, int polarity)
 {
-       if (irq >= 0 && irq < ARRAY_SIZE(acpi_irq_penalty)) {
-               if (trigger != ACPI_MADT_TRIGGER_LEVEL ||
-                   polarity != ACPI_MADT_POLARITY_ACTIVE_LOW)
-                       acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_ALWAYS;
-               else
-                       acpi_irq_penalty[irq] += PIRQ_PENALTY_PCI_USING;
-       }
 }
 
 /*