On Sun, Sep 14 2014 at 07:30:16 AM, "suravee.suthikulpa...@amd.com"
<suravee.suthikulpa...@amd.com> wrote:
> From: Suravee Suthikulpanit <suravee.suthikulpa...@amd.com>
>
> This patch extend GICv2m MSI to support multiple MSI in ARM64.
>
> This requires the common arch_setup_msi_irqs() to be overwriten
> with ARM64 version which does not return 1 for PCI_CAP_ID_MSI and
> nvec > 1.
>
> Cc: Mark Rutland <mark.rutl...@arm.com>
> Cc: Marc Zyngier <marc.zyng...@arm.com>
> Cc: Jason Cooper <ja...@lakedaemon.net>
> Cc: Catalin Marinas <catalin.mari...@arm.com>
> Cc: Will Deacon <will.dea...@arm.com>
> Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpa...@amd.com>
> ---
> arch/arm64/kernel/Makefile | 1 +
> arch/arm64/kernel/msi.c | 41 ++++++++++++++++++++
> drivers/irqchip/irq-gic-v2m.c | 87
> ++++++++++++++++++++++++++++++++++++++-----
> 3 files changed, 119 insertions(+), 10 deletions(-)
> create mode 100644 arch/arm64/kernel/msi.c
>
> diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
> index df7ef87..a921c42 100644
> --- a/arch/arm64/kernel/Makefile
> +++ b/arch/arm64/kernel/Makefile
> @@ -29,6 +29,7 @@ arm64-obj-$(CONFIG_ARM64_CPU_SUSPEND) += sleep.o
> suspend.o
> arm64-obj-$(CONFIG_JUMP_LABEL) += jump_label.o
> arm64-obj-$(CONFIG_KGDB) += kgdb.o
> arm64-obj-$(CONFIG_EFI) += efi.o efi-stub.o efi-entry.o
> +arm64-obj-$(CONFIG_PCI_MSI) += msi.o
>
> obj-y += $(arm64-obj-y) vdso/
> obj-m += $(arm64-obj-m)
> diff --git a/arch/arm64/kernel/msi.c b/arch/arm64/kernel/msi.c
> new file mode 100644
> index 0000000..a295862
> --- /dev/null
> +++ b/arch/arm64/kernel/msi.c
> @@ -0,0 +1,41 @@
> +/*
> + * ARM64 architectural MSI implemention
> + *
> + * Support for Message Signalelled Interrupts for systems that
> + * implement ARM Generic Interrupt Controller: GICv2m.
> + *
> + * Copyright (C) 2014 Advanced Micro Devices, Inc.
> + * Authors: Suravee Suthikulpanit <suravee.suthikulpa...@amd.com>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License version 2 as published
> + * by the Free Software Foundation.
> + */
> +
> +#include <linux/irq.h>
> +#include <linux/msi.h>
> +#include <linux/pci.h>
> +
> +/*
> + * ARM64 function for seting up MSI irqs.
> + * Based on driver/pci/msi.c: arch_setup_msi_irqs().
> + *
> + * Note:
> + * Current implementation assumes that all interrupt controller used in
> + * ARM64 architecture _MUST_ supports multi-MSI.
> + */
> +int arm64_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
> +{
> + struct msi_desc *entry;
> + int ret;
> +
> + list_for_each_entry(entry, &dev->msi_list, list) {
> + ret = arch_setup_msi_irq(dev, entry);
> + if (ret < 0)
> + return ret;
> + if (ret > 0)
> + return -ENOSPC;
> + }
> +
> + return 0;
> +}
> diff --git a/drivers/irqchip/irq-gic-v2m.c b/drivers/irqchip/irq-gic-v2m.c
> index 499bfb9..4ddb47d 100644
> --- a/drivers/irqchip/irq-gic-v2m.c
> +++ b/drivers/irqchip/irq-gic-v2m.c
> @@ -99,13 +99,26 @@ static void gicv2m_teardown_msi_irq(struct msi_chip
> *chip, unsigned int irq)
> spin_unlock(&data->msi_cnt_lock);
> }
>
> +static int gicv2m_msi_get_vec_count(struct pci_dev *pdev, struct msi_desc
> *desc)
> +{
> + int ret = -EINVAL;
> +#ifdef CONFIG_PCI_MSI
> + if (desc->msi_attrib.is_msix)
> + ret = pci_msix_vec_count(pdev);
> + else
> + ret = pci_msi_vec_count(pdev);
> +#endif
> + return ret;
> +}
> +
Since I also have:
https://git.kernel.org/cgit/linux/kernel/git/maz/arm-platforms.git/tree/drivers/irqchip/irq-gic-v3-its.c?h=gicv3/its-split#n1107
Maybe it would be a good thing to make this a core thing (not something
we have to do now though).
> static int gicv2m_setup_msi_irq(struct msi_chip *chip,
> struct pci_dev *pdev,
> struct msi_desc *desc)
> {
> - int irq, avail;
> + int i, irq, nvec, avail;
> struct msi_msg msg;
> phys_addr_t addr;
> + struct msi_desc *entry;
> struct v2m_data *data = container_of(chip, struct v2m_data, msi_chip);
>
> if (!desc) {
> @@ -114,16 +127,70 @@ static int gicv2m_setup_msi_irq(struct msi_chip *chip,
> return -EINVAL;
> }
>
> - avail = alloc_msi_irq(data, 1, &irq);
> - if (avail != 0) {
> - dev_err(&pdev->dev,
> - "GICv2m: MSI setup failed. Cannnot allocate IRQ\n");
> - return -ENOSPC;
> - }
> + if (desc->msi_attrib.is_msix) {
> + /**
> + * For MSIx:
> + * We allocate one irq at a time
> + */
> + avail = alloc_msi_irq(data, 1, &irq);
> + if (avail != 0) {
> + dev_err(&pdev->dev,
> + "GICv2m: MSI setup failed. Cannnot allocate
> IRQ\n");
> + return -ENOSPC;
> + }
>
> - irq_set_chip_data(irq, chip);
> - irq_set_msi_desc(irq, desc);
> - irq_set_irq_type(irq, IRQ_TYPE_EDGE_RISING);
> + irq_set_chip_data(irq, chip);
> + irq_set_msi_desc(irq, desc);
> + irq_set_irq_type(irq, IRQ_TYPE_EDGE_RISING);
> + } else {
> + /**
> + * For MSI and Multi-MSI:
> + * All requested irqs are allocated and setup at
> + * once. Subsequent calls to this function would simply return
> + * success. This is to avoid having to implement a separate
> + * function for setting up multiple irqs.
> + */
> + BUG_ON(list_empty(&pdev->msi_list));
> + WARN_ON(!list_is_singular(&pdev->msi_list));
> +
> + nvec = gicv2m_msi_get_vec_count(pdev, desc);
> + if (WARN_ON(nvec <= 0))
> + return nvec;
> +
> + entry = list_first_entry(&pdev->msi_list,
> + struct msi_desc, list);
> +
> + if ((nvec > 1) && (entry->msi_attrib.multiple))
> + return 0;
> +
> + avail = alloc_msi_irq(data, nvec, &irq);
> + if (avail != 0) {
> + dev_err(&pdev->dev,
> + "GICv2m: Failed to allocate %d irqs.\n", nvec);
> + return avail;
> + }
> +
> + if (nvec > 1) {
> + /* Set lowest of the new interrupts assigned
> + * to the PCI device
> + */
> + entry->nvec_used = nvec;
> + entry->msi_attrib.multiple = ilog2(
> + __roundup_pow_of_two(nvec));
> + }
> +
> + for (i = 0; i < nvec; i++) {
> + irq_set_chip_data(irq+i, chip);
> + if (irq_set_msi_desc_off(irq, i, entry)) {
> + dev_err(&pdev->dev,
> + "GICv2m: Failed to set up MSI irq %d\n",
> + (irq+i));
> + return -EINVAL;
> + }
> +
> + irq_set_irq_type((irq+i), IRQ_TYPE_EDGE_RISING);
> + }
> + }
>
> addr = data->res.start + V2M_MSI_SETSPI_NS;
> msg.address_hi = (u32)(addr >> 32);
Overall, I think you should move this "msi > 1" code directly into the
first patch (not sure the intermediate implementation adds much to the
understanding of the whole driver).
You can then have the arm64-specific code as your second patch.
Thanks,
M.
--
Jazz is not dead. It just smells funny.
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