[RFC Part4 v1 17/17] x86, htirq: Use common MSI code to manage Hypertransport interrupts

From: Jiang Liu
Date: Sun Nov 09 2014 - 10:11:12 EST

Hypertransport interrupt is a type of "Message Signalled Interrupt",
so use common MSI code to manage it.

Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx>
---
arch/x86/kernel/apic/htirq.c | 134 +++++++++++++++---------------------------
drivers/pci/Kconfig | 1 +
drivers/pci/htirq.c | 16 ++---
include/linux/htirq.h | 5 +-
4 files changed, 60 insertions(+), 96 deletions(-)

diff --git a/arch/x86/kernel/apic/htirq.c b/arch/x86/kernel/apic/htirq.c
index b6503510f1af..230e37ab3948 100644
--- a/arch/x86/kernel/apic/htirq.c
+++ b/arch/x86/kernel/apic/htirq.c
@@ -17,37 +17,33 @@
#include <linux/pci.h>
#include <linux/htirq.h>
#include <linux/irqdomain.h>
+#include <linux/msi.h>
#include <asm/hw_irq.h>
#include <asm/apic.h>
#include <asm/hypertransport.h>

static struct irq_domain *htirq_domain;

-/*
- * Hypertransport interrupt support
- */
-static int
-ht_set_affinity(struct irq_data *data, const struct cpumask *mask, bool force)
+static void ht_irq_compose_msg(struct irq_data *data, struct msi_msg *msg)
{
- struct irq_data *parent = data->parent_data;
- int ret;
-
- ret = parent->chip->irq_set_affinity(parent, mask, force);
- if (ret >= 0) {
- struct msi_msg msg;
- struct irq_cfg *cfg = irqd_cfg(data);
-
- fetch_ht_irq_msg(data->irq, &msg);
- msg.address_lo &= ~(HT_IRQ_LOW_VECTOR_MASK |
- HT_IRQ_LOW_DEST_ID_MASK);
- msg.address_lo |= HT_IRQ_LOW_VECTOR(cfg->vector) |
- HT_IRQ_LOW_DEST_ID(cfg->dest_apicid);
- msg.address_hi &= ~(HT_IRQ_HIGH_DEST_ID_MASK);
- msg.address_hi |= HT_IRQ_HIGH_DEST_ID(cfg->dest_apicid);
- write_ht_irq_msg(data->irq, &msg);
- }
-
- return ret;
+ struct irq_cfg *cfg = irqd_cfg(data);
+ struct ht_irq_cfg *ht_cfg = data->chip_data;
+
+ msg->address_hi = HT_IRQ_HIGH_DEST_ID(cfg->dest_apicid);
+ msg->address_lo = HT_IRQ_LOW_BASE |
+ HT_IRQ_LOW_DEST_ID(cfg->dest_apicid) |
+ HT_IRQ_LOW_VECTOR(cfg->vector) |
+ HT_IRQ_LOW_RQEOI_EDGE;
+ if (ht_cfg->masked)
+ msg->address_lo |= HT_IRQ_LOW_IRQ_MASKED;
+ if (apic->irq_dest_mode)
+ msg->address_lo |= HT_IRQ_LOW_DM_LOGICAL;
+ else
+ msg->address_lo |= HT_IRQ_LOW_DM_PHYSICAL;
+ if (apic->irq_delivery_mode == dest_LowestPrio)
+ msg->address_lo |= HT_IRQ_LOW_MT_ARBITRATED;
+ else
+ msg->address_lo |= HT_IRQ_LOW_MT_FIXED;
}

static struct irq_chip ht_irq_chip = {
@@ -55,40 +51,34 @@ static struct irq_chip ht_irq_chip = {
.irq_mask = mask_ht_irq,
.irq_unmask = unmask_ht_irq,
.irq_ack = irq_chip_ack_parent,
- .irq_set_affinity = ht_set_affinity,
+ .irq_set_affinity = msi_domain_set_affinity,
.irq_retrigger = irq_chip_retrigger_hierarchy,
+ .irq_compose_msi_msg = ht_irq_compose_msg,
+ .irq_write_msi_msg = write_ht_irq_msg,
.flags = IRQCHIP_SKIP_SET_WAKE,
};

-static int htirq_domain_alloc(struct irq_domain *domain, unsigned int virq,
- unsigned int nr_irqs, void *arg)
+static irq_hw_number_t ht_irq_get_hwirq(struct msi_domain_info *minfo,
+ void *arg)
{
- struct ht_irq_cfg *ht_cfg;
struct irq_alloc_info *info = arg;
- struct pci_dev *dev;
- irq_hw_number_t hwirq;
- int ret;
+ struct pci_dev *dev = info->ht_dev;

- if (nr_irqs > 1 || !info)
- return -EINVAL;
-
- dev = info->ht_dev;
- hwirq = (info->ht_idx & 0xFF) |
+ return (info->ht_idx & 0xFF) |
PCI_DEVID(dev->bus->number, dev->devfn) << 8 |
(pci_domain_nr(dev->bus) & 0xFFFFFFFF) << 24;
- if (irq_find_mapping(domain, hwirq) > 0)
- return -EEXIST;
+}
+
+static int ht_irq_init(struct irq_domain *domain, struct msi_domain_info *minfo,
+ unsigned int virq, irq_hw_number_t hwirq, void *arg)
+{
+ struct ht_irq_cfg *ht_cfg;
+ struct irq_alloc_info *info = arg;

ht_cfg = kmalloc(sizeof(*ht_cfg), GFP_KERNEL);
if (!ht_cfg)
return -ENOMEM;

- ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, info);
- if (ret < 0) {
- kfree(ht_cfg);
- return ret;
- }
-
/* Initialize msg to a value that will never match the first write. */
ht_cfg->msg.address_lo = 0xffffffff;
ht_cfg->msg.address_hi = 0xffffffff;
@@ -96,58 +86,30 @@ static int htirq_domain_alloc(struct irq_domain *domain, unsigned int virq,
ht_cfg->update = info->ht_update;
ht_cfg->pos = info->ht_pos;
ht_cfg->idx = 0x10 + (info->ht_idx * 2);
- irq_domain_set_info(domain, virq, hwirq, &ht_irq_chip, ht_cfg,
+ ht_cfg->masked = true;
+ irq_domain_set_info(domain, virq, hwirq, minfo->chip, ht_cfg,
handle_edge_irq, NULL, "edge");

return 0;
}

-static void htirq_domain_free(struct irq_domain *domain, unsigned int virq,
- unsigned int nr_irqs)
+static void ht_irq_free(struct irq_domain *domain, struct msi_domain_info *info,
+ unsigned int virq)
{
struct irq_data *irq_data = irq_domain_get_irq_data(domain, virq);

- BUG_ON(nr_irqs != 1);
kfree(irq_data->chip_data);
- irq_domain_free_irqs_top(domain, virq, nr_irqs);
-}
-
-static void htirq_domain_activate(struct irq_domain *domain,
- struct irq_data *irq_data)
-{
- struct msi_msg msg;
- struct irq_cfg *cfg = irqd_cfg(irq_data);
-
- msg.address_hi = HT_IRQ_HIGH_DEST_ID(cfg->dest_apicid);
- msg.address_lo =
- HT_IRQ_LOW_BASE |
- HT_IRQ_LOW_DEST_ID(cfg->dest_apicid) |
- HT_IRQ_LOW_VECTOR(cfg->vector) |
- ((apic->irq_dest_mode == 0) ?
- HT_IRQ_LOW_DM_PHYSICAL :
- HT_IRQ_LOW_DM_LOGICAL) |
- HT_IRQ_LOW_RQEOI_EDGE |
- ((apic->irq_delivery_mode != dest_LowestPrio) ?
- HT_IRQ_LOW_MT_FIXED :
- HT_IRQ_LOW_MT_ARBITRATED) |
- HT_IRQ_LOW_IRQ_MASKED;
- write_ht_irq_msg(irq_data->irq, &msg);
}

-static void htirq_domain_deactivate(struct irq_domain *domain,
- struct irq_data *irq_data)
-{
- struct msi_msg msg;
-
- memset(&msg, 0, sizeof(msg));
- write_ht_irq_msg(irq_data->irq, &msg);
-}
+static struct msi_domain_ops ht_irq_domain_ops = {
+ .get_hwirq = ht_irq_get_hwirq,
+ .msi_init = ht_irq_init,
+ .msi_free = ht_irq_free,
+};

-static struct irq_domain_ops htirq_domain_ops = {
- .alloc = htirq_domain_alloc,
- .free = htirq_domain_free,
- .activate = htirq_domain_activate,
- .deactivate = htirq_domain_deactivate,
+static struct msi_domain_info ht_irq_domain_info = {
+ .ops = &ht_irq_domain_ops,
+ .chip = &ht_irq_chip,
};

void arch_init_htirq_domain(struct irq_domain *parent)
@@ -155,11 +117,9 @@ void arch_init_htirq_domain(struct irq_domain *parent)
if (disable_apic)
return;

- htirq_domain = irq_domain_add_tree(NULL, &htirq_domain_ops, NULL);
+ htirq_domain = msi_create_irq_domain(NULL, &ht_irq_domain_info, parent);
if (!htirq_domain)
pr_warn("failed to initialize irqdomain for HTIRQ.\n");
- else
- htirq_domain->parent = parent;
}

int arch_setup_ht_irq(int idx, int pos, struct pci_dev *dev,
diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index 7a8f1c5e65af..22f948f9738a 100644
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -68,6 +68,7 @@ config HT_IRQ
bool "Interrupts on hypertransport devices"
default y
depends on PCI && X86_LOCAL_APIC
+ select GENERIC_MSI_IRQ_DOMAIN
help
This allows native hypertransport devices to use interrupts.

diff --git a/drivers/pci/htirq.c b/drivers/pci/htirq.c
index 3bbbc5cdcb9b..27b09b266bb6 100644
--- a/drivers/pci/htirq.c
+++ b/drivers/pci/htirq.c
@@ -23,9 +23,9 @@
*/
static DEFINE_SPINLOCK(ht_irq_lock);

-void write_ht_irq_msg(unsigned int irq, struct msi_msg *msg)
+void write_ht_irq_msg(struct irq_data *data, struct msi_msg *msg)
{
- struct ht_irq_cfg *cfg = irq_get_handler_data(irq);
+ struct ht_irq_cfg *cfg = data->chip_data;
unsigned long flags;

spin_lock_irqsave(&ht_irq_lock, flags);
@@ -38,14 +38,14 @@ void write_ht_irq_msg(unsigned int irq, struct msi_msg *msg)
pci_write_config_dword(cfg->dev, cfg->pos + 4, msg->address_hi);
}
if (cfg->update)
- cfg->update(cfg->dev, irq, msg);
+ cfg->update(cfg->dev, data->irq, msg);
spin_unlock_irqrestore(&ht_irq_lock, flags);
cfg->msg = *msg;
}

-void fetch_ht_irq_msg(unsigned int irq, struct msi_msg *msg)
+void fetch_ht_irq_msg(struct irq_data *data, struct msi_msg *msg)
{
- struct ht_irq_cfg *cfg = irq_get_handler_data(irq);
+ struct ht_irq_cfg *cfg = data->chip_data;

*msg = cfg->msg;
}
@@ -56,7 +56,8 @@ void mask_ht_irq(struct irq_data *data)
struct msi_msg msg = cfg->msg;

msg.address_lo |= 1;
- write_ht_irq_msg(data->irq, &msg);
+ write_ht_irq_msg(data, &msg);
+ cfg->masked = true;
}

void unmask_ht_irq(struct irq_data *data)
@@ -65,7 +66,8 @@ void unmask_ht_irq(struct irq_data *data)
struct msi_msg msg = cfg->msg;

msg.address_lo &= ~1;
- write_ht_irq_msg(data->irq, &msg);
+ write_ht_irq_msg(data, &msg);
+ cfg->masked = false;
}

/**
diff --git a/include/linux/htirq.h b/include/linux/htirq.h
index 98e432f7f9b1..c5d03a81809c 100644
--- a/include/linux/htirq.h
+++ b/include/linux/htirq.h
@@ -14,12 +14,13 @@ struct ht_irq_cfg {
ht_irq_update_t *update;
unsigned pos;
unsigned idx;
+ bool masked;
struct msi_msg msg;
};

/* Helper functions.. */
-void fetch_ht_irq_msg(unsigned int irq, struct msi_msg *msg);
-void write_ht_irq_msg(unsigned int irq, struct msi_msg *msg);
+void fetch_ht_irq_msg(struct irq_data *data, struct msi_msg *msg);
+void write_ht_irq_msg(struct irq_data *data, struct msi_msg *msg);
void mask_ht_irq(struct irq_data *data);
void unmask_ht_irq(struct irq_data *data);

--
1.7.10.4

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