diff options
Diffstat (limited to 'drivers/bus/fsl-mc/fsl-mc-msi.c')
| -rw-r--r-- | drivers/bus/fsl-mc/fsl-mc-msi.c | 285 |
1 files changed, 285 insertions, 0 deletions
diff --git a/drivers/bus/fsl-mc/fsl-mc-msi.c b/drivers/bus/fsl-mc/fsl-mc-msi.c new file mode 100644 index 000000000000..ec35e255b496 --- /dev/null +++ b/drivers/bus/fsl-mc/fsl-mc-msi.c @@ -0,0 +1,285 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Freescale Management Complex (MC) bus driver MSI support + * + * Copyright (C) 2015-2016 Freescale Semiconductor, Inc. + * Author: German Rivera <German.Rivera@freescale.com> + * + */ + +#include <linux/of_device.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <linux/irq.h> +#include <linux/irqdomain.h> +#include <linux/msi.h> + +#include "fsl-mc-private.h" + +#ifdef GENERIC_MSI_DOMAIN_OPS +/* + * Generate a unique ID identifying the interrupt (only used within the MSI + * irqdomain. Combine the icid with the interrupt index. + */ +static irq_hw_number_t fsl_mc_domain_calc_hwirq(struct fsl_mc_device *dev, + struct msi_desc *desc) +{ + /* + * Make the base hwirq value for ICID*10000 so it is readable + * as a decimal value in /proc/interrupts. + */ + return (irq_hw_number_t)(desc->fsl_mc.msi_index + (dev->icid * 10000)); +} + +static void fsl_mc_msi_set_desc(msi_alloc_info_t *arg, + struct msi_desc *desc) +{ + arg->desc = desc; + arg->hwirq = fsl_mc_domain_calc_hwirq(to_fsl_mc_device(desc->dev), + desc); +} +#else +#define fsl_mc_msi_set_desc NULL +#endif + +static void fsl_mc_msi_update_dom_ops(struct msi_domain_info *info) +{ + struct msi_domain_ops *ops = info->ops; + + if (!ops) + return; + + /* + * set_desc should not be set by the caller + */ + if (!ops->set_desc) + ops->set_desc = fsl_mc_msi_set_desc; +} + +static void __fsl_mc_msi_write_msg(struct fsl_mc_device *mc_bus_dev, + struct fsl_mc_device_irq *mc_dev_irq) +{ + int error; + struct fsl_mc_device *owner_mc_dev = mc_dev_irq->mc_dev; + struct msi_desc *msi_desc = mc_dev_irq->msi_desc; + struct dprc_irq_cfg irq_cfg; + + /* + * msi_desc->msg.address is 0x0 when this function is invoked in + * the free_irq() code path. In this case, for the MC, we don't + * really need to "unprogram" the MSI, so we just return. + */ + if (msi_desc->msg.address_lo == 0x0 && msi_desc->msg.address_hi == 0x0) + return; + + if (!owner_mc_dev) + return; + + irq_cfg.paddr = ((u64)msi_desc->msg.address_hi << 32) | + msi_desc->msg.address_lo; + irq_cfg.val = msi_desc->msg.data; + irq_cfg.irq_num = msi_desc->irq; + + if (owner_mc_dev == mc_bus_dev) { + /* + * IRQ is for the mc_bus_dev's DPRC itself + */ + error = dprc_set_irq(mc_bus_dev->mc_io, + MC_CMD_FLAG_INTR_DIS | MC_CMD_FLAG_PRI, + mc_bus_dev->mc_handle, + mc_dev_irq->dev_irq_index, + &irq_cfg); + if (error < 0) { + dev_err(&owner_mc_dev->dev, + "dprc_set_irq() failed: %d\n", error); + } + } else { + /* + * IRQ is for for a child device of mc_bus_dev + */ + error = dprc_set_obj_irq(mc_bus_dev->mc_io, + MC_CMD_FLAG_INTR_DIS | MC_CMD_FLAG_PRI, + mc_bus_dev->mc_handle, + owner_mc_dev->obj_desc.type, + owner_mc_dev->obj_desc.id, + mc_dev_irq->dev_irq_index, + &irq_cfg); + if (error < 0) { + dev_err(&owner_mc_dev->dev, + "dprc_obj_set_irq() failed: %d\n", error); + } + } +} + +/* + * NOTE: This function is invoked with interrupts disabled + */ +static void fsl_mc_msi_write_msg(struct irq_data *irq_data, + struct msi_msg *msg) +{ + struct msi_desc *msi_desc = irq_data_get_msi_desc(irq_data); + struct fsl_mc_device *mc_bus_dev = to_fsl_mc_device(msi_desc->dev); + struct fsl_mc_bus *mc_bus = to_fsl_mc_bus(mc_bus_dev); + struct fsl_mc_device_irq *mc_dev_irq = + &mc_bus->irq_resources[msi_desc->fsl_mc.msi_index]; + + msi_desc->msg = *msg; + + /* + * Program the MSI (paddr, value) pair in the device: + */ + __fsl_mc_msi_write_msg(mc_bus_dev, mc_dev_irq); +} + +static void fsl_mc_msi_update_chip_ops(struct msi_domain_info *info) +{ + struct irq_chip *chip = info->chip; + + if (!chip) + return; + + /* + * irq_write_msi_msg should not be set by the caller + */ + if (!chip->irq_write_msi_msg) + chip->irq_write_msi_msg = fsl_mc_msi_write_msg; +} + +/** + * fsl_mc_msi_create_irq_domain - Create a fsl-mc MSI interrupt domain + * @np: Optional device-tree node of the interrupt controller + * @info: MSI domain info + * @parent: Parent irq domain + * + * Updates the domain and chip ops and creates a fsl-mc MSI + * interrupt domain. + * + * Returns: + * A domain pointer or NULL in case of failure. + */ +struct irq_domain *fsl_mc_msi_create_irq_domain(struct fwnode_handle *fwnode, + struct msi_domain_info *info, + struct irq_domain *parent) +{ + struct irq_domain *domain; + + if (info->flags & MSI_FLAG_USE_DEF_DOM_OPS) + fsl_mc_msi_update_dom_ops(info); + if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS) + fsl_mc_msi_update_chip_ops(info); + + domain = msi_create_irq_domain(fwnode, info, parent); + if (domain) + irq_domain_update_bus_token(domain, DOMAIN_BUS_FSL_MC_MSI); + + return domain; +} + +int fsl_mc_find_msi_domain(struct device *mc_platform_dev, + struct irq_domain **mc_msi_domain) +{ + struct irq_domain *msi_domain; + struct device_node *mc_of_node = mc_platform_dev->of_node; + + msi_domain = of_msi_get_domain(mc_platform_dev, mc_of_node, + DOMAIN_BUS_FSL_MC_MSI); + if (!msi_domain) { + pr_err("Unable to find fsl-mc MSI domain for %pOF\n", + mc_of_node); + + return -ENOENT; + } + + *mc_msi_domain = msi_domain; + return 0; +} + +static void fsl_mc_msi_free_descs(struct device *dev) +{ + struct msi_desc *desc, *tmp; + + list_for_each_entry_safe(desc, tmp, dev_to_msi_list(dev), list) { + list_del(&desc->list); + free_msi_entry(desc); + } +} + +static int fsl_mc_msi_alloc_descs(struct device *dev, unsigned int irq_count) + +{ + unsigned int i; + int error; + struct msi_desc *msi_desc; + + for (i = 0; i < irq_count; i++) { + msi_desc = alloc_msi_entry(dev, 1, NULL); + if (!msi_desc) { + dev_err(dev, "Failed to allocate msi entry\n"); + error = -ENOMEM; + goto cleanup_msi_descs; + } + + msi_desc->fsl_mc.msi_index = i; + INIT_LIST_HEAD(&msi_desc->list); + list_add_tail(&msi_desc->list, dev_to_msi_list(dev)); + } + + return 0; + +cleanup_msi_descs: + fsl_mc_msi_free_descs(dev); + return error; +} + +int fsl_mc_msi_domain_alloc_irqs(struct device *dev, + unsigned int irq_count) +{ + struct irq_domain *msi_domain; + int error; + + if (!list_empty(dev_to_msi_list(dev))) + return -EINVAL; + + error = fsl_mc_msi_alloc_descs(dev, irq_count); + if (error < 0) + return error; + + msi_domain = dev_get_msi_domain(dev); + if (!msi_domain) { + error = -EINVAL; + goto cleanup_msi_descs; + } + + /* + * NOTE: Calling this function will trigger the invocation of the + * its_fsl_mc_msi_prepare() callback + */ + error = msi_domain_alloc_irqs(msi_domain, dev, irq_count); + + if (error) { + dev_err(dev, "Failed to allocate IRQs\n"); + goto cleanup_msi_descs; + } + + return 0; + +cleanup_msi_descs: + fsl_mc_msi_free_descs(dev); + return error; +} + +void fsl_mc_msi_domain_free_irqs(struct device *dev) +{ + struct irq_domain *msi_domain; + + msi_domain = dev_get_msi_domain(dev); + if (!msi_domain) + return; + + msi_domain_free_irqs(msi_domain, dev); + + if (list_empty(dev_to_msi_list(dev))) + return; + + fsl_mc_msi_free_descs(dev); +} |