On Fri, Jul 31, 2015 at 8:12 PM, Marc Zyngier <marc.zyngier@xxxxxxx> wrote: > On 31/07/15 11:15, Ley Foon Tan wrote: >> This patch adds Altera PCIe MSI driver. This soft IP supports configurable >> number of vectors, which is a dts parameter. > > I've reviewed the initial drop of this code; basic courtesy would be to > keep me CCed on the follow-up series. Will keep you in CC for the following revision. Sorry about this. >> >> Signed-off-by: Ley Foon Tan <lftan@xxxxxxxxxx> >> --- >> drivers/pci/host/Kconfig | 7 + >> drivers/pci/host/Makefile | 1 + >> drivers/pci/host/pcie-altera-msi.c | 324 +++++++++++++++++++++++++++++++++++++ >> 3 files changed, 332 insertions(+) >> create mode 100644 drivers/pci/host/pcie-altera-msi.c >> >> diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig >> index 108500a..51d0468 100644 >> --- a/drivers/pci/host/Kconfig >> +++ b/drivers/pci/host/Kconfig >> @@ -153,4 +153,11 @@ 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 >> + 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..6014719 >> --- /dev/null >> +++ b/drivers/pci/host/pcie-altera-msi.c >> @@ -0,0 +1,324 @@ >> +/* >> + * 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; >> + >> + 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))); >> + >> + irq = irq_find_mapping(msi->inner_domain, bit); > > Use of irq is a bit confusing, as this is a parameter describing the > chaining interrupt. Consider using a different name for this variable. Okay, will change it to 'virq'. > >> + if (irq) { >> + if (test_bit(bit, msi->used)) >> + generic_handle_irq(irq); >> + else >> + dev_info(&msi->pdev->dev, "unhandled MSI\n"); >> + } else >> + dev_info(&msi->pdev->dev, "unexpected MSI\n"); > > The whole statement could be rewritten as: > > if (irq && test_bit(bit, msi->used)) > generic_handle_irq(irq); > else > dev_err(...); > > In all cases, this is a grave error, so dev_info is not appropriate here. Noted. > >> + >> + /* Clear the bit from status and repeat without reading >> + * again status register. */ >> + clear_bit(bit, &status); > > You don't need an atomic operation here, so __clear_bit() should be enough. Noted. > >> + } while (status); >> + } while (1); >> + >> + 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, >> +}; >> + >> +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) >> +{ >> + u32 mask; >> + struct altera_msi *msi = irq_data_get_irq_chip_data(data); >> + u64 addr = msi->vector_phy + (data->hwirq * sizeof(u32)); > > Use phys_addr_t. Noted. > >> + >> + msg->address_lo = lower_32_bits(addr); >> + msg->address_hi = upper_32_bits(addr); >> + msg->data = data->hwirq; >> + >> + mask = msi_readl(msi, MSI_INTMASK); >> + mask |= 1 << data->hwirq; >> + msi_writel(msi, mask, MSI_INTMASK); > > It feels a bit weird to unmask the interrupt when you compose the > message. I'd expect this to be done in the mask/unmask methods. Do you refer to these 2 callbacks? .irq_mask = pci_msi_mask_irq, .irq_unmask = pci_msi_unmask_irq, How about we move this INTMASK code above to altera_irq_domain_alloc()? We have unmask code in altera_irq_domain_free() now. > >> + dev_dbg(&msi->pdev->dev, "msi#%d address_lo 0x%x\n", (int)data->hwirq, >> + msg->address_lo); > > You may want to print the whole address here. Noted. > >> +} >> + >> +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; >> + int bit; >> + >> + mutex_lock(&msi->lock); >> + >> + bit = find_first_zero_bit(msi->used, msi->num_of_vectors); >> + if (bit < msi->num_of_vectors) >> + set_bit(bit, msi->used); >> + >> + mutex_unlock(&msi->lock); >> + >> + if (bit < 0) >> + return bit; > > How can "bit" be negative here? find_first_zero_bit returns an unsigned > long... You probably want to change the type of "bit" to reflect that. Okay, will change to "unsigned long" type. > >> + else if (bit >= msi->num_of_vectors) > > Useless "else" anyway. I think we still need to check for failing case, if we don't have available unused bit. This could be rewritten as below: bit = find_first_zero_bit(msi->used, msi->num_of_vectors); if (bit < msi->num_of_vectors) set_bit(bit, msi->used); else return -ENOSPC; > >> + return -ENOSPC; >> + >> + 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); >> + >> + 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); > > Put this statement in { } so that it matches the "else" construct. Noted. > >> + else { >> + clear_bit(d->hwirq, msi->used); > > No need for an atomic operation here, you own the mutex. Okay, change to __clear_bit. > >> + 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, > > Please put at least one argument to the function on the same line. This > is otherwise very hard to read. Okay. > >> + &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; >> +} >> + >> +int altera_msi_probe(struct platform_device *pdev) > > Make this static. Okay. > >> +{ >> + 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"); >> + msi->csr_base = devm_ioremap_resource(&pdev->dev, res); >> + if (IS_ERR(msi->csr_base)) { >> + dev_err(&pdev->dev, "get csr resource failed\n"); >> + return PTR_ERR(msi->csr_base); >> + } >> + >> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, >> + "vector_slave"); >> + msi->vector_base = devm_ioremap_resource(&pdev->dev, res); >> + if (IS_ERR(msi->vector_base)) { >> + dev_err(&pdev->dev, "get vector slave resource failed\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(msi->irq, altera_msi_isr); >> + ret = irq_set_handler_data(msi->irq, msi); > > Use irq_set_chained_handler_and_data. Okay. > >> + if (ret) { >> + dev_err(&pdev->dev, "failed to register IRQ handler: %d\n", >> + ret); >> + goto err; >> + } >> + >> + 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 }, >> + { }, >> +}; >> +MODULE_DEVICE_TABLE(of, altera_msi_of_match); >> + >> +static struct platform_driver altera_msi_driver = { >> + .driver = { >> + .name = "altera-msi", >> + .owner = THIS_MODULE, > > Remove this .owner assignment, the core code deals with it. Okay. > >> + .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); > > Hmmm. if you're initializing this as part of the core kernel, it will > never be a module. What is the point of the MODULE_DEVICE_TABLE above? Okay, will remove MODULE_DEVICE_TABLE. Thanks for reviewing. Regards Ley Foon -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
