On 25/08/15 10:35, Ley Foon Tan wrote: > This patch adds Altera PCIe MSI driver. This soft IP supports configurable > number of vectors, which is a dts parameter. > > Signed-off-by: Ley Foon Tan <lftan@xxxxxxxxxx> > --- > drivers/pci/host/Kconfig | 8 + > drivers/pci/host/Makefile | 1 + > drivers/pci/host/pcie-altera-msi.c | 322 +++++++++++++++++++++++++++++++++++++ > 3 files changed, 331 insertions(+) > create mode 100644 drivers/pci/host/pcie-altera-msi.c > > diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig > index 4b4754a..d28cc6d 100644 > --- a/drivers/pci/host/Kconfig > +++ b/drivers/pci/host/Kconfig > @@ -152,4 +152,12 @@ config PCIE_ALTERA > Say Y here if you want to enable PCIe controller support for Altera > SoCFPGA family of SoCs. > > +config PCIE_ALTERA_MSI > + bool "Altera PCIe MSI feature" > + depends on PCI_MSI > + select PCI_MSI_IRQ_DOMAIN > + help > + Say Y here if you want PCIe MSI support for the Altera SocFPGA SoC. > + This MSI driver supports Altera MSI to GIC controller IP. > + > endmenu > diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile > index 6954f76..6c4913d 100644 > --- a/drivers/pci/host/Makefile > +++ b/drivers/pci/host/Makefile > @@ -18,3 +18,4 @@ obj-$(CONFIG_PCIE_IPROC) += pcie-iproc.o > obj-$(CONFIG_PCIE_IPROC_PLATFORM) += pcie-iproc-platform.o > obj-$(CONFIG_PCIE_IPROC_BCMA) += pcie-iproc-bcma.o > obj-$(CONFIG_PCIE_ALTERA) += pcie-altera.o > +obj-$(CONFIG_PCIE_ALTERA_MSI) += pcie-altera-msi.o > diff --git a/drivers/pci/host/pcie-altera-msi.c b/drivers/pci/host/pcie-altera-msi.c > new file mode 100644 > index 0000000..d3ad96f > --- /dev/null > +++ b/drivers/pci/host/pcie-altera-msi.c > @@ -0,0 +1,322 @@ > +/* > + * Copyright Altera Corporation (C) 2013-2015. All rights reserved > + * > + * This program is free software; you can redistribute it and/or modify it > + * under the terms and conditions of the GNU General Public License, > + * version 2, as published by the Free Software Foundation. > + * > + * This program is distributed in the hope 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. > + * > + * You should have received a copy of the GNU General Public License along with > + * this program. If not, see <http://www.gnu.org/licenses/>. > + */ > +#include <linux/interrupt.h> > +#include <linux/irqchip/chained_irq.h> > +#include <linux/module.h> > +#include <linux/msi.h> > +#include <linux/of_address.h> > +#include <linux/of_irq.h> > +#include <linux/of_pci.h> > +#include <linux/pci.h> > +#include <linux/platform_device.h> > +#include <linux/slab.h> > + > +#define MSI_STATUS 0x0 > +#define MSI_ERROR 0x4 > +#define MSI_INTMASK 0x8 > + > +#define MAX_MSI_VECTORS 32 > +struct altera_msi { > + DECLARE_BITMAP(used, MAX_MSI_VECTORS); > + struct mutex lock; /* proctect used variable */ > + struct platform_device *pdev; > + struct irq_domain *msi_domain; > + struct irq_domain *inner_domain; > + void __iomem *csr_base; > + void __iomem *vector_base; > + phys_addr_t vector_phy; > + u32 num_of_vectors; > + int irq; > +}; > + > +static inline void msi_writel(struct altera_msi *msi, u32 value, u32 reg) > +{ > + writel_relaxed(value, msi->csr_base + reg); > +} > + > +static inline u32 msi_readl(struct altera_msi *msi, u32 reg) > +{ > + return readl_relaxed(msi->csr_base + reg); > +} > + > +static void altera_msi_isr(unsigned int irq, struct irq_desc *desc) > +{ > + struct irq_chip *chip = irq_desc_get_chip(desc); > + struct altera_msi *msi; > + unsigned long status; > + u32 num_of_vectors; > + u32 bit; > + u32 virq; > + > + chained_irq_enter(chip, desc); > + msi = irq_desc_get_handler_data(desc); > + num_of_vectors = msi->num_of_vectors; > + > + do { > + status = msi_readl(msi, MSI_STATUS); > + if (!status) > + break; > + > + do { > + bit = find_first_bit(&status, num_of_vectors); > + /* Dummy read from vector to clear the interrupt */ > + readl_relaxed(msi->vector_base + (bit * sizeof(u32))); > + > + virq = irq_find_mapping(msi->inner_domain, bit); > + if (virq && test_bit(bit, msi->used)) I still wonder under which circumstances you can obtain a valid virq and yet not find the bit in the bitmap. Unless you have a scenario when that can happen, I suggest you remove that test. > + generic_handle_irq(virq); > + else > + dev_err(&msi->pdev->dev, "unexpected MSI\n"); > + > + /* Clear the bit from status and repeat without reading > + * again status register. */ > + __clear_bit(bit, &status); > + } while (status); > + } while (1); I think this could be rewritten as: while ((status = msi_readl(msi, MSI_STATUS)) != 0) { for_each_set_bit(bit, &status, msi->num_of_vectors) { /* Dummy read from vector to clear the interrupt */ readl_relaxed(msi->vector_base + (bit * sizeof(u32))); virq = irq_find_mapping(msi->inner_domain, bit); if (virq) generic_handle_irq(virq); else dev_err(&msi->pdev->dev, "unexpected MSI\n"); } } which saves the __clear_bit call and the double test of status which I find a bit awkward. > + > + chained_irq_exit(chip, desc); > +} > + > +static struct irq_chip altera_msi_irq_chip = { > + .name = "Altera PCIe 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, Why do you have both enable/disable and unmask/mask? Specially pointing to the same function? This is completely useless. Just stick with unmask/mask and remove the enable/disable. > +}; > + > +static struct msi_domain_info altera_msi_domain_info = { > + .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS | > + MSI_FLAG_PCI_MSIX), > + .chip = &altera_msi_irq_chip, > +}; > + > +static void altera_compose_msi_msg(struct irq_data *data, struct msi_msg *msg) > +{ > + struct altera_msi *msi = irq_data_get_irq_chip_data(data); > + phys_addr_t addr = msi->vector_phy + (data->hwirq * sizeof(u32)); > + > + msg->address_lo = lower_32_bits(addr); > + msg->address_hi = upper_32_bits(addr); > + msg->data = data->hwirq; > + > + dev_dbg(&msi->pdev->dev, "msi#%d address_lo 0x%x address_hi 0x%x\n", > + (int)data->hwirq, msg->address_hi, msg->address_lo); > +} > + > +static int altera_msi_set_affinity(struct irq_data *irq_data, > + const struct cpumask *mask, bool force) > +{ > + return -EINVAL; > +} > + > +static struct irq_chip altera_msi_bottom_irq_chip = { > + .name = "Altera MSI", > + .irq_compose_msi_msg = altera_compose_msi_msg, > + .irq_set_affinity = altera_msi_set_affinity, > +}; > + > +static int altera_irq_domain_alloc(struct irq_domain *domain, unsigned int virq, > + unsigned int nr_irqs, void *args) > +{ > + struct altera_msi *msi = domain->host_data; > + unsigned long bit; > + u32 mask; > + > + WARN_ON(nr_irqs != 1); > + mutex_lock(&msi->lock); > + > + bit = find_first_zero_bit(msi->used, msi->num_of_vectors); > + if (bit >= msi->num_of_vectors) > + return -ENOSPC; > + > + set_bit(bit, msi->used); > + > + mutex_unlock(&msi->lock); > + > + irq_domain_set_info(domain, virq, bit, &altera_msi_bottom_irq_chip, > + domain->host_data, handle_simple_irq, > + NULL, NULL); > + set_irq_flags(virq, IRQF_VALID); > + > + mask = msi_readl(msi, MSI_INTMASK); > + mask |= 1 << bit; > + msi_writel(msi, mask, MSI_INTMASK); > + > + return 0; > +} > + > +static void altera_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 altera_msi *msi = irq_data_get_irq_chip_data(d); > + u32 mask; > + > + mutex_lock(&msi->lock); > + > + if (!test_bit(d->hwirq, msi->used)) { > + dev_err(&msi->pdev->dev, "trying to free unused MSI#%lu\n", > + d->hwirq); > + } else { > + __clear_bit(d->hwirq, msi->used); > + mask = msi_readl(msi, MSI_INTMASK); > + mask &= ~(1 << d->hwirq); > + msi_writel(msi, mask, MSI_INTMASK); > + } > + > + mutex_unlock(&msi->lock); > +} > + > +static const struct irq_domain_ops msi_domain_ops = { > + .alloc = altera_irq_domain_alloc, > + .free = altera_irq_domain_free, > +}; > + > +static int altera_allocate_domains(struct altera_msi *msi) > +{ > + msi->inner_domain = irq_domain_add_linear(NULL, msi->num_of_vectors, > + &msi_domain_ops, msi); > + if (!msi->inner_domain) { > + dev_err(&msi->pdev->dev, "failed to create IRQ domain\n"); > + return -ENOMEM; > + } > + > + msi->msi_domain = pci_msi_create_irq_domain(msi->pdev->dev.of_node, > + &altera_msi_domain_info, msi->inner_domain); > + if (!msi->msi_domain) { > + dev_err(&msi->pdev->dev, "failed to create MSI domain\n"); > + irq_domain_remove(msi->inner_domain); > + return -ENOMEM; > + } > + > + return 0; > +} > + > +static void altera_free_domains(struct altera_msi *msi) > +{ > + irq_domain_remove(msi->msi_domain); > + irq_domain_remove(msi->inner_domain); > +} > + > +static int altera_msi_remove(struct platform_device *pdev) > +{ > + struct altera_msi *msi = platform_get_drvdata(pdev); > + > + msi_writel(msi, 0, MSI_INTMASK); > + irq_set_chained_handler(msi->irq, NULL); > + irq_set_handler_data(msi->irq, NULL); > + > + altera_free_domains(msi); > + > + platform_set_drvdata(pdev, NULL); > + return 0; > +} > + > +static int altera_msi_probe(struct platform_device *pdev) > +{ > + struct altera_msi *msi; > + struct device_node *np = pdev->dev.of_node; > + struct resource *res; > + int ret; > + > + msi = devm_kzalloc(&pdev->dev, sizeof(struct altera_msi), > + GFP_KERNEL); > + if (!msi) > + return -ENOMEM; > + > + mutex_init(&msi->lock); > + msi->pdev = pdev; > + > + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "csr"); > + if (!res) { > + dev_err(&pdev->dev, > + "no csr memory resource defined\n"); > + return -ENODEV; > + } > + > + msi->csr_base = devm_ioremap_resource(&pdev->dev, res); > + if (IS_ERR(msi->csr_base)) { > + dev_err(&pdev->dev, "failed to map csr memory\n"); > + return PTR_ERR(msi->csr_base); > + } > + > + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, > + "vector_slave"); > + if (!res) { > + dev_err(&pdev->dev, > + "no vector_slave memory resource defined\n"); > + return -ENODEV; > + } > + > + msi->vector_base = devm_ioremap_resource(&pdev->dev, res); > + if (IS_ERR(msi->vector_base)) { > + dev_err(&pdev->dev, "failed to map vector_slave memory\n"); > + return PTR_ERR(msi->vector_base); > + } > + > + msi->vector_phy = res->start; > + > + if (of_property_read_u32(np, "num-vectors", &msi->num_of_vectors)) { > + dev_err(&pdev->dev, "failed to parse the number of vectors\n"); > + return -EINVAL; > + } > + > + ret = altera_allocate_domains(msi); > + if (ret) > + return ret; > + > + msi->irq = platform_get_irq(pdev, 0); > + if (msi->irq <= 0) { > + dev_err(&pdev->dev, "failed to map IRQ: %d\n", msi->irq); > + ret = -ENODEV; > + goto err; > + } > + > + irq_set_chained_handler_and_data(msi->irq, altera_msi_isr, msi); > + platform_set_drvdata(pdev, msi); > + > + return 0; > + > +err: > + altera_msi_remove(pdev); > + return ret; > +} > + > +static const struct of_device_id altera_msi_of_match[] = { > + { .compatible = "altr,msi-1.0", NULL }, > + { }, > +}; > + > +static struct platform_driver altera_msi_driver = { > + .driver = { > + .name = "altera-msi", > + .of_match_table = altera_msi_of_match, > + }, > + .probe = altera_msi_probe, > + .remove = altera_msi_remove, > +}; > + > +static int __init altera_msi_init(void) > +{ > + return platform_driver_register(&altera_msi_driver); > +} > + > +subsys_initcall(altera_msi_init); > + > +MODULE_AUTHOR("Ley Foon Tan <lftan@xxxxxxxxxx>"); > +MODULE_DESCRIPTION("Altera PCIe MSI support"); > +MODULE_LICENSE("GPL v2"); > Once you've fixed the above issues, you can add my: Reviewed-by: Marc Zyngier <marc.zyngier@xxxxxxx> M. -- Jazz is not dead. 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