diff options
Diffstat (limited to 'drivers/pci/hotplug/octep_hp.c')
| -rw-r--r-- | drivers/pci/hotplug/octep_hp.c | 427 |
1 files changed, 427 insertions, 0 deletions
diff --git a/drivers/pci/hotplug/octep_hp.c b/drivers/pci/hotplug/octep_hp.c new file mode 100644 index 000000000000..2bce7296c050 --- /dev/null +++ b/drivers/pci/hotplug/octep_hp.c @@ -0,0 +1,427 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (C) 2024 Marvell. */ + +#include <linux/cleanup.h> +#include <linux/container_of.h> +#include <linux/delay.h> +#include <linux/dev_printk.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/io-64-nonatomic-lo-hi.h> +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/pci.h> +#include <linux/pci_hotplug.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/workqueue.h> + +#define OCTEP_HP_INTR_OFFSET(x) (0x20400 + ((x) << 4)) +#define OCTEP_HP_INTR_VECTOR(x) (16 + (x)) +#define OCTEP_HP_DRV_NAME "octep_hp" + +/* + * Type of MSI-X interrupts. OCTEP_HP_INTR_VECTOR() and + * OCTEP_HP_INTR_OFFSET() generate the vector and offset for an interrupt + * type. + */ +enum octep_hp_intr_type { + OCTEP_HP_INTR_INVALID = -1, + OCTEP_HP_INTR_ENA = 0, + OCTEP_HP_INTR_DIS = 1, + OCTEP_HP_INTR_MAX = 2, +}; + +struct octep_hp_cmd { + struct list_head list; + enum octep_hp_intr_type intr_type; + u64 intr_val; +}; + +struct octep_hp_slot { + struct list_head list; + struct hotplug_slot slot; + u16 slot_number; + struct pci_dev *hp_pdev; + unsigned int hp_devfn; + struct octep_hp_controller *ctrl; +}; + +struct octep_hp_intr_info { + enum octep_hp_intr_type type; + int number; + char name[16]; +}; + +struct octep_hp_controller { + void __iomem *base; + struct pci_dev *pdev; + struct octep_hp_intr_info intr[OCTEP_HP_INTR_MAX]; + struct work_struct work; + struct list_head slot_list; + struct mutex slot_lock; /* Protects slot_list */ + struct list_head hp_cmd_list; + spinlock_t hp_cmd_lock; /* Protects hp_cmd_list */ +}; + +static void octep_hp_enable_pdev(struct octep_hp_controller *hp_ctrl, + struct octep_hp_slot *hp_slot) +{ + guard(mutex)(&hp_ctrl->slot_lock); + if (hp_slot->hp_pdev) { + pci_dbg(hp_slot->hp_pdev, "Slot %s is already enabled\n", + hotplug_slot_name(&hp_slot->slot)); + return; + } + + /* Scan the device and add it to the bus */ + hp_slot->hp_pdev = pci_scan_single_device(hp_ctrl->pdev->bus, + hp_slot->hp_devfn); + pci_bus_assign_resources(hp_ctrl->pdev->bus); + pci_bus_add_device(hp_slot->hp_pdev); + + dev_dbg(&hp_slot->hp_pdev->dev, "Enabled slot %s\n", + hotplug_slot_name(&hp_slot->slot)); +} + +static void octep_hp_disable_pdev(struct octep_hp_controller *hp_ctrl, + struct octep_hp_slot *hp_slot) +{ + guard(mutex)(&hp_ctrl->slot_lock); + if (!hp_slot->hp_pdev) { + pci_dbg(hp_ctrl->pdev, "Slot %s is already disabled\n", + hotplug_slot_name(&hp_slot->slot)); + return; + } + + pci_dbg(hp_slot->hp_pdev, "Disabling slot %s\n", + hotplug_slot_name(&hp_slot->slot)); + + /* Remove the device from the bus */ + pci_stop_and_remove_bus_device_locked(hp_slot->hp_pdev); + hp_slot->hp_pdev = NULL; +} + +static int octep_hp_enable_slot(struct hotplug_slot *slot) +{ + struct octep_hp_slot *hp_slot = + container_of(slot, struct octep_hp_slot, slot); + + octep_hp_enable_pdev(hp_slot->ctrl, hp_slot); + return 0; +} + +static int octep_hp_disable_slot(struct hotplug_slot *slot) +{ + struct octep_hp_slot *hp_slot = + container_of(slot, struct octep_hp_slot, slot); + + octep_hp_disable_pdev(hp_slot->ctrl, hp_slot); + return 0; +} + +static struct hotplug_slot_ops octep_hp_slot_ops = { + .enable_slot = octep_hp_enable_slot, + .disable_slot = octep_hp_disable_slot, +}; + +#define SLOT_NAME_SIZE 16 +static struct octep_hp_slot * +octep_hp_register_slot(struct octep_hp_controller *hp_ctrl, + struct pci_dev *pdev, u16 slot_number) +{ + char slot_name[SLOT_NAME_SIZE]; + struct octep_hp_slot *hp_slot; + int ret; + + hp_slot = kzalloc(sizeof(*hp_slot), GFP_KERNEL); + if (!hp_slot) + return ERR_PTR(-ENOMEM); + + hp_slot->ctrl = hp_ctrl; + hp_slot->hp_pdev = pdev; + hp_slot->hp_devfn = pdev->devfn; + hp_slot->slot_number = slot_number; + hp_slot->slot.ops = &octep_hp_slot_ops; + + snprintf(slot_name, sizeof(slot_name), "octep_hp_%u", slot_number); + ret = pci_hp_register(&hp_slot->slot, hp_ctrl->pdev->bus, + PCI_SLOT(pdev->devfn), slot_name); + if (ret) { + kfree(hp_slot); + return ERR_PTR(ret); + } + + pci_info(pdev, "Registered slot %s for device %s\n", + slot_name, pci_name(pdev)); + + list_add_tail(&hp_slot->list, &hp_ctrl->slot_list); + octep_hp_disable_pdev(hp_ctrl, hp_slot); + + return hp_slot; +} + +static void octep_hp_deregister_slot(void *data) +{ + struct octep_hp_slot *hp_slot = data; + struct octep_hp_controller *hp_ctrl = hp_slot->ctrl; + + pci_hp_deregister(&hp_slot->slot); + octep_hp_enable_pdev(hp_ctrl, hp_slot); + list_del(&hp_slot->list); + kfree(hp_slot); +} + +static const char *octep_hp_cmd_name(enum octep_hp_intr_type type) +{ + switch (type) { + case OCTEP_HP_INTR_ENA: + return "hotplug enable"; + case OCTEP_HP_INTR_DIS: + return "hotplug disable"; + default: + return "invalid"; + } +} + +static void octep_hp_cmd_handler(struct octep_hp_controller *hp_ctrl, + struct octep_hp_cmd *hp_cmd) +{ + struct octep_hp_slot *hp_slot; + + /* + * Enable or disable the slots based on the slot mask. + * intr_val is a bit mask where each bit represents a slot. + */ + list_for_each_entry(hp_slot, &hp_ctrl->slot_list, list) { + if (!(hp_cmd->intr_val & BIT(hp_slot->slot_number))) + continue; + + pci_info(hp_ctrl->pdev, "Received %s command for slot %s\n", + octep_hp_cmd_name(hp_cmd->intr_type), + hotplug_slot_name(&hp_slot->slot)); + + switch (hp_cmd->intr_type) { + case OCTEP_HP_INTR_ENA: + octep_hp_enable_pdev(hp_ctrl, hp_slot); + break; + case OCTEP_HP_INTR_DIS: + octep_hp_disable_pdev(hp_ctrl, hp_slot); + break; + default: + break; + } + } +} + +static void octep_hp_work_handler(struct work_struct *work) +{ + struct octep_hp_controller *hp_ctrl; + struct octep_hp_cmd *hp_cmd; + unsigned long flags; + + hp_ctrl = container_of(work, struct octep_hp_controller, work); + + /* Process all the hotplug commands */ + spin_lock_irqsave(&hp_ctrl->hp_cmd_lock, flags); + while (!list_empty(&hp_ctrl->hp_cmd_list)) { + hp_cmd = list_first_entry(&hp_ctrl->hp_cmd_list, + struct octep_hp_cmd, list); + list_del(&hp_cmd->list); + spin_unlock_irqrestore(&hp_ctrl->hp_cmd_lock, flags); + + octep_hp_cmd_handler(hp_ctrl, hp_cmd); + kfree(hp_cmd); + + spin_lock_irqsave(&hp_ctrl->hp_cmd_lock, flags); + } + spin_unlock_irqrestore(&hp_ctrl->hp_cmd_lock, flags); +} + +static enum octep_hp_intr_type octep_hp_intr_type(struct octep_hp_intr_info *intr, + int irq) +{ + enum octep_hp_intr_type type; + + for (type = OCTEP_HP_INTR_ENA; type < OCTEP_HP_INTR_MAX; type++) { + if (intr[type].number == irq) + return type; + } + + return OCTEP_HP_INTR_INVALID; +} + +static irqreturn_t octep_hp_intr_handler(int irq, void *data) +{ + struct octep_hp_controller *hp_ctrl = data; + struct pci_dev *pdev = hp_ctrl->pdev; + enum octep_hp_intr_type type; + struct octep_hp_cmd *hp_cmd; + u64 intr_val; + + type = octep_hp_intr_type(hp_ctrl->intr, irq); + if (type == OCTEP_HP_INTR_INVALID) { + pci_err(pdev, "Invalid interrupt %d\n", irq); + return IRQ_HANDLED; + } + + /* Read and clear the interrupt */ + intr_val = readq(hp_ctrl->base + OCTEP_HP_INTR_OFFSET(type)); + writeq(intr_val, hp_ctrl->base + OCTEP_HP_INTR_OFFSET(type)); + + hp_cmd = kzalloc(sizeof(*hp_cmd), GFP_ATOMIC); + if (!hp_cmd) + return IRQ_HANDLED; + + hp_cmd->intr_val = intr_val; + hp_cmd->intr_type = type; + + /* Add the command to the list and schedule the work */ + spin_lock(&hp_ctrl->hp_cmd_lock); + list_add_tail(&hp_cmd->list, &hp_ctrl->hp_cmd_list); + spin_unlock(&hp_ctrl->hp_cmd_lock); + schedule_work(&hp_ctrl->work); + + return IRQ_HANDLED; +} + +static void octep_hp_irq_cleanup(void *data) +{ + struct octep_hp_controller *hp_ctrl = data; + + pci_free_irq_vectors(hp_ctrl->pdev); + flush_work(&hp_ctrl->work); +} + +static int octep_hp_request_irq(struct octep_hp_controller *hp_ctrl, + enum octep_hp_intr_type type) +{ + struct pci_dev *pdev = hp_ctrl->pdev; + struct octep_hp_intr_info *intr; + int irq; + + irq = pci_irq_vector(pdev, OCTEP_HP_INTR_VECTOR(type)); + if (irq < 0) + return irq; + + intr = &hp_ctrl->intr[type]; + intr->number = irq; + intr->type = type; + snprintf(intr->name, sizeof(intr->name), "octep_hp_%d", type); + + return devm_request_irq(&pdev->dev, irq, octep_hp_intr_handler, + IRQF_SHARED, intr->name, hp_ctrl); +} + +static int octep_hp_controller_setup(struct pci_dev *pdev, + struct octep_hp_controller *hp_ctrl) +{ + struct device *dev = &pdev->dev; + enum octep_hp_intr_type type; + int ret; + + ret = pcim_enable_device(pdev); + if (ret) + return dev_err_probe(dev, ret, "Failed to enable PCI device\n"); + + hp_ctrl->base = pcim_iomap_region(pdev, 0, OCTEP_HP_DRV_NAME); + if (IS_ERR(hp_ctrl->base)) + return dev_err_probe(dev, PTR_ERR(hp_ctrl->base), + "Failed to map PCI device region\n"); + + pci_set_master(pdev); + pci_set_drvdata(pdev, hp_ctrl); + + INIT_LIST_HEAD(&hp_ctrl->slot_list); + INIT_LIST_HEAD(&hp_ctrl->hp_cmd_list); + mutex_init(&hp_ctrl->slot_lock); + spin_lock_init(&hp_ctrl->hp_cmd_lock); + INIT_WORK(&hp_ctrl->work, octep_hp_work_handler); + hp_ctrl->pdev = pdev; + + ret = pci_alloc_irq_vectors(pdev, 1, + OCTEP_HP_INTR_VECTOR(OCTEP_HP_INTR_MAX), + PCI_IRQ_MSIX); + if (ret < 0) + return dev_err_probe(dev, ret, "Failed to alloc MSI-X vectors\n"); + + ret = devm_add_action(&pdev->dev, octep_hp_irq_cleanup, hp_ctrl); + if (ret) + return dev_err_probe(&pdev->dev, ret, "Failed to add IRQ cleanup action\n"); + + for (type = OCTEP_HP_INTR_ENA; type < OCTEP_HP_INTR_MAX; type++) { + ret = octep_hp_request_irq(hp_ctrl, type); + if (ret) + return dev_err_probe(dev, ret, + "Failed to request IRQ for vector %d\n", + OCTEP_HP_INTR_VECTOR(type)); + } + + return 0; +} + +static int octep_hp_pci_probe(struct pci_dev *pdev, + const struct pci_device_id *id) +{ + struct octep_hp_controller *hp_ctrl; + struct pci_dev *tmp_pdev, *next; + struct octep_hp_slot *hp_slot; + u16 slot_number = 0; + int ret; + + hp_ctrl = devm_kzalloc(&pdev->dev, sizeof(*hp_ctrl), GFP_KERNEL); + if (!hp_ctrl) + return -ENOMEM; + + ret = octep_hp_controller_setup(pdev, hp_ctrl); + if (ret) + return ret; + + /* + * Register all hotplug slots. Hotplug controller is the first function + * of the PCI device. The hotplug slots are the remaining functions of + * the PCI device. The hotplug slot functions are logically removed from + * the bus during probing and are re-enabled by the driver when a + * hotplug event is received. + */ + list_for_each_entry_safe(tmp_pdev, next, &pdev->bus->devices, bus_list) { + if (tmp_pdev == pdev) + continue; + + hp_slot = octep_hp_register_slot(hp_ctrl, tmp_pdev, slot_number); + if (IS_ERR(hp_slot)) + return dev_err_probe(&pdev->dev, PTR_ERR(hp_slot), + "Failed to register hotplug slot %u\n", + slot_number); + + ret = devm_add_action(&pdev->dev, octep_hp_deregister_slot, + hp_slot); + if (ret) + return dev_err_probe(&pdev->dev, ret, + "Failed to add action for deregistering slot %u\n", + slot_number); + slot_number++; + } + + return 0; +} + +#define PCI_DEVICE_ID_CAVIUM_OCTEP_HP_CTLR 0xa0e3 +static struct pci_device_id octep_hp_pci_map[] = { + { PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, PCI_DEVICE_ID_CAVIUM_OCTEP_HP_CTLR) }, + { }, +}; + +static struct pci_driver octep_hp = { + .name = OCTEP_HP_DRV_NAME, + .id_table = octep_hp_pci_map, + .probe = octep_hp_pci_probe, +}; + +module_pci_driver(octep_hp); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Marvell"); +MODULE_DESCRIPTION("Marvell OCTEON PCI Hotplug driver"); |