From f342d940ee0e3a2b5197fd4fbade1cb6bbc960b7 Mon Sep 17 00:00:00 2001 From: Jingoo Han Date: Fri, 6 Sep 2013 15:54:59 +0900 Subject: [PATCH] PCI: exynos: Add support for MSI This patch adds support for Message Signaled Interrupt in the Exynos PCIe driver using Synopsys designware PCIe core IP. Signed-off-by: Siva Reddy Kallam Signed-off-by: Srikanth T Shivanand Signed-off-by: Jingoo Han Signed-off-by: Bjorn Helgaas Cc: Pratyush Anand Cc: Mohit KUMAR --- drivers/pci/host/pci-exynos.c | 44 ++++++ drivers/pci/host/pcie-designware.c | 240 +++++++++++++++++++++++++++++ drivers/pci/host/pcie-designware.h | 14 ++ 3 files changed, 298 insertions(+) diff --git a/drivers/pci/host/pci-exynos.c b/drivers/pci/host/pci-exynos.c index 94e096bb2d0a..f062acaf052a 100644 --- a/drivers/pci/host/pci-exynos.c +++ b/drivers/pci/host/pci-exynos.c @@ -48,6 +48,7 @@ struct exynos_pcie { #define PCIE_IRQ_SPECIAL 0x008 #define PCIE_IRQ_EN_PULSE 0x00c #define PCIE_IRQ_EN_LEVEL 0x010 +#define IRQ_MSI_ENABLE (0x1 << 2) #define PCIE_IRQ_EN_SPECIAL 0x014 #define PCIE_PWR_RESET 0x018 #define PCIE_CORE_RESET 0x01c @@ -342,9 +343,36 @@ static irqreturn_t exynos_pcie_irq_handler(int irq, void *arg) return IRQ_HANDLED; } +static irqreturn_t exynos_pcie_msi_irq_handler(int irq, void *arg) +{ + struct pcie_port *pp = arg; + + dw_handle_msi_irq(pp); + + return IRQ_HANDLED; +} + +static void exynos_pcie_msi_init(struct pcie_port *pp) +{ + u32 val; + struct exynos_pcie *exynos_pcie = to_exynos_pcie(pp); + + dw_pcie_msi_init(pp); + + /* enable MSI interrupt */ + val = exynos_elb_readl(exynos_pcie, PCIE_IRQ_EN_LEVEL); + val |= IRQ_MSI_ENABLE; + exynos_elb_writel(exynos_pcie, val, PCIE_IRQ_EN_LEVEL); + return; +} + static void exynos_pcie_enable_interrupts(struct pcie_port *pp) { exynos_pcie_enable_irq_pulse(pp); + + if (IS_ENABLED(CONFIG_PCI_MSI)) + exynos_pcie_msi_init(pp); + return; } @@ -430,6 +458,22 @@ static int add_pcie_port(struct pcie_port *pp, struct platform_device *pdev) return ret; } + if (IS_ENABLED(CONFIG_PCI_MSI)) { + pp->msi_irq = platform_get_irq(pdev, 0); + if (!pp->msi_irq) { + dev_err(&pdev->dev, "failed to get msi irq\n"); + return -ENODEV; + } + + ret = devm_request_irq(&pdev->dev, pp->msi_irq, + exynos_pcie_msi_irq_handler, + IRQF_SHARED, "exynos-pcie", pp); + if (ret) { + dev_err(&pdev->dev, "failed to request msi irq\n"); + return ret; + } + } + pp->root_bus_nr = -1; pp->ops = &exynos_pcie_host_ops; diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c index c10e9ac9bbbc..896301788e9d 100644 --- a/drivers/pci/host/pcie-designware.c +++ b/drivers/pci/host/pcie-designware.c @@ -11,8 +11,11 @@ * published by the Free Software Foundation. */ +#include +#include #include #include +#include #include #include #include @@ -142,6 +145,204 @@ int dw_pcie_wr_own_conf(struct pcie_port *pp, int where, int size, return ret; } +static struct irq_chip dw_msi_irq_chip = { + .name = "PCI-MSI", + .irq_enable = unmask_msi_irq, + .irq_disable = mask_msi_irq, + .irq_mask = mask_msi_irq, + .irq_unmask = unmask_msi_irq, +}; + +/* MSI int handler */ +void dw_handle_msi_irq(struct pcie_port *pp) +{ + unsigned long val; + int i, pos; + + for (i = 0; i < MAX_MSI_CTRLS; i++) { + dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_STATUS + i * 12, 4, + (u32 *)&val); + if (val) { + pos = 0; + while ((pos = find_next_bit(&val, 32, pos)) != 32) { + generic_handle_irq(pp->msi_irq_start + + (i * 32) + pos); + pos++; + } + } + dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_STATUS + i * 12, 4, val); + } +} + +void dw_pcie_msi_init(struct pcie_port *pp) +{ + pp->msi_data = __get_free_pages(GFP_KERNEL, 0); + + /* program the msi_data */ + dw_pcie_wr_own_conf(pp, PCIE_MSI_ADDR_LO, 4, + virt_to_phys((void *)pp->msi_data)); + dw_pcie_wr_own_conf(pp, PCIE_MSI_ADDR_HI, 4, 0); +} + +static int find_valid_pos0(struct pcie_port *pp, int msgvec, int pos, int *pos0) +{ + int flag = 1; + + do { + pos = find_next_zero_bit(pp->msi_irq_in_use, + MAX_MSI_IRQS, pos); + /*if you have reached to the end then get out from here.*/ + if (pos == MAX_MSI_IRQS) + return -ENOSPC; + /* + * Check if this position is at correct offset.nvec is always a + * power of two. pos0 must be nvec bit alligned. + */ + if (pos % msgvec) + pos += msgvec - (pos % msgvec); + else + flag = 0; + } while (flag); + + *pos0 = pos; + return 0; +} + +static int assign_irq(int no_irqs, struct msi_desc *desc, int *pos) +{ + int res, bit, irq, pos0, pos1, i; + u32 val; + struct pcie_port *pp = sys_to_pcie(desc->dev->bus->sysdata); + + if (!pp) { + BUG(); + return -EINVAL; + } + + pos0 = find_first_zero_bit(pp->msi_irq_in_use, + MAX_MSI_IRQS); + if (pos0 % no_irqs) { + if (find_valid_pos0(pp, no_irqs, pos0, &pos0)) + goto no_valid_irq; + } + if (no_irqs > 1) { + pos1 = find_next_bit(pp->msi_irq_in_use, + MAX_MSI_IRQS, pos0); + /* there must be nvec number of consecutive free bits */ + while ((pos1 - pos0) < no_irqs) { + if (find_valid_pos0(pp, no_irqs, pos1, &pos0)) + goto no_valid_irq; + pos1 = find_next_bit(pp->msi_irq_in_use, + MAX_MSI_IRQS, pos0); + } + } + + irq = (pp->msi_irq_start + pos0); + + if ((irq + no_irqs) > (pp->msi_irq_start + MAX_MSI_IRQS-1)) + goto no_valid_irq; + + i = 0; + while (i < no_irqs) { + set_bit(pos0 + i, pp->msi_irq_in_use); + irq_alloc_descs((irq + i), (irq + i), 1, 0); + irq_set_msi_desc(irq + i, desc); + /*Enable corresponding interrupt in MSI interrupt controller */ + res = ((pos0 + i) / 32) * 12; + bit = (pos0 + i) % 32; + dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4, &val); + val |= 1 << bit; + dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4, val); + i++; + } + + *pos = pos0; + return irq; + +no_valid_irq: + *pos = pos0; + return -ENOSPC; +} + +static void clear_irq(unsigned int irq) +{ + int res, bit, val, pos; + struct irq_desc *desc; + struct msi_desc *msi; + struct pcie_port *pp; + + /* get the port structure */ + desc = irq_to_desc(irq); + msi = irq_desc_get_msi_desc(desc); + pp = sys_to_pcie(msi->dev->bus->sysdata); + if (!pp) { + BUG(); + return; + } + + pos = irq - pp->msi_irq_start; + + irq_free_desc(irq); + + clear_bit(pos, pp->msi_irq_in_use); + + /* Disable corresponding interrupt on MSI interrupt controller */ + res = (pos / 32) * 12; + bit = pos % 32; + dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4, &val); + val &= ~(1 << bit); + dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4, val); +} + +static int dw_msi_setup_irq(struct msi_chip *chip, struct pci_dev *pdev, + struct msi_desc *desc) +{ + int irq, pos, msgvec; + u16 msg_ctr; + struct msi_msg msg; + struct pcie_port *pp = sys_to_pcie(pdev->bus->sysdata); + + if (!pp) { + BUG(); + return -EINVAL; + } + + pci_read_config_word(pdev, desc->msi_attrib.pos+PCI_MSI_FLAGS, + &msg_ctr); + msgvec = (msg_ctr&PCI_MSI_FLAGS_QSIZE) >> 4; + if (msgvec == 0) + msgvec = (msg_ctr & PCI_MSI_FLAGS_QMASK) >> 1; + if (msgvec > 5) + msgvec = 0; + + irq = assign_irq((1 << msgvec), desc, &pos); + if (irq < 0) + return irq; + + msg_ctr &= ~PCI_MSI_FLAGS_QSIZE; + msg_ctr |= msgvec << 4; + pci_write_config_word(pdev, desc->msi_attrib.pos + PCI_MSI_FLAGS, + msg_ctr); + desc->msi_attrib.multiple = msgvec; + + msg.address_lo = virt_to_phys((void *)pp->msi_data); + msg.address_hi = 0x0; + msg.data = pos; + write_msi_msg(irq, &msg); + + return 0; +} + +static void dw_msi_teardown_irq(struct msi_chip *chip, unsigned int irq) +{ + clear_irq(irq); +} + +static struct msi_chip dw_pcie_msi_chip = { + .setup_irq = dw_msi_setup_irq, + .teardown_irq = dw_msi_teardown_irq, +}; + int dw_pcie_link_up(struct pcie_port *pp) { if (pp->ops->link_up) @@ -150,6 +351,20 @@ int dw_pcie_link_up(struct pcie_port *pp) return 0; } +static int dw_pcie_msi_map(struct irq_domain *domain, unsigned int irq, + irq_hw_number_t hwirq) +{ + irq_set_chip_and_handler(irq, &dw_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 = dw_pcie_msi_map, +}; + int __init dw_pcie_host_init(struct pcie_port *pp) { struct device_node *np = pp->dev->of_node; @@ -157,6 +372,8 @@ int __init dw_pcie_host_init(struct pcie_port *pp) struct of_pci_range_parser parser; u32 val; + struct irq_domain *irq_domain; + if (of_pci_range_parser_init(&parser, np)) { dev_err(pp->dev, "missing ranges property\n"); return -EINVAL; @@ -223,6 +440,18 @@ int __init dw_pcie_host_init(struct pcie_port *pp) return -EINVAL; } + if (IS_ENABLED(CONFIG_PCI_MSI)) { + irq_domain = irq_domain_add_linear(pp->dev->of_node, + MAX_MSI_IRQS, &msi_domain_ops, + &dw_pcie_msi_chip); + if (!irq_domain) { + dev_err(pp->dev, "irq domain init failed\n"); + return -ENXIO; + } + + pp->msi_irq_start = irq_find_mapping(irq_domain, 0); + } + if (pp->ops->host_init) pp->ops->host_init(pp); @@ -485,10 +714,21 @@ int dw_pcie_map_irq(const struct pci_dev *dev, u8 slot, u8 pin) return pp->irq; } +static void dw_pcie_add_bus(struct pci_bus *bus) +{ + if (IS_ENABLED(CONFIG_PCI_MSI)) { + struct pcie_port *pp = sys_to_pcie(bus->sysdata); + + dw_pcie_msi_chip.dev = pp->dev; + bus->msi = &dw_pcie_msi_chip; + } +} + static struct hw_pci dw_pci = { .setup = dw_pcie_setup, .scan = dw_pcie_scan_bus, .map_irq = dw_pcie_map_irq, + .add_bus = dw_pcie_add_bus, }; void dw_pcie_setup_rc(struct pcie_port *pp) diff --git a/drivers/pci/host/pcie-designware.h b/drivers/pci/host/pcie-designware.h index 133820f1da97..faccbbf31907 100644 --- a/drivers/pci/host/pcie-designware.h +++ b/drivers/pci/host/pcie-designware.h @@ -20,6 +20,14 @@ struct pcie_port_info { phys_addr_t mem_bus_addr; }; +/* + * Maximum number of MSI IRQs can be 256 per controller. But keep + * it 32 as of now. Probably we will never need more than 32. If needed, + * then increment it in multiple of 32. + */ +#define MAX_MSI_IRQS 32 +#define MAX_MSI_CTRLS (MAX_MSI_IRQS / 32) + struct pcie_port { struct device *dev; u8 root_bus_nr; @@ -38,6 +46,10 @@ struct pcie_port { int irq; u32 lanes; struct pcie_host_ops *ops; + int msi_irq; + int msi_irq_start; + unsigned long msi_data; + DECLARE_BITMAP(msi_irq_in_use, MAX_MSI_IRQS); }; struct pcie_host_ops { @@ -57,6 +69,8 @@ int cfg_read(void __iomem *addr, int where, int size, u32 *val); int cfg_write(void __iomem *addr, int where, int size, u32 val); int dw_pcie_wr_own_conf(struct pcie_port *pp, int where, int size, u32 val); int dw_pcie_rd_own_conf(struct pcie_port *pp, int where, int size, u32 *val); +void dw_handle_msi_irq(struct pcie_port *pp); +void dw_pcie_msi_init(struct pcie_port *pp); int dw_pcie_link_up(struct pcie_port *pp); void dw_pcie_setup_rc(struct pcie_port *pp); int dw_pcie_host_init(struct pcie_port *pp); -- 2.20.1