diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/pci/host/Kconfig | 9 | ||||
| -rw-r--r-- | drivers/pci/host/Makefile | 1 | ||||
| -rw-r--r-- | drivers/pci/host/pci-xgene-msi.c | 596 | ||||
| -rw-r--r-- | drivers/pci/host/pci-xgene.c | 21 |
4 files changed, 627 insertions, 0 deletions
diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig index 1dfb567b3522..9c48e9986bc7 100644 --- a/drivers/pci/host/Kconfig +++ b/drivers/pci/host/Kconfig @@ -89,11 +89,20 @@ config PCI_XGENE depends on ARCH_XGENE depends on OF select PCIEPORTBUS + select PCI_MSI_IRQ_DOMAIN if PCI_MSI help Say Y here if you want internal PCI support on APM X-Gene SoC. There are 5 internal PCIe ports available. Each port is GEN3 capable and have varied lanes from x1 to x8. +config PCI_XGENE_MSI + bool "X-Gene v1 PCIe MSI feature" + depends on PCI_XGENE && PCI_MSI + default y + help + Say Y here if you want PCIe MSI support for the APM X-Gene v1 SoC. + This MSI driver supports 5 PCIe ports on the APM X-Gene v1 SoC. + config PCI_LAYERSCAPE bool "Freescale Layerscape PCIe controller" depends on OF && ARM diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile index f733b4e27642..1957431d3fcc 100644 --- a/drivers/pci/host/Makefile +++ b/drivers/pci/host/Makefile @@ -11,6 +11,7 @@ obj-$(CONFIG_PCIE_SPEAR13XX) += pcie-spear13xx.o obj-$(CONFIG_PCI_KEYSTONE) += pci-keystone-dw.o pci-keystone.o obj-$(CONFIG_PCIE_XILINX) += pcie-xilinx.o obj-$(CONFIG_PCI_XGENE) += pci-xgene.o +obj-$(CONFIG_PCI_XGENE_MSI) += pci-xgene-msi.o obj-$(CONFIG_PCI_LAYERSCAPE) += pci-layerscape.o obj-$(CONFIG_PCI_VERSATILE) += pci-versatile.o obj-$(CONFIG_PCIE_IPROC) += pcie-iproc.o diff --git a/drivers/pci/host/pci-xgene-msi.c b/drivers/pci/host/pci-xgene-msi.c new file mode 100644 index 000000000000..2d31d4d6fd08 --- /dev/null +++ b/drivers/pci/host/pci-xgene-msi.c @@ -0,0 +1,596 @@ +/* + * APM X-Gene MSI Driver + * + * Copyright (c) 2014, Applied Micro Circuits Corporation + * Author: Tanmay Inamdar <tinamdar@apm.com> + * Duc Dang <dhdang@apm.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + * + * 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. See the + * GNU General Public License for more details. + */ +#include <linux/cpu.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/msi.h> +#include <linux/of_irq.h> +#include <linux/irqchip/chained_irq.h> +#include <linux/pci.h> +#include <linux/platform_device.h> +#include <linux/of_pci.h> + +#define MSI_IR0 0x000000 +#define MSI_INT0 0x800000 +#define IDX_PER_GROUP 8 +#define IRQS_PER_IDX 16 +#define NR_HW_IRQS 16 +#define NR_MSI_VEC (IDX_PER_GROUP * IRQS_PER_IDX * NR_HW_IRQS) + +struct xgene_msi_group { + struct xgene_msi *msi; + int gic_irq; + u32 msi_grp; +}; + +struct xgene_msi { + struct device_node *node; + struct msi_controller mchip; + struct irq_domain *domain; + u64 msi_addr; + void __iomem *msi_regs; + unsigned long *bitmap; + struct mutex bitmap_lock; + struct xgene_msi_group *msi_groups; + int num_cpus; +}; + +/* Global data */ +static struct xgene_msi xgene_msi_ctrl; + +static struct irq_chip xgene_msi_top_irq_chip = { + .name = "X-Gene1 MSI", + .irq_enable = pci_msi_unmask_irq, + .irq_disable = pci_msi_mask_irq, + .irq_mask = pci_msi_mask_irq, + .irq_unmask = pci_msi_unmask_irq, +}; + +static struct msi_domain_info xgene_msi_domain_info = { + .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS | + MSI_FLAG_PCI_MSIX), + .chip = &xgene_msi_top_irq_chip, +}; + +/* + * X-Gene v1 has 16 groups of MSI termination registers MSInIRx, where + * n is group number (0..F), x is index of registers in each group (0..7) + * The register layout is as follows: + * MSI0IR0 base_addr + * MSI0IR1 base_addr + 0x10000 + * ... ... + * MSI0IR6 base_addr + 0x60000 + * MSI0IR7 base_addr + 0x70000 + * MSI1IR0 base_addr + 0x80000 + * MSI1IR1 base_addr + 0x90000 + * ... ... + * MSI1IR7 base_addr + 0xF0000 + * MSI2IR0 base_addr + 0x100000 + * ... ... + * MSIFIR0 base_addr + 0x780000 + * MSIFIR1 base_addr + 0x790000 + * ... ... + * MSIFIR7 base_addr + 0x7F0000 + * MSIINT0 base_addr + 0x800000 + * MSIINT1 base_addr + 0x810000 + * ... ... + * MSIINTF base_addr + 0x8F0000 + * + * Each index register supports 16 MSI vectors (0..15) to generate interrupt. + * There are total 16 GIC IRQs assigned for these 16 groups of MSI termination + * registers. + * + * Each MSI termination group has 1 MSIINTn register (n is 0..15) to indicate + * the MSI pending status caused by 1 of its 8 index registers. + */ + +/* MSInIRx read helper */ +static u32 xgene_msi_ir_read(struct xgene_msi *msi, + u32 msi_grp, u32 msir_idx) +{ + return readl_relaxed(msi->msi_regs + MSI_IR0 + + (msi_grp << 19) + (msir_idx << 16)); +} + +/* MSIINTn read helper */ +static u32 xgene_msi_int_read(struct xgene_msi *msi, u32 msi_grp) +{ + return readl_relaxed(msi->msi_regs + MSI_INT0 + (msi_grp << 16)); +} + +/* + * With 2048 MSI vectors supported, the MSI message can be constructed using + * following scheme: + * - Divide into 8 256-vector groups + * Group 0: 0-255 + * Group 1: 256-511 + * Group 2: 512-767 + * ... + * Group 7: 1792-2047 + * - Each 256-vector group is divided into 16 16-vector groups + * As an example: 16 16-vector groups for 256-vector group 0-255 is + * Group 0: 0-15 + * Group 1: 16-32 + * ... + * Group 15: 240-255 + * - The termination address of MSI vector in 256-vector group n and 16-vector + * group x is the address of MSIxIRn + * - The data for MSI vector in 16-vector group x is x + */ +static u32 hwirq_to_reg_set(unsigned long hwirq) +{ + return (hwirq / (NR_HW_IRQS * IRQS_PER_IDX)); +} + +static u32 hwirq_to_group(unsigned long hwirq) +{ + return (hwirq % NR_HW_IRQS); +} + +static u32 hwirq_to_msi_data(unsigned long hwirq) +{ + return ((hwirq / NR_HW_IRQS) % IRQS_PER_IDX); +} + +static void xgene_compose_msi_msg(struct irq_data *data, struct msi_msg *msg) +{ + struct xgene_msi *msi = irq_data_get_irq_chip_data(data); + u32 reg_set = hwirq_to_reg_set(data->hwirq); + u32 group = hwirq_to_group(data->hwirq); + u64 target_addr = msi->msi_addr + (((8 * group) + reg_set) << 16); + + msg->address_hi = upper_32_bits(target_addr); + msg->address_lo = lower_32_bits(target_addr); + msg->data = hwirq_to_msi_data(data->hwirq); +} + +/* + * X-Gene v1 only has 16 MSI GIC IRQs for 2048 MSI vectors. To maintain + * the expected behaviour of .set_affinity for each MSI interrupt, the 16 + * MSI GIC IRQs are statically allocated to 8 X-Gene v1 cores (2 GIC IRQs + * for each core). The MSI vector is moved fom 1 MSI GIC IRQ to another + * MSI GIC IRQ to steer its MSI interrupt to correct X-Gene v1 core. As a + * consequence, the total MSI vectors that X-Gene v1 supports will be + * reduced to 256 (2048/8) vectors. + */ +static int hwirq_to_cpu(unsigned long hwirq) +{ + return (hwirq % xgene_msi_ctrl.num_cpus); +} + +static unsigned long hwirq_to_canonical_hwirq(unsigned long hwirq) +{ + return (hwirq - hwirq_to_cpu(hwirq)); +} + +static int xgene_msi_set_affinity(struct irq_data *irqdata, + const struct cpumask *mask, bool force) +{ + int target_cpu = cpumask_first(mask); + int curr_cpu; + + curr_cpu = hwirq_to_cpu(irqdata->hwirq); + if (curr_cpu == target_cpu) + return IRQ_SET_MASK_OK_DONE; + + /* Update MSI number to target the new CPU */ + irqdata->hwirq = hwirq_to_canonical_hwirq(irqdata->hwirq) + target_cpu; + + return IRQ_SET_MASK_OK; +} + +static struct irq_chip xgene_msi_bottom_irq_chip = { + .name = "MSI", + .irq_set_affinity = xgene_msi_set_affinity, + .irq_compose_msi_msg = xgene_compose_msi_msg, +}; + +static int xgene_irq_domain_alloc(struct irq_domain *domain, unsigned int virq, + unsigned int nr_irqs, void *args) +{ + struct xgene_msi *msi = domain->host_data; + int msi_irq; + + mutex_lock(&msi->bitmap_lock); + + msi_irq = bitmap_find_next_zero_area(msi->bitmap, NR_MSI_VEC, 0, + msi->num_cpus, 0); + if (msi_irq < NR_MSI_VEC) + bitmap_set(msi->bitmap, msi_irq, msi->num_cpus); + else + msi_irq = -ENOSPC; + + mutex_unlock(&msi->bitmap_lock); + + if (msi_irq < 0) + return msi_irq; + + irq_domain_set_info(domain, virq, msi_irq, + &xgene_msi_bottom_irq_chip, domain->host_data, + handle_simple_irq, NULL, NULL); + set_irq_flags(virq, IRQF_VALID); + + return 0; +} + +static void xgene_irq_domain_free(struct irq_domain *domain, + unsigned int virq, unsigned int nr_irqs) +{ + struct irq_data *d = irq_domain_get_irq_data(domain, virq); + struct xgene_msi *msi = irq_data_get_irq_chip_data(d); + u32 hwirq; + + mutex_lock(&msi->bitmap_lock); + + hwirq = hwirq_to_canonical_hwirq(d->hwirq); + bitmap_clear(msi->bitmap, hwirq, msi->num_cpus); + + mutex_unlock(&msi->bitmap_lock); + + irq_domain_free_irqs_parent(domain, virq, nr_irqs); +} + +static const struct irq_domain_ops msi_domain_ops = { + .alloc = xgene_irq_domain_alloc, + .free = xgene_irq_domain_free, +}; + +static int xgene_allocate_domains(struct xgene_msi *msi) +{ + msi->domain = irq_domain_add_linear(NULL, NR_MSI_VEC, + &msi_domain_ops, msi); + if (!msi->domain) + return -ENOMEM; + + msi->mchip.domain = pci_msi_create_irq_domain(msi->mchip.of_node, + &xgene_msi_domain_info, + msi->domain); + + if (!msi->mchip.domain) { + irq_domain_remove(msi->domain); + return -ENOMEM; + } + + return 0; +} + +static void xgene_free_domains(struct xgene_msi *msi) +{ + if (msi->mchip.domain) + irq_domain_remove(msi->mchip.domain); + if (msi->domain) + irq_domain_remove(msi->domain); +} + +static int xgene_msi_init_allocator(struct xgene_msi *xgene_msi) +{ + int size = BITS_TO_LONGS(NR_MSI_VEC) * sizeof(long); + + xgene_msi->bitmap = kzalloc(size, GFP_KERNEL); + if (!xgene_msi->bitmap) + return -ENOMEM; + + mutex_init(&xgene_msi->bitmap_lock); + + xgene_msi->msi_groups = kcalloc(NR_HW_IRQS, + sizeof(struct xgene_msi_group), + GFP_KERNEL); + if (!xgene_msi->msi_groups) + return -ENOMEM; + + return 0; +} + +static void xgene_msi_isr(unsigned int irq, struct irq_desc *desc) +{ + struct irq_chip *chip = irq_desc_get_chip(desc); + struct xgene_msi_group *msi_groups; + struct xgene_msi *xgene_msi; + unsigned int virq; + int msir_index, msir_val, hw_irq; + u32 intr_index, grp_select, msi_grp; + + chained_irq_enter(chip, desc); + + msi_groups = irq_desc_get_handler_data(desc); + xgene_msi = msi_groups->msi; + msi_grp = msi_groups->msi_grp; + + /* + * MSIINTn (n is 0..F) indicates if there is a pending MSI interrupt + * If bit x of this register is set (x is 0..7), one or more interupts + * corresponding to MSInIRx is set. + */ + grp_select = xgene_msi_int_read(xgene_msi, msi_grp); + while (grp_select) { + msir_index = ffs(grp_select) - 1; + /* + * Calculate MSInIRx address to read to check for interrupts + * (refer to termination address and data assignment + * described in xgene_compose_msi_msg() ) + */ + msir_val = xgene_msi_ir_read(xgene_msi, msi_grp, msir_index); + while (msir_val) { + intr_index = ffs(msir_val) - 1; + /* + * Calculate MSI vector number (refer to the termination + * address and data assignment described in + * xgene_compose_msi_msg function) + */ + hw_irq = (((msir_index * IRQS_PER_IDX) + intr_index) * + NR_HW_IRQS) + msi_grp; + /* + * As we have multiple hw_irq that maps to single MSI, + * always look up the virq using the hw_irq as seen from + * CPU0 + */ + hw_irq = hwirq_to_canonical_hwirq(hw_irq); + virq = irq_find_mapping(xgene_msi->domain, hw_irq); + WARN_ON(!virq); + if (virq != 0) + generic_handle_irq(virq); + msir_val &= ~(1 << intr_index); + } + grp_select &= ~(1 << msir_index); + + if (!grp_select) { + /* + * We handled all interrupts happened in this group, + * resample this group MSI_INTx register in case + * something else has been made pending in the meantime + */ + grp_select = xgene_msi_int_read(xgene_msi, msi_grp); + } + } + + chained_irq_exit(chip, desc); +} + +static int xgene_msi_remove(struct platform_device *pdev) +{ + int virq, i; + struct xgene_msi *msi = platform_get_drvdata(pdev); + + for (i = 0; i < NR_HW_IRQS; i++) { + virq = msi->msi_groups[i].gic_irq; + if (virq != 0) { + irq_set_chained_handler(virq, NULL); + irq_set_handler_data(virq, NULL); + } + } + kfree(msi->msi_groups); + + kfree(msi->bitmap); + msi->bitmap = NULL; + + xgene_free_domains(msi); + + return 0; +} + +static int xgene_msi_hwirq_alloc(unsigned int cpu) +{ + struct xgene_msi *msi = &xgene_msi_ctrl; + struct xgene_msi_group *msi_group; + cpumask_var_t mask; + int i; + int err; + + for (i = cpu; i < NR_HW_IRQS; i += msi->num_cpus) { + msi_group = &msi->msi_groups[i]; + if (!msi_group->gic_irq) + continue; + + irq_set_chained_handler(msi_group->gic_irq, + xgene_msi_isr); + err = irq_set_handler_data(msi_group->gic_irq, msi_group); + if (err) { + pr_err("failed to register GIC IRQ handler\n"); + return -EINVAL; + } + /* + * Statically allocate MSI GIC IRQs to each CPU core. + * With 8-core X-Gene v1, 2 MSI GIC IRQs are allocated + * to each core. + */ + if (alloc_cpumask_var(&mask, GFP_KERNEL)) { + cpumask_clear(mask); + cpumask_set_cpu(cpu, mask); + err = irq_set_affinity(msi_group->gic_irq, mask); + if (err) + pr_err("failed to set affinity for GIC IRQ"); + free_cpumask_var(mask); + } else { + pr_err("failed to alloc CPU mask for affinity\n"); + err = -EINVAL; + } + + if (err) { + irq_set_chained_handler(msi_group->gic_irq, NULL); + irq_set_handler_data(msi_group->gic_irq, NULL); + return err; + } + } + + return 0; +} + +static void xgene_msi_hwirq_free(unsigned int cpu) +{ + struct xgene_msi *msi = &xgene_msi_ctrl; + struct xgene_msi_group *msi_group; + int i; + + for (i = cpu; i < NR_HW_IRQS; i += msi->num_cpus) { + msi_group = &msi->msi_groups[i]; + if (!msi_group->gic_irq) + continue; + + irq_set_chained_handler(msi_group->gic_irq, NULL); + irq_set_handler_data(msi_group->gic_irq, NULL); + } +} + +static int xgene_msi_cpu_callback(struct notifier_block *nfb, + unsigned long action, void *hcpu) +{ + unsigned cpu = (unsigned long)hcpu; + + switch (action) { + case CPU_ONLINE: + case CPU_ONLINE_FROZEN: + xgene_msi_hwirq_alloc(cpu); + break; + case CPU_DEAD: + case CPU_DEAD_FROZEN: + xgene_msi_hwirq_free(cpu); + break; + default: + break; + } + + return NOTIFY_OK; +} + +static struct notifier_block xgene_msi_cpu_notifier = { + .notifier_call = xgene_msi_cpu_callback, +}; + +static const struct of_device_id xgene_msi_match_table[] = { + {.compatible = "apm,xgene1-msi"}, + {}, +}; + +static int xgene_msi_probe(struct platform_device *pdev) +{ + struct resource *res; + int rc, irq_index; + struct xgene_msi *xgene_msi; + unsigned int cpu; + int virt_msir; + u32 msi_val, msi_idx; + + xgene_msi = &xgene_msi_ctrl; + + platform_set_drvdata(pdev, xgene_msi); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + xgene_msi->msi_regs = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(xgene_msi->msi_regs)) { + dev_err(&pdev->dev, "no reg space\n"); + rc = -EINVAL; + goto error; + } + xgene_msi->msi_addr = res->start; + + xgene_msi->num_cpus = num_possible_cpus(); + + rc = xgene_msi_init_allocator(xgene_msi); + if (rc) { + dev_err(&pdev->dev, "Error allocating MSI bitmap\n"); + goto error; + } + + rc = xgene_allocate_domains(xgene_msi); + if (rc) { + dev_err(&pdev->dev, "Failed to allocate MSI domain\n"); + goto error; + } + + for (irq_index = 0; irq_index < NR_HW_IRQS; irq_index++) { + virt_msir = platform_get_irq(pdev, irq_index); + if (virt_msir < 0) { + dev_err(&pdev->dev, "Cannot translate IRQ index %d\n", + irq_index); + rc = -EINVAL; + goto error; + } + xgene_msi->msi_groups[irq_index].gic_irq = virt_msir; + xgene_msi->msi_groups[irq_index].msi_grp = irq_index; + xgene_msi->msi_groups[irq_index].msi = xgene_msi; + } + + /* + * MSInIRx registers are read-to-clear; before registering + * interrupt handlers, read all of them to clear spurious + * interrupts that may occur before the driver is probed. + */ + for (irq_index = 0; irq_index < NR_HW_IRQS; irq_index++) { + for (msi_idx = 0; msi_idx < IDX_PER_GROUP; msi_idx++) + msi_val = xgene_msi_ir_read(xgene_msi, irq_index, + msi_idx); + /* Read MSIINTn to confirm */ + msi_val = xgene_msi_int_read(xgene_msi, irq_index); + if (msi_val) { + dev_err(&pdev->dev, "Failed to clear spurious IRQ\n"); + rc = -EINVAL; + goto error; + } + } + + cpu_notifier_register_begin(); + + for_each_online_cpu(cpu) + if (xgene_msi_hwirq_alloc(cpu)) { + dev_err(&pdev->dev, "failed to register MSI handlers\n"); + cpu_notifier_register_done(); + goto error; + } + + rc = __register_hotcpu_notifier(&xgene_msi_cpu_notifier); + if (rc) { + dev_err(&pdev->dev, "failed to add CPU MSI notifier\n"); + cpu_notifier_register_done(); + goto error; + } + + cpu_notifier_register_done(); + + xgene_msi->mchip.of_node = pdev->dev.of_node; + rc = of_pci_msi_chip_add(&xgene_msi->mchip); + if (rc) { + dev_err(&pdev->dev, "failed to add MSI controller chip\n"); + goto error_notifier; + } + + dev_info(&pdev->dev, "APM X-Gene PCIe MSI driver loaded\n"); + + return 0; + +error_notifier: + unregister_hotcpu_notifier(&xgene_msi_cpu_notifier); +error: + xgene_msi_remove(pdev); + return rc; +} + +static struct platform_driver xgene_msi_driver = { + .driver = { + .name = "xgene-msi", + .owner = THIS_MODULE, + .of_match_table = xgene_msi_match_table, + }, + .probe = xgene_msi_probe, + .remove = xgene_msi_remove, +}; + +static int __init xgene_pcie_msi_init(void) +{ + return platform_driver_register(&xgene_msi_driver); +} +subsys_initcall(xgene_pcie_msi_init); diff --git a/drivers/pci/host/pci-xgene.c b/drivers/pci/host/pci-xgene.c index ee082c0366ec..3e5a636c9a9a 100644 --- a/drivers/pci/host/pci-xgene.c +++ b/drivers/pci/host/pci-xgene.c @@ -468,6 +468,23 @@ static int xgene_pcie_setup(struct xgene_pcie_port *port, return 0; } +static int xgene_pcie_msi_enable(struct pci_bus *bus) +{ + struct device_node *msi_node; + + msi_node = of_parse_phandle(bus->dev.of_node, + "msi-parent", 0); + if (!msi_node) + return -ENODEV; + + bus->msi = of_pci_find_msi_chip_by_node(msi_node); + if (!bus->msi) + return -ENODEV; + + bus->msi->dev = &bus->dev; + return 0; +} + static int xgene_pcie_probe_bridge(struct platform_device *pdev) { struct device_node *dn = pdev->dev.of_node; @@ -504,6 +521,10 @@ static int xgene_pcie_probe_bridge(struct platform_device *pdev) if (!bus) return -ENOMEM; + if (IS_ENABLED(CONFIG_PCI_MSI)) + if (xgene_pcie_msi_enable(bus)) + dev_info(port->dev, "failed to enable MSI\n"); + pci_scan_child_bus(bus); pci_assign_unassigned_bus_resources(bus); pci_bus_add_devices(bus); |