[v2,1/9] pci: adding new irq api to pci-designware

Commit Message

Joao Pinto June 5, 2017, 4:19 p.m. UTC

This patch adds the new interrupt api to pcie-designware, keeping the old
one. Although the old API is still available, pcie-designware initiates with
the new one.

Signed-off-by: Joao Pinto <[e-mail]>
---
Change v1->v2:
- num_vectors is now not configurable by DT. Now it is 32 by default and
can be overiden by any specific SoC driver.

 drivers/pci/dwc/pcie-designware-host.c | 291 +++++++++++++++++++++++++++++----
 drivers/pci/dwc/pcie-designware.h      |  17 ++
 2 files changed, 277 insertions(+), 31 deletions(-)

Comments

Lucas Stach June 8, 2017, 6:18 p.m. UTC | #1

Am Montag, den 05.06.2017, 17:19 +0100 schrieb Joao Pinto:
> This patch adds the new interrupt api to pcie-designware, keeping the old
> one. Although the old API is still available, pcie-designware initiates with
> the new one.
> 
> Signed-off-by: Joao Pinto <[e-mail]>
> ---
> Change v1->v2:
> - num_vectors is now not configurable by DT. Now it is 32 by default and
> can be overiden by any specific SoC driver.
> 
>  drivers/pci/dwc/pcie-designware-host.c | 291 +++++++++++++++++++++++++++++----
>  drivers/pci/dwc/pcie-designware.h      |  17 ++
>  2 files changed, 277 insertions(+), 31 deletions(-)
> 
[...]
>  static int assign_irq(int no_irqs, struct msi_desc *desc, int *pos)
> @@ -279,11 +491,14 @@ int dw_pcie_host_init(struct pcie_port *pp)
>  	struct device *dev = pci->dev;
>  	struct device_node *np = dev->of_node;
>  	struct platform_device *pdev = to_platform_device(dev);
> +	struct resource_entry *win, *tmp;
>  	struct pci_bus *bus, *child;
>  	struct resource *cfg_res;
>  	int i, ret;
> +
>  	LIST_HEAD(res);
> -	struct resource_entry *win, *tmp;
> +
> +	spin_lock_init(&pci->pp.lock);
>  
>  	cfg_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "config");
>  	if (cfg_res) {
> @@ -377,18 +592,32 @@ int dw_pcie_host_init(struct pcie_port *pp)
>  		pci->num_viewport = 2;
>  
>  	if (IS_ENABLED(CONFIG_PCI_MSI)) {
> -		if (!pp->ops->msi_host_init) {
> -			pp->irq_domain = irq_domain_add_linear(dev->of_node,
> -						MAX_MSI_IRQS, &msi_domain_ops,
> -						&dw_pcie_msi_chip);
> -			if (!pp->irq_domain) {
> -				dev_err(dev, "irq domain init failed\n");
> -				ret = -ENXIO;
> +		/*
> +		 * If a specific SoC driver needs to change the
> +		 * default number of vectors, it needs to implement
> +		 * the set_num_vectors callback.
> +		 */
No need for a function to implement this. The implementation glue driver
can just set up pcie_port.num_vectors to the correct number before
calling dw_pcie_host_init.

> +		if (!pp->ops->set_num_vectors) {
> +			pp->num_vectors = MSI_DEF_NUM_VECTORS;
> +		} else {
> +			pp->ops->set_num_vectors(pp);
> +
> +			if (pp->num_vectors > MAX_MSI_IRQS ||
> +			    pp->num_vectors == 0) {
> +				dev_err(dev,
> +					"Invalid number of vectors\n");
>  				goto error;
>  			}
> +		}
>  
> -			for (i = 0; i < MAX_MSI_IRQS; i++)
> -				irq_create_mapping(pp->irq_domain, i);
> +		if (!pp->ops->msi_host_init) {
> +			ret = dw_pcie_allocate_domains(pci);
> +			if (ret)
> +				goto error;
> +
> +			irq_set_chained_handler_and_data(pci->pp.msi_irq,
> +							 dw_chained_msi_isr,
> +							 pci);

So this breaks legacy PCI irqs on DWC platforms even more, as the IRQ
line can not be shared, even if the endpoint device doesn't support
MSIs.

Do we have any solution for that? In the worst case we would need a DT
property to enable MSI support and not register the MSI IRQ domain in
that case.

Regards,
Lucas

>  		} else {
>  			ret = pp->ops->msi_host_init(pp, &dw_pcie_msi_chip);
>  			if (ret < 0)
> @@ -400,14 +629,9 @@ int dw_pcie_host_init(struct pcie_port *pp)
>  		pp->ops->host_init(pp);
>  
>  	pp->root_bus_nr = pp->busn->start;
> -	if (IS_ENABLED(CONFIG_PCI_MSI)) {
> -		bus = pci_scan_root_bus_msi(dev, pp->root_bus_nr,
> -					    &dw_pcie_ops, pp, &res,
> -					    &dw_pcie_msi_chip);
> -		dw_pcie_msi_chip.dev = dev;
> -	} else
> -		bus = pci_scan_root_bus(dev, pp->root_bus_nr, &dw_pcie_ops,
> -					pp, &res);
> +
> +	bus = pci_scan_root_bus(dev, pp->root_bus_nr, &dw_pcie_ops,
> +				pp, &res);
>  	if (!bus) {
>  		ret = -ENOMEM;
>  		goto error;
> @@ -579,11 +803,16 @@ static u8 dw_pcie_iatu_unroll_enabled(struct dw_pcie *pci)

Patch

diff --git a/drivers/pci/dwc/pcie-designware-host.c b/drivers/pci/dwc/pcie-designware-host.c
index 28ed32b..b203754 100644
--- a/drivers/pci/dwc/pcie-designware-host.c
+++ b/drivers/pci/dwc/pcie-designware-host.c
@@ -11,6 +11,7 @@ 
  * published by the Free Software Foundation.
  */
 
+#include <linux/irqchip/chained_irq.h>
 #include <linux/irqdomain.h>
 #include <linux/of_address.h>
 #include <linux/of_pci.h>
@@ -53,6 +54,30 @@  static struct irq_chip dw_msi_irq_chip = {
 	.irq_unmask = pci_msi_unmask_irq,
 };
 
+static void dw_msi_mask_irq(struct irq_data *d)
+{
+	pci_msi_mask_irq(d);
+	irq_chip_mask_parent(d);
+}
+
+static void dw_msi_unmask_irq(struct irq_data *d)
+{
+	pci_msi_unmask_irq(d);
+	irq_chip_unmask_parent(d);
+}
+
+static struct irq_chip dw_pcie_msi_irq_chip = {
+	.name = "PCI-MSI",
+	.irq_mask = dw_msi_mask_irq,
+	.irq_unmask = dw_msi_unmask_irq,
+};
+
+static struct msi_domain_info dw_pcie_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	= &dw_pcie_msi_irq_chip,
+};
+
 /* MSI int handler */
 irqreturn_t dw_handle_msi_irq(struct pcie_port *pp)
 {
@@ -81,6 +106,191 @@  irqreturn_t dw_handle_msi_irq(struct pcie_port *pp)
 	return ret;
 }
 
+/* Chained MSI interrupt service routine */
+static void dw_chained_msi_isr(struct irq_desc *desc)
+{
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	struct pcie_port *pp;
+	struct dw_pcie *pci;
+
+	chained_irq_enter(chip, desc);
+	pci = irq_desc_get_handler_data(desc);
+	pp = &pci->pp;
+
+	dw_handle_msi_irq(pp);
+
+	chained_irq_exit(chip, desc);
+}
+
+static void dw_pci_setup_msi_msg(struct irq_data *data, struct msi_msg *msg)
+{
+	struct dw_pcie *pci = irq_data_get_irq_chip_data(data);
+	struct pcie_port *pp = &pci->pp;
+	u64 msi_target;
+
+	if (pp->ops->get_msi_addr)
+		msi_target = pp->ops->get_msi_addr(pp);
+	else
+		msi_target = virt_to_phys((void *)pp->msi_data);
+
+	msg->address_lo = lower_32_bits(msi_target);
+	msg->address_hi = upper_32_bits(msi_target);
+
+	if (pp->ops->get_msi_data)
+		msg->data = pp->ops->get_msi_data(pp, data->hwirq);
+	else
+		msg->data = data->hwirq;
+
+	dev_dbg(pci->dev, "msi#%d address_hi %#x address_lo %#x\n",
+		(int)data->hwirq, msg->address_hi, msg->address_lo);
+}
+
+static int dw_pci_msi_set_affinity(struct irq_data *irq_data,
+				   const struct cpumask *mask, bool force)
+{
+	return -EINVAL;
+}
+
+static void dw_pci_bottom_mask(struct irq_data *data)
+{
+	struct dw_pcie *pci = irq_data_get_irq_chip_data(data);
+	struct pcie_port *pp = &pci->pp;
+	unsigned int res, bit, ctrl;
+	unsigned long flags;
+
+	spin_lock_irqsave(&pp->lock, flags);
+
+	if (pp->ops->msi_clear_irq)
+		pp->ops->msi_clear_irq(pp, data->hwirq);
+	else {
+		ctrl = data->hwirq / 32;
+		res = ctrl * 12;
+		bit = data->hwirq % 32;
+
+		pp->irq_status[ctrl] &= ~(1 << bit);
+		dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4,
+				    pp->irq_status[ctrl]);
+	}
+
+	spin_unlock_irqrestore(&pp->lock, flags);
+}
+
+static void dw_pci_bottom_unmask(struct irq_data *data)
+{
+	struct dw_pcie *pci = irq_data_get_irq_chip_data(data);
+	struct pcie_port *pp = &pci->pp;
+	unsigned int res, bit, ctrl;
+	unsigned long flags;
+
+	spin_lock_irqsave(&pp->lock, flags);
+
+	if (pp->ops->msi_set_irq)
+		pp->ops->msi_set_irq(pp, data->hwirq);
+	else {
+		ctrl = data->hwirq / 32;
+		res = ctrl * 12;
+		bit = data->hwirq % 32;
+
+		pp->irq_status[ctrl] |= 1 << bit;
+		dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4,
+				    pp->irq_status[ctrl]);
+	}
+
+	spin_unlock_irqrestore(&pp->lock, flags);
+}
+
+static struct irq_chip dw_pci_msi_bottom_irq_chip = {
+	.name			= "DWPCI-MSI",
+	.irq_compose_msi_msg	= dw_pci_setup_msi_msg,
+	.irq_set_affinity	= dw_pci_msi_set_affinity,
+	.irq_mask		= dw_pci_bottom_mask,
+	.irq_unmask		= dw_pci_bottom_unmask,
+};
+
+static int dw_pcie_irq_domain_alloc(struct irq_domain *domain,
+				    unsigned int virq, unsigned int nr_irqs,
+				    void *args)
+{
+	struct dw_pcie *pci = domain->host_data;
+	struct pcie_port *pp = &pci->pp;
+	unsigned long flags;
+	unsigned long bit;
+	u32 i;
+
+	spin_lock_irqsave(&pp->lock, flags);
+
+	bit = bitmap_find_next_zero_area(pp->msi_irq_in_use, pp->num_vectors, 0,
+					 nr_irqs, 0);
+
+	if (bit >= pp->num_vectors) {
+		spin_unlock_irqrestore(&pp->lock, flags);
+		return -ENOSPC;
+	}
+
+	bitmap_set(pp->msi_irq_in_use, bit, nr_irqs);
+
+	spin_unlock_irqrestore(&pp->lock, flags);
+
+	for (i = 0; i < nr_irqs; i++)
+		irq_domain_set_info(domain, virq + i, bit + i,
+				    &dw_pci_msi_bottom_irq_chip,
+				    domain->host_data, handle_simple_irq,
+				    NULL, NULL);
+
+	return 0;
+}
+
+static void dw_pcie_irq_domain_free(struct irq_domain *domain,
+				    unsigned int virq, unsigned int nr_irqs)
+{
+	struct irq_data *data = irq_domain_get_irq_data(domain, virq);
+	struct dw_pcie *pci = irq_data_get_irq_chip_data(data);
+	struct pcie_port *pp = &pci->pp;
+	unsigned long flags;
+
+	spin_lock_irqsave(&pp->lock, flags);
+	bitmap_clear(pp->msi_irq_in_use, data->hwirq, nr_irqs);
+	spin_unlock_irqrestore(&pp->lock, flags);
+}
+
+static const struct irq_domain_ops dw_pcie_msi_domain_ops = {
+	.alloc	= dw_pcie_irq_domain_alloc,
+	.free	= dw_pcie_irq_domain_free,
+};
+
+int dw_pcie_allocate_domains(struct dw_pcie *pci)
+{
+	struct pcie_port *pp = &pci->pp;
+	struct fwnode_handle *fwnode = of_node_to_fwnode(pci->dev->of_node);
+
+	pp->irq_domain = irq_domain_create_linear(fwnode, pp->num_vectors,
+					       &dw_pcie_msi_domain_ops, pci);
+	if (!pp->irq_domain) {
+		dev_err(pci->dev, "failed to create IRQ domain\n");
+		return -ENOMEM;
+	}
+
+	pp->msi_domain = pci_msi_create_irq_domain(fwnode,
+						   &dw_pcie_msi_domain_info,
+						   pp->irq_domain);
+	if (!pp->msi_domain) {
+		dev_err(pci->dev, "failed to create MSI domain\n");
+		irq_domain_remove(pp->irq_domain);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+void dw_pcie_free_msi(struct pcie_port *pp)
+{
+	irq_set_chained_handler(pp->msi_irq, NULL);
+	irq_set_handler_data(pp->msi_irq, NULL);
+
+	irq_domain_remove(pp->msi_domain);
+	irq_domain_remove(pp->irq_domain);
+}
+
 void dw_pcie_msi_init(struct pcie_port *pp)
 {
 	u64 msi_target;
@@ -90,20 +300,21 @@  void dw_pcie_msi_init(struct pcie_port *pp)
 
 	/* program the msi_data */
 	dw_pcie_wr_own_conf(pp, PCIE_MSI_ADDR_LO, 4,
-			    (u32)(msi_target & 0xffffffff));
+			    lower_32_bits(msi_target));
 	dw_pcie_wr_own_conf(pp, PCIE_MSI_ADDR_HI, 4,
-			    (u32)(msi_target >> 32 & 0xffffffff));
+			    upper_32_bits(msi_target));
 }
 
 static void dw_pcie_msi_clear_irq(struct pcie_port *pp, int irq)
 {
-	unsigned int res, bit, val;
+	unsigned int res, bit, ctrl;
 
-	res = (irq / 32) * 12;
+	ctrl = irq / 32;
+	res = ctrl * 12;
 	bit = irq % 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);
+	pp->irq_status[ctrl] &= ~(1 << bit);
+	dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4,
+			    pp->irq_status[ctrl]);
 }
 
 static void clear_irq_range(struct pcie_port *pp, unsigned int irq_base,
@@ -125,13 +336,14 @@  static void clear_irq_range(struct pcie_port *pp, unsigned int irq_base,
 
 static void dw_pcie_msi_set_irq(struct pcie_port *pp, int irq)
 {
-	unsigned int res, bit, val;
+	unsigned int res, bit, ctrl;
 
-	res = (irq / 32) * 12;
+	ctrl = irq / 32;
+	res = ctrl * 12;
 	bit = irq % 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);
+	pp->irq_status[ctrl] |= 1 << bit;
+	dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_ENABLE + res, 4,
+			    pp->irq_status[ctrl]);
 }
 
 static int assign_irq(int no_irqs, struct msi_desc *desc, int *pos)
@@ -279,11 +491,14 @@  int dw_pcie_host_init(struct pcie_port *pp)
 	struct device *dev = pci->dev;
 	struct device_node *np = dev->of_node;
 	struct platform_device *pdev = to_platform_device(dev);
+	struct resource_entry *win, *tmp;
 	struct pci_bus *bus, *child;
 	struct resource *cfg_res;
 	int i, ret;
+
 	LIST_HEAD(res);
-	struct resource_entry *win, *tmp;
+
+	spin_lock_init(&pci->pp.lock);
 
 	cfg_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "config");
 	if (cfg_res) {
@@ -377,18 +592,32 @@  int dw_pcie_host_init(struct pcie_port *pp)
 		pci->num_viewport = 2;
 
 	if (IS_ENABLED(CONFIG_PCI_MSI)) {
-		if (!pp->ops->msi_host_init) {
-			pp->irq_domain = irq_domain_add_linear(dev->of_node,
-						MAX_MSI_IRQS, &msi_domain_ops,
-						&dw_pcie_msi_chip);
-			if (!pp->irq_domain) {
-				dev_err(dev, "irq domain init failed\n");
-				ret = -ENXIO;
+		/*
+		 * If a specific SoC driver needs to change the
+		 * default number of vectors, it needs to implement
+		 * the set_num_vectors callback.
+		 */
+		if (!pp->ops->set_num_vectors) {
+			pp->num_vectors = MSI_DEF_NUM_VECTORS;
+		} else {
+			pp->ops->set_num_vectors(pp);
+
+			if (pp->num_vectors > MAX_MSI_IRQS ||
+			    pp->num_vectors == 0) {
+				dev_err(dev,
+					"Invalid number of vectors\n");
 				goto error;
 			}
+		}
 
-			for (i = 0; i < MAX_MSI_IRQS; i++)
-				irq_create_mapping(pp->irq_domain, i);
+		if (!pp->ops->msi_host_init) {
+			ret = dw_pcie_allocate_domains(pci);
+			if (ret)
+				goto error;
+
+			irq_set_chained_handler_and_data(pci->pp.msi_irq,
+							 dw_chained_msi_isr,
+							 pci);
 		} else {
 			ret = pp->ops->msi_host_init(pp, &dw_pcie_msi_chip);
 			if (ret < 0)
@@ -400,14 +629,9 @@  int dw_pcie_host_init(struct pcie_port *pp)
 		pp->ops->host_init(pp);
 
 	pp->root_bus_nr = pp->busn->start;
-	if (IS_ENABLED(CONFIG_PCI_MSI)) {
-		bus = pci_scan_root_bus_msi(dev, pp->root_bus_nr,
-					    &dw_pcie_ops, pp, &res,
-					    &dw_pcie_msi_chip);
-		dw_pcie_msi_chip.dev = dev;
-	} else
-		bus = pci_scan_root_bus(dev, pp->root_bus_nr, &dw_pcie_ops,
-					pp, &res);
+
+	bus = pci_scan_root_bus(dev, pp->root_bus_nr, &dw_pcie_ops,
+				pp, &res);
 	if (!bus) {
 		ret = -ENOMEM;
 		goto error;
@@ -579,11 +803,16 @@  static u8 dw_pcie_iatu_unroll_enabled(struct dw_pcie *pci)
 
 void dw_pcie_setup_rc(struct pcie_port *pp)
 {
-	u32 val;
+	u32 val, ctrl;
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
 
 	dw_pcie_setup(pci);
 
+	/* Initialize IRQ Status array */
+	for (ctrl = 0; ctrl < MAX_MSI_CTRLS; ctrl++)
+		dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_ENABLE + (ctrl * 12), 4,
+				    &pp->irq_status[ctrl]);
+
 	/* setup RC BARs */
 	dw_pcie_writel_dbi(pci, PCI_BASE_ADDRESS_0, 0x00000004);
 	dw_pcie_writel_dbi(pci, PCI_BASE_ADDRESS_1, 0x00000000);
diff --git a/drivers/pci/dwc/pcie-designware.h b/drivers/pci/dwc/pcie-designware.h
index c6a8405..9838d6d 100644
--- a/drivers/pci/dwc/pcie-designware.h
+++ b/drivers/pci/dwc/pcie-designware.h
@@ -109,6 +109,7 @@ 
  */
 #define MAX_MSI_IRQS			32
 #define MAX_MSI_CTRLS			(MAX_MSI_IRQS / 32)
+#define MSI_DEF_NUM_VECTORS		32
 
 struct pcie_port;
 struct dw_pcie;
@@ -140,6 +141,7 @@  struct dw_pcie_host_ops {
 	phys_addr_t (*get_msi_addr)(struct pcie_port *pp);
 	u32 (*get_msi_data)(struct pcie_port *pp, int pos);
 	void (*scan_bus)(struct pcie_port *pp);
+	void (*set_num_vectors)(struct pcie_port *pp);
 	int (*msi_host_init)(struct pcie_port *pp, struct msi_controller *chip);
 };
 
@@ -165,7 +167,11 @@  struct pcie_port {
 	struct dw_pcie_host_ops	*ops;
 	int			msi_irq;
 	struct irq_domain	*irq_domain;
+	struct irq_domain	*msi_domain;
 	unsigned long		msi_data;
+	u32			num_vectors;
+	u32			irq_status[MAX_MSI_CTRLS];
+	spinlock_t		lock;
 	DECLARE_BITMAP(msi_irq_in_use, MAX_MSI_IRQS);
 };
 
@@ -282,8 +288,10 @@  static inline u32 dw_pcie_readl_dbi2(struct dw_pcie *pci, u32 reg)
 #ifdef CONFIG_PCIE_DW_HOST
 irqreturn_t dw_handle_msi_irq(struct pcie_port *pp);
 void dw_pcie_msi_init(struct pcie_port *pp);
+void dw_pcie_free_msi(struct pcie_port *pp);
 void dw_pcie_setup_rc(struct pcie_port *pp);
 int dw_pcie_host_init(struct pcie_port *pp);
+int dw_pcie_allocate_domains(struct dw_pcie *pci);
 #else
 static inline irqreturn_t dw_handle_msi_irq(struct pcie_port *pp)
 {
@@ -294,6 +302,10 @@  static inline void dw_pcie_msi_init(struct pcie_port *pp)
 {
 }
 
+static inline void dw_pcie_free_msi(struct pcie_port *pp)
+{
+}
+
 static inline void dw_pcie_setup_rc(struct pcie_port *pp)
 {
 }
@@ -302,6 +314,11 @@  static inline int dw_pcie_host_init(struct pcie_port *pp)
 {
 	return 0;
 }
+
+static inline int dw_pcie_allocate_domains(struct dw_pcie *pci)
+{
+	return 0;
+}
 #endif
 
 #ifdef CONFIG_PCIE_DW_EP