[PATCH V2 1/3] acpi,pci,irq: reduce resource requirements

Sinan Kaya
2016-04-09T01:26:49Z

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. Command line penalty assignment has been
limited to ISA interrupts only.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
---
drivers/acpi/pci_link.c | 176 ++++++++++++++++++++++++++++++++++++++----------
1 file changed, 140 insertions(+), 36 deletions(-)

diff --git a/drivers/acpi/pci_link.c b/drivers/acpi/pci_link.c
index ededa90..25695ea 100644
--- a/drivers/acpi/pci_link.c
+++ b/drivers/acpi/pci_link.c
@@ -437,17 +437,15 @@ 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)
#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_irq_penalty[ACPI_MAX_IRQS] = {
+static int acpi_isa_irq_penalty[ACPI_MAX_ISA_IRQ] = {
PIRQ_PENALTY_ISA_ALWAYS, /* IRQ0 timer */
PIRQ_PENALTY_ISA_ALWAYS, /* IRQ1 keyboard */
PIRQ_PENALTY_ISA_ALWAYS, /* IRQ2 cascade */
@@ -457,9 +455,9 @@ 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 +465,121 @@ static int acpi_irq_penalty[ACPI_MAX_IRQS] = {
/* >IRQ15 */
};

+static int acpi_link_trigger(int irq, u8 *polarity, u8 *triggering)
+{
+ struct acpi_pci_link *link;
+ bool found = false;
+
+ *polarity = ~0;
+ *triggering = ~0;
+
+ list_for_each_entry(link, &acpi_link_list, list) {
+ int i;
+
+ if (link->irq.active && link->irq.active == irq) {
+ if (*polarity == ~0)
+ *polarity = link->irq.polarity;
+
+ if (*triggering == ~0)
+ *triggering = link->irq.triggering;
+
+ if (*polarity != link->irq.polarity)
+ return -EINVAL;
+
+ if (*triggering != link->irq.triggering)
+ return -EINVAL;
+
+ found = true;
+ }
+
+ for (i = 0; i < link->irq.possible_count; i++)
+ if (link->irq.possible[i] == irq) {
+ if (*polarity == ~0)
+ *polarity = link->irq.polarity;
+
+ if (*triggering == ~0)
+ *triggering = link->irq.triggering;
+
+ if (*polarity != link->irq.polarity)
+ return -EINVAL;
+
+ if (*triggering != link->irq.triggering)
+ return -EINVAL;
+
+ found = true;
+ }
+ }
+
+ return found ? 0 : -EINVAL;
+}
+
+static int acpi_pci_compatible_trigger(int irq)
+{
+ u8 polarity;
+ u8 triggering;
+
+ return acpi_link_trigger(irq, &polarity, &triggering);
+}
+
+static int acpi_irq_pci_sharing_penalty(int irq)
+{
+ struct acpi_pci_link *link;
+ int penalty = 0;
+
+ if (acpi_pci_compatible_trigger(irq))
+ return ~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, rc;
+
+ if (irq < ACPI_MAX_ISA_IRQ)
+ penalty += acpi_isa_irq_penalty[irq];
+
+ if (irq == acpi_gbl_FADT.sci_interrupt) {
+ u8 sci_polarity;
+ u8 sci_trigger;
+
+ rc = acpi_link_trigger(irq, &sci_polarity, &sci_trigger);
+ if (!rc) {
+ if (sci_trigger != ACPI_LEVEL_SENSITIVE ||
+ sci_polarity != ACPI_ACTIVE_LOW)
+ penalty += PIRQ_PENALTY_ISA_ALWAYS;
+ else
+ penalty += PIRQ_PENALTY_PCI_USING;
+ } else {
+ return ~0;
+ }
+ }
+
+ penalty += acpi_irq_pci_sharing_penalty(irq);
+ return penalty;
+}
+
int __init acpi_irq_penalty_init(void)
{
struct acpi_pci_link *link;
@@ -488,13 +601,14 @@ int __init acpi_irq_penalty_init(void)

for (i = 0; i < link->irq.possible_count; i++) {
if (link->irq.possible[i] < ACPI_MAX_ISA_IRQ)
- acpi_irq_penalty[link->irq.
- possible[i]] +=
+ acpi_isa_irq_penalty[link->irq.
+ possible[i]] +=
penalty;
}

- } else if (link->irq.active) {
- acpi_irq_penalty[link->irq.active] +=
+ } else if (link->irq.active &&
+ (link->irq.active < ACPI_MAX_ISA_IRQ)) {
+ acpi_isa_irq_penalty[link->irq.active] +=
PIRQ_PENALTY_PCI_POSSIBLE;
}
}
@@ -547,12 +661,12 @@ 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 +682,6 @@ 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);
@@ -778,7 +891,7 @@ static void acpi_pci_link_remove(struct acpi_device *device)
}

/*
- * modify acpi_irq_penalty[] from cmdline
+ * modify acpi_isa_irq_penalty[] from cmdline
*/
static int __init acpi_irq_penalty_update(char *str, int used)
{
@@ -787,23 +900,24 @@ static int __init acpi_irq_penalty_update(char *str, int used)
for (i = 0; i < 16; i++) {
int retval;
int irq;
+ int new_penalty;

retval = get_option(&str, &irq);

if (!retval)
break; /* no number found */

- if (irq < 0)
- continue;
-
- if (irq >= ARRAY_SIZE(acpi_irq_penalty))
+ /* see if this is a ISA IRQ */
+ if ((irq < 0) || (irq >= ACPI_MAX_ISA_IRQ))
continue;

if (used)
- acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
+ new_penalty = acpi_irq_get_penalty(irq) +
+ PIRQ_PENALTY_ISA_USED;
else
- acpi_irq_penalty[irq] = PIRQ_PENALTY_PCI_AVAILABLE;
+ new_penalty = 0;

+ acpi_isa_irq_penalty[irq] = new_penalty;
if (retval != 2) /* no next number */
break;
}
@@ -819,18 +933,15 @@ 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_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_irq_penalty) ||
- acpi_irq_penalty[irq] < PIRQ_PENALTY_ISA_ALWAYS);
+ return irq >= 0 && (irq >= ARRAY_SIZE(acpi_isa_irq_penalty) ||
+ acpi_isa_irq_penalty[irq] < PIRQ_PENALTY_ISA_ALWAYS);
}

/*
@@ -840,13 +951,6 @@ bool acpi_isa_irq_available(int irq)
*/
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;
- }
}

/*
--
1.8.2.1