diff options
| -rw-r--r-- | MAINTAINERS | 1 | ||||
| -rw-r--r-- | arch/x86/include/asm/pci.h | 15 | ||||
| -rw-r--r-- | drivers/pci/Kconfig | 8 | ||||
| -rw-r--r-- | drivers/pci/host/Makefile | 1 | ||||
| -rw-r--r-- | drivers/pci/host/pci-hyperv.c | 2346 | ||||
| -rw-r--r-- | drivers/pci/probe.c | 15 | ||||
| -rw-r--r-- | include/linux/pci.h | 4 |
7 files changed, 2389 insertions, 1 deletions
diff --git a/MAINTAINERS b/MAINTAINERS index b2122f7ea727..85d7907e4095 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -5193,6 +5193,7 @@ F: arch/x86/kernel/cpu/mshyperv.c F: drivers/hid/hid-hyperv.c F: drivers/hv/ F: drivers/input/serio/hyperv-keyboard.c +F: drivers/pci/host/pci-hyperv.c F: drivers/net/hyperv/ F: drivers/scsi/storvsc_drv.c F: drivers/video/fbdev/hyperv_fb.c diff --git a/arch/x86/include/asm/pci.h b/arch/x86/include/asm/pci.h index 7fd8eaa8714d..9ab7507ca1c2 100644 --- a/arch/x86/include/asm/pci.h +++ b/arch/x86/include/asm/pci.h @@ -20,6 +20,9 @@ struct pci_sysdata { #ifdef CONFIG_X86_64 void *iommu; /* IOMMU private data */ #endif +#ifdef CONFIG_PCI_MSI_IRQ_DOMAIN + void *fwnode; /* IRQ domain for MSI assignment */ +#endif }; extern int pci_routeirq; @@ -32,6 +35,7 @@ extern int noioapicreroute; static inline int pci_domain_nr(struct pci_bus *bus) { struct pci_sysdata *sd = bus->sysdata; + return sd->domain; } @@ -41,6 +45,17 @@ static inline int pci_proc_domain(struct pci_bus *bus) } #endif +#ifdef CONFIG_PCI_MSI_IRQ_DOMAIN +static inline void *_pci_root_bus_fwnode(struct pci_bus *bus) +{ + struct pci_sysdata *sd = bus->sysdata; + + return sd->fwnode; +} + +#define pci_root_bus_fwnode _pci_root_bus_fwnode +#endif + /* Can be used to override the logic in pci_scan_bus for skipping already-configured bus numbers - to be used for buggy BIOSes or architectures with incomplete PCI setup by the loader */ diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig index 616165d72a17..a1f37db745ab 100644 --- a/drivers/pci/Kconfig +++ b/drivers/pci/Kconfig @@ -121,5 +121,11 @@ config PCI_LABEL def_bool y if (DMI || ACPI) select NLS -source "drivers/pci/hotplug/Kconfig" +config PCI_HYPERV + tristate "Hyper-V PCI Frontend" + depends on PCI && X86 && HYPERV && PCI_MSI && PCI_MSI_IRQ_DOMAIN && X86_64 + help + The PCI device frontend driver allows the kernel to import arbitrary + PCI devices from a PCI backend to support PCI driver domains. + source "drivers/pci/host/Kconfig" diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile index 3ccd743e20b9..d85b5faf9bbc 100644 --- a/drivers/pci/host/Makefile +++ b/drivers/pci/host/Makefile @@ -3,6 +3,7 @@ obj-$(CONFIG_PCIE_DW_PLAT) += pcie-designware-plat.o obj-$(CONFIG_PCI_DRA7XX) += pci-dra7xx.o obj-$(CONFIG_PCI_EXYNOS) += pci-exynos.o obj-$(CONFIG_PCI_IMX6) += pci-imx6.o +obj-$(CONFIG_PCI_HYPERV) += pci-hyperv.o obj-$(CONFIG_PCI_MVEBU) += pci-mvebu.o obj-$(CONFIG_PCI_TEGRA) += pci-tegra.o obj-$(CONFIG_PCI_RCAR_GEN2) += pci-rcar-gen2.o diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c new file mode 100644 index 000000000000..ed651baa7c50 --- /dev/null +++ b/drivers/pci/host/pci-hyperv.c @@ -0,0 +1,2346 @@ +/* + * Copyright (c) Microsoft Corporation. + * + * Author: + * Jake Oshins <jakeo@microsoft.com> + * + * This driver acts as a paravirtual front-end for PCI Express root buses. + * When a PCI Express function (either an entire device or an SR-IOV + * Virtual Function) is being passed through to the VM, this driver exposes + * a new bus to the guest VM. This is modeled as a root PCI bus because + * no bridges are being exposed to the VM. In fact, with a "Generation 2" + * VM within Hyper-V, there may seem to be no PCI bus at all in the VM + * until a device as been exposed using this driver. + * + * Each root PCI bus has its own PCI domain, which is called "Segment" in + * the PCI Firmware Specifications. Thus while each device passed through + * to the VM using this front-end will appear at "device 0", the domain will + * be unique. Typically, each bus will have one PCI function on it, though + * this driver does support more than one. + * + * In order to map the interrupts from the device through to the guest VM, + * this driver also implements an IRQ Domain, which handles interrupts (either + * MSI or MSI-X) associated with the functions on the bus. As interrupts are + * set up, torn down, or reaffined, this driver communicates with the + * underlying hypervisor to adjust the mappings in the I/O MMU so that each + * interrupt will be delivered to the correct virtual processor at the right + * vector. This driver does not support level-triggered (line-based) + * interrupts, and will report that the Interrupt Line register in the + * function's configuration space is zero. + * + * The rest of this driver mostly maps PCI concepts onto underlying Hyper-V + * facilities. For instance, the configuration space of a function exposed + * by Hyper-V is mapped into a single page of memory space, and the + * read and write handlers for config space must be aware of this mechanism. + * Similarly, device setup and teardown involves messages sent to and from + * the PCI back-end driver in Hyper-V. + * + * 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. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or + * NON INFRINGEMENT. See the GNU General Public License for more + * details. + * + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/pci.h> +#include <linux/semaphore.h> +#include <linux/irqdomain.h> +#include <asm/irqdomain.h> +#include <asm/apic.h> +#include <linux/msi.h> +#include <linux/hyperv.h> +#include <asm/mshyperv.h> + +/* + * Protocol versions. The low word is the minor version, the high word the + * major version. + */ + +#define PCI_MAKE_VERSION(major, minor) ((u32)(((major) << 16) | (major))) +#define PCI_MAJOR_VERSION(version) ((u32)(version) >> 16) +#define PCI_MINOR_VERSION(version) ((u32)(version) & 0xff) + +enum { + PCI_PROTOCOL_VERSION_1_1 = PCI_MAKE_VERSION(1, 1), + PCI_PROTOCOL_VERSION_CURRENT = PCI_PROTOCOL_VERSION_1_1 +}; + +#define PCI_CONFIG_MMIO_LENGTH 0x2000 +#define CFG_PAGE_OFFSET 0x1000 +#define CFG_PAGE_SIZE (PCI_CONFIG_MMIO_LENGTH - CFG_PAGE_OFFSET) + +#define MAX_SUPPORTED_MSI_MESSAGES 0x400 + +/* + * Message Types + */ + +enum pci_message_type { + /* + * Version 1.1 + */ + PCI_MESSAGE_BASE = 0x42490000, + PCI_BUS_RELATIONS = PCI_MESSAGE_BASE + 0, + PCI_QUERY_BUS_RELATIONS = PCI_MESSAGE_BASE + 1, + PCI_POWER_STATE_CHANGE = PCI_MESSAGE_BASE + 4, + PCI_QUERY_RESOURCE_REQUIREMENTS = PCI_MESSAGE_BASE + 5, + PCI_QUERY_RESOURCE_RESOURCES = PCI_MESSAGE_BASE + 6, + PCI_BUS_D0ENTRY = PCI_MESSAGE_BASE + 7, + PCI_BUS_D0EXIT = PCI_MESSAGE_BASE + 8, + PCI_READ_BLOCK = PCI_MESSAGE_BASE + 9, + PCI_WRITE_BLOCK = PCI_MESSAGE_BASE + 0xA, + PCI_EJECT = PCI_MESSAGE_BASE + 0xB, + PCI_QUERY_STOP = PCI_MESSAGE_BASE + 0xC, + PCI_REENABLE = PCI_MESSAGE_BASE + 0xD, + PCI_QUERY_STOP_FAILED = PCI_MESSAGE_BASE + 0xE, + PCI_EJECTION_COMPLETE = PCI_MESSAGE_BASE + 0xF, + PCI_RESOURCES_ASSIGNED = PCI_MESSAGE_BASE + 0x10, + PCI_RESOURCES_RELEASED = PCI_MESSAGE_BASE + 0x11, + PCI_INVALIDATE_BLOCK = PCI_MESSAGE_BASE + 0x12, + PCI_QUERY_PROTOCOL_VERSION = PCI_MESSAGE_BASE + 0x13, + PCI_CREATE_INTERRUPT_MESSAGE = PCI_MESSAGE_BASE + 0x14, + PCI_DELETE_INTERRUPT_MESSAGE = PCI_MESSAGE_BASE + 0x15, + PCI_MESSAGE_MAXIMUM +}; + +/* + * Structures defining the virtual PCI Express protocol. + */ + +union pci_version { + struct { + u16 minor_version; + u16 major_version; + } parts; + u32 version; +} __packed; + +/* + * Function numbers are 8-bits wide on Express, as interpreted through ARI, + * which is all this driver does. This representation is the one used in + * Windows, which is what is expected when sending this back and forth with + * the Hyper-V parent partition. + */ +union win_slot_encoding { + struct { + u32 func:8; + u32 reserved:24; + } bits; + u32 slot; +} __packed; + +/* + * Pretty much as defined in the PCI Specifications. + */ +struct pci_function_description { + u16 v_id; /* vendor ID */ + u16 d_id; /* device ID */ + u8 rev; + u8 prog_intf; + u8 subclass; + u8 base_class; + u32 subsystem_id; + union win_slot_encoding win_slot; + u32 ser; /* serial number */ +} __packed; + +/** + * struct hv_msi_desc + * @vector: IDT entry + * @delivery_mode: As defined in Intel's Programmer's + * Reference Manual, Volume 3, Chapter 8. + * @vector_count: Number of contiguous entries in the + * Interrupt Descriptor Table that are + * occupied by this Message-Signaled + * Interrupt. For "MSI", as first defined + * in PCI 2.2, this can be between 1 and + * 32. For "MSI-X," as first defined in PCI + * 3.0, this must be 1, as each MSI-X table + * entry would have its own descriptor. + * @reserved: Empty space + * @cpu_mask: All the target virtual processors. + */ +struct hv_msi_desc { + u8 vector; + u8 delivery_mode; + u16 vector_count; + u32 reserved; + u64 cpu_mask; +} __packed; + +/** + * struct tran_int_desc + * @reserved: unused, padding + * @vector_count: same as in hv_msi_desc + * @data: This is the "data payload" value that is + * written by the device when it generates + * a message-signaled interrupt, either MSI + * or MSI-X. + * @address: This is the address to which the data + * payload is written on interrupt + * generation. + */ +struct tran_int_desc { + u16 reserved; + u16 vector_count; + u32 data; + u64 address; +} __packed; + +/* + * A generic message format for virtual PCI. + * Specific message formats are defined later in the file. + */ + +struct pci_message { + u32 message_type; +} __packed; + +struct pci_child_message { + u32 message_type; + union win_slot_encoding wslot; +} __packed; + +struct pci_incoming_message { + struct vmpacket_descriptor hdr; + struct pci_message message_type; +} __packed; + +struct pci_response { + struct vmpacket_descriptor hdr; + s32 status; /* negative values are failures */ +} __packed; + +struct pci_packet { + void (*completion_func)(void *context, struct pci_response *resp, + int resp_packet_size); + void *compl_ctxt; + struct pci_message message; +}; + +/* + * Specific message types supporting the PCI protocol. + */ + +/* + * Version negotiation message. Sent from the guest to the host. + * The guest is free to try different versions until the host + * accepts the version. + * + * pci_version: The protocol version requested. + * is_last_attempt: If TRUE, this is the last version guest will request. + * reservedz: Reserved field, set to zero. + */ + +struct pci_version_request { + struct pci_message message_type; + enum pci_message_type protocol_version; +} __packed; + +/* + * Bus D0 Entry. This is sent from the guest to the host when the virtual + * bus (PCI Express port) is ready for action. + */ + +struct pci_bus_d0_entry { + struct pci_message message_type; + u32 reserved; + u64 mmio_base; +} __packed; + +struct pci_bus_relations { + struct pci_incoming_message incoming; + u32 device_count; + struct pci_function_description func[1]; +} __packed; + +struct pci_q_res_req_response { + struct vmpacket_descriptor hdr; + s32 status; /* negative values are failures */ + u32 probed_bar[6]; +} __packed; + +struct pci_set_power { + struct pci_message message_type; + union win_slot_encoding wslot; + u32 power_state; /* In Windows terms */ + u32 reserved; +} __packed; + +struct pci_set_power_response { + struct vmpacket_descriptor hdr; + s32 status; /* negative values are failures */ + union win_slot_encoding wslot; + u32 resultant_state; /* In Windows terms */ + u32 reserved; +} __packed; + +struct pci_resources_assigned { + struct pci_message message_type; + union win_slot_encoding wslot; + u8 memory_range[0x14][6]; /* not used here */ + u32 msi_descriptors; + u32 reserved[4]; +} __packed; + +struct pci_create_interrupt { + struct pci_message message_type; + union win_slot_encoding wslot; + struct hv_msi_desc int_desc; +} __packed; + +struct pci_create_int_response { + struct pci_response response; + u32 reserved; + struct tran_int_desc int_desc; +} __packed; + +struct pci_delete_interrupt { + struct pci_message message_type; + union win_slot_encoding wslot; + struct tran_int_desc int_desc; +} __packed; + +struct pci_dev_incoming { + struct pci_incoming_message incoming; + union win_slot_encoding wslot; +} __packed; + +struct pci_eject_response { + u32 message_type; + union win_slot_encoding wslot; + u32 status; +} __packed; + +static int pci_ring_size = (4 * PAGE_SIZE); + +/* + * Definitions or interrupt steering hypercall. + */ +#define HV_PARTITION_ID_SELF ((u64)-1) +#define HVCALL_RETARGET_INTERRUPT 0x7e + +struct retarget_msi_interrupt { + u64 partition_id; /* use "self" */ + u64 device_id; + u32 source; /* 1 for MSI(-X) */ + u32 reserved1; + u32 address; + u32 data; + u64 reserved2; + u32 vector; + u32 flags; + u64 vp_mask; +} __packed; + +/* + * Driver specific state. + */ + +enum hv_pcibus_state { + hv_pcibus_init = 0, + hv_pcibus_probed, + hv_pcibus_installed, + hv_pcibus_maximum +}; + +struct hv_pcibus_device { + struct pci_sysdata sysdata; + enum hv_pcibus_state state; + atomic_t remove_lock; + struct hv_device *hdev; + resource_size_t low_mmio_space; + resource_size_t high_mmio_space; + struct resource *mem_config; + struct resource *low_mmio_res; + struct resource *high_mmio_res; + struct completion *survey_event; + struct completion remove_event; + struct pci_bus *pci_bus; + spinlock_t config_lock; /* Avoid two threads writing index page */ + spinlock_t device_list_lock; /* Protect lists below */ + void __iomem *cfg_addr; + + struct semaphore enum_sem; + struct list_head resources_for_children; + + struct list_head children; + struct list_head dr_list; + struct work_struct wrk; + + struct msi_domain_info msi_info; + struct msi_controller msi_chip; + struct irq_domain *irq_domain; +}; + +/* + * Tracks "Device Relations" messages from the host, which must be both + * processed in order and deferred so that they don't run in the context + * of the incoming packet callback. + */ +struct hv_dr_work { + struct work_struct wrk; + struct hv_pcibus_device *bus; +}; + +struct hv_dr_state { + struct list_head list_entry; + u32 device_count; + struct pci_function_description func[1]; +}; + +enum hv_pcichild_state { + hv_pcichild_init = 0, + hv_pcichild_requirements, + hv_pcichild_resourced, + hv_pcichild_ejecting, + hv_pcichild_maximum +}; + +enum hv_pcidev_ref_reason { + hv_pcidev_ref_invalid = 0, + hv_pcidev_ref_initial, + hv_pcidev_ref_by_slot, + hv_pcidev_ref_packet, + hv_pcidev_ref_pnp, + hv_pcidev_ref_childlist, + hv_pcidev_irqdata, + hv_pcidev_ref_max +}; + +struct hv_pci_dev { + /* List protected by pci_rescan_remove_lock */ + struct list_head list_entry; + atomic_t refs; + enum hv_pcichild_state state; + struct pci_function_description desc; + bool reported_missing; + struct hv_pcibus_device *hbus; + struct work_struct wrk; + + /* + * What would be observed if one wrote 0xFFFFFFFF to a BAR and then + * read it back, for each of the BAR offsets within config space. + */ + u32 probed_bar[6]; +}; + +struct hv_pci_compl { + struct completion host_event; + s32 completion_status; +}; + +/** + * hv_pci_generic_compl() - Invoked for a completion packet + * @context: Set up by the sender of the packet. + * @resp: The response packet + * @resp_packet_size: Size in bytes of the packet + * + * This function is used to trigger an event and report status + * for any message for which the completion packet contains a + * status and nothing else. + */ +static +void +hv_pci_generic_compl(void *context, struct pci_response *resp, + int resp_packet_size) +{ + struct hv_pci_compl *comp_pkt = context; + + if (resp_packet_size >= offsetofend(struct pci_response, status)) + comp_pkt->completion_status = resp->status; + complete(&comp_pkt->host_event); +} + +static struct hv_pci_dev *get_pcichild_wslot(struct hv_pcibus_device *hbus, + u32 wslot); +static void get_pcichild(struct hv_pci_dev *hv_pcidev, + enum hv_pcidev_ref_reason reason); +static void put_pcichild(struct hv_pci_dev *hv_pcidev, + enum hv_pcidev_ref_reason reason); + +static void get_hvpcibus(struct hv_pcibus_device *hv_pcibus); +static void put_hvpcibus(struct hv_pcibus_device *hv_pcibus); + +/** + * devfn_to_wslot() - Convert from Linux PCI slot to Windows + * @devfn: The Linux representation of PCI slot + * + * Windows uses a slightly different representation of PCI slot. + * + * Return: The Windows representation + */ +static u32 devfn_to_wslot(int devfn) +{ + union win_slot_encoding wslot; + + wslot.slot = 0; + wslot.bits.func = PCI_SLOT(devfn) | (PCI_FUNC(devfn) << 5); + + return wslot.slot; +} + +/** + * wslot_to_devfn() - Convert from Windows PCI slot to Linux + * @wslot: The Windows representation of PCI slot + * + * Windows uses a slightly different representation of PCI slot. + * + * Return: The Linux representation + */ +static int wslot_to_devfn(u32 wslot) +{ + union win_slot_encoding slot_no; + + slot_no.slot = wslot; + return PCI_DEVFN(0, slot_no.bits.func); +} + +/* + * PCI Configuration Space for these root PCI buses is implemented as a pair + * of pages in memory-mapped I/O space. Writing to the first page chooses + * the PCI function being written or read. Once the first page has been + * written to, the following page maps in the entire configuration space of + * the function. + */ + +/** + * _hv_pcifront_read_config() - Internal PCI config read + * @hpdev: The PCI driver's representation of the device + * @where: Offset within config space + * @size: Size of the transfer + * @val: Pointer to the buffer receiving the data + */ +static void _hv_pcifront_read_config(struct hv_pci_dev *hpdev, int where, + int size, u32 *val) +{ + unsigned long flags; + void __iomem *addr = hpdev->hbus->cfg_addr + CFG_PAGE_OFFSET + where; + + /* + * If the attempt is to read the IDs or the ROM BAR, simulate that. + */ + if (where + size <= PCI_COMMAND) { + memcpy(val, ((u8 *)&hpdev->desc.v_id) + where, size); + } else if (where >= PCI_CLASS_REVISION && where + size <= + PCI_CACHE_LINE_SIZE) { + memcpy(val, ((u8 *)&hpdev->desc.rev) + where - + PCI_CLASS_REVISION, size); + } else if (where >= PCI_SUBSYSTEM_VENDOR_ID && where + size <= + PCI_ROM_ADDRESS) { + memcpy(val, (u8 *)&hpdev->desc.subsystem_id + where - + PCI_SUBSYSTEM_VENDOR_ID, size); + } else if (where >= PCI_ROM_ADDRESS && where + size <= + PCI_CAPABILITY_LIST) { + /* ROM BARs are unimplemented */ + *val = 0; + } else if (where >= PCI_INTERRUPT_LINE && where + size <= + PCI_INTERRUPT_PIN) { + /* + * Interrupt Line and Interrupt PIN are hard-wired to zero + * because this front-end only supports message-signaled + * interrupts. + */ + *val = 0; + } else if (where + size <= CFG_PAGE_SIZE) { + spin_lock_irqsave(&hpdev->hbus->config_lock, flags); + /* Choose the function to be read. (See comment above) */ + writel(hpdev->desc.win_slot.slot, hpdev->hbus->cfg_addr); + /* Read from that function's config space. */ + switch (size) { + case 1: + *val = readb(addr); + break; + case 2: + *val = readw(addr); + break; + default: + *val = readl(addr); + break; + } + spin_unlock_irqrestore(&hpdev->hbus->config_lock, flags); + } else { + dev_err(&hpdev->hbus->hdev->device, + "Attempt to read beyond a function's config space.\n"); + } +} + +/** + * _hv_pcifront_write_config() - Internal PCI config write + * @hpdev: The PCI driver's representation of the device + * @where: Offset within config space + * @size: Size of the transfer + * @val: The data being transferred + */ +static void _hv_pcifront_write_config(struct hv_pci_dev *hpdev, int where, + int size, u32 val) +{ + unsigned long flags; + void __iomem *addr = hpdev->hbus->cfg_addr + CFG_PAGE_OFFSET + where; + + if (where >= PCI_SUBSYSTEM_VENDOR_ID && + where + size <= PCI_CAPABILITY_LIST) { + /* SSIDs and ROM BARs are read-only */ + } else if (where >= PCI_COMMAND && where + size <= CFG_PAGE_SIZE) { + spin_lock_irqsave(&hpdev->hbus->config_lock, flags); + /* Choose the function to be written. (See comment above) */ + writel(hpdev->desc.win_slot.slot, hpdev->hbus->cfg_addr); + /* Write to that function's config space. */ + switch (size) { + case 1: + writeb(val, addr); + break; + case 2: + writew(val, addr); + break; + default: + writel(val, addr); + break; + } + spin_unlock_irqrestore(&hpdev->hbus->config_lock, flags); + } else { + dev_err(&hpdev->hbus->hdev->device, + "Attempt to write beyond a function's config space.\n"); + } +} + +/** + * hv_pcifront_read_config() - Read configuration space + * @bus: PCI Bus structure + * @devfn: Device/function + * @where: Offset from base + * @size: Byte/word/dword + * @val: Value to be read + * + * Return: PCIBIOS_SUCCESSFUL on success + * PCIBIOS_DEVICE_NOT_FOUND on failure + */ +static int hv_pcifront_read_config(struct pci_bus *bus, unsigned int devfn, + int where, int size, u32 *val) +{ + struct hv_pcibus_device *hbus = + container_of(bus->sysdata, struct hv_pcibus_device, sysdata); + struct hv_pci_dev *hpdev; + + hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(devfn)); + if (!hpdev) + return PCIBIOS_DEVICE_NOT_FOUND; + + _hv_pcifront_read_config(hpdev, where, size, val); + + put_pcichild(hpdev, hv_pcidev_ref_by_slot); + return PCIBIOS_SUCCESSFUL; +} + +/** + * hv_pcifront_write_config() - Write configuration space + * @bus: PCI Bus structure + * @devfn: Device/function + * @where: Offset from base + * @size: Byte/word/dword + * @val: Value to be written to device + * + * Return: PCIBIOS_SUCCESSFUL on success + * PCIBIOS_DEVICE_NOT_FOUND on failure + */ +static int hv_pcifront_write_config(struct pci_bus *bus, unsigned int devfn, + int where, int size, u32 val) +{ + struct hv_pcibus_device *hbus = + container_of(bus->sysdata, struct hv_pcibus_device, sysdata); + struct hv_pci_dev *hpdev; + + hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(devfn)); + if (!hpdev) + return PCIBIOS_DEVICE_NOT_FOUND; + + _hv_pcifront_write_config(hpdev, where, size, val); + + put_pcichild(hpdev, hv_pcidev_ref_by_slot); + return PCIBIOS_SUCCESSFUL; +} + +/* PCIe operations */ +static struct pci_ops hv_pcifront_ops = { + .read = hv_pcifront_read_config, + .write = hv_pcifront_write_config, +}; + +/* Interrupt management hooks */ +static void hv_int_desc_free(struct hv_pci_dev *hpdev, + struct tran_int_desc *int_desc) +{ + struct pci_delete_interrupt *int_pkt; + struct { + struct pci_packet pkt; + u8 buffer[sizeof(struct pci_delete_interrupt) - + sizeof(struct pci_message)]; + } ctxt; + + memset(&ctxt, 0, sizeof(ctxt)); + int_pkt = (struct pci_delete_interrupt *)&ctxt.pkt.message; + int_pkt->message_type.message_type = + PCI_DELETE_INTERRUPT_MESSAGE; + int_pkt->wslot.slot = hpdev->desc.win_slot.slot; + int_pkt->int_desc = *int_desc; + vmbus_sendpacket(hpdev->hbus->hdev->channel, int_pkt, sizeof(*int_pkt), + (unsigned long)&ctxt.pkt, VM_PKT_DATA_INBAND, 0); + kfree(int_desc); +} + +/** + * hv_msi_free() - Free the MSI. + * @domain: The interrupt domain pointer + * @info: Extra MSI-related context + * @irq: Identifies the IRQ. + * + * The Hyper-V parent partition and hypervisor are tracking the + * messages that are in use, keeping the interrupt redirection + * table up to date. This callback sends a message that frees + * the IRT entry and related tracking nonsense. + */ +static void hv_msi_free(struct irq_domain *domain, struct msi_domain_info *info, + unsigned int irq) +{ + struct hv_pcibus_device *hbus; + struct hv_pci_dev *hpdev; + struct pci_dev *pdev; + struct tran_int_desc *int_desc; + struct irq_data *irq_data = irq_domain_get_irq_data(domain, irq); + struct msi_desc *msi = irq_data_get_msi_desc(irq_data); + + pdev = msi_desc_to_pci_dev(msi); + hbus = info->data; + hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(pdev->devfn)); + if (!hpdev) + return; + + int_desc = irq_data_get_irq_chip_data(irq_data); + if (int_desc) { + irq_data->chip_data = NULL; + hv_int_desc_free(hpdev, int_desc); + } + + put_pcichild(hpdev, hv_pcidev_ref_by_slot); +} + +static int hv_set_affinity(struct irq_data *data, const struct cpumask *dest, + bool force) +{ + struct irq_data *parent = data->parent_data; + + return parent->chip->irq_set_affinity(parent, dest, force); +} + +void hv_irq_mask(struct irq_data *data) +{ + pci_msi_mask_irq(data); +} + +/** + * hv_irq_unmask() - "Unmask" the IRQ by setting its current + * affinity. + * @data: Describes the IRQ + * + * Build new a destination for the MSI and make a hypercall to + * update the Interrupt Redirection Table. "Device Logical ID" + * is built out of this PCI bus's instance GUID and the function + * number of the device. + */ +void hv_irq_unmask(struct irq_data *data) +{ + struct msi_desc *msi_desc = irq_data_get_msi_desc(data); + struct irq_cfg *cfg = irqd_cfg(data); + struct retarget_msi_interrupt params; + struct hv_pcibus_device *hbus; + struct cpumask *dest; + struct pci_bus *pbus; + struct pci_dev *pdev; + int cpu; + + dest = irq_data_get_affinity_mask(data); + pdev = msi_desc_to_pci_dev(msi_desc); + pbus = pdev->bus; + hbus = container_of(pbus->sysdata, struct hv_pcibus_device, sysdata); + + memset(¶ms, 0, sizeof(params)); + params.partition_id = HV_PARTITION_ID_SELF; + params.source = 1; /* MSI(-X) */ + params.address = msi_desc->msg.address_lo; + params.data = msi_desc->msg.data; + params.device_id = (hbus->hdev->dev_instance.b[5] << 24) | + (hbus->hdev->dev_instance.b[4] << 16) | + (hbus->hdev->dev_instance.b[7] << 8) | + (hbus->hdev->dev_instance.b[6] & 0xf8) | + PCI_FUNC(pdev->devfn); + params.vector = cfg->vector; + + for_each_cpu_and(cpu, dest, cpu_online_mask) + params.vp_mask |= (1ULL << vmbus_cpu_number_to_vp_number(cpu)); + + hv_do_hypercall(HVCALL_RETARGET_INTERRUPT, ¶ms, NULL); + + pci_msi_unmask_irq(data); +} + +struct compose_comp_ctxt { + struct hv_pci_compl comp_pkt; + struct tran_int_desc int_desc; +}; + +static void hv_pci_compose_compl(void *context, struct pci_response *resp, + int resp_packet_size) +{ + struct compose_comp_ctxt *comp_pkt = context; + struct pci_create_int_response *int_resp = + (struct pci_create_int_response *)resp; + + comp_pkt->comp_pkt.completion_status = resp->status; + comp_pkt->int_desc = int_resp->int_desc; + complete(&comp_pkt->comp_pkt.host_event); +} + +/** + * hv_compose_msi_msg() - Supplies a valid MSI address/data + * @data: Everything about this MSI + * @msg: Buffer that is filled in by this function + * + * This function unpacks the IRQ looking for target CPU set, IDT + * vector and mode and sends a message to the parent partition + * asking for a mapping for that tuple in this partition. The + * response supplies a data value and address to which that data + * should be written to trigger that interrupt. + */ +static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg) +{ + struct irq_cfg *cfg = irqd_cfg(data); + struct hv_pcibus_device *hbus; + struct hv_pci_dev *hpdev; + struct pci_bus *pbus; + struct pci_dev *pdev; + struct pci_create_interrupt *int_pkt; + struct compose_comp_ctxt comp; + struct tran_int_desc *int_desc; + struct cpumask *affinity; + struct { + struct pci_packet pkt; + u8 buffer[sizeof(struct pci_create_interrupt) - + sizeof(struct pci_message)]; + } ctxt; + int cpu; + int ret; + + pdev = msi_desc_to_pci_dev(irq_data_get_msi_desc(data)); + pbus = pdev->bus; + hbus = container_of(pbus->sysdata, struct hv_pcibus_device, sysdata); + hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(pdev->devfn)); + if (!hpdev) + goto return_null_message; + + /* Free any previous message that might have already been composed. */ + if (data->chip_data) { + int_desc = data->chip_data; + data->chip_data = NULL; + hv_int_desc_free(hpdev, int_desc); + } + + int_desc = kzalloc(sizeof(*int_desc), GFP_KERNEL); + if (!int_desc) + goto drop_reference; + + memset(&ctxt, 0, sizeof(ctxt)); + init_completion(&comp.comp_pkt.host_event); + ctxt.pkt.completion_func = hv_pci_compose_compl; + ctxt.pkt.compl_ctxt = ∁ + int_pkt = (struct pci_create_interrupt *)&ctxt.pkt.message; + int_pkt->message_type.message_type = PCI_CREATE_INTERRUPT_MESSAGE; + int_pkt->wslot.slot = hpdev->desc.win_slot.slot; + int_pkt->int_desc.vector = cfg->vector; + int_pkt->int_desc.vector_count = 1; + int_pkt->int_desc.delivery_mode = + (apic->irq_delivery_mode == dest_LowestPrio) ? 1 : 0; + + /* + * This bit doesn't have to work on machines with more than 64 + * processors because Hyper-V only supports 64 in a guest. + */ + affinity = irq_data_get_affinity_mask(data); + for_each_cpu_and(cpu, affinity, cpu_online_mask) { + int_pkt->int_desc.cpu_mask |= + (1ULL << vmbus_cpu_number_to_vp_number(cpu)); + } + + ret = vmbus_sendpacket(hpdev->hbus->hdev->channel, int_pkt, + sizeof(*int_pkt), (unsigned long)&ctxt.pkt, + VM_PKT_DATA_INBAND, + VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED); + if (!ret) + wait_for_completion(&comp.comp_pkt.host_event); + + if (comp.comp_pkt.completion_status < 0) { + dev_err(&hbus->hdev->device, + "Request for interrupt failed: 0x%x", + comp.comp_pkt.completion_status); + goto free_int_desc; + } + + /* + * Record the assignment so that this can be unwound later. Using + * irq_set_chip_data() here would be appropriate, but the lock it takes + * is already held. + */ + *int_desc = comp.int_desc; + data->chip_data = int_desc; + + /* Pass up the result. */ + msg->address_hi = comp.int_desc.address >> 32; + msg->address_lo = comp.int_desc.address & 0xffffffff; + msg->data = comp.int_desc.data; + + put_pcichild(hpdev, hv_pcidev_ref_by_slot); + return; + +free_int_desc: + kfree(int_desc); +drop_reference: + put_pcichild(hpdev, hv_pcidev_ref_by_slot); +return_null_message: + msg->address_hi = 0; + msg->address_lo = 0; + msg->data = 0; +} + +/* HW Interrupt Chip Descriptor */ +static struct irq_chip hv_msi_irq_chip = { + .name = "Hyper-V PCIe MSI", + .irq_compose_msi_msg = hv_compose_msi_msg, + .irq_set_affinity = hv_set_affinity, + .irq_ack = irq_chip_ack_parent, + .irq_mask = hv_irq_mask, + .irq_unmask = hv_irq_unmask, +}; + +static irq_hw_number_t hv_msi_domain_ops_get_hwirq(struct msi_domain_info *info, + msi_alloc_info_t *arg) +{ + return arg->msi_hwirq; +} + +static struct msi_domain_ops hv_msi_ops = { + .get_hwirq = hv_msi_domain_ops_get_hwirq, + .msi_prepare = pci_msi_prepare, + .set_desc = pci_msi_set_desc, + .msi_free = hv_msi_free, +}; + +/** + * hv_pcie_init_irq_domain() - Initialize IRQ domain + * @hbus: The root PCI bus + * + * This function creates an IRQ domain which will be used for + * interrupts from devices that have been passed through. These + * devices only support MSI and MSI-X, not line-based interrupts + * or simulations of line-based interrupts through PCIe's + * fabric-layer messages. Because interrupts are remapped, we + * can support multi-message MSI here. + * + * Return: '0' on success and error value on failure + */ +static int hv_pcie_init_irq_domain(struct hv_pcibus_device *hbus) +{ + hbus->msi_info.chip = &hv_msi_irq_chip; + hbus->msi_info.ops = &hv_msi_ops; + hbus->msi_info.flags = (MSI_FLAG_USE_DEF_DOM_OPS | + MSI_FLAG_USE_DEF_CHIP_OPS | MSI_FLAG_MULTI_PCI_MSI | + MSI_FLAG_PCI_MSIX); + hbus->msi_info.handler = handle_edge_irq; + hbus->msi_info.handler_name = "edge"; + hbus->msi_info.data = hbus; + hbus->irq_domain = pci_msi_create_irq_domain(hbus->sysdata.fwnode, + &hbus->msi_info, + x86_vector_domain); + if (!hbus->irq_domain) { + dev_err(&hbus->hdev->device, + "Failed to build an MSI IRQ domain\n"); + return -ENODEV; + } + + return 0; +} + +/** + * get_bar_size() - Get the address space consumed by a BAR + * @bar_val: Value that a BAR returned after -1 was written + * to it. + * + * This function returns the size of the BAR, rounded up to 1 + * page. It has to be rounded up because the hypervisor's page + * table entry that maps the BAR into the VM can't specify an + * offset within a page. The invariant is that the hypervisor + * |