Adds MSI support for Mobiveil PCIe Host Bridge IP driver
Signed-off-by: Subrahmanya Lingappa <l.subrahmanya@xxxxxxxxxxxxxx>
Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Cc: Marc Zyngier <marc.zyngier@xxxxxxx>
Cc: linux-pci@xxxxxxxxxxxxxxx
---
drivers/pci/host/pcie-mobiveil.c | 222 ++++++++++++++++++++++++++++++++++++++-
1 file changed, 220 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/host/pcie-mobiveil.c b/drivers/pci/host/pcie-mobiveil.c
index 8611aaa..39818d5 100644
--- a/drivers/pci/host/pcie-mobiveil.c
+++ b/drivers/pci/host/pcie-mobiveil.c
@@ -14,6 +14,7 @@
#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_platform.h>
@@ -55,6 +56,7 @@
#define PAB_INTP_AMBA_MISC_ENB 0x0b0c
#define PAB_INTP_AMBA_MISC_STAT 0x0b1c
#define PAB_INTP_INTX_MASK 0x1e0
+#define PAB_INTP_MSI_MASK 0x8
#define PAB_AXI_AMAP_CTRL(win) PAB_REG_ADDR_16(0x0ba0, win)
#define WIN_ENABLE_SHIFT 0
@@ -85,8 +87,19 @@
/* supported number of interrupts */
#define PCI_NUM_INTX 4
+#define PCI_NUM_MSI 16
#define PAB_INTA_POS 5
+/* MSI registers */
+#define MSI_BASE_LO_OFFSET 0x04
+#define MSI_BASE_HI_OFFSET 0x08
+#define MSI_SIZE_OFFSET 0x0c
+#define MSI_ENABLE_OFFSET 0x14
+#define MSI_STATUS_OFFSET 0x18
+#define MSI_DATA_OFFSET 0x20
+#define MSI_ADDR_L_OFFSET 0x24
+#define MSI_ADDR_H_OFFSET 0x28
+
/* outbound and inbound window definitions */
#define WIN_NUM_0 0
#define WIN_NUM_1 1
@@ -105,11 +118,22 @@
#define UINT64_MAX (u64)(~((u64)0))
#endif
+struct mobiveil_msi { /* MSI information */
+ struct mutex lock; /* protect bitmap variable */
+ struct irq_domain *msi_domain;
+ struct irq_domain *dev_domain;
+ phys_addr_t msi_pages_phys;
+ int *msi_pages;
+ int num_of_vectors;
+ DECLARE_BITMAP(msi_irq_in_use, PCI_NUM_MSI);
+};
+
struct mobiveil_pcie {
struct platform_device *pdev;
struct list_head resources;
void __iomem *config_axi_slave_base; /* endpoint config base */
void __iomem *csr_axi_slave_base; /* root port config base */
+ void __iomem *apb_csr_base; /* MSI register base */
struct irq_domain *intx_domain;
int irq;
int apio_wins;
@@ -118,6 +142,7 @@ struct mobiveil_pcie {
int ib_wins_configured; /* configured inbound windows */
struct resource *ob_io_res;
char root_bus_nr;
+ struct mobiveil_msi msi;
};
static inline void csr_writel(struct mobiveil_pcie *pcie, const u32 value,
@@ -202,11 +227,18 @@ static void mobiveil_pcie_isr(struct irq_desc *desc)
struct irq_chip *chip = irq_desc_get_chip(desc);
struct mobiveil_pcie *pcie = irq_desc_get_handler_data(desc);
struct device *dev = &pcie->pdev->dev;
- u32 intr_status;
+ struct mobiveil_msi *msi = &pcie->msi;
+ u32 msi_data, msi_addr_lo, msi_addr_hi;
+ u32 intr_status, msi_status;
unsigned long shifted_status;
u32 bit, virq;
u32 val, mask;
+ /*
+ * The core provides a single interrupt for both INTx/MSI messages.
+ * So we'll read both INTx and MSI status
+ */
+
chained_irq_enter(chip, desc);
/* read INTx status */
@@ -241,6 +273,41 @@ static void mobiveil_pcie_isr(struct irq_desc *desc)
} while ((shifted_status >> PAB_INTA_POS) != 0);
}
+ /* read extra MSI status register */
+ msi_status = readl(pcie->apb_csr_base + MSI_STATUS_OFFSET);
+
+ /* handle MSI interrupts */
+ if ((intr_status & PAB_INTP_MSI_MASK) || (msi_status & 1)) {
+ do {
+ msi_data = readl(pcie->apb_csr_base + MSI_DATA_OFFSET);
+
+ /*
+ * MSI_STATUS_OFFSET gets updated to zero once we have
+ * popped not only the data but also address from MSI
+ * hardware FIFO.so keeping these following two dummy
+ * reads.
+ */
+ msi_addr_lo = readl(pcie->apb_csr_base +
+ MSI_ADDR_L_OFFSET);
+ msi_addr_hi = readl(pcie->apb_csr_base +
+ MSI_ADDR_H_OFFSET);
+ dev_dbg(dev,
+ "MSI registers, data: %08x, addr: %08x:%08x\n",
+ msi_data, msi_addr_hi, msi_addr_lo);
+
+ if (msi_data) {
+ virq = irq_find_mapping(msi->dev_domain,
+ msi_data);
+ if (virq)
+ generic_handle_irq(virq);
+ } else
+ dev_err_ratelimited(dev, "MSI data null\n");
+
+ msi_status = readl(pcie->apb_csr_base +
+ MSI_STATUS_OFFSET);
+ } while (msi_status & 1);
+ }
+
csr_writel(pcie, intr_status, PAB_INTP_AMBA_MISC_STAT);
chained_irq_exit(chip, desc);
}
@@ -274,6 +341,12 @@ static int mobiveil_pcie_parse_dt(struct mobiveil_pcie *pcie)
if (IS_ERR(pcie->csr_axi_slave_base))
return PTR_ERR(pcie->csr_axi_slave_base);
+ /* map MSI config resource */
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "apb_csr");
+ pcie->apb_csr_base = devm_pci_remap_cfg_resource(dev, res);
+ if (IS_ERR(pcie->apb_csr_base))
+ return PTR_ERR(pcie->apb_csr_base);
+
/* read the number of windows requested */
if (!pcie->apio_wins &&
of_property_read_u32(node, "apio-wins", &pcie->apio_wins)) {
@@ -430,6 +503,27 @@ static int mobiveil_bringup_link(struct mobiveil_pcie *pcie)
return -ETIMEDOUT;
}
+static void mobiveil_pcie_enable_msi(struct mobiveil_pcie *pcie)
+{
+ phys_addr_t msg_addr;
+ struct mobiveil_msi *msi = &pcie->msi;
+
+
+ pcie->msi.num_of_vectors = PCI_NUM_MSI;
+
+ msi->msi_pages = (void *)__get_free_pages(GFP_DMA, 0);
+ msg_addr = virt_to_phys((void *)msi->msi_pages);
+ msi->msi_pages_phys = (phys_addr_t)msg_addr;
+
+ writel_relaxed(lower_32_bits(msg_addr),
+ pcie->apb_csr_base + MSI_BASE_LO_OFFSET);
+ writel_relaxed(upper_32_bits(msg_addr),
+ pcie->apb_csr_base + MSI_BASE_HI_OFFSET);
+ writel_relaxed(4096, pcie->apb_csr_base + MSI_SIZE_OFFSET);
+ writel_relaxed(1,
+ pcie->apb_csr_base + MSI_ENABLE_OFFSET);
+}
+
static int mobiveil_host_init(struct mobiveil_pcie *pcie)
{
u32 value;
@@ -465,7 +559,8 @@ static int mobiveil_host_init(struct mobiveil_pcie *pcie)
(1 << PEX_PIO_ENABLE_SHIFT),
PAB_CTRL);
- csr_writel(pcie, PAB_INTP_INTX_MASK, PAB_INTP_AMBA_MISC_ENB);
+ csr_writel(pcie, (PAB_INTP_INTX_MASK | PAB_INTP_MSI_MASK),
+ PAB_INTP_AMBA_MISC_ENB);
/* program PIO Enable Bit to 1 and Config Window Enable Bit to 1 in
* PAB_AXI_PIO_CTRL Register
@@ -503,6 +598,10 @@ static int mobiveil_host_init(struct mobiveil_pcie *pcie)
}
}
+ /* setup MSI hardware registers */
+ if (IS_ENABLED(CONFIG_PCI_MSI))
+ mobiveil_pcie_enable_msi(pcie);
+
return err;
}
@@ -520,6 +619,118 @@ static int mobiveil_pcie_intx_map(struct irq_domain *domain, unsigned int irq,
.map = mobiveil_pcie_intx_map,
};
+static struct irq_chip mobiveil_msi_irq_chip = {
+ .name = "Mobiveil PCIe MSI",
+ .irq_mask = pci_msi_mask_irq,
+ .irq_unmask = pci_msi_unmask_irq,
+};
+
+static struct msi_domain_info mobiveil_msi_domain_info = {
+ .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
+ MSI_FLAG_PCI_MSIX),
+ .chip = &mobiveil_msi_irq_chip,
+};
+
+static void mobiveil_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
+{
+ struct mobiveil_pcie *pcie = irq_data_get_irq_chip_data(data);
+ phys_addr_t addr = virt_to_phys((void *)pcie->msi.msi_pages +
+ (data->hwirq * sizeof(int)));
+
+ msg->address_lo = lower_32_bits(addr);
+ msg->address_hi = upper_32_bits(addr);
+ msg->data = data->hwirq;
+
+ dev_dbg(&pcie->pdev->dev, "msi#%d address_hi %#x address_lo %#x\n",
+ (int)data->hwirq, msg->address_hi, msg->address_lo);
+}
+
+static int mobiveil_msi_set_affinity(struct irq_data *irq_data,
+ const struct cpumask *mask, bool force)
+{
+ return -EINVAL;
+}
+
+static struct irq_chip mobiveil_msi_bottom_irq_chip = {
+ .name = "Mobiveil MSI",
+ .irq_compose_msi_msg = mobiveil_compose_msi_msg,
+ .irq_set_affinity = mobiveil_msi_set_affinity,
+};
+
+static int mobiveil_irq_msi_domain_alloc(struct irq_domain *domain,
+ unsigned int virq, unsigned int nr_irqs, void *args)
+{
+ struct mobiveil_pcie *pcie = domain->host_data;
+ struct mobiveil_msi *msi = &pcie->msi;
+ unsigned long bit;
+
+ WARN_ON(nr_irqs != 1);
+ mutex_lock(&msi->lock);
+
+ bit = find_first_zero_bit(msi->msi_irq_in_use, msi->num_of_vectors);
+ if (bit >= msi->num_of_vectors) {
+ mutex_unlock(&msi->lock);
+ return -ENOSPC;
+ }
+
+ set_bit(bit, msi->msi_irq_in_use);
+
+ mutex_unlock(&msi->lock);
+
+ irq_domain_set_info(domain, virq, bit, &mobiveil_msi_bottom_irq_chip,
+ domain->host_data, handle_simple_irq,
+ NULL, NULL);
+ return 0;
+}
+
+static void mobiveil_irq_msi_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 mobiveil_pcie *pcie = irq_data_get_irq_chip_data(d);
+ struct mobiveil_msi *msi = &pcie->msi;
+
+ mutex_lock(&msi->lock);
+
+ if (!test_bit(d->hwirq, msi->msi_irq_in_use)) {
+ dev_err(&pcie->pdev->dev, "trying to free unused MSI#%lu\n",
+ d->hwirq);
+ } else {
+ __clear_bit(d->hwirq, msi->msi_irq_in_use);
+ }
+
+ mutex_unlock(&msi->lock);
+}
+
+static const struct irq_domain_ops msi_domain_ops = {
+ .alloc = mobiveil_irq_msi_domain_alloc,
+ .free = mobiveil_irq_msi_domain_free,
+};
+
+static int mobiveil_allocate_msi_domains(struct mobiveil_pcie *pcie)
+{
+ struct device *dev = &pcie->pdev->dev;
+ struct fwnode_handle *fwnode = of_node_to_fwnode(dev->of_node);
+ struct mobiveil_msi *msi = &pcie->msi;
+
+ mutex_init(&pcie->msi.lock);
+ msi->dev_domain = irq_domain_add_linear(NULL, msi->num_of_vectors,
+ &msi_domain_ops, pcie);
+ if (!msi->dev_domain) {
+ dev_err(dev, "failed to create IRQ domain\n");
+ return -ENOMEM;
+ }
+
+ msi->msi_domain = pci_msi_create_irq_domain(fwnode,
+ &mobiveil_msi_domain_info, msi->dev_domain);
+ if (!msi->msi_domain) {
+ dev_err(dev, "failed to create MSI domain\n");
+ irq_domain_remove(msi->dev_domain);
+ return -ENOMEM;
+ }
+ return 0;
+}
+
static int mobiveil_pcie_init_irq_domain(struct mobiveil_pcie *pcie)
{
struct device *dev = &pcie->pdev->dev;
@@ -535,6 +746,13 @@ static int mobiveil_pcie_init_irq_domain(struct mobiveil_pcie *pcie)
return -ENODEV;
}
+#ifdef CONFIG_PCI_MSI
+ /* setup MSI */
+ ret = mobiveil_allocate_msi_domains(pcie);
+ if (ret)
+ return ret;
+#endif
+
return 0;
}
--
1.8.3.1
