On 3/3/2016 10:12 AM, Sinan Kaya wrote:
> On 3/3/2016 10:10 AM, Bjorn Helgaas wrote:
>> That was my idea, but your minimal patch from last night looks awfully
>> attractive, and maybe it's not worth moving it to arch/x86. I do think we
>> could simplify the code significantly by getting rid of the kzalloc and
>> acpi_irq_penalty_list from acpi_irq_set_penalty(). How about pushing on
>> that a little bit first, and see what it looks like then?
>
> OK. Let me go that direction.
>
How about this?
--
Sinan Kaya
Qualcomm Technologies, Inc. on behalf of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project
>From 6cc33747feb469fe4da2088f34e2c875a36f58f4 Mon Sep 17 00:00:00 2001
From: Sinan Kaya <okaya@xxxxxxxxxxxxxx>
Date: Thu, 3 Mar 2016 10:14:22 -0500
Subject: [PATCH] acpi,pci,irq: account for early penalty assignment
---
drivers/acpi/pci_link.c | 77 ++++++++++++++++++++++++++++++-------------------
1 file changed, 47 insertions(+), 30 deletions(-)
diff --git a/drivers/acpi/pci_link.c b/drivers/acpi/pci_link.c
index fa28635..09eea42 100644
--- a/drivers/acpi/pci_link.c
+++ b/drivers/acpi/pci_link.c
@@ -87,6 +87,7 @@ struct acpi_pci_link {
static LIST_HEAD(acpi_link_list);
static DEFINE_MUTEX(acpi_link_lock);
+static int sci_irq, sci_irq_penalty;
/* --------------------------------------------------------------------------
PCI Link Device Management
@@ -466,56 +467,71 @@ static int acpi_irq_isa_penalty[ACPI_MAX_ISA_IRQ] = {
PIRQ_PENALTY_ISA_USED, /* IRQ15 ide1 */
};
-struct irq_penalty_info {
- int irq;
- int penalty;
- struct list_head node;
-};
+static int acpi_irq_pci_sharing_penalty(int irq)
+{
+ struct acpi_pci_link *link;
+ int penalty = 0;
+ bool found = false;
+
+ 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;
+ found = true;
+ } else {
+ int i;
+
+ /*
+ * If a link is inactive, penalize the IRQs it
+ * might, 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;
+ found = true;
+ }
+ }
+ }
+ }
-static LIST_HEAD(acpi_irq_penalty_list);
+ if (found)
+ return penalty;
+
+ return PIRQ_PENALTY_PCI_AVAILABLE;
+}
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;
- }
+ if (irq == sci_irq)
+ return sci_irq_penalty;
- return 0;
+ return acpi_irq_pci_sharing_penalty(irq);
}
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;
- }
+ if (irq == sci_irq) {
+ sci_irq_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);
-
+ /*
+ * This is the remaining PCI IRQs. They are calculated on the
+ * flight in acpi_irq_get_penalty function.
+ */
return 0;
}
@@ -900,6 +916,7 @@ void acpi_penalize_sci_irq(int irq, int trigger, int polarity)
if (irq < 0)
return;
+ sci_irq = irq;
if (trigger != ACPI_MADT_TRIGGER_LEVEL ||
polarity != ACPI_MADT_POLARITY_ACTIVE_LOW)
penalty = PIRQ_PENALTY_ISA_ALWAYS;
--
1.8.2.1
