diff mbox series

[v16,08/22] PCI: designware-ep: Add INTx IRQs support

Message ID 20230510062234.201499-9-yoshihiro.shimoda.uh@renesas.com (mailing list archive)
State Superseded
Delegated to: Krzysztof WilczyƄski
Headers show
Series PCI: rcar-gen4: Add R-Car Gen4 PCIe support | expand

Commit Message

Yoshihiro Shimoda May 10, 2023, 6:22 a.m. UTC
Add support for triggering INTx IRQs by using outbound iATU.
Outbound iATU is utilized to send assert and de-assert INTx TLPs.
The message is generated based on the payloadless Msg TLP with type
0x14, where 0x4 is the routing code implying the Terminate at
Receiver message. The message code is specified as b1000xx for
the INTx assertion and b1001xx for the INTx de-assertion.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
---
 .../pci/controller/dwc/pcie-designware-ep.c   | 66 +++++++++++++++++--
 drivers/pci/controller/dwc/pcie-designware.h  |  2 +
 2 files changed, 64 insertions(+), 4 deletions(-)

Comments

Serge Semin June 5, 2023, 8:05 a.m. UTC | #1
On Wed, May 10, 2023 at 03:22:20PM +0900, Yoshihiro Shimoda wrote:
> Add support for triggering INTx IRQs by using outbound iATU.
> Outbound iATU is utilized to send assert and de-assert INTx TLPs.
> The message is generated based on the payloadless Msg TLP with type
> 0x14, where 0x4 is the routing code implying the Terminate at
> Receiver message. The message code is specified as b1000xx for
> the INTx assertion and b1001xx for the INTx de-assertion.
> 
> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> ---
>  .../pci/controller/dwc/pcie-designware-ep.c   | 66 +++++++++++++++++--
>  drivers/pci/controller/dwc/pcie-designware.h  |  2 +
>  2 files changed, 64 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
> index fe2e0d765be9..0abc0073b1cf 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-ep.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
> @@ -6,9 +6,11 @@
>   * Author: Kishon Vijay Abraham I <kishon@ti.com>
>   */
>  
> +#include <linux/delay.h>
>  #include <linux/of.h>
>  #include <linux/platform_device.h>
>  
> +#include "../../pci.h"
>  #include "pcie-designware.h"
>  #include <linux/pci-epc.h>
>  #include <linux/pci-epf.h>
> @@ -484,14 +486,57 @@ static const struct pci_epc_ops epc_ops = {
>  	.get_features		= dw_pcie_ep_get_features,
>  };
>  
> +static int dw_pcie_ep_send_msg(struct dw_pcie_ep *ep, u8 func_no, u8 code,
> +			       u8 routing)
> +{
> +	struct dw_pcie_ob_atu_cfg atu = { 0 };
> +	struct pci_epc *epc = ep->epc;
> +	int ret;
> +
> +	atu.func_no = func_no;
> +	atu.code = code;
> +	atu.routing = routing;
> +	atu.type = PCIE_ATU_TYPE_MSG;
> +	atu.cpu_addr = ep->intx_mem_phys;
> +	atu.size = epc->mem->window.page_size;
> +
> +	ret = dw_pcie_ep_outbound_atu(ep, &atu);
> +	if (ret)
> +		return ret;
> +
> +	writel(0, ep->intx_mem);
> +
> +	dw_pcie_ep_unmap_addr(epc, func_no, 0, ep->intx_mem_phys);
> +
> +	return 0;
> +}
> +
>  int dw_pcie_ep_raise_intx_irq(struct dw_pcie_ep *ep, u8 func_no)
>  {
>  	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
>  	struct device *dev = pci->dev;
> +	int ret;
>  
> -	dev_err(dev, "EP cannot trigger INTx IRQs\n");
> +	if (!ep->intx_mem) {
> +		dev_err(dev, "INTx not supported\n");
> +		return -EOPNOTSUPP;
> +	}
>  
> -	return -EINVAL;
> +	/*

> +	 * According to the document of PCIe, the INTx emulation should be
> +	 * level-triggered. However, the Linux PCIe Endpoint framework only
> +	 * supports edge-triggered for now. So, this function asserts INTx for
> +	 * 50 usec, and then deasserts it.

"Document of PCIe"?)
What about the next message:
Even though the PCI bus specification implies the level-triggered INTx
interrupts the kernel PCIe endpoint framework has a single
PCI_EPC_IRQ_INTx flag defined for the legacy IRQs simulation. Thus
this function sends the Deassert_INTx PCIe TLP after the Assert_INTx
message with the 50 usec duration basically implementing the
rising-edge triggering IRQ. Hopefully the interrupt controller will
still be able to register the incoming IRQ event...

Other than that the change looks good.

-Serge(y)

> +	 */
> +	ret = dw_pcie_ep_send_msg(ep, func_no, PCI_CODE_ASSERT_INTA,
> +				  PCI_MSG_ROUTING_LOCAL);
> +	if (ret)
> +		return ret;
> +
> +	usleep_range(50, 100);
> +
> +	return dw_pcie_ep_send_msg(ep, func_no, PCI_CODE_DEASSERT_INTA,
> +				   PCI_MSG_ROUTING_LOCAL);
>  }
>  EXPORT_SYMBOL_GPL(dw_pcie_ep_raise_intx_irq);
>  
> @@ -622,6 +667,10 @@ void dw_pcie_ep_exit(struct dw_pcie_ep *ep)
>  
>  	dw_pcie_edma_remove(pci);
>  
> +	if (ep->intx_mem)
> +		pci_epc_mem_free_addr(epc, ep->intx_mem_phys, ep->intx_mem,
> +				      epc->mem->window.page_size);
> +
>  	pci_epc_mem_free_addr(epc, ep->msi_mem_phys, ep->msi_mem,
>  			      epc->mem->window.page_size);
>  
> @@ -793,9 +842,14 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
>  		goto err_exit_epc_mem;
>  	}
>  
> +	ep->intx_mem = pci_epc_mem_alloc_addr(epc, &ep->intx_mem_phys,
> +					      epc->mem->window.page_size);
> +	if (!ep->intx_mem)
> +		dev_warn(dev, "Failed to reserve memory for INTx\n");
> +
>  	ret = dw_pcie_edma_detect(pci);
>  	if (ret)
> -		goto err_free_epc_mem;
> +		goto err_free_epc_mem_intx;
>  
>  	if (ep->ops->get_features) {
>  		epc_features = ep->ops->get_features(ep);
> @@ -812,7 +866,11 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
>  err_remove_edma:
>  	dw_pcie_edma_remove(pci);
>  
> -err_free_epc_mem:
> +err_free_epc_mem_intx:
> +	if (ep->intx_mem)
> +		pci_epc_mem_free_addr(epc, ep->intx_mem_phys, ep->intx_mem,
> +				      epc->mem->window.page_size);
> +
>  	pci_epc_mem_free_addr(epc, ep->msi_mem_phys, ep->msi_mem,
>  			      epc->mem->window.page_size);
>  
> diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
> index c83d1d176e62..06e044e2163a 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.h
> +++ b/drivers/pci/controller/dwc/pcie-designware.h
> @@ -369,6 +369,8 @@ struct dw_pcie_ep {
>  	unsigned long		*ob_window_map;
>  	void __iomem		*msi_mem;
>  	phys_addr_t		msi_mem_phys;
> +	void __iomem		*intx_mem;
> +	phys_addr_t		intx_mem_phys;
>  	struct pci_epf_bar	*epf_bar[PCI_STD_NUM_BARS];
>  };
>  
> -- 
> 2.25.1
>
Yoshihiro Shimoda June 6, 2023, 9:20 a.m. UTC | #2
Hello Serge,

> From: Serge Semin, Sent: Monday, June 5, 2023 5:06 PM
> 
> On Wed, May 10, 2023 at 03:22:20PM +0900, Yoshihiro Shimoda wrote:
> > Add support for triggering INTx IRQs by using outbound iATU.
> > Outbound iATU is utilized to send assert and de-assert INTx TLPs.
> > The message is generated based on the payloadless Msg TLP with type
> > 0x14, where 0x4 is the routing code implying the Terminate at
> > Receiver message. The message code is specified as b1000xx for
> > the INTx assertion and b1001xx for the INTx de-assertion.
> >
> > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> > ---
> >  .../pci/controller/dwc/pcie-designware-ep.c   | 66 +++++++++++++++++--
> >  drivers/pci/controller/dwc/pcie-designware.h  |  2 +
> >  2 files changed, 64 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
> > index fe2e0d765be9..0abc0073b1cf 100644
> > --- a/drivers/pci/controller/dwc/pcie-designware-ep.c
> > +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
> > @@ -6,9 +6,11 @@
> >   * Author: Kishon Vijay Abraham I <kishon@ti.com>
> >   */
> >
> > +#include <linux/delay.h>
> >  #include <linux/of.h>
> >  #include <linux/platform_device.h>
> >
> > +#include "../../pci.h"
> >  #include "pcie-designware.h"
> >  #include <linux/pci-epc.h>
> >  #include <linux/pci-epf.h>
> > @@ -484,14 +486,57 @@ static const struct pci_epc_ops epc_ops = {
> >  	.get_features		= dw_pcie_ep_get_features,
> >  };
> >
> > +static int dw_pcie_ep_send_msg(struct dw_pcie_ep *ep, u8 func_no, u8 code,
> > +			       u8 routing)
> > +{
> > +	struct dw_pcie_ob_atu_cfg atu = { 0 };
> > +	struct pci_epc *epc = ep->epc;
> > +	int ret;
> > +
> > +	atu.func_no = func_no;
> > +	atu.code = code;
> > +	atu.routing = routing;
> > +	atu.type = PCIE_ATU_TYPE_MSG;
> > +	atu.cpu_addr = ep->intx_mem_phys;
> > +	atu.size = epc->mem->window.page_size;
> > +
> > +	ret = dw_pcie_ep_outbound_atu(ep, &atu);
> > +	if (ret)
> > +		return ret;
> > +
> > +	writel(0, ep->intx_mem);
> > +
> > +	dw_pcie_ep_unmap_addr(epc, func_no, 0, ep->intx_mem_phys);
> > +
> > +	return 0;
> > +}
> > +
> >  int dw_pcie_ep_raise_intx_irq(struct dw_pcie_ep *ep, u8 func_no)
> >  {
> >  	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> >  	struct device *dev = pci->dev;
> > +	int ret;
> >
> > -	dev_err(dev, "EP cannot trigger INTx IRQs\n");
> > +	if (!ep->intx_mem) {
> > +		dev_err(dev, "INTx not supported\n");
> > +		return -EOPNOTSUPP;
> > +	}
> >
> > -	return -EINVAL;
> > +	/*
> 
> > +	 * According to the document of PCIe, the INTx emulation should be
> > +	 * level-triggered. However, the Linux PCIe Endpoint framework only
> > +	 * supports edge-triggered for now. So, this function asserts INTx for
> > +	 * 50 usec, and then deasserts it.
> 
> "Document of PCIe"?)
> What about the next message:
> Even though the PCI bus specification implies the level-triggered INTx
> interrupts the kernel PCIe endpoint framework has a single
> PCI_EPC_IRQ_INTx flag defined for the legacy IRQs simulation. Thus
> this function sends the Deassert_INTx PCIe TLP after the Assert_INTx
> message with the 50 usec duration basically implementing the
> rising-edge triggering IRQ. Hopefully the interrupt controller will
> still be able to register the incoming IRQ event...

Thank you for your suggestion! I'll use your comment on v17.

> Other than that the change looks good.

Thanks!

Best regards,
Yoshihiro Shimoda

> -Serge(y)
> 
> > +	 */
> > +	ret = dw_pcie_ep_send_msg(ep, func_no, PCI_CODE_ASSERT_INTA,
> > +				  PCI_MSG_ROUTING_LOCAL);
> > +	if (ret)
> > +		return ret;
> > +
> > +	usleep_range(50, 100);
> > +
> > +	return dw_pcie_ep_send_msg(ep, func_no, PCI_CODE_DEASSERT_INTA,
> > +				   PCI_MSG_ROUTING_LOCAL);
> >  }
> >  EXPORT_SYMBOL_GPL(dw_pcie_ep_raise_intx_irq);
> >
> > @@ -622,6 +667,10 @@ void dw_pcie_ep_exit(struct dw_pcie_ep *ep)
> >
> >  	dw_pcie_edma_remove(pci);
> >
> > +	if (ep->intx_mem)
> > +		pci_epc_mem_free_addr(epc, ep->intx_mem_phys, ep->intx_mem,
> > +				      epc->mem->window.page_size);
> > +
> >  	pci_epc_mem_free_addr(epc, ep->msi_mem_phys, ep->msi_mem,
> >  			      epc->mem->window.page_size);
> >
> > @@ -793,9 +842,14 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
> >  		goto err_exit_epc_mem;
> >  	}
> >
> > +	ep->intx_mem = pci_epc_mem_alloc_addr(epc, &ep->intx_mem_phys,
> > +					      epc->mem->window.page_size);
> > +	if (!ep->intx_mem)
> > +		dev_warn(dev, "Failed to reserve memory for INTx\n");
> > +
> >  	ret = dw_pcie_edma_detect(pci);
> >  	if (ret)
> > -		goto err_free_epc_mem;
> > +		goto err_free_epc_mem_intx;
> >
> >  	if (ep->ops->get_features) {
> >  		epc_features = ep->ops->get_features(ep);
> > @@ -812,7 +866,11 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
> >  err_remove_edma:
> >  	dw_pcie_edma_remove(pci);
> >
> > -err_free_epc_mem:
> > +err_free_epc_mem_intx:
> > +	if (ep->intx_mem)
> > +		pci_epc_mem_free_addr(epc, ep->intx_mem_phys, ep->intx_mem,
> > +				      epc->mem->window.page_size);
> > +
> >  	pci_epc_mem_free_addr(epc, ep->msi_mem_phys, ep->msi_mem,
> >  			      epc->mem->window.page_size);
> >
> > diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
> > index c83d1d176e62..06e044e2163a 100644
> > --- a/drivers/pci/controller/dwc/pcie-designware.h
> > +++ b/drivers/pci/controller/dwc/pcie-designware.h
> > @@ -369,6 +369,8 @@ struct dw_pcie_ep {
> >  	unsigned long		*ob_window_map;
> >  	void __iomem		*msi_mem;
> >  	phys_addr_t		msi_mem_phys;
> > +	void __iomem		*intx_mem;
> > +	phys_addr_t		intx_mem_phys;
> >  	struct pci_epf_bar	*epf_bar[PCI_STD_NUM_BARS];
> >  };
> >
> > --
> > 2.25.1
> >
diff mbox series

Patch

diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
index fe2e0d765be9..0abc0073b1cf 100644
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -6,9 +6,11 @@ 
  * Author: Kishon Vijay Abraham I <kishon@ti.com>
  */
 
+#include <linux/delay.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
 
+#include "../../pci.h"
 #include "pcie-designware.h"
 #include <linux/pci-epc.h>
 #include <linux/pci-epf.h>
@@ -484,14 +486,57 @@  static const struct pci_epc_ops epc_ops = {
 	.get_features		= dw_pcie_ep_get_features,
 };
 
+static int dw_pcie_ep_send_msg(struct dw_pcie_ep *ep, u8 func_no, u8 code,
+			       u8 routing)
+{
+	struct dw_pcie_ob_atu_cfg atu = { 0 };
+	struct pci_epc *epc = ep->epc;
+	int ret;
+
+	atu.func_no = func_no;
+	atu.code = code;
+	atu.routing = routing;
+	atu.type = PCIE_ATU_TYPE_MSG;
+	atu.cpu_addr = ep->intx_mem_phys;
+	atu.size = epc->mem->window.page_size;
+
+	ret = dw_pcie_ep_outbound_atu(ep, &atu);
+	if (ret)
+		return ret;
+
+	writel(0, ep->intx_mem);
+
+	dw_pcie_ep_unmap_addr(epc, func_no, 0, ep->intx_mem_phys);
+
+	return 0;
+}
+
 int dw_pcie_ep_raise_intx_irq(struct dw_pcie_ep *ep, u8 func_no)
 {
 	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
 	struct device *dev = pci->dev;
+	int ret;
 
-	dev_err(dev, "EP cannot trigger INTx IRQs\n");
+	if (!ep->intx_mem) {
+		dev_err(dev, "INTx not supported\n");
+		return -EOPNOTSUPP;
+	}
 
-	return -EINVAL;
+	/*
+	 * According to the document of PCIe, the INTx emulation should be
+	 * level-triggered. However, the Linux PCIe Endpoint framework only
+	 * supports edge-triggered for now. So, this function asserts INTx for
+	 * 50 usec, and then deasserts it.
+	 */
+	ret = dw_pcie_ep_send_msg(ep, func_no, PCI_CODE_ASSERT_INTA,
+				  PCI_MSG_ROUTING_LOCAL);
+	if (ret)
+		return ret;
+
+	usleep_range(50, 100);
+
+	return dw_pcie_ep_send_msg(ep, func_no, PCI_CODE_DEASSERT_INTA,
+				   PCI_MSG_ROUTING_LOCAL);
 }
 EXPORT_SYMBOL_GPL(dw_pcie_ep_raise_intx_irq);
 
@@ -622,6 +667,10 @@  void dw_pcie_ep_exit(struct dw_pcie_ep *ep)
 
 	dw_pcie_edma_remove(pci);
 
+	if (ep->intx_mem)
+		pci_epc_mem_free_addr(epc, ep->intx_mem_phys, ep->intx_mem,
+				      epc->mem->window.page_size);
+
 	pci_epc_mem_free_addr(epc, ep->msi_mem_phys, ep->msi_mem,
 			      epc->mem->window.page_size);
 
@@ -793,9 +842,14 @@  int dw_pcie_ep_init(struct dw_pcie_ep *ep)
 		goto err_exit_epc_mem;
 	}
 
+	ep->intx_mem = pci_epc_mem_alloc_addr(epc, &ep->intx_mem_phys,
+					      epc->mem->window.page_size);
+	if (!ep->intx_mem)
+		dev_warn(dev, "Failed to reserve memory for INTx\n");
+
 	ret = dw_pcie_edma_detect(pci);
 	if (ret)
-		goto err_free_epc_mem;
+		goto err_free_epc_mem_intx;
 
 	if (ep->ops->get_features) {
 		epc_features = ep->ops->get_features(ep);
@@ -812,7 +866,11 @@  int dw_pcie_ep_init(struct dw_pcie_ep *ep)
 err_remove_edma:
 	dw_pcie_edma_remove(pci);
 
-err_free_epc_mem:
+err_free_epc_mem_intx:
+	if (ep->intx_mem)
+		pci_epc_mem_free_addr(epc, ep->intx_mem_phys, ep->intx_mem,
+				      epc->mem->window.page_size);
+
 	pci_epc_mem_free_addr(epc, ep->msi_mem_phys, ep->msi_mem,
 			      epc->mem->window.page_size);
 
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index c83d1d176e62..06e044e2163a 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -369,6 +369,8 @@  struct dw_pcie_ep {
 	unsigned long		*ob_window_map;
 	void __iomem		*msi_mem;
 	phys_addr_t		msi_mem_phys;
+	void __iomem		*intx_mem;
+	phys_addr_t		intx_mem_phys;
 	struct pci_epf_bar	*epf_bar[PCI_STD_NUM_BARS];
 };