Implement MSI support for Mobiveil PCIe Host Bridge IP device 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 | 209 +++++++++++++++++++++++++++++++++++++--
1 file changed, 202 insertions(+), 7 deletions(-)
diff --git a/drivers/pci/host/pcie-mobiveil.c b/drivers/pci/host/pcie-mobiveil.c
index 02b1f5d..2b67a2e 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>
@@ -56,6 +57,7 @@
#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(0x0ba0, win)
#define WIN_ENABLE_SHIFT 0
@@ -84,7 +86,18 @@
#define PAB_PEX_AMAP_PEX_WIN_H(win) PAB_REG_ADDR(0x4bac, win)
/* supported number of interrupts */
-#define PAB_INTX_START 5
+#define PAB_INTX_START 5
+#define PCI_NUM_MSI 16
+
+/* 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
@@ -97,14 +110,24 @@
/* Parameters for the waiting for link up routine */
#define LINK_WAIT_MAX_RETRIES 10
-#define LINK_WAIT_MIN 90000
-#define LINK_WAIT_MAX 100000
+#define LINK_WAIT_MIN 90000
+#define LINK_WAIT_MAX 100000
+
+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 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 */
void __iomem *pcie_reg_base; /* Physical PCIe Controller Base */
struct irq_domain *intx_domain;
raw_spinlock_t intx_mask_lock;
@@ -115,6 +138,7 @@ 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,
@@ -194,13 +218,15 @@ 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, val, mask;
/*
- * The core provides interrupt for INTx.
- * So we'll read INTx status.
+ * 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);
@@ -232,6 +258,35 @@ static void mobiveil_pcie_isr(struct irq_desc *desc)
} while ((shifted_status >> PAB_INTX_START) != 0);
}
+ /* read extra MSI status register */
+ msi_status = readl_relaxed(pcie->apb_csr_base + MSI_STATUS_OFFSET);
+
+ /* handle MSI interrupts */
+ while (msi_status & 1) {
+ msi_data = readl_relaxed(pcie->apb_csr_base
+ + MSI_DATA_OFFSET);
+
+ /*
+ * MSI_STATUS_OFFSET register gets updated to zero
+ * once we pop not only the MSI data but also address
+ * from MSI hardware FIFO. So keeping these following
+ * two dummy reads.
+ */
+ msi_addr_lo = readl_relaxed(pcie->apb_csr_base +
+ MSI_ADDR_L_OFFSET);
+ msi_addr_hi = readl_relaxed(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);
+
+ virq = irq_find_mapping(msi->dev_domain, msi_data);
+ if (virq)
+ generic_handle_irq(virq);
+
+ msi_status = readl_relaxed(pcie->apb_csr_base +
+ MSI_STATUS_OFFSET);
+ }
+
/* Clear the interrupt status */
csr_writel(pcie, intr_status, PAB_INTP_AMBA_MISC_STAT);
chained_irq_exit(chip, desc);
@@ -267,6 +322,12 @@ static int mobiveil_pcie_parse_dt(struct mobiveil_pcie *pcie)
return PTR_ERR(pcie->csr_axi_slave_base);
pcie->pcie_reg_base = res->start;
+ /* 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 (of_property_read_u32(node, "apio-wins", &pcie->apio_wins))
pcie->apio_wins = MAX_PIO_WINDOWS;
@@ -416,6 +477,22 @@ 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 = pcie->pcie_reg_base;
+ struct mobiveil_msi *msi = &pcie->msi;
+
+ pcie->msi.num_of_vectors = PCI_NUM_MSI;
+ 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, pab_ctrl, type = 0;
@@ -445,7 +522,7 @@ static int mobiveil_host_init(struct mobiveil_pcie *pcie)
(1 << PEX_PIO_ENABLE_SHIFT),
PAB_CTRL);
- csr_writel(pcie, (PAB_INTP_INTX_MASK),
+ csr_writel(pcie, (PAB_INTP_INTX_MASK | PAB_INTP_MSI_MASK),
PAB_INTP_AMBA_MISC_ENB);
/*
@@ -485,6 +562,9 @@ static int mobiveil_host_init(struct mobiveil_pcie *pcie)
}
}
+ /* setup MSI hardware registers */
+ mobiveil_pcie_enable_msi(pcie);
+
return err;
}
@@ -540,6 +620,116 @@ 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_MULTI_PCI_MSI | 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 = pcie->pcie_reg_base + (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_level_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;
@@ -557,6 +747,11 @@ static int mobiveil_pcie_init_irq_domain(struct mobiveil_pcie *pcie)
raw_spin_lock_init(&pcie->intx_mask_lock);
+ /* setup MSI */
+ ret = mobiveil_allocate_msi_domains(pcie);
+ if (ret)
+ return ret;
+
return 0;
}
--
1.8.3.1
