[PATCH v2 4/8] irqchip: armada-370-xp: implement MSI support
Thomas Petazzoni
thomas.petazzoni at free-electrons.com
Thu Jun 6 12:41:24 EDT 2013
This commit introduces the support for the MSI interrupts in the
armada-370-xp interrupt controller driver. It registers an MSI chip to
the MSI chip registry, which will be used by the Marvell PCIe host
controller driver.
The MSI interrupts use the 16 high doorbells, and are therefore
notified using IRQ1 of the main interrupt controller.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
---
drivers/irqchip/irq-armada-370-xp.c | 166 +++++++++++++++++++++++++++++++++++-
1 file changed, 165 insertions(+), 1 deletion(-)
diff --git a/drivers/irqchip/irq-armada-370-xp.c b/drivers/irqchip/irq-armada-370-xp.c
index 26adc74..c7c904d 100644
--- a/drivers/irqchip/irq-armada-370-xp.c
+++ b/drivers/irqchip/irq-armada-370-xp.c
@@ -22,6 +22,8 @@
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/irqdomain.h>
+#include <linux/slab.h>
+#include <linux/msi.h>
#include <asm/mach/arch.h>
#include <asm/exception.h>
#include <asm/smp_plat.h>
@@ -51,12 +53,22 @@
#define IPI_DOORBELL_START (0)
#define IPI_DOORBELL_END (8)
#define IPI_DOORBELL_MASK 0xFF
+#define PCI_MSI_DOORBELL_START (16)
+#define PCI_MSI_DOORBELL_NR (16)
+#define PCI_MSI_DOORBELL_END (32)
+#define PCI_MSI_DOORBELL_MASK 0xFFFF0000
static DEFINE_RAW_SPINLOCK(irq_controller_lock);
static void __iomem *per_cpu_int_base;
static void __iomem *main_int_base;
static struct irq_domain *armada_370_xp_mpic_domain;
+#ifdef CONFIG_PCI_MSI
+static struct irq_domain *armada_370_xp_msi_domain;
+static DECLARE_BITMAP(msi_used, PCI_MSI_DOORBELL_NR);
+static DEFINE_MUTEX(msi_used_lock);
+static phys_addr_t msi_doorbell_addr;
+#endif
/*
* In SMP mode:
@@ -87,6 +99,126 @@ static void armada_370_xp_irq_unmask(struct irq_data *d)
ARMADA_370_XP_INT_CLEAR_MASK_OFFS);
}
+#ifdef CONFIG_PCI_MSI
+static int armada_370_xp_alloc_msi(void)
+{
+ int hwirq;
+
+ mutex_lock(&msi_used_lock);
+ hwirq = find_first_zero_bit(&msi_used, PCI_MSI_DOORBELL_NR);
+ if (hwirq >= PCI_MSI_DOORBELL_NR)
+ hwirq = -ENOSPC;
+ else
+ set_bit(hwirq, msi_used);
+ mutex_unlock(&msi_used_lock);
+
+ return hwirq;
+}
+
+static void armada_370_xp_free_msi(int hwirq)
+{
+ mutex_lock(&msi_used_lock);
+ if (!test_bit(hwirq, msi_used))
+ pr_err("trying to free unused MSI#%d\n", hwirq);
+ else
+ clear_bit(hwirq, msi_used);
+ mutex_unlock(&msi_used_lock);
+}
+
+static int armada_370_xp_setup_msi_irq(struct msi_chip *chip,
+ struct pci_dev *pdev,
+ struct msi_desc *desc)
+{
+ struct msi_msg msg;
+ int hwirq, irq;
+
+ hwirq = armada_370_xp_alloc_msi();
+ if (hwirq < 0)
+ return hwirq;
+
+ irq = irq_create_mapping(armada_370_xp_msi_domain, hwirq);
+ if (!irq) {
+ armada_370_xp_free_msi(hwirq);
+ return -EINVAL;
+ }
+
+ irq_set_msi_desc(irq, desc);
+
+ msg.address_lo = msi_doorbell_addr;
+ msg.address_hi = 0;
+ msg.data = 0xf00 | (hwirq + 16);
+
+ write_msi_msg(irq, &msg);
+ return 0;
+}
+
+static void armada_370_xp_teardown_msi_irq(struct msi_chip *chip,
+ unsigned int irq)
+{
+ struct irq_data *d = irq_get_irq_data(irq);
+ armada_370_xp_free_msi(d->hwirq);
+}
+
+static struct irq_chip armada_370_xp_msi_irq_chip = {
+ .name = "armada_370_xp_msi_irq",
+ .irq_enable = unmask_msi_irq,
+ .irq_disable = mask_msi_irq,
+ .irq_mask = mask_msi_irq,
+ .irq_unmask = unmask_msi_irq,
+};
+
+static int armada_370_xp_msi_map(struct irq_domain *domain, unsigned int virq,
+ irq_hw_number_t hw)
+{
+ irq_set_chip_and_handler(virq, &armada_370_xp_msi_irq_chip,
+ handle_simple_irq);
+ set_irq_flags(virq, IRQF_VALID);
+
+ return 0;
+}
+
+static const struct irq_domain_ops armada_370_xp_msi_irq_ops = {
+ .map = armada_370_xp_msi_map,
+};
+
+static int armada_370_xp_msi_init(struct device_node *node)
+{
+ struct msi_chip *msi_chip;
+ u32 reg;
+
+ msi_chip = kzalloc(sizeof(*msi_chip), GFP_KERNEL);
+ if (!msi_chip)
+ return -ENOMEM;
+
+ armada_370_xp_msi_domain =
+ irq_domain_add_linear(NULL, PCI_MSI_DOORBELL_NR,
+ &armada_370_xp_msi_irq_ops, NULL);
+ if (!armada_370_xp_msi_domain) {
+ kfree(msi_chip);
+ return -ENOMEM;
+ }
+
+ msi_chip->of_node = node;
+ msi_chip->setup_irq = armada_370_xp_setup_msi_irq;
+ msi_chip->teardown_irq = armada_370_xp_teardown_msi_irq;
+
+ msi_chip_add(msi_chip);
+
+ reg = readl(per_cpu_int_base + ARMADA_370_XP_IN_DRBEL_MSK_OFFS)
+ | PCI_MSI_DOORBELL_MASK;
+
+ writel(reg, per_cpu_int_base +
+ ARMADA_370_XP_IN_DRBEL_MSK_OFFS);
+
+ /* Unmask IPI interrupt */
+ writel(1, per_cpu_int_base + ARMADA_370_XP_INT_CLEAR_MASK_OFFS);
+
+ return 0;
+}
+#else
+static inline int armada_370_xp_msi_init(struct device_node *node) { return 0; }
+#endif
+
#ifdef CONFIG_SMP
static int armada_xp_set_affinity(struct irq_data *d,
const struct cpumask *mask_val, bool force)
@@ -214,12 +346,39 @@ armada_370_xp_handle_irq(struct pt_regs *regs)
if (irqnr > 1022)
break;
- if (irqnr > 0) {
+ if (irqnr > 1) {
irqnr = irq_find_mapping(armada_370_xp_mpic_domain,
irqnr);
handle_IRQ(irqnr, regs);
continue;
}
+
+#ifdef CONFIG_PCI_MSI
+ /* MSI handling */
+ if (irqnr == 1) {
+ u32 msimask, msinr;
+
+ msimask = readl_relaxed(per_cpu_int_base +
+ ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS)
+ & PCI_MSI_DOORBELL_MASK;
+
+ writel(~PCI_MSI_DOORBELL_MASK, per_cpu_int_base +
+ ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS);
+
+ for (msinr = PCI_MSI_DOORBELL_START;
+ msinr < PCI_MSI_DOORBELL_END; msinr++) {
+ int irq;
+
+ if (!(msimask & BIT(msinr)))
+ continue;
+
+ irq = irq_find_mapping(armada_370_xp_msi_domain,
+ msinr - 16);
+ handle_IRQ(irq, regs);
+ }
+ }
+#endif
+
#ifdef CONFIG_SMP
/* IPI Handling */
if (irqnr == 0) {
@@ -269,6 +428,9 @@ static int __init armada_370_xp_mpic_of_init(struct device_node *node,
resource_size(&per_cpu_int_res));
BUG_ON(!per_cpu_int_base);
+ msi_doorbell_addr = main_int_res.start +
+ ARMADA_370_XP_SW_TRIG_INT_OFFS;
+
control = readl(main_int_base + ARMADA_370_XP_INT_CONTROL);
armada_370_xp_mpic_domain =
@@ -292,6 +454,8 @@ static int __init armada_370_xp_mpic_of_init(struct device_node *node,
#endif
+ armada_370_xp_msi_init(node);
+
set_handle_irq(armada_370_xp_handle_irq);
return 0;
--
1.8.1.2
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