[v9,5/7] PCI: mediatek-gen3: Add MSI support

Jianjun Wang
2021-03-24T03:06:43Z

Add MSI support for MediaTek Gen3 PCIe controller.

This PCIe controller supports up to 256 MSI vectors, the MSI hardware
block diagram is as follows:

+-----+
| GIC |
+-----+
^
|
port->irq
|
+-+-+-+-+-+-+-+-+
|0|1|2|3|4|5|6|7| (PCIe intc)
+-+-+-+-+-+-+-+-+
^ ^ ^
| | ... |
+-------+ +------+ +-----------+
| | |
+-+-+---+--+--+ +-+-+---+--+--+ +-+-+---+--+--+
|0|1|...|30|31| |0|1|...|30|31| |0|1|...|30|31| (MSI sets)
+-+-+---+--+--+ +-+-+---+--+--+ +-+-+---+--+--+
^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^
| | | | | | | | | | | | (MSI vectors)
| | | | | | | | | | | |

(MSI SET0) (MSI SET1) ... (MSI SET7)

With 256 MSI vectors supported, the MSI vectors are composed of 8 sets,
each set has its own address for MSI message, and supports 32 MSI vectors
to generate interrupt.

Signed-off-by: Jianjun Wang <jianjun.wang@mediatek.com>
Acked-by: Ryder Lee <ryder.lee@mediatek.com>
---
drivers/pci/controller/pcie-mediatek-gen3.c | 276 ++++++++++++++++++++
1 file changed, 276 insertions(+)

diff --git a/drivers/pci/controller/pcie-mediatek-gen3.c b/drivers/pci/controller/pcie-mediatek-gen3.c
index ff91ad587461..ee1b51207d11 100644
--- a/drivers/pci/controller/pcie-mediatek-gen3.c
+++ b/drivers/pci/controller/pcie-mediatek-gen3.c
@@ -14,6 +14,7 @@
#include <linux/irqdomain.h>
#include <linux/kernel.h>
#include <linux/module.h>
+#include <linux/msi.h>
#include <linux/pci.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
@@ -48,12 +49,29 @@
#define PCIE_LINK_STATUS_REG 0x154
#define PCIE_PORT_LINKUP BIT(8)

+#define PCIE_MSI_SET_NUM 8
+#define PCIE_MSI_IRQS_PER_SET 32
+#define PCIE_MSI_IRQS_NUM \
+ (PCIE_MSI_IRQS_PER_SET * PCIE_MSI_SET_NUM)
+
#define PCIE_INT_ENABLE_REG 0x180
+#define PCIE_MSI_ENABLE GENMASK(PCIE_MSI_SET_NUM + 8 - 1, 8)
+#define PCIE_MSI_SHIFT 8
#define PCIE_INTX_SHIFT 24
#define PCIE_INTX_ENABLE \
GENMASK(PCIE_INTX_SHIFT + PCI_NUM_INTX - 1, PCIE_INTX_SHIFT)

#define PCIE_INT_STATUS_REG 0x184
+#define PCIE_MSI_SET_ENABLE_REG 0x190
+#define PCIE_MSI_SET_ENABLE GENMASK(PCIE_MSI_SET_NUM - 1, 0)
+
+#define PCIE_MSI_SET_BASE_REG 0xc00
+#define PCIE_MSI_SET_OFFSET 0x10
+#define PCIE_MSI_SET_STATUS_OFFSET 0x04
+#define PCIE_MSI_SET_ENABLE_OFFSET 0x08
+
+#define PCIE_MSI_SET_ADDR_HI_BASE 0xc80
+#define PCIE_MSI_SET_ADDR_HI_OFFSET 0x04

#define PCIE_TRANS_TABLE_BASE_REG 0x800
#define PCIE_ATR_SRC_ADDR_MSB_OFFSET 0x4
@@ -73,6 +91,16 @@
#define PCIE_ATR_TLP_TYPE_MEM PCIE_ATR_TLP_TYPE(0)
#define PCIE_ATR_TLP_TYPE_IO PCIE_ATR_TLP_TYPE(2)

+/**
+ * struct mtk_msi_set - MSI information for each set
+ * @base: IO mapped register base
+ * @msg_addr: MSI message address
+ */
+struct mtk_msi_set {
+ void __iomem *base;
+ phys_addr_t msg_addr;
+};
+
/**
* struct mtk_pcie_port - PCIe port information
* @dev: pointer to PCIe device
@@ -86,6 +114,11 @@
* @irq: PCIe controller interrupt number
* @irq_lock: lock protecting IRQ register access
* @intx_domain: legacy INTx IRQ domain
+ * @msi_domain: MSI IRQ domain
+ * @msi_bottom_domain: MSI IRQ bottom domain
+ * @msi_sets: MSI sets information
+ * @lock: lock protecting IRQ bit map
+ * @msi_irq_in_use: bit map for assigned MSI IRQ
*/
struct mtk_pcie_port {
struct device *dev;
@@ -100,6 +133,11 @@ struct mtk_pcie_port {
int irq;
raw_spinlock_t irq_lock;
struct irq_domain *intx_domain;
+ struct irq_domain *msi_domain;
+ struct irq_domain *msi_bottom_domain;
+ struct mtk_msi_set msi_sets[PCIE_MSI_SET_NUM];
+ struct mutex lock;
+ DECLARE_BITMAP(msi_irq_in_use, PCIE_MSI_IRQS_NUM);
};

/**
@@ -196,6 +234,35 @@ static int mtk_pcie_set_trans_table(struct mtk_pcie_port *port,
return 0;
}

+static void mtk_pcie_enable_msi(struct mtk_pcie_port *port)
+{
+ int i;
+ u32 val;
+
+ for (i = 0; i < PCIE_MSI_SET_NUM; i++) {
+ struct mtk_msi_set *msi_set = &port->msi_sets[i];
+
+ msi_set->base = port->base + PCIE_MSI_SET_BASE_REG +
+ i * PCIE_MSI_SET_OFFSET;
+ msi_set->msg_addr = port->reg_base + PCIE_MSI_SET_BASE_REG +
+ i * PCIE_MSI_SET_OFFSET;
+
+ /* Configure the MSI capture address */
+ writel_relaxed(lower_32_bits(msi_set->msg_addr), msi_set->base);
+ writel_relaxed(upper_32_bits(msi_set->msg_addr),
+ port->base + PCIE_MSI_SET_ADDR_HI_BASE +
+ i * PCIE_MSI_SET_ADDR_HI_OFFSET);
+ }
+
+ val = readl_relaxed(port->base + PCIE_MSI_SET_ENABLE_REG);
+ val |= PCIE_MSI_SET_ENABLE;
+ writel_relaxed(val, port->base + PCIE_MSI_SET_ENABLE_REG);
+
+ val = readl_relaxed(port->base + PCIE_INT_ENABLE_REG);
+ val |= PCIE_MSI_ENABLE;
+ writel_relaxed(val, port->base + PCIE_INT_ENABLE_REG);
+}
+
static int mtk_pcie_startup_port(struct mtk_pcie_port *port)
{
struct resource_entry *entry;
@@ -247,6 +314,8 @@ static int mtk_pcie_startup_port(struct mtk_pcie_port *port)
return err;
}

+ mtk_pcie_enable_msi(port);
+
/* Set PCIe translation windows */
resource_list_for_each_entry(entry, &host->windows) {
struct resource *res = entry->res;
@@ -289,6 +358,147 @@ static int mtk_pcie_set_affinity(struct irq_data *data,
return -EINVAL;
}

+static void mtk_pcie_msi_irq_mask(struct irq_data *data)
+{
+ pci_msi_mask_irq(data);
+ irq_chip_mask_parent(data);
+}
+
+static void mtk_pcie_msi_irq_unmask(struct irq_data *data)
+{
+ pci_msi_unmask_irq(data);
+ irq_chip_unmask_parent(data);
+}
+
+static struct irq_chip mtk_msi_irq_chip = {
+ .irq_ack = irq_chip_ack_parent,
+ .irq_mask = mtk_pcie_msi_irq_mask,
+ .irq_unmask = mtk_pcie_msi_irq_unmask,
+ .name = "MSI",
+};
+
+static struct msi_domain_info mtk_msi_domain_info = {
+ .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
+ MSI_FLAG_PCI_MSIX | MSI_FLAG_MULTI_PCI_MSI),
+ .chip = &mtk_msi_irq_chip,
+};
+
+static void mtk_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
+{
+ struct mtk_msi_set *msi_set = irq_data_get_irq_chip_data(data);
+ struct mtk_pcie_port *port = data->domain->host_data;
+ unsigned long hwirq;
+
+ hwirq = data->hwirq % PCIE_MSI_IRQS_PER_SET;
+
+ msg->address_hi = upper_32_bits(msi_set->msg_addr);
+ msg->address_lo = lower_32_bits(msi_set->msg_addr);
+ msg->data = hwirq;
+ dev_dbg(port->dev, "msi#%#lx address_hi %#x address_lo %#x data %d\n",
+ hwirq, msg->address_hi, msg->address_lo, msg->data);
+}
+
+static void mtk_msi_bottom_irq_ack(struct irq_data *data)
+{
+ struct mtk_msi_set *msi_set = irq_data_get_irq_chip_data(data);
+ unsigned long hwirq;
+
+ hwirq = data->hwirq % PCIE_MSI_IRQS_PER_SET;
+
+ writel_relaxed(BIT(hwirq), msi_set->base + PCIE_MSI_SET_STATUS_OFFSET);
+}
+
+static void mtk_msi_bottom_irq_mask(struct irq_data *data)
+{
+ struct mtk_msi_set *msi_set = irq_data_get_irq_chip_data(data);
+ struct mtk_pcie_port *port = data->domain->host_data;
+ unsigned long hwirq, flags;
+ u32 val;
+
+ hwirq = data->hwirq % PCIE_MSI_IRQS_PER_SET;
+
+ raw_spin_lock_irqsave(&port->irq_lock, flags);
+ val = readl_relaxed(msi_set->base + PCIE_MSI_SET_ENABLE_OFFSET);
+ val &= ~BIT(hwirq);
+ writel_relaxed(val, msi_set->base + PCIE_MSI_SET_ENABLE_OFFSET);
+ raw_spin_unlock_irqrestore(&port->irq_lock, flags);
+}
+
+static void mtk_msi_bottom_irq_unmask(struct irq_data *data)
+{
+ struct mtk_msi_set *msi_set = irq_data_get_irq_chip_data(data);
+ struct mtk_pcie_port *port = data->domain->host_data;
+ unsigned long hwirq, flags;
+ u32 val;
+
+ hwirq = data->hwirq % PCIE_MSI_IRQS_PER_SET;
+
+ raw_spin_lock_irqsave(&port->irq_lock, flags);
+ val = readl_relaxed(msi_set->base + PCIE_MSI_SET_ENABLE_OFFSET);
+ val |= BIT(hwirq);
+ writel_relaxed(val, msi_set->base + PCIE_MSI_SET_ENABLE_OFFSET);
+ raw_spin_unlock_irqrestore(&port->irq_lock, flags);
+}
+
+static struct irq_chip mtk_msi_bottom_irq_chip = {
+ .irq_ack = mtk_msi_bottom_irq_ack,
+ .irq_mask = mtk_msi_bottom_irq_mask,
+ .irq_unmask = mtk_msi_bottom_irq_unmask,
+ .irq_compose_msi_msg = mtk_compose_msi_msg,
+ .irq_set_affinity = mtk_pcie_set_affinity,
+ .name = "MSI",
+};
+
+static int mtk_msi_bottom_domain_alloc(struct irq_domain *domain,
+ unsigned int virq, unsigned int nr_irqs,
+ void *arg)
+{
+ struct mtk_pcie_port *port = domain->host_data;
+ struct mtk_msi_set *msi_set;
+ int i, hwirq, set_idx;
+
+ mutex_lock(&port->lock);
+
+ hwirq = bitmap_find_free_region(port->msi_irq_in_use, PCIE_MSI_IRQS_NUM,
+ order_base_2(nr_irqs));
+
+ mutex_unlock(&port->lock);
+
+ if (hwirq < 0)
+ return -ENOSPC;
+
+ set_idx = hwirq / PCIE_MSI_IRQS_PER_SET;
+ msi_set = &port->msi_sets[set_idx];
+
+ for (i = 0; i < nr_irqs; i++)
+ irq_domain_set_info(domain, virq + i, hwirq + i,
+ &mtk_msi_bottom_irq_chip, msi_set,
+ handle_edge_irq, NULL, NULL);
+
+ return 0;
+}
+
+static void mtk_msi_bottom_domain_free(struct irq_domain *domain,
+ unsigned int virq, unsigned int nr_irqs)
+{
+ struct mtk_pcie_port *port = domain->host_data;
+ struct irq_data *data = irq_domain_get_irq_data(domain, virq);
+
+ mutex_lock(&port->lock);
+
+ bitmap_release_region(port->msi_irq_in_use, data->hwirq,
+ order_base_2(nr_irqs));
+
+ mutex_unlock(&port->lock);
+
+ irq_domain_free_irqs_common(domain, virq, nr_irqs);
+}
+
+static const struct irq_domain_ops mtk_msi_bottom_domain_ops = {
+ .alloc = mtk_msi_bottom_domain_alloc,
+ .free = mtk_msi_bottom_domain_free,
+};
+
static void mtk_intx_mask(struct irq_data *data)
{
struct mtk_pcie_port *port = irq_data_get_irq_chip_data(data);
@@ -357,6 +567,7 @@ static int mtk_pcie_init_irq_domains(struct mtk_pcie_port *port)
{
struct device *dev = port->dev;
struct device_node *intc_node, *node = dev->of_node;
+ int ret;

raw_spin_lock_init(&port->irq_lock);

@@ -374,7 +585,34 @@ static int mtk_pcie_init_irq_domains(struct mtk_pcie_port *port)
return -ENODEV;
}

+ /* Setup MSI */
+ mutex_init(&port->lock);
+
+ port->msi_bottom_domain = irq_domain_add_linear(node, PCIE_MSI_IRQS_NUM,
+ &mtk_msi_bottom_domain_ops, port);
+ if (!port->msi_bottom_domain) {
+ dev_err(dev, "failed to create MSI bottom domain\n");
+ ret = -ENODEV;
+ goto err_msi_bottom_domain;
+ }
+
+ port->msi_domain = pci_msi_create_irq_domain(dev->fwnode,
+ &mtk_msi_domain_info,
+ port->msi_bottom_domain);
+ if (!port->msi_domain) {
+ dev_err(dev, "failed to create MSI domain\n");
+ ret = -ENODEV;
+ goto err_msi_domain;
+ }
+
return 0;
+
+err_msi_domain:
+ irq_domain_remove(port->msi_bottom_domain);
+err_msi_bottom_domain:
+ irq_domain_remove(port->intx_domain);
+
+ return ret;
}

static void mtk_pcie_irq_teardown(struct mtk_pcie_port *port)
@@ -384,9 +622,39 @@ static void mtk_pcie_irq_teardown(struct mtk_pcie_port *port)
if (port->intx_domain)
irq_domain_remove(port->intx_domain);

+ if (port->msi_domain)
+ irq_domain_remove(port->msi_domain);
+
+ if (port->msi_bottom_domain)
+ irq_domain_remove(port->msi_bottom_domain);
+
irq_dispose_mapping(port->irq);
}

+static void mtk_pcie_msi_handler(struct mtk_pcie_port *port, int set_idx)
+{
+ struct mtk_msi_set *msi_set = &port->msi_sets[set_idx];
+ unsigned long msi_enable, msi_status;
+ unsigned int virq;
+ irq_hw_number_t bit, hwirq;
+
+ msi_enable = readl_relaxed(msi_set->base + PCIE_MSI_SET_ENABLE_OFFSET);
+
+ do {
+ msi_status = readl_relaxed(msi_set->base +
+ PCIE_MSI_SET_STATUS_OFFSET);
+ msi_status &= msi_enable;
+ if (!msi_status)
+ break;
+
+ for_each_set_bit(bit, &msi_status, PCIE_MSI_IRQS_PER_SET) {
+ hwirq = bit + set_idx * PCIE_MSI_IRQS_PER_SET;
+ virq = irq_find_mapping(port->msi_bottom_domain, hwirq);
+ generic_handle_irq(virq);
+ }
+ } while (true);
+}
+
static void mtk_pcie_irq_handler(struct irq_desc *desc)
{
struct mtk_pcie_port *port = irq_desc_get_handler_data(desc);
@@ -405,6 +673,14 @@ static void mtk_pcie_irq_handler(struct irq_desc *desc)
generic_handle_irq(virq);
}

+ irq_bit = PCIE_MSI_SHIFT;
+ for_each_set_bit_from(irq_bit, &status, PCIE_MSI_SET_NUM +
+ PCIE_MSI_SHIFT) {
+ mtk_pcie_msi_handler(port, irq_bit - PCIE_MSI_SHIFT);
+
+ writel_relaxed(BIT(irq_bit), port->base + PCIE_INT_STATUS_REG);
+ }
+
chained_irq_exit(irqchip, desc);
}

--
2.25.1