Revert "ACPI, PCI, irq: remove interrupt count restriction"

Revert commit b5bd02695471 (ACPI, PCI, irq: remove interrupt count
restriction) that introduced a boot regression on some systems
where it caused kmalloc() to be used too early.

Link: http://marc.info/?l=linux-acpi&m=145580159209240&w=2
Reported-by: Nalla, Ravikanth <ravikanth.nalla@hpe.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 34 insertions, 102 deletions

diff --git a/drivers/acpi/pci_link.c b/drivers/acpi/pci_link.c
index 5114d8007aa0..ededa909df2f 100644
--- a/drivers/acpi/pci_link.c
+++ b/drivers/acpi/pci_link.c
@@ -4,7 +4,6 @@
  *  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>
- *  Copyright (c) 2015, The Linux Foundation. All rights reserved.
  *
  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  *
@@ -438,6 +437,7 @@ static int acpi_pci_link_set(struct acpi_pci_link *link, int irq)
  * enabled system.
  */
 
+#define ACPI_MAX_IRQS           256
 #define ACPI_MAX_ISA_IRQ        16
 
 #define PIRQ_PENALTY_PCI_AVAILABLE      (0)
@@ -447,7 +447,7 @@ static int acpi_pci_link_set(struct acpi_pci_link *link, int irq)
 #define PIRQ_PENALTY_ISA_USED           (16*16*16*16*16)
 #define PIRQ_PENALTY_ISA_ALWAYS         (16*16*16*16*16*16)
 
-static int acpi_irq_isa_penalty[ACPI_MAX_ISA_IRQ] = {
+static int acpi_irq_penalty[ACPI_MAX_IRQS] = {
         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ0 timer */
         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ1 keyboard */
         PIRQ_PENALTY_ISA_ALWAYS,        /* IRQ2 cascade */
@@ -464,68 +464,9 @@ static int acpi_irq_isa_penalty[ACPI_MAX_ISA_IRQ] = {
         PIRQ_PENALTY_ISA_USED,          /* IRQ13 fpe, sometimes */
         PIRQ_PENALTY_ISA_USED,          /* IRQ14 ide0 */
         PIRQ_PENALTY_ISA_USED,          /* IRQ15 ide1 */
+        /* >IRQ15 */
 };
 
-struct irq_penalty_info {
-        int irq;
-        int penalty;
-        struct list_head node;
-};
-
-static LIST_HEAD(acpi_irq_penalty_list);
-
-static int acpi_irq_get_penalty(int irq)
-{
-        struct irq_penalty_info *irq_info;
-
-        if (irq < ACPI_MAX_ISA_IRQ)
-                return acpi_irq_isa_penalty[irq];
-
-        list_for_each_entry(irq_info, &acpi_irq_penalty_list, node) {
-                if (irq_info->irq == irq)
-                        return irq_info->penalty;
-        }
-
-        return 0;
-}
-
-static int acpi_irq_set_penalty(int irq, int new_penalty)
-{
-        struct irq_penalty_info *irq_info;
-
-        /* see if this is a ISA IRQ */
-        if (irq < ACPI_MAX_ISA_IRQ) {
-                acpi_irq_isa_penalty[irq] = new_penalty;
-                return 0;
-        }
-
-        /* next, try to locate from the dynamic list */
-        list_for_each_entry(irq_info, &acpi_irq_penalty_list, node) {
-                if (irq_info->irq == irq) {
-                        irq_info->penalty  = new_penalty;
-                        return 0;
-                }
-        }
-
-        /* nope, let's allocate a slot for this IRQ */
-        irq_info = kzalloc(sizeof(*irq_info), GFP_KERNEL);
-        if (!irq_info)
-                return -ENOMEM;
-
-        irq_info->irq = irq;
-        irq_info->penalty = new_penalty;
-        list_add_tail(&irq_info->node, &acpi_irq_penalty_list);
-
-        return 0;
-}
-
-static void acpi_irq_add_penalty(int irq, int penalty)
-{
-        int curpen = acpi_irq_get_penalty(irq);
-
-        acpi_irq_set_penalty(irq, curpen + penalty);
-}
-
 int __init acpi_irq_penalty_init(void)
 {
         struct acpi_pci_link *link;
@@ -546,16 +487,15 @@ int __init acpi_irq_penalty_init(void)
                             link->irq.possible_count;
 
                         for (i = 0; i < link->irq.possible_count; i++) {
-                                if (link->irq.possible[i] < ACPI_MAX_ISA_IRQ) {
-                                        int irqpos = link->irq.possible[i];
-
-                                        acpi_irq_add_penalty(irqpos, penalty);
-                                }
+                                if (link->irq.possible[i] < ACPI_MAX_ISA_IRQ)
+                                        acpi_irq_penalty[link->irq.
+                                                         possible[i]] +=
+                                            penalty;
                         }
 
                 } else if (link->irq.active) {
-                        acpi_irq_add_penalty(link->irq.active,
-                                             PIRQ_PENALTY_PCI_POSSIBLE);
+                        acpi_irq_penalty[link->irq.active] +=
+                            PIRQ_PENALTY_PCI_POSSIBLE;
                 }
         }
 
@@ -607,12 +547,12 @@ 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_get_penalty(irq) >
-                            acpi_irq_get_penalty(link->irq.possible[i]))
+                        if (acpi_irq_penalty[irq] >
+                            acpi_irq_penalty[link->irq.possible[i]])
                                 irq = link->irq.possible[i];
                 }
         }
-        if (acpi_irq_get_penalty(irq) >= PIRQ_PENALTY_ISA_ALWAYS) {
+        if (acpi_irq_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),
@@ -628,8 +568,7 @@ static int acpi_pci_link_allocate(struct acpi_pci_link *link)
                             acpi_device_bid(link->device));
                 return -ENODEV;
         } else {
-                acpi_irq_add_penalty(link->irq.active, PIRQ_PENALTY_PCI_USING);
-
+                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);
@@ -839,7 +778,7 @@ static void acpi_pci_link_remove(struct acpi_device *device)
 }
 
 /*
- * modify penalty from cmdline
+ * modify acpi_irq_penalty[] from cmdline
  */
 static int __init acpi_irq_penalty_update(char *str, int used)
 {
@@ -857,10 +796,13 @@ static int __init acpi_irq_penalty_update(char *str, int used)
                 if (irq < 0)
                         continue;
 
+                if (irq >= ARRAY_SIZE(acpi_irq_penalty))
+                        continue;
+
                 if (used)
-                        acpi_irq_add_penalty(irq, PIRQ_PENALTY_ISA_USED);
+                        acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
                 else
-                        acpi_irq_set_penalty(irq, PIRQ_PENALTY_PCI_AVAILABLE);
+                        acpi_irq_penalty[irq] = PIRQ_PENALTY_PCI_AVAILABLE;
 
                 if (retval != 2)        /* no next number */
                         break;
@@ -877,23 +819,18 @@ static int __init acpi_irq_penalty_update(char *str, int used)
  */
 void acpi_penalize_isa_irq(int irq, int active)
 {
-        int penalty;
-
-        if (irq < 0)
-                return;
-
-        if (active)
-                penalty = PIRQ_PENALTY_ISA_USED;
-        else
-                penalty = PIRQ_PENALTY_PCI_USING;
-
-        acpi_irq_add_penalty(irq, penalty);
+        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;
+        }
 }
 
 bool acpi_isa_irq_available(int irq)
 {
-        return irq >= 0 &&
-                (acpi_irq_get_penalty(irq) < PIRQ_PENALTY_ISA_ALWAYS);
+        return irq >= 0 && (irq >= ARRAY_SIZE(acpi_irq_penalty) ||
+                            acpi_irq_penalty[irq] < PIRQ_PENALTY_ISA_ALWAYS);
 }
 
 /*
@@ -903,18 +840,13 @@ bool acpi_isa_irq_available(int irq)
  */
 void acpi_penalize_sci_irq(int irq, int trigger, int polarity)
 {
-        int penalty;
-
-        if (irq < 0)
-                return;
-
-        if (trigger != ACPI_MADT_TRIGGER_LEVEL ||
-            polarity != ACPI_MADT_POLARITY_ACTIVE_LOW)
-                penalty = PIRQ_PENALTY_ISA_ALWAYS;
-        else
-                penalty = PIRQ_PENALTY_PCI_USING;
-
-        acpi_irq_add_penalty(irq, penalty);
+        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;
+        }
 }
 
 /*