[PATCHv8 06/10] irqchip: armada-370-xp: implement MSI support
Gregory CLEMENT
gregory.clement at free-electrons.com
Fri Aug 9 02:44:46 EDT 2013
On 09/08/2013 00:17, Thomas Petazzoni wrote:
> 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>
Acked-by: Gregory CLEMENT <gregory.clement at free-electrons.com>
> ---
> .../devicetree/bindings/arm/armada-370-xp-mpic.txt | 3 +
> drivers/irqchip/irq-armada-370-xp.c | 182 ++++++++++++++++++++-
> 2 files changed, 184 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/devicetree/bindings/arm/armada-370-xp-mpic.txt b/Documentation/devicetree/bindings/arm/armada-370-xp-mpic.txt
> index 61df564..d74091a 100644
> --- a/Documentation/devicetree/bindings/arm/armada-370-xp-mpic.txt
> +++ b/Documentation/devicetree/bindings/arm/armada-370-xp-mpic.txt
> @@ -4,6 +4,8 @@ Marvell Armada 370 and Armada XP Interrupt Controller
> Required properties:
> - compatible: Should be "marvell,mpic"
> - interrupt-controller: Identifies the node as an interrupt controller.
> +- msi-controller: Identifies the node as an PCI Message Signaled
> + Interrupt controller.
> - #interrupt-cells: The number of cells to define the interrupts. Should be 1.
> The cell is the IRQ number
>
> @@ -24,6 +26,7 @@ Example:
> #address-cells = <1>;
> #size-cells = <1>;
> interrupt-controller;
> + msi-controller;
> reg = <0xd0020a00 0x1d0>,
> <0xd0021070 0x58>;
> };
> diff --git a/drivers/irqchip/irq-armada-370-xp.c b/drivers/irqchip/irq-armada-370-xp.c
> index 26adc74..433cc85 100644
> --- a/drivers/irqchip/irq-armada-370-xp.c
> +++ b/drivers/irqchip/irq-armada-370-xp.c
> @@ -21,7 +21,10 @@
> #include <linux/io.h>
> #include <linux/of_address.h>
> #include <linux/of_irq.h>
> +#include <linux/of_pci.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 +54,22 @@
> #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 +100,144 @@ 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;
> + irq_hw_number_t hwirq;
> + int virq;
> +
> + hwirq = armada_370_xp_alloc_msi();
> + if (hwirq < 0)
> + return hwirq;
> +
> + virq = irq_create_mapping(armada_370_xp_msi_domain, hwirq);
> + if (!virq) {
> + armada_370_xp_free_msi(hwirq);
> + return -EINVAL;
> + }
> +
> + irq_set_msi_desc(virq, desc);
> +
> + msg.address_lo = msi_doorbell_addr;
> + msg.address_hi = 0;
> + msg.data = 0xf00 | (hwirq + 16);
> +
> + write_msi_msg(virq, &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);
> + irq_dispose_mapping(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,
> + phys_addr_t main_int_phys_base)
> +{
> + struct msi_chip *msi_chip;
> + u32 reg;
> + int ret;
> +
> + msi_doorbell_addr = main_int_phys_base +
> + ARMADA_370_XP_SW_TRIG_INT_OFFS;
> +
> + msi_chip = kzalloc(sizeof(*msi_chip), GFP_KERNEL);
> + if (!msi_chip)
> + return -ENOMEM;
> +
> + msi_chip->setup_irq = armada_370_xp_setup_msi_irq;
> + msi_chip->teardown_irq = armada_370_xp_teardown_msi_irq;
> + msi_chip->of_node = node;
> +
> + 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;
> + }
> +
> + ret = of_pci_msi_chip_add(msi_chip);
> + if (ret < 0) {
> + irq_domain_remove(armada_370_xp_msi_domain);
> + kfree(msi_chip);
> + return ret;
> + }
> +
> + 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,
> + phys_addr_t main_int_phys_base)
> +{
> + 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 +365,39 @@ 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) {
> @@ -292,6 +470,8 @@ static int __init armada_370_xp_mpic_of_init(struct device_node *node,
>
> #endif
>
> + armada_370_xp_msi_init(node, main_int_res.start);
> +
> set_handle_irq(armada_370_xp_handle_irq);
>
> return 0;
>
--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
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