Re: [PATCH v6] PCI: Xilinx-NWL-PCIe: Added support for Xilinx NWL PCIe Host Controller

2015-10-30 Thread Marc Zyngier
On Fri, 30 Oct 2015 17:47:08 +0530
Bharat Kumar Gogada  wrote:

> Adding PCIe Root Port driver for Xilinx PCIe NWL bridge IP.
> 
> Signed-off-by: Bharat Kumar Gogada 
> Signed-off-by: Ravi Kiran Gummaluri 
> ---
> Changes for v6:
> Removed repetitive code for msi handlers.
> Corrected typo mistakes in device tree documentation.
> ---
>  .../devicetree/bindings/pci/xilinx-nwl-pcie.txt|   68 ++
>  drivers/pci/host/Kconfig   |9 +
>  drivers/pci/host/Makefile  |1 +
>  drivers/pci/host/pcie-xilinx-nwl.c | 1025 
> 
>  4 files changed, 1103 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/pci/xilinx-nwl-pcie.txt
>  create mode 100644 drivers/pci/host/pcie-xilinx-nwl.c
> 

[...]

> diff --git a/drivers/pci/host/pcie-xilinx-nwl.c 
> b/drivers/pci/host/pcie-xilinx-nwl.c
> new file mode 100644
> index 000..bee1bee
> --- /dev/null
> +++ b/drivers/pci/host/pcie-xilinx-nwl.c
> @@ -0,0 +1,1025 @@
> +/*
> + * PCIe host controller driver for NWL PCIe Bridge
> + * Based on pcie-xilinx.c, pci-tegra.c
> + *
> + * (C) Copyright 2014 - 2015, Xilinx, Inc.
> + *
> + * This program is free software: you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation, either version 2 of the License, or
> + * (at your option) any later version.
> + */
> +
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 

[...]

> +
> +struct nwl_msi { /* MSI information */
> + struct msi_controller msi_chip; /* MSI domain */

NAK.

I've mentioned it clearly when I first reviewed this patch: There
should be no new msi_controller structure added, and definitely none
for arm64.

So please get rid of this cruft. Select CONFIG_PCI_MSI_IRQ_DOMAIN, and
everything will be taken care of for you. No populating of bus->msi,
just have your own domain field for the MSI domain.

> + DECLARE_BITMAP(used, INT_PCI_MSI_NR);   /* used: Declare Bitmap
> + for MSI */
> + struct irq_domain *dev_domain;
> + unsigned long pages;/* pages: MSI pages */
> + struct mutex lock;  /* protect used variable */
> + int irq_msi0;
> + int irq_msi1;
> +};

[...]

> +#ifdef CONFIG_PCI_MSI
> +static struct irq_chip nwl_msi_irq_chip = {
> + .name = "nwl_pcie:msi",
> + .irq_enable = unmask_msi_irq,
> + .irq_disable = mask_msi_irq,
> + .irq_mask = mask_msi_irq,
> + .irq_unmask = unmask_msi_irq,
> +
> +};
> +
> +static struct msi_domain_info nwl_msi_domain_info = {
> + .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),

So you cannot support MSI-X? Why? The spec seems to say otherwise  (it
also says you could support multi-MSI, but I'm not sure it is worth the
hassle).

> + .chip = &nwl_msi_irq_chip,
> +};
> +#endif
> +
> +static void nwl_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
> +{
> + struct nwl_pcie *pcie = irq_data_get_irq_chip_data(data);
> + struct nwl_msi *msi = &pcie->msi;
> +
> + msg->address_lo = virt_to_phys((void *)msi->pages);
> + msg->address_hi = 0;

Do you know for sure that this page will never be above 4GB? Given
that this IP can be synthesized, I seriously doubt this is the case.
Please properly populate both fields.

> + msg->data = data->hwirq;
> +}
> +
> +static int nwl_msi_set_affinity(struct irq_data *irq_data,
> + const struct cpumask *mask, bool force)
> +{
> + return -EINVAL;
> +}
> +
> +static struct irq_chip nwl_irq_chip = {
> + .name = "Xilinx MSI",
> + .irq_compose_msi_msg = nwl_compose_msi_msg,
> + .irq_set_affinity = nwl_msi_set_affinity,
> +};
> +
> +static int nwl_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
> + unsigned int nr_irqs, void *args)
> +{
> + struct nwl_pcie *pcie = domain->host_data;
> + struct nwl_msi *msi = &pcie->msi;
> + unsigned long bit;
> +
> + mutex_lock(&msi->lock);
> + bit = find_first_zero_bit(msi->used, INT_PCI_MSI_NR);
> + if (bit < INT_PCI_MSI_NR)
> + set_bit(bit, msi->used);
> + else
> + bit = -ENOSPC;
> +
> + mutex_unlock(&msi->lock);
> + irq_domain_set_info(domain, virq, bit, &nwl_irq_chip,
> + domain->host_data, handle_simple_irq,
> + NULL, NULL);

I'm sure irq_domain_set_info will enjoy being passed -ENOSPC as a hwirq.

> + return 0;

And let's ignore the error case, they are usually overrated.

> +}

I've stopped here (after all, I'm still on holiday).

Thanks,

M.
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[PATCH v6] PCI: Xilinx-NWL-PCIe: Added support for Xilinx NWL PCIe Host Controller

2015-10-30 Thread Bharat Kumar Gogada
Adding PCIe Root Port driver for Xilinx PCIe NWL bridge IP.

Signed-off-by: Bharat Kumar Gogada 
Signed-off-by: Ravi Kiran Gummaluri 
---
Changes for v6:
Removed repetitive code for msi handlers.
Corrected typo mistakes in device tree documentation.
---
 .../devicetree/bindings/pci/xilinx-nwl-pcie.txt|   68 ++
 drivers/pci/host/Kconfig   |9 +
 drivers/pci/host/Makefile  |1 +
 drivers/pci/host/pcie-xilinx-nwl.c | 1025 
 4 files changed, 1103 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pci/xilinx-nwl-pcie.txt
 create mode 100644 drivers/pci/host/pcie-xilinx-nwl.c

diff --git a/Documentation/devicetree/bindings/pci/xilinx-nwl-pcie.txt 
b/Documentation/devicetree/bindings/pci/xilinx-nwl-pcie.txt
new file mode 100644
index 000..3b2a9ad
--- /dev/null
+++ b/Documentation/devicetree/bindings/pci/xilinx-nwl-pcie.txt
@@ -0,0 +1,68 @@
+* Xilinx NWL PCIe Root Port Bridge DT description
+
+Required properties:
+- compatible: Should contain "xlnx,nwl-pcie-2.11"
+- #address-cells: Address representation for root ports, set to <3>
+- #size-cells: Size representation for root ports, set to <2>
+- #interrupt-cells: specifies the number of cells needed to encode an
+   interrupt source. The value must be 1.
+- reg: Should contain Bridge, PCIe Controller registers location,
+   configuration sapce, and length
+- reg-names: Must include the following entries:
+   "breg": bridge registers
+   "pcireg": PCIe controller registers
+   "cfg": configuration space region
+- device_type: must be "pci"
+- interrupts: Should contain NWL PCIe interrupt
+- interrupt-names: Must include the following entries:
+   "msi1, msi0": interrupt asserted when msi is received
+   "intx": interrupt that is asserted when an legacy interrupt is received
+   "misc": interrupt asserted when miscellaneous is received
+- interrupt-map-mask and interrupt-map: standard PCI properties to define the
+   mapping of the PCI interface to interrupt numbers.
+- ranges: ranges for the PCI memory regions (I/O space region is not
+   supported by hardware)
+   Please refer to the standard PCI bus binding document for a more
+   detailed explanation
+- msi-controller: indicates that this is MSI controller node
+- msi-parent:  MSI parent of the root complex itself
+- legacy-interrupt-controller: Interrupt controller device node for Legacy 
interrupts
+   - interrupt-controller: identifies the node as an interrupt controller
+   - #interrupt-cells: should be set to 1
+   - #address-cells: specifies the number of cells needed to encode an
+   address. The value must be 0.
+
+
+Example:
+
+
+nwl_pcie: pcie@fd0e {
+   #address-cells = <3>;
+   #size-cells = <2>;
+   compatible = "xlnx,nwl-pcie-2.11";
+   #interrupt-cells = <1>;
+   msi-controller;
+   device_type = "pci";
+   interrupt-parent = <&gic>;
+   interrupts = <0 114 4>, <0 115 4>, <0 116 4>, <0 117 4>, <0 118 4>;
+   interrupt-names = "msi0", "msi1", "intx", "dummy", "misc";
+   interrupt-map-mask = <0x0 0x0 0x0 0x7>;
+   interrupt-map = <0x0 0x0 0x0 0x1 &pcie_intc 0x1>,
+   <0x0 0x0 0x0 0x2 &pcie_intc 0x2>,
+   <0x0 0x0 0x0 0x3 &pcie_intc 0x3>,
+   <0x0 0x0 0x0 0x4 &pcie_intc 0x4>;
+
+   msi-parent = <&nwl_pcie>;
+   reg = <0x0 0xfd0e 0x1000>,
+ <0x0 0xfd48 0x1000>,
+ <0x0 0xe000 0x100>;
+   reg-names = "breg", "pcireg", "cfg";
+   ranges = <0x0200 0x 0xe100 0x 0xe100 0 
0x0f00>;
+
+   pcie_intc: legacy-interrupt-controller {
+   interrupt-controller;
+   #address-cells = <0>;
+   #interrupt-cells = <1>;
+   };
+
+};
diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
index c132bdd..33bbddb 100644
--- a/drivers/pci/host/Kconfig
+++ b/drivers/pci/host/Kconfig
@@ -15,6 +15,15 @@ config PCI_MVEBU
depends on ARCH_MVEBU || ARCH_DOVE
depends on OF

+config PCIE_XILINX_NWL
+   bool "NWL PCIe Core"
+   depends on ARCH_ZYNQMP
+   help
+Say 'Y' here if you want kernel to support for Xilinx
+NWL PCIe controller. The controller can act as Root Port
+or End Point. The current option selection will only
+support root port enabling.
+
 config PCIE_DW
bool

diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
index 140d66f..6a56df7 100644
--- a/drivers/pci/host/Makefile
+++ b/drivers/pci/host/Makefile
@@ -10,6 +10,7 @@ obj-$(CONFIG_PCI_HOST_GENERIC) += pci-host-generic.o
 obj-$(CONFIG_PCIE_SPEAR13XX) += pcie-spear13xx.o
 obj-$(CONFIG_PCI_KEYSTONE) += pci-keystone-dw.o pci-keystone.o
 obj-$(CONFIG_PCIE_XILINX) += pcie-xilinx.o
+obj-$(CONFIG_PCIE_XILINX_NWL) += pcie-xilinx-nwl.o
 obj-$(CONFIG_PCI_XGENE