diff options
author | Marc Gonzalez <marc_gonzalez@sigmadesigns.com> | 2017-09-26 13:27:39 +0300 |
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committer | Bjorn Helgaas <bhelgaas@google.com> | 2017-10-05 23:52:35 +0300 |
commit | d76bdce394bf48140cbb33b07509c32df1cef8e7 (patch) | |
tree | f2ee013ddbae88d1b2d9482f78ff7053ebeae2fb /drivers | |
parent | 1e61a57cac560844580ab532a4e2f5061ef77039 (diff) | |
download | linux-d76bdce394bf48140cbb33b07509c32df1cef8e7.tar.xz |
PCI: tango: Add MSI controller support
Add support for the MSI controller in Tango, which supports 256
message-signaled interrupts and a single doorbell address.
Signed-off-by: Marc Gonzalez <marc_gonzalez@sigmadesigns.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/pci/host/pcie-tango.c | 205 |
1 files changed, 202 insertions, 3 deletions
diff --git a/drivers/pci/host/pcie-tango.c b/drivers/pci/host/pcie-tango.c index 6bbb81f06a53..e23f7383ac33 100644 --- a/drivers/pci/host/pcie-tango.c +++ b/drivers/pci/host/pcie-tango.c @@ -1,12 +1,172 @@ +#include <linux/irqchip/chained_irq.h> +#include <linux/irqdomain.h> #include <linux/pci-ecam.h> #include <linux/delay.h> -#include <linux/of.h> +#include <linux/msi.h> +#include <linux/of_address.h> + +#define MSI_MAX 256 #define SMP8759_MUX 0x48 #define SMP8759_TEST_OUT 0x74 +#define SMP8759_DOORBELL 0x7c +#define SMP8759_STATUS 0x80 +#define SMP8759_ENABLE 0xa0 struct tango_pcie { - void __iomem *base; + DECLARE_BITMAP(used_msi, MSI_MAX); + u64 msi_doorbell; + spinlock_t used_msi_lock; + void __iomem *base; + struct irq_domain *dom; +}; + +static void tango_msi_isr(struct irq_desc *desc) +{ + struct irq_chip *chip = irq_desc_get_chip(desc); + struct tango_pcie *pcie = irq_desc_get_handler_data(desc); + unsigned long status, base, virq, idx, pos = 0; + + chained_irq_enter(chip, desc); + spin_lock(&pcie->used_msi_lock); + + while ((pos = find_next_bit(pcie->used_msi, MSI_MAX, pos)) < MSI_MAX) { + base = round_down(pos, 32); + status = readl_relaxed(pcie->base + SMP8759_STATUS + base / 8); + for_each_set_bit(idx, &status, 32) { + virq = irq_find_mapping(pcie->dom, base + idx); + generic_handle_irq(virq); + } + pos = base + 32; + } + + spin_unlock(&pcie->used_msi_lock); + chained_irq_exit(chip, desc); +} + +static void tango_ack(struct irq_data *d) +{ + struct tango_pcie *pcie = d->chip_data; + u32 offset = (d->hwirq / 32) * 4; + u32 bit = BIT(d->hwirq % 32); + + writel_relaxed(bit, pcie->base + SMP8759_STATUS + offset); +} + +static void update_msi_enable(struct irq_data *d, bool unmask) +{ + unsigned long flags; + struct tango_pcie *pcie = d->chip_data; + u32 offset = (d->hwirq / 32) * 4; + u32 bit = BIT(d->hwirq % 32); + u32 val; + + spin_lock_irqsave(&pcie->used_msi_lock, flags); + val = readl_relaxed(pcie->base + SMP8759_ENABLE + offset); + val = unmask ? val | bit : val & ~bit; + writel_relaxed(val, pcie->base + SMP8759_ENABLE + offset); + spin_unlock_irqrestore(&pcie->used_msi_lock, flags); +} + +static void tango_mask(struct irq_data *d) +{ + update_msi_enable(d, false); +} + +static void tango_unmask(struct irq_data *d) +{ + update_msi_enable(d, true); +} + +static int tango_set_affinity(struct irq_data *d, const struct cpumask *mask, + bool force) +{ + return -EINVAL; +} + +static void tango_compose_msi_msg(struct irq_data *d, struct msi_msg *msg) +{ + struct tango_pcie *pcie = d->chip_data; + msg->address_lo = lower_32_bits(pcie->msi_doorbell); + msg->address_hi = upper_32_bits(pcie->msi_doorbell); + msg->data = d->hwirq; +} + +static struct irq_chip tango_chip = { + .irq_ack = tango_ack, + .irq_mask = tango_mask, + .irq_unmask = tango_unmask, + .irq_set_affinity = tango_set_affinity, + .irq_compose_msi_msg = tango_compose_msi_msg, +}; + +static void msi_ack(struct irq_data *d) +{ + irq_chip_ack_parent(d); +} + +static void msi_mask(struct irq_data *d) +{ + pci_msi_mask_irq(d); + irq_chip_mask_parent(d); +} + +static void msi_unmask(struct irq_data *d) +{ + pci_msi_unmask_irq(d); + irq_chip_unmask_parent(d); +} + +static struct irq_chip msi_chip = { + .name = "MSI", + .irq_ack = msi_ack, + .irq_mask = msi_mask, + .irq_unmask = msi_unmask, +}; + +static struct msi_domain_info msi_dom_info = { + .flags = MSI_FLAG_PCI_MSIX + | MSI_FLAG_USE_DEF_DOM_OPS + | MSI_FLAG_USE_DEF_CHIP_OPS, + .chip = &msi_chip, +}; + +static int tango_irq_domain_alloc(struct irq_domain *dom, unsigned int virq, + unsigned int nr_irqs, void *args) +{ + struct tango_pcie *pcie = dom->host_data; + unsigned long flags; + int pos; + + spin_lock_irqsave(&pcie->used_msi_lock, flags); + pos = find_first_zero_bit(pcie->used_msi, MSI_MAX); + if (pos >= MSI_MAX) { + spin_unlock_irqrestore(&pcie->used_msi_lock, flags); + return -ENOSPC; + } + __set_bit(pos, pcie->used_msi); + spin_unlock_irqrestore(&pcie->used_msi_lock, flags); + irq_domain_set_info(dom, virq, pos, &tango_chip, + pcie, handle_edge_irq, NULL, NULL); + + return 0; +} + +static void tango_irq_domain_free(struct irq_domain *dom, unsigned int virq, + unsigned int nr_irqs) +{ + unsigned long flags; + struct irq_data *d = irq_domain_get_irq_data(dom, virq); + struct tango_pcie *pcie = d->chip_data; + + spin_lock_irqsave(&pcie->used_msi_lock, flags); + __clear_bit(d->hwirq, pcie->used_msi); + spin_unlock_irqrestore(&pcie->used_msi_lock, flags); +} + +static const struct irq_domain_ops dom_ops = { + .alloc = tango_irq_domain_alloc, + .free = tango_irq_domain_free, }; static int smp8759_config_read(struct pci_bus *bus, unsigned int devfn, @@ -76,7 +236,11 @@ static int tango_pcie_probe(struct platform_device *pdev) struct device *dev = &pdev->dev; struct tango_pcie *pcie; struct resource *res; - int ret; + struct fwnode_handle *fwnode = of_node_to_fwnode(dev->of_node); + struct irq_domain *msi_dom, *irq_dom; + struct of_pci_range_parser parser; + struct of_pci_range range; + int virq, offset; dev_warn(dev, "simultaneous PCI config and MMIO accesses may cause data corruption\n"); add_taint(TAINT_CRAP, LOCKDEP_STILL_OK); @@ -95,6 +259,41 @@ static int tango_pcie_probe(struct platform_device *pdev) if (!tango_pcie_link_up(pcie)) return -ENODEV; + if (of_pci_dma_range_parser_init(&parser, dev->of_node) < 0) + return -ENOENT; + + if (of_pci_range_parser_one(&parser, &range) == NULL) + return -ENOENT; + + range.pci_addr += range.size; + pcie->msi_doorbell = range.pci_addr + res->start + SMP8759_DOORBELL; + + for (offset = 0; offset < MSI_MAX / 8; offset += 4) + writel_relaxed(0, pcie->base + SMP8759_ENABLE + offset); + + virq = platform_get_irq(pdev, 1); + if (virq <= 0) { + dev_err(dev, "Failed to map IRQ\n"); + return -ENXIO; + } + + irq_dom = irq_domain_create_linear(fwnode, MSI_MAX, &dom_ops, pcie); + if (!irq_dom) { + dev_err(dev, "Failed to create IRQ domain\n"); + return -ENOMEM; + } + + msi_dom = pci_msi_create_irq_domain(fwnode, &msi_dom_info, irq_dom); + if (!msi_dom) { + dev_err(dev, "Failed to create MSI domain\n"); + irq_domain_remove(irq_dom); + return -ENOMEM; + } + + pcie->dom = irq_dom; + spin_lock_init(&pcie->used_msi_lock); + irq_set_chained_handler_and_data(virq, tango_msi_isr, pcie); + return pci_host_common_probe(pdev, &smp8759_ecam_ops); } |