[PATCH] Initial generic hypertransport interrupt support

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.

[akpm@osdl.org: Kconfig fix]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Greg KH <greg@kroah.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

8 files changed, 486 insertions, 0 deletions

diff --git a/arch/i386/kernel/io_apic.c b/arch/i386/kernel/io_apic.c
index 03e7606be6e6..100406b453b8 100644
--- a/arch/i386/kernel/io_apic.c
+++ b/arch/i386/kernel/io_apic.c
@@ -40,6 +40,7 @@
 #include <asm/i8259.h>
 #include <asm/nmi.h>
 #include <asm/msidef.h>
+#include <asm/hypertransport.h>
 
 #include <mach_apic.h>
 #include <mach_apicdef.h>
@@ -2518,6 +2519,95 @@ 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 7cc29b50b0c1..31c270fee337 100644
--- a/arch/x86_64/kernel/io_apic.c
+++ b/arch/x86_64/kernel/io_apic.c
@@ -43,6 +43,7 @@
 #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);
 
@@ -1772,6 +1773,101 @@ 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 c27e782e6df9..0af6d7288415 100644
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -52,3 +52,12 @@ config PCI_DEBUG
 
           When in doubt, say N.
 
+config HT_IRQ
+        bool "Interrupts on hypertransport devices"
+        default y
+        depends on PCI_MSI
+        depends on X86_LOCAL_APIC && X86_IO_APIC
+        help
+           This allows native hypertransport devices to use interrupts.
+
+           If unsure say Y.
diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
index 983d0f86aa33..2752c57ecf01 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 000000000000..4ba46359d367
--- /dev/null
+++ b/drivers/pci/htirq.c
@@ -0,0 +1,189 @@
+/*
+ * 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 000000000000..c16c6ff4bdd7
--- /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 000000000000..c16c6ff4bdd7
--- /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 2aabe90f1cd2..9b34bc8f34e4 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -681,6 +681,23 @@ extern int msi_register(struct msi_ops *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);