[PATCH 2/2] Initial generic hypertransport interrupt support.

Eric W. Biederman
2006-07-10T22:27:39Z

This patch implements two functions ht_create_irq and ht_destroy_irq
for use by drivers. Several other functions are implemented as helpers
for arch specific irq_chip handlers.

The driver for the card I tested this on isn't yet ready to be merged.
However this code is and hypertransport irqs are in use in a few other
places in the kernel. Not that any of this will get merged before
2.6.19

Because the ipath-ht400 is slightly out of spec this code will need
to be generalized to work there.

I think all of the powerpc uses are for a plain interrupt controller
in a chipset so support for native hypertransport devices is a little
less interesting.

However I think this is a half way decent model on how to separate
arch specific and generic helper code, and I think this is a
functional model of how to get the architecture dependencies out of
the msi code.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
arch/i386/kernel/io_apic.c | 90 +++++++++++++++++
arch/x86_64/kernel/io_apic.c | 96 ++++++++++++++++++
drivers/pci/Kconfig | 10 ++
drivers/pci/Makefile | 1
drivers/pci/htirq.c | 190 +++++++++++++++++++++++++++++++++++
include/asm-i386/hypertransport.h | 42 ++++++++
include/asm-x86_64/hypertransport.h | 42 ++++++++
include/linux/pci.h | 17 +++
8 files changed, 488 insertions(+), 0 deletions(-)

diff --git a/arch/i386/kernel/io_apic.c b/arch/i386/kernel/io_apic.c
index 70b5962..168e407 100644
--- a/arch/i386/kernel/io_apic.c
+++ b/arch/i386/kernel/io_apic.c
@@ -40,6 +40,7 @@ #include <asm/timer.h>
#include <asm/i8259.h>
#include <asm/nmi.h>
#include <asm/msidef.h>
+#include <asm/hypertransport.h>

#include <mach_apic.h>
#include <mach_apicdef.h>
@@ -2532,6 +2533,95 @@ struct msi_ops arch_msi_ops = {

#endif /* CONFIG_PCI_MSI */

+/*
+ * Hypertransport interrupt support
+ */
+#ifdef CONFIG_HT_IRQ
+
+#ifdef CONFIG_SMP
+
+static void target_ht_irq(unsigned int irq, unsigned int dest)
+{
+ u32 low, high;
+ low = read_ht_irq_low(irq);
+ high = read_ht_irq_high(irq);
+
+ low &= ~(HT_IRQ_LOW_DEST_ID_MASK);
+ high &= ~(HT_IRQ_HIGH_DEST_ID_MASK);
+
+ low |= HT_IRQ_LOW_DEST_ID(dest);
+ high |= HT_IRQ_HIGH_DEST_ID(dest);
+
+ write_ht_irq_low(irq, low);
+ write_ht_irq_high(irq, high);
+}
+
+static void set_ht_irq_affinity(unsigned int irq, cpumask_t mask)
+{
+ unsigned int dest;
+ cpumask_t tmp;
+
+ cpus_and(tmp, mask, cpu_online_map);
+ if (cpus_empty(tmp))
+ tmp = TARGET_CPUS;
+
+ cpus_and(mask, tmp, CPU_MASK_ALL);
+
+ dest = cpu_mask_to_apicid(mask);
+
+ target_ht_irq(irq, dest);
+ set_native_irq_info(irq, mask);
+}
+#endif
+
+static struct hw_interrupt_type ht_irq_chip = {
+ .name = "PCI-HT",
+ .mask = mask_ht_irq,
+ .unmask = unmask_ht_irq,
+ .ack = ack_ioapic_irq,
+#ifdef CONFIG_SMP
+ .set_affinity = set_ht_irq_affinity,
+#endif
+ .retrigger = ioapic_retrigger_irq,
+};
+
+int arch_setup_ht_irq(unsigned int irq, struct pci_dev *dev)
+{
+ int vector;
+
+ vector = assign_irq_vector(irq);
+ if (vector >= 0) {
+ u32 low, high;
+ unsigned dest;
+ cpumask_t tmp;
+
+ cpus_clear(tmp);
+ cpu_set(vector >> 8, tmp);
+ dest = cpu_mask_to_apicid(tmp);
+
+ high = HT_IRQ_HIGH_DEST_ID(dest);
+
+ low = HT_IRQ_LOW_BASE |
+ HT_IRQ_LOW_DEST_ID(dest) |
+ HT_IRQ_LOW_VECTOR(vector) |
+ ((INT_DEST_MODE == 0) ?
+ HT_IRQ_LOW_DM_PHYSICAL :
+ HT_IRQ_LOW_DM_LOGICAL) |
+ HT_IRQ_LOW_RQEOI_EDGE |
+ ((INT_DELIVERY_MODE != dest_LowestPrio) ?
+ HT_IRQ_LOW_MT_FIXED :
+ HT_IRQ_LOW_MT_ARBITRATED) |
+ HT_IRQ_LOW_IRQ_MASKED;
+
+ write_ht_irq_low(irq, low);
+ write_ht_irq_high(irq, high);
+
+ set_irq_chip_and_handler(irq, &ht_irq_chip, handle_edge_irq);
+ }
+ return vector;
+}
+#endif /* CONFIG_HT_IRQ */
+
/* --------------------------------------------------------------------------
ACPI-based IOAPIC Configuration
-------------------------------------------------------------------------- */
diff --git a/arch/x86_64/kernel/io_apic.c b/arch/x86_64/kernel/io_apic.c
index 8d030b4..317439e 100644
--- a/arch/x86_64/kernel/io_apic.c
+++ b/arch/x86_64/kernel/io_apic.c
@@ -42,6 +42,7 @@ #include <asm/acpi.h>
#include <asm/dma.h>
#include <asm/nmi.h>
#include <asm/msidef.h>
+#include <asm/hypertransport.h>

static int assign_irq_vector(int irq, cpumask_t mask);

@@ -2093,6 +2094,101 @@ struct msi_ops arch_msi_ops = {

#endif

+/*
+ * Hypertransport interrupt support
+ */
+#ifdef CONFIG_HT_IRQ
+
+#ifdef CONFIG_SMP
+
+static void target_ht_irq(unsigned int irq, unsigned int dest, u8 vector)
+{
+ u32 low, high;
+ low = read_ht_irq_low(irq);
+ high = read_ht_irq_high(irq);
+
+ low &= ~(HT_IRQ_LOW_VECTOR_MASK | HT_IRQ_LOW_DEST_ID_MASK);
+ high &= ~(HT_IRQ_HIGH_DEST_ID_MASK);
+
+ low |= HT_IRQ_LOW_VECTOR(vector) | HT_IRQ_LOW_DEST_ID(dest);
+ high |= HT_IRQ_HIGH_DEST_ID(dest);
+
+ write_ht_irq_low(irq, low);
+ write_ht_irq_high(irq, high);
+}
+
+static void set_ht_irq_affinity(unsigned int irq, cpumask_t mask)
+{
+ unsigned int dest;
+ cpumask_t tmp;
+ int vector;
+
+ cpus_and(tmp, mask, cpu_online_map);
+ if (cpus_empty(tmp))
+ tmp = TARGET_CPUS;
+
+ cpus_and(mask, tmp, CPU_MASK_ALL);
+
+ vector = assign_irq_vector(irq, mask);
+ if (vector < 0)
+ return;
+
+ cpus_clear(tmp);
+ cpu_set(vector >> 8, tmp);
+ dest = cpu_mask_to_apicid(tmp);
+
+ target_ht_irq(irq, dest, vector & 0xff);
+ set_native_irq_info(irq, mask);
+}
+#endif
+
+static struct hw_interrupt_type ht_irq_chip = {
+ .name = "PCI-HT",
+ .mask = mask_ht_irq,
+ .unmask = unmask_ht_irq,
+ .ack = ack_apic_edge,
+#ifdef CONFIG_SMP
+ .set_affinity = set_ht_irq_affinity,
+#endif
+ .retrigger = ioapic_retrigger_irq,
+};
+
+int arch_setup_ht_irq(unsigned int irq, struct pci_dev *dev)
+{
+ int vector;
+
+ vector = assign_irq_vector(irq, TARGET_CPUS);
+ if (vector >= 0) {
+ u32 low, high;
+ unsigned dest;
+ cpumask_t tmp;
+
+ cpus_clear(tmp);
+ cpu_set(vector >> 8, tmp);
+ dest = cpu_mask_to_apicid(tmp);
+
+ high = HT_IRQ_HIGH_DEST_ID(dest);
+
+ low = HT_IRQ_LOW_BASE |
+ HT_IRQ_LOW_DEST_ID(dest) |
+ HT_IRQ_LOW_VECTOR(vector) |
+ ((INT_DEST_MODE == 0) ?
+ HT_IRQ_LOW_DM_PHYSICAL :
+ HT_IRQ_LOW_DM_LOGICAL) |
+ HT_IRQ_LOW_RQEOI_EDGE |
+ ((INT_DELIVERY_MODE != dest_LowestPrio) ?
+ HT_IRQ_LOW_MT_FIXED :
+ HT_IRQ_LOW_MT_ARBITRATED);
+
+ write_ht_irq_low(irq, low);
+ write_ht_irq_high(irq, high);
+
+ set_irq_chip_and_handler(irq, &ht_irq_chip, handle_edge_irq);
+ }
+ return vector;
+}
+#endif /* CONFIG_HT_IRQ */
+
/* --------------------------------------------------------------------------
ACPI-based IOAPIC Configuration
-------------------------------------------------------------------------- */
diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index 4d762fc..3ec83ac 100644
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -27,3 +27,13 @@ config PCI_DEBUG

When in doubt, say N.

+config HT_IRQ
+ bool "Interrupts on hypertransport devices"
+ default y
+ depends on PCI
+ depends on X86_LOCAL_APIC && X86_IO_APIC
+ help
+ This allows native hypertransport devices to use interrupts.
+
+ If unsure say Y.
+
\ No newline at end of file
diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
index 983d0f8..2752c57 100644
--- a/drivers/pci/Makefile
+++ b/drivers/pci/Makefile
@@ -26,6 +26,7 @@ obj-$(CONFIG_PPC32) += setup-irq.o
obj-$(CONFIG_PPC64) += setup-bus.o
obj-$(CONFIG_MIPS) += setup-bus.o setup-irq.o
obj-$(CONFIG_X86_VISWS) += setup-irq.o
+obj-$(CONFIG_HT_IRQ) += htirq.o

msiobj-y := msi.o
msiobj-$(CONFIG_IA64) += msi-apic.o
diff --git a/drivers/pci/htirq.c b/drivers/pci/htirq.c
new file mode 100644
index 0000000..d8f894b
--- /dev/null
+++ b/drivers/pci/htirq.c
@@ -0,0 +1,190 @@
+/*
+ * File: htirq.c
+ * Purpose: Hypertransport Interrupt Capability
+ *
+ * Copyright (C) 2006 Linux Networx
+ * Copyright (C) Eric Biederman <ebiederman@lnxi.com>
+ */
+
+#include <linux/irq.h>
+#include <linux/pci.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/gfp.h>
+
+/* Global ht irq lock.
+ *
+ * This is needed to serialize access to the data port in hypertransport
+ * irq capability.
+ *
+ * With multiple simultaneous hypertransport irq devices it might pay
+ * to make this more fine grained. But start with simple, stupid, and correct.
+ */
+static DEFINE_SPINLOCK(ht_irq_lock);
+
+struct ht_irq_cfg {
+ struct pci_dev *dev;
+ unsigned pos;
+ unsigned idx;
+};
+
+void write_ht_irq_low(unsigned int irq, u32 data)
+{
+ struct ht_irq_cfg *cfg = get_irq_data(irq);
+ unsigned long flags;
+ spin_lock_irqsave(&ht_irq_lock, flags);
+ pci_write_config_byte(cfg->dev, cfg->pos + 2, cfg->idx);
+ pci_write_config_dword(cfg->dev, cfg->pos + 4, data);
+ spin_unlock_irqrestore(&ht_irq_lock, flags);
+}
+
+void write_ht_irq_high(unsigned int irq, u32 data)
+{
+ struct ht_irq_cfg *cfg = get_irq_data(irq);
+ unsigned long flags;
+ spin_lock_irqsave(&ht_irq_lock, flags);
+ pci_write_config_byte(cfg->dev, cfg->pos + 2, cfg->idx + 1);
+ pci_write_config_dword(cfg->dev, cfg->pos + 4, data);
+ spin_unlock_irqrestore(&ht_irq_lock, flags);
+}
+
+u32 read_ht_irq_low(unsigned int irq)
+{
+ struct ht_irq_cfg *cfg = get_irq_data(irq);
+ unsigned long flags;
+ u32 data;
+ spin_lock_irqsave(&ht_irq_lock, flags);
+ pci_write_config_byte(cfg->dev, cfg->pos + 2, cfg->idx);
+ pci_read_config_dword(cfg->dev, cfg->pos + 4, &data);
+ spin_unlock_irqrestore(&ht_irq_lock, flags);
+ return data;
+}
+
+
+u32 read_ht_irq_high(unsigned int irq)
+{
+ struct ht_irq_cfg *cfg = get_irq_data(irq);
+ unsigned long flags;
+ u32 data;
+ spin_lock_irqsave(&ht_irq_lock, flags);
+ pci_write_config_byte(cfg->dev, cfg->pos + 2, cfg->idx + 1);
+ pci_read_config_dword(cfg->dev, cfg->pos + 4, &data);
+ spin_unlock_irqrestore(&ht_irq_lock, flags);
+ return data;
+}
+
+void mask_ht_irq(unsigned int irq)
+{
+ struct ht_irq_cfg *cfg;
+ unsigned long flags;
+ u32 data;
+
+ cfg = get_irq_data(irq);
+
+ spin_lock_irqsave(&ht_irq_lock, flags);
+ pci_write_config_byte(cfg->dev, cfg->pos + 2, cfg->idx);
+ pci_read_config_dword(cfg->dev, cfg->pos + 4, &data);
+ data |= 1;
+ pci_write_config_dword(cfg->dev, cfg->pos + 4, data);
+ spin_unlock_irqrestore(&ht_irq_lock, flags);
+}
+
+void unmask_ht_irq(unsigned int irq)
+{
+ struct ht_irq_cfg *cfg;
+ unsigned long flags;
+ u32 data;
+
+ cfg = get_irq_data(irq);
+
+ spin_lock_irqsave(&ht_irq_lock, flags);
+ pci_write_config_byte(cfg->dev, cfg->pos + 2, cfg->idx);
+ pci_read_config_dword(cfg->dev, cfg->pos + 4, &data);
+ data &= ~1;
+ pci_write_config_dword(cfg->dev, cfg->pos + 4, data);
+ spin_unlock_irqrestore(&ht_irq_lock, flags);
+}
+
+/**
+ * ht_create_irq - create an irq and attach it to a device.
+ * @dev: The hypertransport device to find the irq capability on.
+ * @idx: Which of the possible irqs to attach to.
+ *
+ * ht_create_irq is needs to be called for all hypertransport devices
+ * that generate irqs.
+ *
+ * The irq number of the new irq or a negative error value is returned.
+ */
+int ht_create_irq(struct pci_dev *dev, int idx)
+{
+ struct ht_irq_cfg *cfg;
+ unsigned long flags;
+ u32 data;
+ int max_irq;
+ int pos;
+ int irq;
+
+ pos = pci_find_capability(dev, PCI_CAP_ID_HT);
+ while (pos) {
+ u8 subtype;
+ pci_read_config_byte(dev, pos + 3, &subtype);
+ if (subtype == HT_CAPTYPE_IRQ)
+ break;
+ pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_HT);
+ }
+ if (!pos)
+ return -EINVAL;
+
+ /* Verify the idx I want to use is in range */
+ spin_lock_irqsave(&ht_irq_lock, flags);
+ pci_write_config_byte(dev, pos + 2, 1);
+ pci_read_config_dword(dev, pos + 4, &data);
+ spin_unlock_irqrestore(&ht_irq_lock, flags);
+
+ max_irq = (data >> 16) & 0xff;
+ if ( idx > max_irq)
+ return -EINVAL;
+
+ cfg = kmalloc(sizeof(*cfg), GFP_KERNEL);
+ if (!cfg)
+ return -ENOMEM;
+
+ cfg->dev = dev;
+ cfg->pos = pos;
+ cfg->idx = 0x10 + (idx * 2);
+
+ irq = create_irq();
+ if (irq < 0) {
+ kfree(cfg);
+ return -EBUSY;
+ }
+ set_irq_data(irq, cfg);
+
+ if (arch_setup_ht_irq(irq, dev) < 0) {
+ ht_destroy_irq(irq);
+ return -EBUSY;
+ }
+
+ return irq;
+}
+
+/**
+ * ht_destroy_irq - destroy an irq created with ht_create_irq
+ *
+ * This reverses ht_create_irq removing the specified irq from
+ * existence. The irq should be free before this happens.
+ */
+void ht_destroy_irq(unsigned int irq)
+{
+ struct ht_irq_cfg *cfg;
+
+ cfg = get_irq_data(irq);
+ set_irq_chip(irq, NULL);
+ set_irq_data(irq, NULL);
+ destroy_irq(irq);
+
+ kfree(cfg);
+}
+
+EXPORT_SYMBOL(ht_create_irq);
+EXPORT_SYMBOL(ht_destroy_irq);
diff --git a/include/asm-i386/hypertransport.h b/include/asm-i386/hypertransport.h
new file mode 100644
index 0000000..c16c6ff
--- /dev/null
+++ b/include/asm-i386/hypertransport.h
@@ -0,0 +1,42 @@
+#ifndef ASM_HYPERTRANSPORT_H
+#define ASM_HYPERTRANSPORT_H
+
+/*
+ * Constants for x86 Hypertransport Interrupts.
+ */
+
+#define HT_IRQ_LOW_BASE 0xf8000000
+
+#define HT_IRQ_LOW_VECTOR_SHIFT 16
+#define HT_IRQ_LOW_VECTOR_MASK 0x00ff0000
+#define HT_IRQ_LOW_VECTOR(v) (((v) << HT_IRQ_LOW_VECTOR_SHIFT) & HT_IRQ_LOW_VECTOR_MASK)
+
+#define HT_IRQ_LOW_DEST_ID_SHIFT 8
+#define HT_IRQ_LOW_DEST_ID_MASK 0x0000ff00
+#define HT_IRQ_LOW_DEST_ID(v) (((v) << HT_IRQ_LOW_DEST_ID_SHIFT) & HT_IRQ_LOW_DEST_ID_MASK)
+
+#define HT_IRQ_LOW_DM_PHYSICAL 0x0000000
+#define HT_IRQ_LOW_DM_LOGICAL 0x0000040
+
+#define HT_IRQ_LOW_RQEOI_EDGE 0x0000000
+#define HT_IRQ_LOW_RQEOI_LEVEL 0x0000020
+
+
+#define HT_IRQ_LOW_MT_FIXED 0x0000000
+#define HT_IRQ_LOW_MT_ARBITRATED 0x0000004
+#define HT_IRQ_LOW_MT_SMI 0x0000008
+#define HT_IRQ_LOW_MT_NMI 0x000000c
+#define HT_IRQ_LOW_MT_INIT 0x0000010
+#define HT_IRQ_LOW_MT_STARTUP 0x0000014
+#define HT_IRQ_LOW_MT_EXTINT 0x0000018
+#define HT_IRQ_LOW_MT_LINT1 0x000008c
+#define HT_IRQ_LOW_MT_LINT0 0x0000098
+
+#define HT_IRQ_LOW_IRQ_MASKED 0x0000001
+
+
+#define HT_IRQ_HIGH_DEST_ID_SHIFT 0
+#define HT_IRQ_HIGH_DEST_ID_MASK 0x00ffffff
+#define HT_IRQ_HIGH_DEST_ID(v) ((((v) >> 8) << HT_IRQ_HIGH_DEST_ID_SHIFT) & HT_IRQ_HIGH_DEST_ID_MASK)
+
+#endif /* ASM_HYPERTRANSPORT_H */
diff --git a/include/asm-x86_64/hypertransport.h b/include/asm-x86_64/hypertransport.h
new file mode 100644
index 0000000..c16c6ff
--- /dev/null
+++ b/include/asm-x86_64/hypertransport.h
@@ -0,0 +1,42 @@
+#ifndef ASM_HYPERTRANSPORT_H
+#define ASM_HYPERTRANSPORT_H
+
+/*
+ * Constants for x86 Hypertransport Interrupts.
+ */
+
+#define HT_IRQ_LOW_BASE 0xf8000000
+
+#define HT_IRQ_LOW_VECTOR_SHIFT 16
+#define HT_IRQ_LOW_VECTOR_MASK 0x00ff0000
+#define HT_IRQ_LOW_VECTOR(v) (((v) << HT_IRQ_LOW_VECTOR_SHIFT) & HT_IRQ_LOW_VECTOR_MASK)
+
+#define HT_IRQ_LOW_DEST_ID_SHIFT 8
+#define HT_IRQ_LOW_DEST_ID_MASK 0x0000ff00
+#define HT_IRQ_LOW_DEST_ID(v) (((v) << HT_IRQ_LOW_DEST_ID_SHIFT) & HT_IRQ_LOW_DEST_ID_MASK)
+
+#define HT_IRQ_LOW_DM_PHYSICAL 0x0000000
+#define HT_IRQ_LOW_DM_LOGICAL 0x0000040
+
+#define HT_IRQ_LOW_RQEOI_EDGE 0x0000000
+#define HT_IRQ_LOW_RQEOI_LEVEL 0x0000020
+
+
+#define HT_IRQ_LOW_MT_FIXED 0x0000000
+#define HT_IRQ_LOW_MT_ARBITRATED 0x0000004
+#define HT_IRQ_LOW_MT_SMI 0x0000008
+#define HT_IRQ_LOW_MT_NMI 0x000000c
+#define HT_IRQ_LOW_MT_INIT 0x0000010
+#define HT_IRQ_LOW_MT_STARTUP 0x0000014
+#define HT_IRQ_LOW_MT_EXTINT 0x0000018
+#define HT_IRQ_LOW_MT_LINT1 0x000008c
+#define HT_IRQ_LOW_MT_LINT0 0x0000098
+
+#define HT_IRQ_LOW_IRQ_MASKED 0x0000001
+
+
+#define HT_IRQ_HIGH_DEST_ID_SHIFT 0
+#define HT_IRQ_HIGH_DEST_ID_MASK 0x00ffffff
+#define HT_IRQ_HIGH_DEST_ID(v) ((((v) >> 8) << HT_IRQ_HIGH_DEST_ID_SHIFT) & HT_IRQ_HIGH_DEST_ID_MASK)
+
+#endif /* ASM_HYPERTRANSPORT_H */
diff --git a/include/linux/pci.h b/include/linux/pci.h
index eb950d6..fd31b1c 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -672,6 +672,23 @@ extern int msi_register(struct msi_ops *

#endif

+#ifdef CONFIG_HT_IRQ
+/* Helper functions.. */
+void write_ht_irq_low(unsigned int irq, u32 data);
+void write_ht_irq_high(unsigned int irq, u32 data);
+u32 read_ht_irq_low(unsigned int irq);
+u32 read_ht_irq_high(unsigned int irq);
+void mask_ht_irq(unsigned int irq);
+void unmask_ht_irq(unsigned int irq);
+
+/* The functions a driver should call */
+int ht_create_irq(struct pci_dev *dev, int idx);
+void ht_destroy_irq(unsigned int irq);
+
+/* The arch hook for getting things started */
+int arch_setup_ht_irq(unsigned int irq, struct pci_dev *dev);
+#endif /* CONFIG_HT_IRQ */
+
extern void pci_block_user_cfg_access(struct pci_dev *dev);
extern void pci_unblock_user_cfg_access(struct pci_dev *dev);

--
1.4.1.gac83a