| Message ID | 1395397968-6242-3-git-send-email-phil.edworthy@renesas.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Am Freitag, den 21.03.2014, 10:32 +0000 schrieb Phil Edworthy: > Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com> > --- > drivers/pci/host/pcie-rcar.c | 232 ++++++++++++++++++++++++++++++++++++++++++- > drivers/pci/host/pcie-rcar.h | 5 + > 2 files changed, 236 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/host/pcie-rcar.c b/drivers/pci/host/pcie-rcar.c > index 16670e5..cbbcd77 100644 > --- a/drivers/pci/host/pcie-rcar.c > +++ b/drivers/pci/host/pcie-rcar.c [...] > + > +static irqreturn_t rcar_pcie_msi_irq(int irq, void *data) > +{ > + struct rcar_pcie *pcie = data; > + struct rcar_msi *msi = &pcie->msi; > + unsigned long reg; > + > + reg = pci_read_reg(pcie, PCIEMSIFR); > + > + while (reg) { > + unsigned int index = find_first_bit(®, 32); > + unsigned int irq; > + > + /* clear the interrupt */ > + pci_write_reg(pcie, 1 << index, PCIEMSIFR); > + > + irq = irq_find_mapping(msi->domain, index); > + if (irq) { > + if (test_bit(index, msi->used)) > + generic_handle_irq(irq); > + else > + dev_info(pcie->dev, "unhandled MSI\n"); > + } else { > + /* > + * that's weird who triggered this? > + * just clear it > + */ > + dev_info(pcie->dev, "unexpected MSI\n"); > + } > + > + /* see if there's any more pending in this vector */ > + reg = pci_read_reg(pcie, PCIEMSIFR); > + } > + > + return IRQ_HANDLED; > +} > + From your DT binding it seems you have only one interrupt from the PCIe core, shared between the MSI irqs and the PCI legacy interrupts. This means this handler may get called without an MSI irq pending, so this function really should have a path where it's returning IRQ_NONE. Regards, Lucas
Hi Lucas, Thanks for the review. On 21/03/2014 11:18, Lucas wrote: > Subject: Re: [PATCH v4 2/9] PCI: host: rcar: Add MSI support > > Am Freitag, den 21.03.2014, 10:32 +0000 schrieb Phil Edworthy: > > Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com> > > --- > > drivers/pci/host/pcie-rcar.c | 232 ++++++++++++++++++++++++++++++++++++++++++- > > drivers/pci/host/pcie-rcar.h | 5 + > > 2 files changed, 236 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/pci/host/pcie-rcar.c b/drivers/pci/host/pcie-rcar.c > > index 16670e5..cbbcd77 100644 > > --- a/drivers/pci/host/pcie-rcar.c > > +++ b/drivers/pci/host/pcie-rcar.c > [...] > > + > > +static irqreturn_t rcar_pcie_msi_irq(int irq, void *data) > > +{ > > + struct rcar_pcie *pcie = data; > > + struct rcar_msi *msi = &pcie->msi; > > + unsigned long reg; > > + > > + reg = pci_read_reg(pcie, PCIEMSIFR); > > + > > + while (reg) { > > + unsigned int index = find_first_bit(®, 32); > > + unsigned int irq; > > + > > + /* clear the interrupt */ > > + pci_write_reg(pcie, 1 << index, PCIEMSIFR); > > + > > + irq = irq_find_mapping(msi->domain, index); > > + if (irq) { > > + if (test_bit(index, msi->used)) > > + generic_handle_irq(irq); > > + else > > + dev_info(pcie->dev, "unhandled MSI\n"); > > + } else { > > + /* > > + * that's weird who triggered this? > > + * just clear it > > + */ > > + dev_info(pcie->dev, "unexpected MSI\n"); > > + } > > + > > + /* see if there's any more pending in this vector */ > > + reg = pci_read_reg(pcie, PCIEMSIFR); > > + } > > + > > + return IRQ_HANDLED; > > +} > > + > From your DT binding it seems you have only one interrupt from the PCIe > core, shared between the MSI irqs and the PCI legacy interrupts. > This means this handler may get called without an MSI irq pending, so > this function really should have a path where it's returning IRQ_NONE. Ah, yes you are right... though actually there are two interrupts, one has some MSI and INTx, the other has the rest of the MSIs. > Regards, > Lucas > > -- > Pengutronix e.K. | Lucas Stach | > Industrial Linux Solutions | http://www.pengutronix.de/ | > Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-5076 | > Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | > Thanks Phil
Am Freitag, den 21.03.2014, 14:15 +0000 schrieb Phil.Edworthy@renesas.com: > Hi Lucas, > > Thanks for the review. > > On 21/03/2014 11:18, Lucas wrote: > > Subject: Re: [PATCH v4 2/9] PCI: host: rcar: Add MSI support > > > > Am Freitag, den 21.03.2014, 10:32 +0000 schrieb Phil Edworthy: > > > Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com> > > > --- > > > drivers/pci/host/pcie-rcar.c | 232 > ++++++++++++++++++++++++++++++++++++++++++- > > > drivers/pci/host/pcie-rcar.h | 5 + > > > 2 files changed, 236 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/pci/host/pcie-rcar.c > b/drivers/pci/host/pcie-rcar.c > > > index 16670e5..cbbcd77 100644 > > > --- a/drivers/pci/host/pcie-rcar.c > > > +++ b/drivers/pci/host/pcie-rcar.c > > [...] > > > + > > > +static irqreturn_t rcar_pcie_msi_irq(int irq, void *data) > > > +{ > > > + struct rcar_pcie *pcie = data; > > > + struct rcar_msi *msi = &pcie->msi; > > > + unsigned long reg; > > > + > > > + reg = pci_read_reg(pcie, PCIEMSIFR); > > > + > > > + while (reg) { > > > + unsigned int index = find_first_bit(®, 32); > > > + unsigned int irq; > > > + > > > + /* clear the interrupt */ > > > + pci_write_reg(pcie, 1 << index, PCIEMSIFR); > > > + > > > + irq = irq_find_mapping(msi->domain, index); > > > + if (irq) { > > > + if (test_bit(index, msi->used)) > > > + generic_handle_irq(irq); > > > + else > > > + dev_info(pcie->dev, "unhandled MSI\n"); > > > + } else { > > > + /* > > > + * that's weird who triggered this? > > > + * just clear it > > > + */ > > > + dev_info(pcie->dev, "unexpected MSI\n"); > > > + } > > > + > > > + /* see if there's any more pending in this vector */ > > > + reg = pci_read_reg(pcie, PCIEMSIFR); > > > + } > > > + > > > + return IRQ_HANDLED; > > > +} > > > + > > From your DT binding it seems you have only one interrupt from the PCIe > > core, shared between the MSI irqs and the PCI legacy interrupts. > > This means this handler may get called without an MSI irq pending, so > > this function really should have a path where it's returning IRQ_NONE. > Ah, yes you are right... though actually there are two interrupts, one has > some MSI and INTx, the other has the rest of the MSIs. > This isn't reflected in the DT binding. If you already know that there may be more than a single interrupt for MSI, please push this into the binding by using named interrupts. Even if your driver doesn't support it yet, additional functionality can always be added later, but the DT should be a stable ABI describing your hardware. So if you already know your hardware has more than one interrupt, please put it in the binding, to avoid churn later on. Regards, Lucas
Hi Lucas, On 21/03/2014 14:27, Lucas wrote: > Subject: Re: [PATCH v4 2/9] PCI: host: rcar: Add MSI support > > Am Freitag, den 21.03.2014, 14:15 +0000 schrieb > Phil.Edworthy@renesas.com: > > Hi Lucas, > > > > Thanks for the review. > > > > On 21/03/2014 11:18, Lucas wrote: > > > Subject: Re: [PATCH v4 2/9] PCI: host: rcar: Add MSI support > > > > > > Am Freitag, den 21.03.2014, 10:32 +0000 schrieb Phil Edworthy: > > > > Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com> > > > > --- > > > > drivers/pci/host/pcie-rcar.c | 232 > > ++++++++++++++++++++++++++++++++++++++++++- > > > > drivers/pci/host/pcie-rcar.h | 5 + > > > > 2 files changed, 236 insertions(+), 1 deletion(-) > > > > > > > > diff --git a/drivers/pci/host/pcie-rcar.c > > b/drivers/pci/host/pcie-rcar.c > > > > index 16670e5..cbbcd77 100644 > > > > --- a/drivers/pci/host/pcie-rcar.c > > > > +++ b/drivers/pci/host/pcie-rcar.c > > > [...] > > > > + > > > > +static irqreturn_t rcar_pcie_msi_irq(int irq, void *data) > > > > +{ > > > > + struct rcar_pcie *pcie = data; > > > > + struct rcar_msi *msi = &pcie->msi; > > > > + unsigned long reg; > > > > + > > > > + reg = pci_read_reg(pcie, PCIEMSIFR); > > > > + > > > > + while (reg) { > > > > + unsigned int index = find_first_bit(®, 32); > > > > + unsigned int irq; > > > > + > > > > + /* clear the interrupt */ > > > > + pci_write_reg(pcie, 1 << index, PCIEMSIFR); > > > > + > > > > + irq = irq_find_mapping(msi->domain, index); > > > > + if (irq) { > > > > + if (test_bit(index, msi->used)) > > > > + generic_handle_irq(irq); > > > > + else > > > > + dev_info(pcie->dev, "unhandled MSI\n"); > > > > + } else { > > > > + /* > > > > + * that's weird who triggered this? > > > > + * just clear it > > > > + */ > > > > + dev_info(pcie->dev, "unexpected MSI\n"); > > > > + } > > > > + > > > > + /* see if there's any more pending in this vector */ > > > > + reg = pci_read_reg(pcie, PCIEMSIFR); > > > > + } > > > > + > > > > + return IRQ_HANDLED; > > > > +} > > > > + > > > From your DT binding it seems you have only one interrupt from the PCIe > > > core, shared between the MSI irqs and the PCI legacy interrupts. > > > This means this handler may get called without an MSI irq pending, so > > > this function really should have a path where it's returning IRQ_NONE. > > Ah, yes you are right... though actually there are two interrupts, one has > > some MSI and INTx, the other has the rest of the MSIs. > > > This isn't reflected in the DT binding. If you already know that there > may be more than a single interrupt for MSI, please push this into the > binding by using named interrupts. Even if your driver doesn't support > it yet, additional functionality can always be added later, but the DT > should be a stable ABI describing your hardware. > > So if you already know your hardware has more than one interrupt, please > put it in the binding, to avoid churn later on. At the moment we support both interrupts but the code implicitly gets the 'next' interrupt for MSI. I'll change that so that all the interrupts are specified in the binding. > Regards, > Lucas > -- > Pengutronix e.K. | Lucas Stach | > Industrial Linux Solutions | http://www.pengutronix.de/ | > Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-5076 | > Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | > Thanks Phil
diff --git a/drivers/pci/host/pcie-rcar.c b/drivers/pci/host/pcie-rcar.c index 16670e5..cbbcd77 100644 --- a/drivers/pci/host/pcie-rcar.c +++ b/drivers/pci/host/pcie-rcar.c @@ -15,8 +15,11 @@ #include <linux/clk.h> #include <linux/delay.h> #include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/irqdomain.h> #include <linux/kernel.h> #include <linux/module.h> +#include <linux/msi.h> #include <linux/of_address.h> #include <linux/of_irq.h> #include <linux/of_pci.h> @@ -33,6 +36,8 @@ enum chip_id { RCAR_H1, }; +#define INT_PCI_MSI_NR 32 + #define RCONF(x) (PCICONF(0)+(x)) #define RPMCAP(x) (PMCAP(0)+(x)) #define REXPCAP(x) (EXPCAP(0)+(x)) @@ -52,6 +57,20 @@ static const struct of_device_id rcar_pcie_of_match[] = { }; MODULE_DEVICE_TABLE(of, rcar_pcie_of_match); +struct rcar_msi { + DECLARE_BITMAP(used, INT_PCI_MSI_NR); + struct irq_domain *domain; + struct msi_chip chip; + unsigned long pages; + struct mutex lock; + int irq; +}; + +static inline struct rcar_msi *to_rcar_msi(struct msi_chip *chip) +{ + return container_of(chip, struct rcar_msi, chip); +} + /* Structure representing the PCIe interface */ struct rcar_pcie { struct device *dev; @@ -61,6 +80,7 @@ struct rcar_pcie { enum chip_id chip; u8 root_bus_nr; struct clk *clk; + struct rcar_msi msi; }; static inline struct rcar_pcie *sys_to_pcie(struct pci_sys_data *sys) @@ -312,6 +332,15 @@ static int rcar_pcie_setup(int nr, struct pci_sys_data *sys) return 1; } +static void rcar_pcie_add_bus(struct pci_bus *bus) +{ + if (IS_ENABLED(CONFIG_PCI_MSI)) { + struct rcar_pcie *pcie = sys_to_pcie(bus->sysdata); + + bus->msi = &pcie->msi.chip; + } +} + static void __init rcar_pcie_enable(struct rcar_pcie *pcie) { struct platform_device *pdev = to_platform_device(pcie->dev); @@ -324,6 +353,7 @@ static void __init rcar_pcie_enable(struct rcar_pcie *pcie) hw.setup = rcar_pcie_setup, hw.map_irq = of_irq_parse_and_map_pci, hw.ops = &rcar_pcie_ops, + hw.add_bus = rcar_pcie_add_bus; pci_common_init_dev(&pdev->dev, &hw); } @@ -478,6 +508,10 @@ static void __init rcar_pcie_hw_init(struct rcar_pcie *pcie) /* Enable MAC data scrambling. */ rcar_rmw32(pcie, MACCTLR, SCRAMBLE_DISABLE, 0); + /* Enable MSI */ + if (IS_ENABLED(CONFIG_PCI_MSI)) + pci_write_reg(pcie, 0x101f0000, PCIEMSITXR); + /* Finish initialization - establish a PCI Express link */ pci_write_reg(pcie, CFINIT, PCIETCTLR); @@ -495,11 +529,190 @@ static void __init rcar_pcie_hw_init(struct rcar_pcie *pcie) wmb(); } +static int rcar_msi_alloc(struct rcar_msi *chip) +{ + int msi; + + mutex_lock(&chip->lock); + + msi = find_first_zero_bit(chip->used, INT_PCI_MSI_NR); + if (msi < INT_PCI_MSI_NR) + set_bit(msi, chip->used); + else + msi = -ENOSPC; + + mutex_unlock(&chip->lock); + + return msi; +} + +static void rcar_msi_free(struct rcar_msi *chip, unsigned long irq) +{ + struct device *dev = chip->chip.dev; + + mutex_lock(&chip->lock); + + if (!test_bit(irq, chip->used)) + dev_err(dev, "trying to free unused MSI#%lu\n", irq); + else + clear_bit(irq, chip->used); + + mutex_unlock(&chip->lock); +} + +static irqreturn_t rcar_pcie_msi_irq(int irq, void *data) +{ + struct rcar_pcie *pcie = data; + struct rcar_msi *msi = &pcie->msi; + unsigned long reg; + + reg = pci_read_reg(pcie, PCIEMSIFR); + + while (reg) { + unsigned int index = find_first_bit(®, 32); + unsigned int irq; + + /* clear the interrupt */ + pci_write_reg(pcie, 1 << index, PCIEMSIFR); + + irq = irq_find_mapping(msi->domain, index); + if (irq) { + if (test_bit(index, msi->used)) + generic_handle_irq(irq); + else + dev_info(pcie->dev, "unhandled MSI\n"); + } else { + /* + * that's weird who triggered this? + * just clear it + */ + dev_info(pcie->dev, "unexpected MSI\n"); + } + + /* see if there's any more pending in this vector */ + reg = pci_read_reg(pcie, PCIEMSIFR); + } + + return IRQ_HANDLED; +} + +static int rcar_msi_setup_irq(struct msi_chip *chip, struct pci_dev *pdev, + struct msi_desc *desc) +{ + struct rcar_msi *msi = to_rcar_msi(chip); + struct rcar_pcie *pcie = container_of(chip, struct rcar_pcie, msi.chip); + struct msi_msg msg; + unsigned int irq; + int hwirq; + + hwirq = rcar_msi_alloc(msi); + if (hwirq < 0) + return hwirq; + + irq = irq_create_mapping(msi->domain, hwirq); + if (!irq) { + rcar_msi_free(msi, hwirq); + return -EINVAL; + } + + irq_set_msi_desc(irq, desc); + + msg.address_lo = pci_read_reg(pcie, PCIEMSIALR) & ~MSIFE; + msg.address_hi = pci_read_reg(pcie, PCIEMSIAUR); + msg.data = hwirq; + + write_msi_msg(irq, &msg); + + return 0; +} + +static void rcar_msi_teardown_irq(struct msi_chip *chip, unsigned int irq) +{ + struct rcar_msi *msi = to_rcar_msi(chip); + struct irq_data *d = irq_get_irq_data(irq); + + rcar_msi_free(msi, d->hwirq); +} + +static struct irq_chip rcar_msi_irq_chip = { + .name = "R-Car PCIe MSI", + .irq_enable = unmask_msi_irq, + .irq_disable = mask_msi_irq, + .irq_mask = mask_msi_irq, + .irq_unmask = unmask_msi_irq, +}; + +static int rcar_msi_map(struct irq_domain *domain, unsigned int irq, + irq_hw_number_t hwirq) +{ + irq_set_chip_and_handler(irq, &rcar_msi_irq_chip, handle_simple_irq); + irq_set_chip_data(irq, domain->host_data); + set_irq_flags(irq, IRQF_VALID); + + return 0; +} + +static const struct irq_domain_ops msi_domain_ops = { + .map = rcar_msi_map, +}; + +static int rcar_pcie_enable_msi(struct rcar_pcie *pcie) +{ + struct platform_device *pdev = to_platform_device(pcie->dev); + struct rcar_msi *msi = &pcie->msi; + unsigned long base; + int err; + + mutex_init(&msi->lock); + + msi->chip.dev = pcie->dev; + msi->chip.setup_irq = rcar_msi_setup_irq; + msi->chip.teardown_irq = rcar_msi_teardown_irq; + + msi->domain = irq_domain_add_linear(pcie->dev->of_node, INT_PCI_MSI_NR, + &msi_domain_ops, &msi->chip); + if (!msi->domain) { + dev_err(&pdev->dev, "failed to create IRQ domain\n"); + return -ENOMEM; + } + + /* Two irqs are for MSI, but they are also used for non-MSI irqs */ + err = devm_request_irq(&pdev->dev, msi->irq, rcar_pcie_msi_irq, + IRQF_SHARED, rcar_msi_irq_chip.name, pcie); + if (err < 0) { + dev_err(&pdev->dev, "failed to request IRQ: %d\n", err); + goto err; + } + + err = devm_request_irq(&pdev->dev, msi->irq+1, rcar_pcie_msi_irq, + IRQF_SHARED, rcar_msi_irq_chip.name, pcie); + if (err < 0) { + dev_err(&pdev->dev, "failed to request IRQ: %d\n", err); + goto err; + } + + /* setup MSI data target */ + msi->pages = __get_free_pages(GFP_KERNEL, 0); + base = virt_to_phys((void *)msi->pages); + + pci_write_reg(pcie, base | MSIFE, PCIEMSIALR); + pci_write_reg(pcie, 0, PCIEMSIAUR); + + /* enable all MSI interrupts */ + pci_write_reg(pcie, 0xffffffff, PCIEMSIIER); + + return 0; + +err: + irq_domain_remove(msi->domain); + return err; +} + static int __init rcar_pcie_get_resources(struct platform_device *pdev, struct rcar_pcie *pcie) { struct resource res; - int err; + int err, i; err = of_address_to_resource(pdev->dev.of_node, 0, &res); if (err) @@ -511,6 +724,13 @@ static int __init rcar_pcie_get_resources(struct platform_device *pdev, return PTR_ERR(pcie->clk); } + i = irq_of_parse_and_map(pdev->dev.of_node, 0); + if (i < 0) { + dev_err(pcie->dev, "cannot get platform resources for msi interrupt\n"); + return -ENOENT; + } + pcie->msi.irq = i; + clk_prepare_enable(pcie->clk); pcie->base = devm_ioremap_resource(&pdev->dev, &res); @@ -566,6 +786,16 @@ static int __init rcar_pcie_probe(struct platform_device *pdev) break; } + if (IS_ENABLED(CONFIG_PCI_MSI)) { + err = rcar_pcie_enable_msi(pcie); + if (err < 0) { + dev_err(&pdev->dev, + "failed to enable MSI support: %d\n", + err); + return err; + } + } + rcar_pcie_hw_init(pcie); if (!pcie->haslink) { diff --git a/drivers/pci/host/pcie-rcar.h b/drivers/pci/host/pcie-rcar.h index 3dc026b..4f0c678 100644 --- a/drivers/pci/host/pcie-rcar.h +++ b/drivers/pci/host/pcie-rcar.h @@ -13,6 +13,7 @@ #define PCIEMSR 0x000028 #define PCIEINTXR 0x000400 #define PCIEPHYSR 0x0007f0 +#define PCIEMSITXR 0x000840 /* Transfer control */ #define PCIETCTLR 0x02000 @@ -28,6 +29,10 @@ #define PCIEPMSR 0x02034 #define PCIEPMSCIER 0x02038 #define PCIEMSIFR 0x02044 +#define PCIEMSIALR 0x02048 +#define MSIFE 1 +#define PCIEMSIAUR 0x0204c +#define PCIEMSIIER 0x02050 /* root port address */ #define PCIEPRAR(x) (0x02080 + ((x) * 0x4))
Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com> --- drivers/pci/host/pcie-rcar.c | 232 ++++++++++++++++++++++++++++++++++++++++++- drivers/pci/host/pcie-rcar.h | 5 + 2 files changed, 236 insertions(+), 1 deletion(-)