2019-12-03 04:58:21

by Srinath Mannam

[permalink] [raw]
Subject: [PATCH v3 0/6] PAXB INTx support with proper model

This patch series adds PCIe legacy interrupt (INTx) support to the iProc
PCIe driver by modeling it with its own IRQ domain. All 4 interrupts INTA,
INTB, INTC, INTD share the same interrupt line connected to the GIC
in the system. This is now modeled by using its own IRQ domain.

Also update all relevant devicetree files to adapt to the new model.

This patch set is based on Linux-5.4.

Changes from v2:
- Addressed Lorenzo's comments
- Corrected INTx to PIN mapping.

Changes from v1:
- Addressed Rob, Lorenzo, Arnd's comments
- Used child node for interrupt controller.
- Addressed Andy Shevchenko's comments
- Replaced while loop with do-while.

Ray Jui (6):
dt-bindings: pci: Update iProc PCI binding for INTx support
PCI: iproc: Add INTx support with better modeling
arm: dts: Change PCIe INTx mapping for Cygnus
arm: dts: Change PCIe INTx mapping for NSP
arm: dts: Change PCIe INTx mapping for HR2
arm64: dts: Change PCIe INTx mapping for NS2

.../devicetree/bindings/pci/brcm,iproc-pcie.txt | 48 ++++++++--
arch/arm/boot/dts/bcm-cygnus.dtsi | 30 ++++++-
arch/arm/boot/dts/bcm-hr2.dtsi | 30 ++++++-
arch/arm/boot/dts/bcm-nsp.dtsi | 45 ++++++++--
arch/arm64/boot/dts/broadcom/northstar2/ns2.dtsi | 28 +++++-
drivers/pci/controller/pcie-iproc.c | 100 ++++++++++++++++++++-
drivers/pci/controller/pcie-iproc.h | 6 ++
7 files changed, 260 insertions(+), 27 deletions(-)

--
2.7.4


2019-12-03 04:58:27

by Srinath Mannam

[permalink] [raw]
Subject: [PATCH v3 1/6] dt-bindings: pci: Update iProc PCI binding for INTx support

From: Ray Jui <[email protected]>

Update the iProc PCIe binding document for better modeling of the legacy
interrupt (INTx) support

Signed-off-by: Ray Jui <[email protected]>
Signed-off-by: Srinath Mannam <[email protected]>
---
.../devicetree/bindings/pci/brcm,iproc-pcie.txt | 48 ++++++++++++++++++----
1 file changed, 41 insertions(+), 7 deletions(-)

diff --git a/Documentation/devicetree/bindings/pci/brcm,iproc-pcie.txt b/Documentation/devicetree/bindings/pci/brcm,iproc-pcie.txt
index df065aa..d3f833a 100644
--- a/Documentation/devicetree/bindings/pci/brcm,iproc-pcie.txt
+++ b/Documentation/devicetree/bindings/pci/brcm,iproc-pcie.txt
@@ -13,9 +13,6 @@ controller, used in Stingray
PAXB-based root complex is used for external endpoint devices. PAXC-based
root complex is connected to emulated endpoint devices internal to the ASIC
- reg: base address and length of the PCIe controller I/O register space
-- #interrupt-cells: set to <1>
-- interrupt-map-mask and interrupt-map, standard PCI properties to define the
- mapping of the PCIe interface to interrupt numbers
- linux,pci-domain: PCI domain ID. Should be unique for each host controller
- bus-range: PCI bus numbers covered
- #address-cells: set to <3>
@@ -41,6 +38,21 @@ Required:
- brcm,pcie-ob-axi-offset: The offset from the AXI address to the internal
address used by the iProc PCIe core (not the PCIe address)

+Legacy interrupt (INTx) support (optional):
+
+Note INTx is for PAXB only.
+- interrupt-map-mask and interrupt-map, standard PCI properties to define
+the mapping of the PCIe interface to interrupt numbers
+
+In addition, a sub-node that describes the legacy interrupt controller built
+into the PCIe controller.
+This sub-node must have the following properties:
+ - compatible: must be "brcm,iproc-intc"
+ - interrupt-controller: claims itself as an interrupt controller for INTx
+ - #interrupt-cells: set to <1>
+ - interrupts: interrupt line wired to the generic GIC for INTx support
+ - interrupt-parent: Phandle to the parent interrupt controller
+
MSI support (optional):

For older platforms without MSI integrated in the GIC, iProc PCIe core provides
@@ -77,8 +89,11 @@ Example:
reg = <0x18012000 0x1000>;

#interrupt-cells = <1>;
- interrupt-map-mask = <0 0 0 0>;
- interrupt-map = <0 0 0 0 &gic GIC_SPI 100 IRQ_TYPE_NONE>;
+ interrupt-map-mask = <0 0 0 7>;
+ interrupt-map = <0 0 0 1 &pcie0_intc 0>,
+ <0 0 0 2 &pcie0_intc 1>,
+ <0 0 0 3 &pcie0_intc 2>,
+ <0 0 0 4 &pcie0_intc 3>;

linux,pci-domain = <0>;

@@ -98,6 +113,14 @@ Example:

msi-parent = <&msi0>;

+ pcie0_intc: interrupt-controller {
+ compatible = "brcm,iproc-intc";
+ interrupt-controller;
+ #interrupt-cells = <1>;
+ interrupt-parent = <&gic>;
+ interrupts = <GIC_SPI 100 IRQ_TYPE_NONE>;
+ };
+
/* iProc event queue based MSI */
msi0: msi@18012000 {
compatible = "brcm,iproc-msi";
@@ -115,8 +138,11 @@ Example:
reg = <0x18013000 0x1000>;

#interrupt-cells = <1>;
- interrupt-map-mask = <0 0 0 0>;
- interrupt-map = <0 0 0 0 &gic GIC_SPI 106 IRQ_TYPE_NONE>;
+ interrupt-map-mask = <0 0 0 7>;
+ interrupt-map = <0 0 0 1 &pcie1_intc 0>,
+ <0 0 0 2 &pcie1_intc 1>,
+ <0 0 0 3 &pcie1_intc 2>,
+ <0 0 0 4 &pcie1_intc 3>;

linux,pci-domain = <1>;

@@ -130,4 +156,12 @@ Example:

phys = <&phy 1 6>;
phy-names = "pcie-phy";
+
+ pcie1_intc: interrupt-controller {
+ compatible = "brcm,iproc-intc";
+ interrupt-controller;
+ #interrupt-cells = <1>;
+ interrupt-parent = <&gic>;
+ interrupts = <GIC_SPI 106 IRQ_TYPE_NONE>;
+ };
};
--
2.7.4

2019-12-03 04:58:35

by Srinath Mannam

[permalink] [raw]
Subject: [PATCH v3 2/6] PCI: iproc: Add INTx support with better modeling

From: Ray Jui <[email protected]>

Add PCIe legacy interrupt INTx support to the iProc PCIe driver by
modeling it with its own IRQ domain. All 4 interrupts INTA, INTB, INTC,
INTD share the same interrupt line connected to the GIC in the system,
while the status of each INTx can be obtained through the INTX CSR
register

Signed-off-by: Ray Jui <[email protected]>
Signed-off-by: Srinath Mannam <[email protected]>
---
drivers/pci/controller/pcie-iproc.c | 100 +++++++++++++++++++++++++++++++++++-
drivers/pci/controller/pcie-iproc.h | 6 +++
2 files changed, 104 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/controller/pcie-iproc.c b/drivers/pci/controller/pcie-iproc.c
index 2d457bf..e90c22e 100644
--- a/drivers/pci/controller/pcie-iproc.c
+++ b/drivers/pci/controller/pcie-iproc.c
@@ -14,6 +14,7 @@
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/irqchip/arm-gic-v3.h>
+#include <linux/irqchip/chained_irq.h>
#include <linux/platform_device.h>
#include <linux/of_address.h>
#include <linux/of_pci.h>
@@ -270,6 +271,7 @@ enum iproc_pcie_reg {

/* enable INTx */
IPROC_PCIE_INTX_EN,
+ IPROC_PCIE_INTX_CSR,

/* outbound address mapping */
IPROC_PCIE_OARR0,
@@ -314,6 +316,7 @@ static const u16 iproc_pcie_reg_paxb_bcma[] = {
[IPROC_PCIE_CFG_ADDR] = 0x1f8,
[IPROC_PCIE_CFG_DATA] = 0x1fc,
[IPROC_PCIE_INTX_EN] = 0x330,
+ [IPROC_PCIE_INTX_CSR] = 0x334,
[IPROC_PCIE_LINK_STATUS] = 0xf0c,
};

@@ -325,6 +328,7 @@ static const u16 iproc_pcie_reg_paxb[] = {
[IPROC_PCIE_CFG_ADDR] = 0x1f8,
[IPROC_PCIE_CFG_DATA] = 0x1fc,
[IPROC_PCIE_INTX_EN] = 0x330,
+ [IPROC_PCIE_INTX_CSR] = 0x334,
[IPROC_PCIE_OARR0] = 0xd20,
[IPROC_PCIE_OMAP0] = 0xd40,
[IPROC_PCIE_OARR1] = 0xd28,
@@ -341,6 +345,7 @@ static const u16 iproc_pcie_reg_paxb_v2[] = {
[IPROC_PCIE_CFG_ADDR] = 0x1f8,
[IPROC_PCIE_CFG_DATA] = 0x1fc,
[IPROC_PCIE_INTX_EN] = 0x330,
+ [IPROC_PCIE_INTX_CSR] = 0x334,
[IPROC_PCIE_OARR0] = 0xd20,
[IPROC_PCIE_OMAP0] = 0xd40,
[IPROC_PCIE_OARR1] = 0xd28,
@@ -846,9 +851,95 @@ static int iproc_pcie_check_link(struct iproc_pcie *pcie)
return link_is_active ? 0 : -ENODEV;
}

-static void iproc_pcie_enable(struct iproc_pcie *pcie)
+static int iproc_pcie_intx_map(struct irq_domain *domain, unsigned int irq,
+ irq_hw_number_t hwirq)
{
+ irq_set_chip_and_handler(irq, &dummy_irq_chip, handle_simple_irq);
+ irq_set_chip_data(irq, domain->host_data);
+
+ return 0;
+}
+
+static const struct irq_domain_ops intx_domain_ops = {
+ .map = iproc_pcie_intx_map,
+};
+
+static void iproc_pcie_isr(struct irq_desc *desc)
+{
+ struct irq_chip *chip = irq_desc_get_chip(desc);
+ struct iproc_pcie *pcie;
+ struct device *dev;
+ unsigned long status;
+ u32 bit, virq;
+
+ chained_irq_enter(chip, desc);
+ pcie = irq_desc_get_handler_data(desc);
+ dev = pcie->dev;
+
+ /* go through INTx A, B, C, D until all interrupts are handled */
+ do {
+ status = iproc_pcie_read_reg(pcie, IPROC_PCIE_INTX_CSR);
+ for_each_set_bit(bit, &status, PCI_NUM_INTX) {
+ virq = irq_find_mapping(pcie->irq_domain, bit);
+ if (virq)
+ generic_handle_irq(virq);
+ else
+ dev_err(dev, "unexpected INTx%u\n", bit);
+ }
+ } while ((status & SYS_RC_INTX_MASK) != 0);
+
+ chained_irq_exit(chip, desc);
+}
+
+static int iproc_pcie_intx_enable(struct iproc_pcie *pcie)
+{
+ struct device *dev = pcie->dev;
+ struct device_node *node;
+ int ret;
+
iproc_pcie_write_reg(pcie, IPROC_PCIE_INTX_EN, SYS_RC_INTX_MASK);
+ /*
+ * BCMA devices do not map INTx the same way as platform devices. All
+ * BCMA needs is the above code to enable INTx
+ */
+
+ node = of_get_compatible_child(dev->of_node, "brcm,iproc-intc");
+ if (node)
+ pcie->irq = of_irq_get(node, 0);
+
+ if (!node || pcie->irq <= 0)
+ return 0;
+
+ /* set IRQ handler */
+ irq_set_chained_handler_and_data(pcie->irq, iproc_pcie_isr, pcie);
+
+ /* add IRQ domain for INTx */
+ pcie->irq_domain = irq_domain_add_linear(node, PCI_NUM_INTX,
+ &intx_domain_ops, pcie);
+ if (!pcie->irq_domain) {
+ dev_err(dev, "failed to add INTx IRQ domain\n");
+ ret = -ENOMEM;
+ goto err_rm_handler_data;
+ }
+
+ return 0;
+
+err_rm_handler_data:
+ of_node_put(node);
+ irq_set_chained_handler_and_data(pcie->irq, NULL, NULL);
+
+ return ret;
+}
+
+static void iproc_pcie_intx_disable(struct iproc_pcie *pcie)
+{
+ iproc_pcie_write_reg(pcie, IPROC_PCIE_INTX_EN, 0x0);
+
+ if (pcie->irq <= 0)
+ return;
+
+ irq_domain_remove(pcie->irq_domain);
+ irq_set_chained_handler_and_data(pcie->irq, NULL, NULL);
}

static inline bool iproc_pcie_ob_is_valid(struct iproc_pcie *pcie,
@@ -1537,7 +1628,11 @@ int iproc_pcie_setup(struct iproc_pcie *pcie, struct list_head *res)
goto err_power_off_phy;
}

- iproc_pcie_enable(pcie);
+ ret = iproc_pcie_intx_enable(pcie);
+ if (ret) {
+ dev_err(dev, "failed to enable INTx\n");
+ goto err_power_off_phy;
+ }

if (IS_ENABLED(CONFIG_PCI_MSI))
if (iproc_pcie_msi_enable(pcie))
@@ -1582,6 +1677,7 @@ int iproc_pcie_remove(struct iproc_pcie *pcie)
pci_remove_root_bus(pcie->root_bus);

iproc_pcie_msi_disable(pcie);
+ iproc_pcie_intx_disable(pcie);

phy_power_off(pcie->phy);
phy_exit(pcie->phy);
diff --git a/drivers/pci/controller/pcie-iproc.h b/drivers/pci/controller/pcie-iproc.h
index 4f03ea5..103e568 100644
--- a/drivers/pci/controller/pcie-iproc.h
+++ b/drivers/pci/controller/pcie-iproc.h
@@ -74,6 +74,9 @@ struct iproc_msi;
* @ib: inbound mapping related parameters
* @ib_map: outbound mapping region related parameters
*
+ * @irq: interrupt line wired to the generic GIC for INTx
+ * @irq_domain: IRQ domain for INTx
+ *
* @need_msi_steer: indicates additional configuration of the iProc PCIe
* controller is required to steer MSI writes to external interrupt controller
* @msi: MSI data
@@ -102,6 +105,9 @@ struct iproc_pcie {
struct iproc_pcie_ib ib;
const struct iproc_pcie_ib_map *ib_map;

+ int irq;
+ struct irq_domain *irq_domain;
+
bool need_msi_steer;
struct iproc_msi *msi;
};
--
2.7.4

2019-12-03 04:58:39

by Srinath Mannam

[permalink] [raw]
Subject: [PATCH v3 3/6] arm: dts: Change PCIe INTx mapping for Cygnus

From: Ray Jui <[email protected]>

Change the PCIe INTx mapping to model the 4 INTx interrupts in the
IRQ domain of the iProc PCIe controller itself

Signed-off-by: Ray Jui <[email protected]>
Signed-off-by: Srinath Mannam <[email protected]>
---
arch/arm/boot/dts/bcm-cygnus.dtsi | 30 ++++++++++++++++++++++++++----
1 file changed, 26 insertions(+), 4 deletions(-)

diff --git a/arch/arm/boot/dts/bcm-cygnus.dtsi b/arch/arm/boot/dts/bcm-cygnus.dtsi
index 2dac3ef..ca23e82 100644
--- a/arch/arm/boot/dts/bcm-cygnus.dtsi
+++ b/arch/arm/boot/dts/bcm-cygnus.dtsi
@@ -264,8 +264,11 @@
reg = <0x18012000 0x1000>;

#interrupt-cells = <1>;
- interrupt-map-mask = <0 0 0 0>;
- interrupt-map = <0 0 0 0 &gic GIC_SPI 100 IRQ_TYPE_LEVEL_HIGH>;
+ interrupt-map-mask = <0 0 0 7>;
+ interrupt-map = <0 0 0 1 &pcie0_intc 0>,
+ <0 0 0 2 &pcie0_intc 1>,
+ <0 0 0 3 &pcie0_intc 2>,
+ <0 0 0 4 &pcie0_intc 3>;

linux,pci-domain = <0>;

@@ -292,6 +295,14 @@
<GIC_SPI 98 IRQ_TYPE_LEVEL_HIGH>,
<GIC_SPI 99 IRQ_TYPE_LEVEL_HIGH>;
};
+
+ pcie0_intc: interrupt-controller {
+ compatible = "brcm,iproc-intc";
+ interrupt-controller;
+ #interrupt-cells = <1>;
+ interrupt-parent = <&gic>;
+ interrupts = <GIC_SPI 100 IRQ_TYPE_LEVEL_HIGH>;
+ };
};

pcie1: pcie@18013000 {
@@ -299,8 +310,11 @@
reg = <0x18013000 0x1000>;

#interrupt-cells = <1>;
- interrupt-map-mask = <0 0 0 0>;
- interrupt-map = <0 0 0 0 &gic GIC_SPI 106 IRQ_TYPE_LEVEL_HIGH>;
+ interrupt-map-mask = <0 0 0 7>;
+ interrupt-map = <0 0 0 1 &pcie1_intc 0>,
+ <0 0 0 2 &pcie1_intc 1>,
+ <0 0 0 3 &pcie1_intc 2>,
+ <0 0 0 4 &pcie1_intc 3>;

linux,pci-domain = <1>;

@@ -327,6 +341,14 @@
<GIC_SPI 104 IRQ_TYPE_LEVEL_HIGH>,
<GIC_SPI 105 IRQ_TYPE_LEVEL_HIGH>;
};
+
+ pcie1_intc: interrupt-controller {
+ compatible = "brcm,iproc-intc";
+ interrupt-controller;
+ #interrupt-cells = <1>;
+ interrupt-parent = <&gic>;
+ interrupts = <GIC_SPI 106 IRQ_TYPE_LEVEL_HIGH>;
+ };
};

dma0: dma@18018000 {
--
2.7.4

2019-12-03 04:58:59

by Srinath Mannam

[permalink] [raw]
Subject: [PATCH v3 4/6] arm: dts: Change PCIe INTx mapping for NSP

From: Ray Jui <[email protected]>

Change the PCIe INTx mapping to model the 4 INTx interrupts in the
IRQ domain of the iProc PCIe controller itself

Signed-off-by: Ray Jui <[email protected]>
Signed-off-by: Srinath Mannam <[email protected]>
---
arch/arm/boot/dts/bcm-nsp.dtsi | 45 ++++++++++++++++++++++++++++++++++++------
1 file changed, 39 insertions(+), 6 deletions(-)

diff --git a/arch/arm/boot/dts/bcm-nsp.dtsi b/arch/arm/boot/dts/bcm-nsp.dtsi
index da6d70f..6d73221 100644
--- a/arch/arm/boot/dts/bcm-nsp.dtsi
+++ b/arch/arm/boot/dts/bcm-nsp.dtsi
@@ -529,8 +529,11 @@
reg = <0x18012000 0x1000>;

#interrupt-cells = <1>;
- interrupt-map-mask = <0 0 0 0>;
- interrupt-map = <0 0 0 0 &gic GIC_SPI 131 IRQ_TYPE_LEVEL_HIGH>;
+ interrupt-map-mask = <0 0 0 7>;
+ interrupt-map = <0 0 0 1 &pcie0_intc 0>,
+ <0 0 0 2 &pcie0_intc 1>,
+ <0 0 0 3 &pcie0_intc 2>,
+ <0 0 0 4 &pcie0_intc 3>;

linux,pci-domain = <0>;

@@ -559,6 +562,14 @@
<GIC_SPI 130 IRQ_TYPE_LEVEL_HIGH>;
brcm,pcie-msi-inten;
};
+
+ pcie0_intc: interrupt-controller {
+ compatible = "brcm,iproc-intc";
+ interrupt-controller;
+ #interrupt-cells = <1>;
+ interrupt-parent = <&gic>;
+ interrupts = <GIC_SPI 131 IRQ_TYPE_LEVEL_HIGH>;
+ };
};

pcie1: pcie@18013000 {
@@ -566,8 +577,11 @@
reg = <0x18013000 0x1000>;

#interrupt-cells = <1>;
- interrupt-map-mask = <0 0 0 0>;
- interrupt-map = <0 0 0 0 &gic GIC_SPI 137 IRQ_TYPE_LEVEL_HIGH>;
+ interrupt-map-mask = <0 0 0 7>;
+ interrupt-map = <0 0 0 1 &pcie1_intc 0>,
+ <0 0 0 2 &pcie1_intc 1>,
+ <0 0 0 3 &pcie1_intc 2>,
+ <0 0 0 4 &pcie1_intc 3>;

linux,pci-domain = <1>;

@@ -596,6 +610,14 @@
<GIC_SPI 136 IRQ_TYPE_LEVEL_HIGH>;
brcm,pcie-msi-inten;
};
+
+ pcie1_intc: interrupt-controller {
+ compatible = "brcm,iproc-intc";
+ interrupt-controller;
+ #interrupt-cells = <1>;
+ interrupt-parent = <&gic>;
+ interrupts = <GIC_SPI 137 IRQ_TYPE_LEVEL_HIGH>;
+ };
};

pcie2: pcie@18014000 {
@@ -603,8 +625,11 @@
reg = <0x18014000 0x1000>;

#interrupt-cells = <1>;
- interrupt-map-mask = <0 0 0 0>;
- interrupt-map = <0 0 0 0 &gic GIC_SPI 143 IRQ_TYPE_LEVEL_HIGH>;
+ interrupt-map-mask = <0 0 0 7>;
+ interrupt-map = <0 0 0 1 &pcie2_intc 0>,
+ <0 0 0 2 &pcie2_intc 1>,
+ <0 0 0 3 &pcie2_intc 2>,
+ <0 0 0 4 &pcie2_intc 3>;

linux,pci-domain = <2>;

@@ -633,6 +658,14 @@
<GIC_SPI 142 IRQ_TYPE_LEVEL_HIGH>;
brcm,pcie-msi-inten;
};
+
+ pcie2_intc: interrupt-controller {
+ compatible = "brcm,iproc-intc";
+ interrupt-controller;
+ #interrupt-cells = <1>;
+ interrupt-parent = <&gic>;
+ interrupts = <GIC_SPI 143 IRQ_TYPE_LEVEL_HIGH>;
+ };
};

thermal-zones {
--
2.7.4

2019-12-03 04:59:17

by Srinath Mannam

[permalink] [raw]
Subject: [PATCH v3 6/6] arm64: dts: Change PCIe INTx mapping for NS2

From: Ray Jui <[email protected]>

Change the PCIe INTx mapping to model the 4 INTx interrupts in the
IRQ domain of the iProc PCIe controller itself

Signed-off-by: Ray Jui <[email protected]>
Signed-off-by: Srinath Mannam <[email protected]>
---
arch/arm64/boot/dts/broadcom/northstar2/ns2.dtsi | 28 ++++++++++++++++++++----
1 file changed, 24 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/boot/dts/broadcom/northstar2/ns2.dtsi b/arch/arm64/boot/dts/broadcom/northstar2/ns2.dtsi
index 15f7b0e..489bfd5 100644
--- a/arch/arm64/boot/dts/broadcom/northstar2/ns2.dtsi
+++ b/arch/arm64/boot/dts/broadcom/northstar2/ns2.dtsi
@@ -117,8 +117,11 @@
dma-coherent;

#interrupt-cells = <1>;
- interrupt-map-mask = <0 0 0 0>;
- interrupt-map = <0 0 0 0 &gic 0 GIC_SPI 281 IRQ_TYPE_LEVEL_HIGH>;
+ interrupt-map-mask = <0 0 0 7>;
+ interrupt-map = <0 0 0 1 &pcie0_intc 0>,
+ <0 0 0 2 &pcie0_intc 1>,
+ <0 0 0 3 &pcie0_intc 2>,
+ <0 0 0 4 &pcie0_intc 3>;

linux,pci-domain = <0>;

@@ -140,6 +143,13 @@
phy-names = "pcie-phy";

msi-parent = <&v2m0>;
+ pcie0_intc: interrupt-controller {
+ compatible = "brcm,iproc-intc";
+ interrupt-controller;
+ #interrupt-cells = <1>;
+ interrupt-parent = <&gic>;
+ interrupts = <GIC_SPI 281 IRQ_TYPE_LEVEL_HIGH>;
+ };
};

pcie4: pcie@50020000 {
@@ -148,8 +158,11 @@
dma-coherent;

#interrupt-cells = <1>;
- interrupt-map-mask = <0 0 0 0>;
- interrupt-map = <0 0 0 0 &gic 0 GIC_SPI 305 IRQ_TYPE_LEVEL_HIGH>;
+ interrupt-map-mask = <0 0 0 7>;
+ interrupt-map = <0 0 0 1 &pcie4_intc 0>,
+ <0 0 0 2 &pcie4_intc 1>,
+ <0 0 0 3 &pcie4_intc 2>,
+ <0 0 0 4 &pcie4_intc 3>;

linux,pci-domain = <4>;

@@ -171,6 +184,13 @@
phy-names = "pcie-phy";

msi-parent = <&v2m0>;
+ pcie4_intc: interrupt-controller {
+ compatible = "brcm,iproc-intc";
+ interrupt-controller;
+ #interrupt-cells = <1>;
+ interrupt-parent = <&gic>;
+ interrupts = <GIC_SPI 305 IRQ_TYPE_LEVEL_HIGH>;
+ };
};

pcie8: pcie@60c00000 {
--
2.7.4

2019-12-03 05:00:04

by Srinath Mannam

[permalink] [raw]
Subject: [PATCH v3 5/6] arm: dts: Change PCIe INTx mapping for HR2

From: Ray Jui <[email protected]>

Change the PCIe INTx mapping to model the 4 INTx interrupts in the
IRQ domain of the iProc PCIe controller itself

Signed-off-by: Ray Jui <[email protected]>
Signed-off-by: Srinath Mannam <[email protected]>
---
arch/arm/boot/dts/bcm-hr2.dtsi | 30 ++++++++++++++++++++++++++----
1 file changed, 26 insertions(+), 4 deletions(-)

diff --git a/arch/arm/boot/dts/bcm-hr2.dtsi b/arch/arm/boot/dts/bcm-hr2.dtsi
index e4d4973..d840190 100644
--- a/arch/arm/boot/dts/bcm-hr2.dtsi
+++ b/arch/arm/boot/dts/bcm-hr2.dtsi
@@ -299,8 +299,11 @@
reg = <0x18012000 0x1000>;

#interrupt-cells = <1>;
- interrupt-map-mask = <0 0 0 0>;
- interrupt-map = <0 0 0 0 &gic GIC_SPI 186 IRQ_TYPE_LEVEL_HIGH>;
+ interrupt-map-mask = <0 0 0 7>;
+ interrupt-map = <0 0 0 1 &pcie0_intc 0>,
+ <0 0 0 2 &pcie0_intc 1>,
+ <0 0 0 3 &pcie0_intc 2>,
+ <0 0 0 4 &pcie0_intc 3>;

linux,pci-domain = <0>;

@@ -328,6 +331,14 @@
<GIC_SPI 185 IRQ_TYPE_LEVEL_HIGH>;
brcm,pcie-msi-inten;
};
+
+ pcie0_intc: interrupt-controller {
+ compatible = "brcm,iproc-intc";
+ interrupt-controller;
+ #interrupt-cells = <1>;
+ interrupt-parent = <&gic>;
+ interrupts = <GIC_SPI 186 IRQ_TYPE_LEVEL_HIGH>;
+ };
};

pcie1: pcie@18013000 {
@@ -335,8 +346,11 @@
reg = <0x18013000 0x1000>;

#interrupt-cells = <1>;
- interrupt-map-mask = <0 0 0 0>;
- interrupt-map = <0 0 0 0 &gic GIC_SPI 192 IRQ_TYPE_LEVEL_HIGH>;
+ interrupt-map-mask = <0 0 0 7>;
+ interrupt-map = <0 0 0 1 &pcie1_intc 0>,
+ <0 0 0 2 &pcie1_intc 1>,
+ <0 0 0 3 &pcie1_intc 2>,
+ <0 0 0 4 &pcie1_intc 3>;

linux,pci-domain = <1>;

@@ -364,5 +378,13 @@
<GIC_SPI 191 IRQ_TYPE_LEVEL_HIGH>;
brcm,pcie-msi-inten;
};
+
+ pcie1_intc: interrupt-controller {
+ compatible = "brcm,iproc-intc";
+ interrupt-controller;
+ #interrupt-cells = <1>;
+ interrupt-parent = <&gic>;
+ interrupts = <GIC_SPI 192 IRQ_TYPE_LEVEL_HIGH>;
+ };
};
};
--
2.7.4

2019-12-03 15:56:11

by Andrew Murray

[permalink] [raw]
Subject: Re: [PATCH v3 2/6] PCI: iproc: Add INTx support with better modeling

On Tue, Dec 03, 2019 at 10:27:02AM +0530, Srinath Mannam wrote:
> From: Ray Jui <[email protected]>
>
> Add PCIe legacy interrupt INTx support to the iProc PCIe driver by
> modeling it with its own IRQ domain. All 4 interrupts INTA, INTB, INTC,
> INTD share the same interrupt line connected to the GIC in the system,
> while the status of each INTx can be obtained through the INTX CSR
> register
>
> Signed-off-by: Ray Jui <[email protected]>
> Signed-off-by: Srinath Mannam <[email protected]>
> ---
> drivers/pci/controller/pcie-iproc.c | 100 +++++++++++++++++++++++++++++++++++-
> drivers/pci/controller/pcie-iproc.h | 6 +++
> 2 files changed, 104 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/pci/controller/pcie-iproc.c b/drivers/pci/controller/pcie-iproc.c
> index 2d457bf..e90c22e 100644
> --- a/drivers/pci/controller/pcie-iproc.c
> +++ b/drivers/pci/controller/pcie-iproc.c
> @@ -14,6 +14,7 @@
> #include <linux/delay.h>
> #include <linux/interrupt.h>
> #include <linux/irqchip/arm-gic-v3.h>
> +#include <linux/irqchip/chained_irq.h>
> #include <linux/platform_device.h>
> #include <linux/of_address.h>
> #include <linux/of_pci.h>
> @@ -270,6 +271,7 @@ enum iproc_pcie_reg {
>
> /* enable INTx */
> IPROC_PCIE_INTX_EN,
> + IPROC_PCIE_INTX_CSR,
>
> /* outbound address mapping */
> IPROC_PCIE_OARR0,
> @@ -314,6 +316,7 @@ static const u16 iproc_pcie_reg_paxb_bcma[] = {
> [IPROC_PCIE_CFG_ADDR] = 0x1f8,
> [IPROC_PCIE_CFG_DATA] = 0x1fc,
> [IPROC_PCIE_INTX_EN] = 0x330,
> + [IPROC_PCIE_INTX_CSR] = 0x334,
> [IPROC_PCIE_LINK_STATUS] = 0xf0c,
> };
>
> @@ -325,6 +328,7 @@ static const u16 iproc_pcie_reg_paxb[] = {
> [IPROC_PCIE_CFG_ADDR] = 0x1f8,
> [IPROC_PCIE_CFG_DATA] = 0x1fc,
> [IPROC_PCIE_INTX_EN] = 0x330,
> + [IPROC_PCIE_INTX_CSR] = 0x334,
> [IPROC_PCIE_OARR0] = 0xd20,
> [IPROC_PCIE_OMAP0] = 0xd40,
> [IPROC_PCIE_OARR1] = 0xd28,
> @@ -341,6 +345,7 @@ static const u16 iproc_pcie_reg_paxb_v2[] = {
> [IPROC_PCIE_CFG_ADDR] = 0x1f8,
> [IPROC_PCIE_CFG_DATA] = 0x1fc,
> [IPROC_PCIE_INTX_EN] = 0x330,
> + [IPROC_PCIE_INTX_CSR] = 0x334,
> [IPROC_PCIE_OARR0] = 0xd20,
> [IPROC_PCIE_OMAP0] = 0xd40,
> [IPROC_PCIE_OARR1] = 0xd28,
> @@ -846,9 +851,95 @@ static int iproc_pcie_check_link(struct iproc_pcie *pcie)
> return link_is_active ? 0 : -ENODEV;
> }
>
> -static void iproc_pcie_enable(struct iproc_pcie *pcie)
> +static int iproc_pcie_intx_map(struct irq_domain *domain, unsigned int irq,
> + irq_hw_number_t hwirq)
> {
> + irq_set_chip_and_handler(irq, &dummy_irq_chip, handle_simple_irq);
> + irq_set_chip_data(irq, domain->host_data);
> +
> + return 0;
> +}
> +
> +static const struct irq_domain_ops intx_domain_ops = {
> + .map = iproc_pcie_intx_map,
> +};
> +
> +static void iproc_pcie_isr(struct irq_desc *desc)
> +{
> + struct irq_chip *chip = irq_desc_get_chip(desc);
> + struct iproc_pcie *pcie;
> + struct device *dev;
> + unsigned long status;
> + u32 bit, virq;
> +
> + chained_irq_enter(chip, desc);
> + pcie = irq_desc_get_handler_data(desc);
> + dev = pcie->dev;
> +
> + /* go through INTx A, B, C, D until all interrupts are handled */
> + do {
> + status = iproc_pcie_read_reg(pcie, IPROC_PCIE_INTX_CSR);

By performing this read once and outside of the do/while loop you may improve
performance. I wonder how probable it is to get another INTx whilst handling
one?


> + for_each_set_bit(bit, &status, PCI_NUM_INTX) {
> + virq = irq_find_mapping(pcie->irq_domain, bit);
> + if (virq)
> + generic_handle_irq(virq);
> + else
> + dev_err(dev, "unexpected INTx%u\n", bit);
> + }
> + } while ((status & SYS_RC_INTX_MASK) != 0);
> +
> + chained_irq_exit(chip, desc);
> +}
> +
> +static int iproc_pcie_intx_enable(struct iproc_pcie *pcie)
> +{
> + struct device *dev = pcie->dev;
> + struct device_node *node;
> + int ret;
> +
> iproc_pcie_write_reg(pcie, IPROC_PCIE_INTX_EN, SYS_RC_INTX_MASK);
> + /*
> + * BCMA devices do not map INTx the same way as platform devices. All
> + * BCMA needs is the above code to enable INTx
> + */

NIT: Move this comment above the line of code?


> +
> + node = of_get_compatible_child(dev->of_node, "brcm,iproc-intc");

As the interrupt controller is built into the PCI controller, what is the
rationale for representing this as a separate device tree device?

Thanks,

Andrew Murray

> + if (node)
> + pcie->irq = of_irq_get(node, 0);
> +
> + if (!node || pcie->irq <= 0)
> + return 0;
> +
> + /* set IRQ handler */
> + irq_set_chained_handler_and_data(pcie->irq, iproc_pcie_isr, pcie);
> +
> + /* add IRQ domain for INTx */
> + pcie->irq_domain = irq_domain_add_linear(node, PCI_NUM_INTX,
> + &intx_domain_ops, pcie);
> + if (!pcie->irq_domain) {
> + dev_err(dev, "failed to add INTx IRQ domain\n");
> + ret = -ENOMEM;
> + goto err_rm_handler_data;
> + }
> +
> + return 0;
> +
> +err_rm_handler_data:
> + of_node_put(node);
> + irq_set_chained_handler_and_data(pcie->irq, NULL, NULL);
> +
> + return ret;
> +}
> +
> +static void iproc_pcie_intx_disable(struct iproc_pcie *pcie)
> +{
> + iproc_pcie_write_reg(pcie, IPROC_PCIE_INTX_EN, 0x0);
> +
> + if (pcie->irq <= 0)
> + return;
> +
> + irq_domain_remove(pcie->irq_domain);
> + irq_set_chained_handler_and_data(pcie->irq, NULL, NULL);
> }
>
> static inline bool iproc_pcie_ob_is_valid(struct iproc_pcie *pcie,
> @@ -1537,7 +1628,11 @@ int iproc_pcie_setup(struct iproc_pcie *pcie, struct list_head *res)
> goto err_power_off_phy;
> }
>
> - iproc_pcie_enable(pcie);
> + ret = iproc_pcie_intx_enable(pcie);
> + if (ret) {
> + dev_err(dev, "failed to enable INTx\n");
> + goto err_power_off_phy;
> + }
>
> if (IS_ENABLED(CONFIG_PCI_MSI))
> if (iproc_pcie_msi_enable(pcie))
> @@ -1582,6 +1677,7 @@ int iproc_pcie_remove(struct iproc_pcie *pcie)
> pci_remove_root_bus(pcie->root_bus);
>
> iproc_pcie_msi_disable(pcie);
> + iproc_pcie_intx_disable(pcie);
>
> phy_power_off(pcie->phy);
> phy_exit(pcie->phy);
> diff --git a/drivers/pci/controller/pcie-iproc.h b/drivers/pci/controller/pcie-iproc.h
> index 4f03ea5..103e568 100644
> --- a/drivers/pci/controller/pcie-iproc.h
> +++ b/drivers/pci/controller/pcie-iproc.h
> @@ -74,6 +74,9 @@ struct iproc_msi;
> * @ib: inbound mapping related parameters
> * @ib_map: outbound mapping region related parameters
> *
> + * @irq: interrupt line wired to the generic GIC for INTx
> + * @irq_domain: IRQ domain for INTx
> + *
> * @need_msi_steer: indicates additional configuration of the iProc PCIe
> * controller is required to steer MSI writes to external interrupt controller
> * @msi: MSI data
> @@ -102,6 +105,9 @@ struct iproc_pcie {
> struct iproc_pcie_ib ib;
> const struct iproc_pcie_ib_map *ib_map;
>
> + int irq;
> + struct irq_domain *irq_domain;
> +
> bool need_msi_steer;
> struct iproc_msi *msi;
> };
> --
> 2.7.4
>

2019-12-03 19:20:25

by Rob Herring

[permalink] [raw]
Subject: Re: [PATCH v3 1/6] dt-bindings: pci: Update iProc PCI binding for INTx support

On Tue, 3 Dec 2019 10:27:01 +0530, Srinath Mannam wrote:
> From: Ray Jui <[email protected]>
>
> Update the iProc PCIe binding document for better modeling of the legacy
> interrupt (INTx) support
>
> Signed-off-by: Ray Jui <[email protected]>
> Signed-off-by: Srinath Mannam <[email protected]>
> ---
> .../devicetree/bindings/pci/brcm,iproc-pcie.txt | 48 ++++++++++++++++++----
> 1 file changed, 41 insertions(+), 7 deletions(-)
>

Please add Acked-by/Reviewed-by tags when posting new versions. However,
there's no need to repost patches *only* to add the tags. The upstream
maintainer will do that for acks received on the version they apply.

If a tag was not added on purpose, please state why and what changed.

2019-12-03 19:29:39

by Andy Shevchenko

[permalink] [raw]
Subject: Re: [PATCH v3 2/6] PCI: iproc: Add INTx support with better modeling

On Tue, Dec 3, 2019 at 5:55 PM Andrew Murray <[email protected]> wrote:
> On Tue, Dec 03, 2019 at 10:27:02AM +0530, Srinath Mannam wrote:

> > + /* go through INTx A, B, C, D until all interrupts are handled */
> > + do {
> > + status = iproc_pcie_read_reg(pcie, IPROC_PCIE_INTX_CSR);
>
> By performing this read once and outside of the do/while loop you may improve
> performance. I wonder how probable it is to get another INTx whilst handling
> one?

May I ask how it can be improved?
One read will be needed any way, and so does this code.

> > + for_each_set_bit(bit, &status, PCI_NUM_INTX) {
> > + virq = irq_find_mapping(pcie->irq_domain, bit);
> > + if (virq)
> > + generic_handle_irq(virq);
> > + else
> > + dev_err(dev, "unexpected INTx%u\n", bit);
> > + }
> > + } while ((status & SYS_RC_INTX_MASK) != 0);

--
With Best Regards,
Andy Shevchenko

2019-12-03 22:10:29

by Ray Jui

[permalink] [raw]
Subject: Re: [PATCH v3 2/6] PCI: iproc: Add INTx support with better modeling



On 12/3/19 11:27 AM, Andy Shevchenko wrote:
> On Tue, Dec 3, 2019 at 5:55 PM Andrew Murray <[email protected]> wrote:
>> On Tue, Dec 03, 2019 at 10:27:02AM +0530, Srinath Mannam wrote:
>
>>> + /* go through INTx A, B, C, D until all interrupts are handled */
>>> + do {
>>> + status = iproc_pcie_read_reg(pcie, IPROC_PCIE_INTX_CSR);
>>
>> By performing this read once and outside of the do/while loop you may improve
>> performance. I wonder how probable it is to get another INTx whilst handling
>> one?
>
> May I ask how it can be improved?
> One read will be needed any way, and so does this code.
>

I guess the current code will cause the IPROC_PCIE_INTX_CSR register to
be read TWICE, if it's ever set to start with.

But then if we do it outside of the while loop, if we ever receive an
interrupt while servicing one, the interrupt will still need to be
serviced, and in this case, it will cause additional context switch
overhead by going out and back in the interrupt context.

My take is that it's probably more ideal to leave this portion of code
as it is.

>>> + for_each_set_bit(bit, &status, PCI_NUM_INTX) {
>>> + virq = irq_find_mapping(pcie->irq_domain, bit);
>>> + if (virq)
>>> + generic_handle_irq(virq);
>>> + else
>>> + dev_err(dev, "unexpected INTx%u\n", bit);
>>> + }
>>> + } while ((status & SYS_RC_INTX_MASK) != 0);
>

2019-12-04 08:30:56

by Andy Shevchenko

[permalink] [raw]
Subject: Re: [PATCH v3 2/6] PCI: iproc: Add INTx support with better modeling

On Wed, Dec 4, 2019 at 12:09 AM Ray Jui <[email protected]> wrote:
> On 12/3/19 11:27 AM, Andy Shevchenko wrote:
> > On Tue, Dec 3, 2019 at 5:55 PM Andrew Murray <[email protected]> wrote:
> >> On Tue, Dec 03, 2019 at 10:27:02AM +0530, Srinath Mannam wrote:
> >
> >>> + /* go through INTx A, B, C, D until all interrupts are handled */
> >>> + do {
> >>> + status = iproc_pcie_read_reg(pcie, IPROC_PCIE_INTX_CSR);
> >>
> >> By performing this read once and outside of the do/while loop you may improve
> >> performance. I wonder how probable it is to get another INTx whilst handling
> >> one?
> >
> > May I ask how it can be improved?
> > One read will be needed any way, and so does this code.
> >
>
> I guess the current code will cause the IPROC_PCIE_INTX_CSR register to
> be read TWICE, if it's ever set to start with.
>
> But then if we do it outside of the while loop, if we ever receive an
> interrupt while servicing one, the interrupt will still need to be
> serviced, and in this case, it will cause additional context switch
> overhead by going out and back in the interrupt context.
>
> My take is that it's probably more ideal to leave this portion of code
> as it is.

Can't we simple drop a do-while completely and leave only
for_each_set_bit() loop?

>
> >>> + for_each_set_bit(bit, &status, PCI_NUM_INTX) {
> >>> + virq = irq_find_mapping(pcie->irq_domain, bit);
> >>> + if (virq)
> >>> + generic_handle_irq(virq);
> >>> + else
> >>> + dev_err(dev, "unexpected INTx%u\n", bit);
> >>> + }
> >>> + } while ((status & SYS_RC_INTX_MASK) != 0);
> >



--
With Best Regards,
Andy Shevchenko

2019-12-04 16:10:39

by Andrew Murray

[permalink] [raw]
Subject: Re: [PATCH v3 2/6] PCI: iproc: Add INTx support with better modeling

On Wed, Dec 04, 2019 at 10:29:51AM +0200, Andy Shevchenko wrote:
> On Wed, Dec 4, 2019 at 12:09 AM Ray Jui <[email protected]> wrote:
> > On 12/3/19 11:27 AM, Andy Shevchenko wrote:
> > > On Tue, Dec 3, 2019 at 5:55 PM Andrew Murray <[email protected]> wrote:
> > >> On Tue, Dec 03, 2019 at 10:27:02AM +0530, Srinath Mannam wrote:
> > >
> > >>> + /* go through INTx A, B, C, D until all interrupts are handled */
> > >>> + do {
> > >>> + status = iproc_pcie_read_reg(pcie, IPROC_PCIE_INTX_CSR);
> > >>
> > >> By performing this read once and outside of the do/while loop you may improve
> > >> performance. I wonder how probable it is to get another INTx whilst handling
> > >> one?
> > >
> > > May I ask how it can be improved?
> > > One read will be needed any way, and so does this code.
> > >
> >
> > I guess the current code will cause the IPROC_PCIE_INTX_CSR register to
> > be read TWICE, if it's ever set to start with.
> >
> > But then if we do it outside of the while loop, if we ever receive an
> > interrupt while servicing one, the interrupt will still need to be
> > serviced, and in this case, it will cause additional context switch
> > overhead by going out and back in the interrupt context.

Yes it's a trade off - if you dropped the do/while loop and thus had a single
read you'd reduce the overhead on interrupt handling in every case except
where another INTx is received whilst in this function. But as you point out
each time that does happen you'll pay the penalty of a context switch.

I don't have any knowledge of this platform so I have no idea if such a change
would be good/bad or material. However I thought I'd point it out. Looking at
the other controller drivers, some handle in a loop and some don't.


> >
> > My take is that it's probably more ideal to leave this portion of code
> > as it is.
>
> Can't we simple drop a do-while completely and leave only
> for_each_set_bit() loop?
>

I'm happy either way.

Thanks,

Andrew Murray

> >
> > >>> + for_each_set_bit(bit, &status, PCI_NUM_INTX) {
> > >>> + virq = irq_find_mapping(pcie->irq_domain, bit);
> > >>> + if (virq)
> > >>> + generic_handle_irq(virq);
> > >>> + else
> > >>> + dev_err(dev, "unexpected INTx%u\n", bit);
> > >>> + }
> > >>> + } while ((status & SYS_RC_INTX_MASK) != 0);
> > >
>
>
>
> --
> With Best Regards,
> Andy Shevchenko

2019-12-04 18:37:46

by Ray Jui

[permalink] [raw]
Subject: Re: [PATCH v3 2/6] PCI: iproc: Add INTx support with better modeling



On 12/4/19 8:07 AM, Andrew Murray wrote:
> On Wed, Dec 04, 2019 at 10:29:51AM +0200, Andy Shevchenko wrote:
>> On Wed, Dec 4, 2019 at 12:09 AM Ray Jui <[email protected]> wrote:
>>> On 12/3/19 11:27 AM, Andy Shevchenko wrote:
>>>> On Tue, Dec 3, 2019 at 5:55 PM Andrew Murray <[email protected]> wrote:
>>>>> On Tue, Dec 03, 2019 at 10:27:02AM +0530, Srinath Mannam wrote:
>>>>
>>>>>> + /* go through INTx A, B, C, D until all interrupts are handled */
>>>>>> + do {
>>>>>> + status = iproc_pcie_read_reg(pcie, IPROC_PCIE_INTX_CSR);
>>>>>
>>>>> By performing this read once and outside of the do/while loop you may improve
>>>>> performance. I wonder how probable it is to get another INTx whilst handling
>>>>> one?
>>>>
>>>> May I ask how it can be improved?
>>>> One read will be needed any way, and so does this code.
>>>>
>>>
>>> I guess the current code will cause the IPROC_PCIE_INTX_CSR register to
>>> be read TWICE, if it's ever set to start with.
>>>
>>> But then if we do it outside of the while loop, if we ever receive an
>>> interrupt while servicing one, the interrupt will still need to be
>>> serviced, and in this case, it will cause additional context switch
>>> overhead by going out and back in the interrupt context.
>
> Yes it's a trade off - if you dropped the do/while loop and thus had a single
> read you'd reduce the overhead on interrupt handling in every case except
> where another INTx is received whilst in this function. But as you point out
> each time that does happen you'll pay the penalty of a context switch.
>

Exactly, it's a tradeoff between: 1) saving one register read (which is
likely in the 10th of nanosecond range) in all INTx handling; and 2)
saving context switches (which is likely in 10th of microsecond range)
in cases when we have multiple INTx when servicing it.

The current implementation takes 2), which I thought it makes sense.

> I don't have any knowledge of this platform so I have no idea if such a change
> would be good/bad or material. However I thought I'd point it out. Looking at
> the other controller drivers, some handle in a loop and some don't.
>
>
>>>
>>> My take is that it's probably more ideal to leave this portion of code
>>> as it is.
>>
>> Can't we simple drop a do-while completely and leave only
>> for_each_set_bit() loop?
>>

Like both Andrew and I pointed out. There's a tradeoff here. Could you
please help to justify why you favor 1) than 2)?

>
> I'm happy either way.
>
> Thanks,
>
> Andrew Murray
>
>>>
>>>>>> + for_each_set_bit(bit, &status, PCI_NUM_INTX) {
>>>>>> + virq = irq_find_mapping(pcie->irq_domain, bit);
>>>>>> + if (virq)
>>>>>> + generic_handle_irq(virq);
>>>>>> + else
>>>>>> + dev_err(dev, "unexpected INTx%u\n", bit);
>>>>>> + }
>>>>>> + } while ((status & SYS_RC_INTX_MASK) != 0);
>>>>
>>
>>
>>
>> --
>> With Best Regards,
>> Andy Shevchenko

2019-12-06 09:45:07

by Srinath Mannam

[permalink] [raw]
Subject: Re: [PATCH v3 2/6] PCI: iproc: Add INTx support with better modeling

On Tue, Dec 3, 2019 at 9:25 PM Andrew Murray <[email protected]> wrote:
>
> On Tue, Dec 03, 2019 at 10:27:02AM +0530, Srinath Mannam wrote:
> > From: Ray Jui <[email protected]>
> >
> > Add PCIe legacy interrupt INTx support to the iProc PCIe driver by
> > modeling it with its own IRQ domain. All 4 interrupts INTA, INTB, INTC,
> > INTD share the same interrupt line connected to the GIC in the system,
> > while the status of each INTx can be obtained through the INTX CSR
> > register
> >
> > Signed-off-by: Ray Jui <[email protected]>
> > Signed-off-by: Srinath Mannam <[email protected]>
> > ---
> > drivers/pci/controller/pcie-iproc.c | 100 +++++++++++++++++++++++++++++++++++-
> > drivers/pci/controller/pcie-iproc.h | 6 +++
> > 2 files changed, 104 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/pci/controller/pcie-iproc.c b/drivers/pci/controller/pcie-iproc.c
> > index 2d457bf..e90c22e 100644
> > --- a/drivers/pci/controller/pcie-iproc.c
> > +++ b/drivers/pci/controller/pcie-iproc.c
> > @@ -14,6 +14,7 @@
> > #include <linux/delay.h>
> > #include <linux/interrupt.h>
> > #include <linux/irqchip/arm-gic-v3.h>
> > +#include <linux/irqchip/chained_irq.h>
> > #include <linux/platform_device.h>
> > #include <linux/of_address.h>
> > #include <linux/of_pci.h>
> > @@ -270,6 +271,7 @@ enum iproc_pcie_reg {
> >
> > /* enable INTx */
> > IPROC_PCIE_INTX_EN,
> > + IPROC_PCIE_INTX_CSR,
> >
> > /* outbound address mapping */
> > IPROC_PCIE_OARR0,
> > @@ -314,6 +316,7 @@ static const u16 iproc_pcie_reg_paxb_bcma[] = {
> > [IPROC_PCIE_CFG_ADDR] = 0x1f8,
> > [IPROC_PCIE_CFG_DATA] = 0x1fc,
> > [IPROC_PCIE_INTX_EN] = 0x330,
> > + [IPROC_PCIE_INTX_CSR] = 0x334,
> > [IPROC_PCIE_LINK_STATUS] = 0xf0c,
> > };
> >
> > @@ -325,6 +328,7 @@ static const u16 iproc_pcie_reg_paxb[] = {
> > [IPROC_PCIE_CFG_ADDR] = 0x1f8,
> > [IPROC_PCIE_CFG_DATA] = 0x1fc,
> > [IPROC_PCIE_INTX_EN] = 0x330,
> > + [IPROC_PCIE_INTX_CSR] = 0x334,
> > [IPROC_PCIE_OARR0] = 0xd20,
> > [IPROC_PCIE_OMAP0] = 0xd40,
> > [IPROC_PCIE_OARR1] = 0xd28,
> > @@ -341,6 +345,7 @@ static const u16 iproc_pcie_reg_paxb_v2[] = {
> > [IPROC_PCIE_CFG_ADDR] = 0x1f8,
> > [IPROC_PCIE_CFG_DATA] = 0x1fc,
> > [IPROC_PCIE_INTX_EN] = 0x330,
> > + [IPROC_PCIE_INTX_CSR] = 0x334,
> > [IPROC_PCIE_OARR0] = 0xd20,
> > [IPROC_PCIE_OMAP0] = 0xd40,
> > [IPROC_PCIE_OARR1] = 0xd28,
> > @@ -846,9 +851,95 @@ static int iproc_pcie_check_link(struct iproc_pcie *pcie)
> > return link_is_active ? 0 : -ENODEV;
> > }
> >
> > -static void iproc_pcie_enable(struct iproc_pcie *pcie)
> > +static int iproc_pcie_intx_map(struct irq_domain *domain, unsigned int irq,
> > + irq_hw_number_t hwirq)
> > {
> > + irq_set_chip_and_handler(irq, &dummy_irq_chip, handle_simple_irq);
> > + irq_set_chip_data(irq, domain->host_data);
> > +
> > + return 0;
> > +}
> > +
> > +static const struct irq_domain_ops intx_domain_ops = {
> > + .map = iproc_pcie_intx_map,
> > +};
> > +
> > +static void iproc_pcie_isr(struct irq_desc *desc)
> > +{
> > + struct irq_chip *chip = irq_desc_get_chip(desc);
> > + struct iproc_pcie *pcie;
> > + struct device *dev;
> > + unsigned long status;
> > + u32 bit, virq;
> > +
> > + chained_irq_enter(chip, desc);
> > + pcie = irq_desc_get_handler_data(desc);
> > + dev = pcie->dev;
> > +
> > + /* go through INTx A, B, C, D until all interrupts are handled */
> > + do {
> > + status = iproc_pcie_read_reg(pcie, IPROC_PCIE_INTX_CSR);
>
> By performing this read once and outside of the do/while loop you may improve
> performance. I wonder how probable it is to get another INTx whilst handling
> one?
>
>
> > + for_each_set_bit(bit, &status, PCI_NUM_INTX) {
> > + virq = irq_find_mapping(pcie->irq_domain, bit);
> > + if (virq)
> > + generic_handle_irq(virq);
> > + else
> > + dev_err(dev, "unexpected INTx%u\n", bit);
> > + }
> > + } while ((status & SYS_RC_INTX_MASK) != 0);
> > +
> > + chained_irq_exit(chip, desc);
> > +}
> > +
> > +static int iproc_pcie_intx_enable(struct iproc_pcie *pcie)
> > +{
> > + struct device *dev = pcie->dev;
> > + struct device_node *node;
> > + int ret;
> > +
> > iproc_pcie_write_reg(pcie, IPROC_PCIE_INTX_EN, SYS_RC_INTX_MASK);
> > + /*
> > + * BCMA devices do not map INTx the same way as platform devices. All
> > + * BCMA needs is the above code to enable INTx
> > + */
>
> NIT: Move this comment above the line of code?
I will change in the next patch set.
>
>
> > +
> > + node = of_get_compatible_child(dev->of_node, "brcm,iproc-intc");
>
> As the interrupt controller is built into the PCI controller, what is the
> rationale for representing this as a separate device tree device?
In patchset v1, PCIe controller was taken as interrupt controller
which is not correct.
So that, separate DT node was taken, based on comments below link.
https://lore.kernel.org/linux-pci/CAL_Jsq+ac6dmHKS6m0h5N3bv=VseKVL8XLU5K7j1Rn=mgFNLsA@mail.gmail.com/
>
> Thanks,
>
> Andrew Murray
>
> > + if (node)
> > + pcie->irq = of_irq_get(node, 0);
> > +
> > + if (!node || pcie->irq <= 0)
> > + return 0;
> > +
> > + /* set IRQ handler */
> > + irq_set_chained_handler_and_data(pcie->irq, iproc_pcie_isr, pcie);
> > +
> > + /* add IRQ domain for INTx */
> > + pcie->irq_domain = irq_domain_add_linear(node, PCI_NUM_INTX,
> > + &intx_domain_ops, pcie);
> > + if (!pcie->irq_domain) {
> > + dev_err(dev, "failed to add INTx IRQ domain\n");
> > + ret = -ENOMEM;
> > + goto err_rm_handler_data;
> > + }
> > +
> > + return 0;
> > +
> > +err_rm_handler_data:
> > + of_node_put(node);
> > + irq_set_chained_handler_and_data(pcie->irq, NULL, NULL);
> > +
> > + return ret;
> > +}
> > +
> > +static void iproc_pcie_intx_disable(struct iproc_pcie *pcie)
> > +{
> > + iproc_pcie_write_reg(pcie, IPROC_PCIE_INTX_EN, 0x0);
> > +
> > + if (pcie->irq <= 0)
> > + return;
> > +
> > + irq_domain_remove(pcie->irq_domain);
> > + irq_set_chained_handler_and_data(pcie->irq, NULL, NULL);
> > }
> >
> > static inline bool iproc_pcie_ob_is_valid(struct iproc_pcie *pcie,
> > @@ -1537,7 +1628,11 @@ int iproc_pcie_setup(struct iproc_pcie *pcie, struct list_head *res)
> > goto err_power_off_phy;
> > }
> >
> > - iproc_pcie_enable(pcie);
> > + ret = iproc_pcie_intx_enable(pcie);
> > + if (ret) {
> > + dev_err(dev, "failed to enable INTx\n");
> > + goto err_power_off_phy;
> > + }
> >
> > if (IS_ENABLED(CONFIG_PCI_MSI))
> > if (iproc_pcie_msi_enable(pcie))
> > @@ -1582,6 +1677,7 @@ int iproc_pcie_remove(struct iproc_pcie *pcie)
> > pci_remove_root_bus(pcie->root_bus);
> >
> > iproc_pcie_msi_disable(pcie);
> > + iproc_pcie_intx_disable(pcie);
> >
> > phy_power_off(pcie->phy);
> > phy_exit(pcie->phy);
> > diff --git a/drivers/pci/controller/pcie-iproc.h b/drivers/pci/controller/pcie-iproc.h
> > index 4f03ea5..103e568 100644
> > --- a/drivers/pci/controller/pcie-iproc.h
> > +++ b/drivers/pci/controller/pcie-iproc.h
> > @@ -74,6 +74,9 @@ struct iproc_msi;
> > * @ib: inbound mapping related parameters
> > * @ib_map: outbound mapping region related parameters
> > *
> > + * @irq: interrupt line wired to the generic GIC for INTx
> > + * @irq_domain: IRQ domain for INTx
> > + *
> > * @need_msi_steer: indicates additional configuration of the iProc PCIe
> > * controller is required to steer MSI writes to external interrupt controller
> > * @msi: MSI data
> > @@ -102,6 +105,9 @@ struct iproc_pcie {
> > struct iproc_pcie_ib ib;
> > const struct iproc_pcie_ib_map *ib_map;
> >
> > + int irq;
> > + struct irq_domain *irq_domain;
> > +
> > bool need_msi_steer;
> > struct iproc_msi *msi;
> > };
> > --
> > 2.7.4
> >