diff options
Diffstat (limited to 'drivers/pci/controller/pci-hyperv.c')
| -rw-r--r-- | drivers/pci/controller/pci-hyperv.c | 2694 |
1 files changed, 2694 insertions, 0 deletions
diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c new file mode 100644 index 000000000000..6cc5036ac83c --- /dev/null +++ b/drivers/pci/controller/pci-hyperv.c @@ -0,0 +1,2694 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * 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. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/pci.h> +#include <linux/delay.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 <linux/refcount.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) | (minor))) +#define PCI_MAJOR_VERSION(version) ((u32)(version) >> 16) +#define PCI_MINOR_VERSION(version) ((u32)(version) & 0xff) + +enum pci_protocol_version_t { + PCI_PROTOCOL_VERSION_1_1 = PCI_MAKE_VERSION(1, 1), /* Win10 */ + PCI_PROTOCOL_VERSION_1_2 = PCI_MAKE_VERSION(1, 2), /* RS1 */ +}; + +#define CPU_AFFINITY_ALL -1ULL + +/* + * Supported protocol versions in the order of probing - highest go + * first. + */ +static enum pci_protocol_version_t pci_protocol_versions[] = { + PCI_PROTOCOL_VERSION_1_2, + PCI_PROTOCOL_VERSION_1_1, +}; + +/* + * Protocol version negotiated by hv_pci_protocol_negotiation(). + */ +static enum pci_protocol_version_t pci_protocol_version; + +#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 + +#define STATUS_REVISION_MISMATCH 0xC0000059 + +/* + * 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_RESOURCES_ASSIGNED2 = PCI_MESSAGE_BASE + 0x16, + PCI_CREATE_INTERRUPT_MESSAGE2 = PCI_MESSAGE_BASE + 0x17, + PCI_DELETE_INTERRUPT_MESSAGE2 = PCI_MESSAGE_BASE + 0x18, /* unused */ + 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 dev:5; + u32 func:3; + 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 hv_msi_desc2 - 1.2 version of 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. + * @processor_count: number of bits enabled in array. + * @processor_array: All the target virtual processors. + */ +struct hv_msi_desc2 { + u8 vector; + u8 delivery_mode; + u16 vector_count; + u16 processor_count; + u16 processor_array[32]; +} __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 type; +} __packed; + +struct pci_child_message { + struct pci_message 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[0]; +}; + +/* + * 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; + u32 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[0]; +} __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_resources_assigned2 { + struct pci_message message_type; + union win_slot_encoding wslot; + u8 memory_range[0x14][6]; /* not used here */ + u32 msi_descriptor_count; + u8 reserved[70]; +} __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_create_interrupt2 { + struct pci_message message_type; + union win_slot_encoding wslot; + struct hv_msi_desc2 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 { + struct pci_message 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 hv_interrupt_entry { + u32 source; /* 1 for MSI(-X) */ + u32 reserved1; + u32 address; + u32 data; +}; + +#define HV_VP_SET_BANK_COUNT_MAX 5 /* current implementation limit */ + +struct hv_vp_set { + u64 format; /* 0 (HvGenericSetSparse4k) */ + u64 valid_banks; + u64 masks[HV_VP_SET_BANK_COUNT_MAX]; +}; + +/* + * flags for hv_device_interrupt_target.flags + */ +#define HV_DEVICE_INTERRUPT_TARGET_MULTICAST 1 +#define HV_DEVICE_INTERRUPT_TARGET_PROCESSOR_SET 2 + +struct hv_device_interrupt_target { + u32 vector; + u32 flags; + union { + u64 vp_mask; + struct hv_vp_set vp_set; + }; +}; + +struct retarget_msi_interrupt { + u64 partition_id; /* use "self" */ + u64 device_id; + struct hv_interrupt_entry int_entry; + u64 reserved2; + struct hv_device_interrupt_target int_target; +} __packed; + +/* + * Driver specific state. + */ + +enum hv_pcibus_state { + hv_pcibus_init = 0, + hv_pcibus_probed, + hv_pcibus_installed, + hv_pcibus_removed, + hv_pcibus_maximum +}; + +struct hv_pcibus_device { + struct pci_sysdata sysdata; + enum hv_pcibus_state state; + refcount_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 list_head resources_for_children; + + struct list_head children; + struct list_head dr_list; + + struct msi_domain_info msi_info; + struct msi_controller msi_chip; + struct irq_domain *irq_domain; + + /* hypercall arg, must not cross page boundary */ + struct retarget_msi_interrupt retarget_msi_interrupt_params; + + spinlock_t retarget_msi_interrupt_lock; + + struct workqueue_struct *wq; +}; + +/* + * 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[0]; +}; + +enum hv_pcichild_state { + hv_pcichild_init = 0, + hv_pcichild_requirements, + hv_pcichild_resourced, + hv_pcichild_ejecting, + hv_pcichild_maximum +}; + +struct hv_pci_dev { + /* List protected by pci_rescan_remove_lock */ + struct list_head list_entry; + refcount_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; +}; + +static void hv_pci_onchannelcallback(void *context); + +/** + * 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; + else + comp_pkt->completion_status = -1; + + 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 *hpdev) +{ + refcount_inc(&hpdev->refs); +} + +static void put_pcichild(struct hv_pci_dev *hpdev) +{ + if (refcount_dec_and_test(&hpdev->refs)) + kfree(hpdev); +} + +static void get_hvpcibus(struct hv_pcibus_device *hv_pcibus); +static void put_hvpcibus(struct hv_pcibus_device *hv_pcibus); + +/* + * There is no good way to get notified from vmbus_onoffer_rescind(), + * so let's use polling here, since this is not a hot path. + */ +static int wait_for_response(struct hv_device *hdev, + struct completion *comp) +{ + while (true) { + if (hdev->channel->rescind) { + dev_warn_once(&hdev->device, "The device is gone.\n"); + return -ENODEV; + } + + if (wait_for_completion_timeout(comp, HZ / 10)) + break; + } + + return 0; +} + +/** + * 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.dev = PCI_SLOT(devfn); + wslot.bits.func = PCI_FUNC(devfn); + + 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(slot_no.bits.dev, 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); + /* Make sure the function was chosen before we start reading. */ + mb(); + /* 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; + } + /* + * Make sure the read was done before we release the spinlock + * allowing consecutive reads/writes. + */ + mb(); + 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"); + } +} + +static u16 hv_pcifront_get_vendor_id(struct hv_pci_dev *hpdev) +{ + u16 ret; + unsigned long flags; + void __iomem *addr = hpdev->hbus->cfg_addr + CFG_PAGE_OFFSET + + PCI_VENDOR_ID; + + 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); + /* Make sure the function was chosen before we start reading. */ + mb(); + /* Read from that function's config space. */ + ret = readw(addr); + /* + * mb() is not required here, because the spin_unlock_irqrestore() + * is a barrier. + */ + + spin_unlock_irqrestore(&hpdev->hbus->config_lock, flags); + + return ret; +} + +/** + * _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); + /* Make sure the function was chosen before we start writing. */ + wmb(); + /* 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; + } + /* + * Make sure the write was done before we release the spinlock + * allowing consecutive reads/writes. + */ + mb(); + 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); + 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); + 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)]; + } ctxt; + + memset(&ctxt, 0, sizeof(ctxt)); + int_pkt = (struct pci_delete_interrupt *)&ctxt.pkt.message; + int_pkt->message_type.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; + int_desc = irq_data_get_irq_chip_data(irq_data); + if (!int_desc) + return; + + irq_data->chip_data = NULL; + hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(pdev->devfn)); + if (!hpdev) { + kfree(int_desc); + return; + } + + hv_int_desc_free(hpdev, int_desc); + put_pcichild(hpdev); +} + +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); +} + +static 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. + */ +static 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; + unsigned long flags; + u32 var_size = 0; + int cpu_vmbus; + int cpu; + u64 res; + + dest = irq_data_get_effective_affinity_mask(data); + pdev = msi_desc_to_pci_dev(msi_desc); + pbus = pdev->bus; + hbus = container_of(pbus->sysdata, struct hv_pcibus_device, sysdata); + + spin_lock_irqsave(&hbus->retarget_msi_interrupt_lock, flags); + + params = &hbus->retarget_msi_interrupt_params; + memset(params, 0, sizeof(*params)); + params->partition_id = HV_PARTITION_ID_SELF; + params->int_entry.source = 1; /* MSI(-X) */ + params->int_entry.address = msi_desc->msg.address_lo; + params->int_entry.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->int_target.vector = cfg->vector; + + /* + * Honoring apic->irq_delivery_mode set to dest_Fixed by + * setting the HV_DEVICE_INTERRUPT_TARGET_MULTICAST flag results in a + * spurious interrupt storm. Not doing so does not seem to have a + * negative effect (yet?). + */ + + if (pci_protocol_version >= PCI_PROTOCOL_VERSION_1_2) { + /* + * PCI_PROTOCOL_VERSION_1_2 supports the VP_SET version of the + * HVCALL_RETARGET_INTERRUPT hypercall, which also coincides + * with >64 VP support. + * ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED + * is not sufficient for this hypercall. + */ + params->int_target.flags |= + HV_DEVICE_INTERRUPT_TARGET_PROCESSOR_SET; + params->int_target.vp_set.valid_banks = + (1ull << HV_VP_SET_BANK_COUNT_MAX) - 1; + + /* + * var-sized hypercall, var-size starts after vp_mask (thus + * vp_set.format does not count, but vp_set.valid_banks does). + */ + var_size = 1 + HV_VP_SET_BANK_COUNT_MAX; + + for_each_cpu_and(cpu, dest, cpu_online_mask) { + cpu_vmbus = hv_cpu_number_to_vp_number(cpu); + + if (cpu_vmbus >= HV_VP_SET_BANK_COUNT_MAX * 64) { + dev_err(&hbus->hdev->device, + "too high CPU %d", cpu_vmbus); + res = 1; + goto exit_unlock; + } + + params->int_target.vp_set.masks[cpu_vmbus / 64] |= + (1ULL << (cpu_vmbus & 63)); + } + } else { + for_each_cpu_and(cpu, dest, cpu_online_mask) { + params->int_target.vp_mask |= + (1ULL << hv_cpu_number_to_vp_number(cpu)); + } + } + + res = hv_do_hypercall(HVCALL_RETARGET_INTERRUPT | (var_size << 17), + params, NULL); + +exit_unlock: + spin_unlock_irqrestore(&hbus->retarget_msi_interrupt_lock, flags); + + if (res) { + dev_err(&hbus->hdev->device, + "%s() failed: %#llx", __func__, res); + return; + } + + 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); +} + +static u32 hv_compose_msi_req_v1( + struct pci_create_interrupt *int_pkt, struct cpumask *affinity, + u32 slot, u8 vector) +{ + int_pkt->message_type.type = PCI_CREATE_INTERRUPT_MESSAGE; + int_pkt->wslot.slot = slot; + int_pkt->int_desc.vector = vector; + int_pkt->int_desc.vector_count = 1; + int_pkt->int_desc.delivery_mode = dest_Fixed; + + /* + * Create MSI w/ dummy vCPU set, overwritten by subsequent retarget in + * hv_irq_unmask(). + */ + int_pkt->int_desc.cpu_mask = CPU_AFFINITY_ALL; + + return sizeof(*int_pkt); +} + +static u32 hv_compose_msi_req_v2( + struct pci_create_interrupt2 *int_pkt, struct cpumask *affinity, + u32 slot, u8 vector) +{ + int cpu; + + int_pkt->message_type.type = PCI_CREATE_INTERRUPT_MESSAGE2; + int_pkt->wslot.slot = slot; + int_pkt->int_desc.vector = vector; + int_pkt->int_desc.vector_count = 1; + int_pkt->int_desc.delivery_mode = dest_Fixed; + + /* + * Create MSI w/ dummy vCPU set targeting just one vCPU, overwritten + * by subsequent retarget in hv_irq_unmask(). + */ + cpu = cpumask_first_and(affinity, cpu_online_mask); + int_pkt->int_desc.processor_array[0] = + hv_cpu_number_to_vp_number(cpu); + int_pkt->int_desc.processor_count = 1; + + return sizeof(*int_pkt); +} + +/** + * 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 cpumask *dest; + struct compose_comp_ctxt comp; + struct tran_int_desc *int_desc; + struct { + struct pci_packet pci_pkt; + union { + struct pci_create_interrupt v1; + struct pci_create_interrupt2 v2; + } int_pkts; + } __packed ctxt; + + u32 size; + int ret; + + pdev = msi_desc_to_pci_dev(irq_data_get_msi_desc(data)); + dest = irq_data_get_effective_affinity_mask(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_ATOMIC); + if (!int_desc) + goto drop_reference; + + memset(&ctxt, 0, sizeof(ctxt)); + init_completion(&comp.comp_pkt.host_event); + ctxt.pci_pkt.completion_func = hv_pci_compose_compl; + ctxt.pci_pkt.compl_ctxt = ∁ + + switch (pci_protocol_version) { + case PCI_PROTOCOL_VERSION_1_1: + size = hv_compose_msi_req_v1(&ctxt.int_pkts.v1, + dest, + hpdev->desc.win_slot.slot, + cfg->vector); + break; + + case PCI_PROTOCOL_VERSION_1_2: |