On Thu, 12 Sep 2019 18:32:04 -0700
Megha Dey <megha.dey@xxxxxxxxxxxxxxx> wrote:
> This patch adds support for the creation of a new IMS irq domain. It
> creates a new irq_chip associated with the IMS domain and adds the
> necessary domain operations to it.
>
> Cc: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
> Signed-off-by: Sanjay Kumar <sanjay.k.kumar@xxxxxxxxx>
> Signed-off-by: Megha Dey <megha.dey@xxxxxxxxxxxxxxx>
> ---
> arch/x86/include/asm/msi.h | 4 ++
> arch/x86/kernel/apic/Makefile | 1 +
> arch/x86/kernel/apic/ims.c | 93 ++++++++++++++++++++++++++++++++++++++++
> arch/x86/kernel/apic/msi.c | 4 +-
> drivers/vfio/mdev/mdev_core.c | 6 +++
> drivers/vfio/mdev/mdev_private.h | 1 -
> include/linux/mdev.h | 2 +
> 7 files changed, 108 insertions(+), 3 deletions(-)
> create mode 100644 arch/x86/kernel/apic/ims.c
>
> diff --git a/arch/x86/include/asm/msi.h b/arch/x86/include/asm/msi.h
> index 25ddd09..51f9d25 100644
> --- a/arch/x86/include/asm/msi.h
> +++ b/arch/x86/include/asm/msi.h
> @@ -11,4 +11,8 @@ int pci_msi_prepare(struct irq_domain *domain, struct device *dev, int nvec,
>
> void pci_msi_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc);
>
> +struct msi_domain_info;
> +
> +irq_hw_number_t msi_get_hwirq(struct msi_domain_info *info,
> + msi_alloc_info_t *arg);
> #endif /* _ASM_X86_MSI_H */
> diff --git a/arch/x86/kernel/apic/Makefile b/arch/x86/kernel/apic/Makefile
> index a6fcaf16..75a2270 100644
> --- a/arch/x86/kernel/apic/Makefile
> +++ b/arch/x86/kernel/apic/Makefile
> @@ -12,6 +12,7 @@ obj-y += hw_nmi.o
>
> obj-$(CONFIG_X86_IO_APIC) += io_apic.o
> obj-$(CONFIG_PCI_MSI) += msi.o
> +obj-$(CONFIG_MSI_IMS) += ims.o
> obj-$(CONFIG_SMP) += ipi.o
>
> ifeq ($(CONFIG_X86_64),y)
> diff --git a/arch/x86/kernel/apic/ims.c b/arch/x86/kernel/apic/ims.c
> new file mode 100644
> index 0000000..d9808a5
> --- /dev/null
> +++ b/arch/x86/kernel/apic/ims.c
> @@ -0,0 +1,93 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright © 2019 Intel Corporation.
> + *
> + * Author: Megha Dey <megha.dey@xxxxxxxxx>
> + */
> +
> +#include <linux/dmar.h>
> +#include <linux/irq.h>
> +#include <linux/mdev.h>
> +#include <linux/pci.h>
> +
> +/*
> + * Determine if a dev is mdev or not. Return NULL if not mdev device.
> + * Return mdev's parent dev if success.
> + */
> +static inline struct device *mdev_to_parent(struct device *dev)
> +{
> + struct device *ret = NULL;
> + struct device *(*fn)(struct device *dev);
> + struct bus_type *bus = symbol_get(mdev_bus_type);
> +
> + if (bus && dev->bus == bus) {
> + fn = symbol_get(mdev_dev_to_parent_dev);
> + ret = fn(dev);
> + symbol_put(mdev_dev_to_parent_dev);
> + symbol_put(mdev_bus_type);
Leaks a reference to the mdev module if dev->bus != bus. The new
version of dev_is_mdev() unconditionally leaks a reference. Thanks,
Alex
> + }
> +
> + return ret;
> +}
> +
> +static struct pci_dev *ims_get_pci_dev(struct device *dev)
> +{
> + struct pci_dev *pdev;
> +
> + if (dev_is_mdev(dev)) {
> + struct device *parent = mdev_to_parent(dev);
> +
> + pdev = to_pci_dev(parent);
> + } else {
> + pdev = to_pci_dev(dev);
> + }
> +
> + return pdev;
> +}
> +
> +int dev_ims_prepare(struct irq_domain *domain, struct device *dev, int nvec,
> + msi_alloc_info_t *arg)
> +{
> + struct pci_dev *pdev = ims_get_pci_dev(dev);
> +
> + init_irq_alloc_info(arg, NULL);
> + arg->msi_dev = pdev;
> + arg->type = X86_IRQ_ALLOC_TYPE_MSIX;
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(dev_ims_prepare);
> +
> +#ifdef CONFIG_IRQ_REMAP
> +
> +static struct msi_domain_ops dev_ims_domain_ops = {
> + .get_hwirq = msi_get_hwirq,
> + .msi_prepare = dev_ims_prepare,
> +};
> +
> +static struct irq_chip dev_ims_ir_controller = {
> + .name = "IR-DEV-IMS",
> + .irq_unmask = dev_ims_unmask_irq,
> + .irq_mask = dev_ims_mask_irq,
> + .irq_ack = irq_chip_ack_parent,
> + .irq_retrigger = irq_chip_retrigger_hierarchy,
> + .irq_set_vcpu_affinity = irq_chip_set_vcpu_affinity_parent,
> + .flags = IRQCHIP_SKIP_SET_WAKE,
> + .irq_write_msi_msg = dev_ims_write_msg,
> +};
> +
> +static struct msi_domain_info ims_ir_domain_info = {
> + .flags = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
> + MSI_FLAG_MULTI_PCI_MSI | MSI_FLAG_PCI_MSIX,
> + .ops = &dev_ims_domain_ops,
> + .chip = &dev_ims_ir_controller,
> + .handler = handle_edge_irq,
> + .handler_name = "edge",
> +};
> +
> +struct irq_domain *arch_create_ims_irq_domain(struct irq_domain *parent)
> +{
> + return pci_msi_create_irq_domain(NULL, &ims_ir_domain_info, parent);
> +}
> +
> +#endif
> diff --git a/arch/x86/kernel/apic/msi.c b/arch/x86/kernel/apic/msi.c
> index 435bcda..65da813 100644
> --- a/arch/x86/kernel/apic/msi.c
> +++ b/arch/x86/kernel/apic/msi.c
> @@ -84,7 +84,7 @@ void native_teardown_msi_irq(unsigned int irq)
> irq_domain_free_irqs(irq, 1);
> }
>
> -static irq_hw_number_t pci_msi_get_hwirq(struct msi_domain_info *info,
> +irq_hw_number_t msi_get_hwirq(struct msi_domain_info *info,
> msi_alloc_info_t *arg)
> {
> return arg->msi_hwirq;
> @@ -116,7 +116,7 @@ void pci_msi_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc)
> EXPORT_SYMBOL_GPL(pci_msi_set_desc);
>
> static struct msi_domain_ops pci_msi_domain_ops = {
> - .get_hwirq = pci_msi_get_hwirq,
> + .get_hwirq = msi_get_hwirq,
> .msi_prepare = pci_msi_prepare,
> .set_desc = pci_msi_set_desc,
> };
> diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
> index b558d4c..cecc6a6 100644
> --- a/drivers/vfio/mdev/mdev_core.c
> +++ b/drivers/vfio/mdev/mdev_core.c
> @@ -33,6 +33,12 @@ struct device *mdev_parent_dev(struct mdev_device *mdev)
> }
> EXPORT_SYMBOL(mdev_parent_dev);
>
> +struct device *mdev_dev_to_parent_dev(struct device *dev)
> +{
> + return to_mdev_device(dev)->parent->dev;
> +}
> +EXPORT_SYMBOL(mdev_dev_to_parent_dev);
> +
> void *mdev_get_drvdata(struct mdev_device *mdev)
> {
> return mdev->driver_data;
> diff --git a/drivers/vfio/mdev/mdev_private.h b/drivers/vfio/mdev/mdev_private.h
> index 7d92295..c21f130 100644
> --- a/drivers/vfio/mdev/mdev_private.h
> +++ b/drivers/vfio/mdev/mdev_private.h
> @@ -36,7 +36,6 @@ struct mdev_device {
> };
>
> #define to_mdev_device(dev) container_of(dev, struct mdev_device, dev)
> -#define dev_is_mdev(d) ((d)->bus == &mdev_bus_type)
>
> struct mdev_type {
> struct kobject kobj;
> diff --git a/include/linux/mdev.h b/include/linux/mdev.h
> index 0ce30ca..9dcbffe 100644
> --- a/include/linux/mdev.h
> +++ b/include/linux/mdev.h
> @@ -144,5 +144,7 @@ void mdev_unregister_driver(struct mdev_driver *drv);
> struct device *mdev_parent_dev(struct mdev_device *mdev);
> struct device *mdev_dev(struct mdev_device *mdev);
> struct mdev_device *mdev_from_dev(struct device *dev);
> +struct device *mdev_dev_to_parent_dev(struct device *dev);
>
> +#define dev_is_mdev(d) ((d)->bus == symbol_get(mdev_bus_type))
> #endif /* MDEV_H */
