Re: [PATCH v3 pci] PCI/MSI: pci-xgene-msi: Enable MSI support in ACPI boot for X-Gene v1

Marc Zyngier
2017-08-14T08:21:55Z

On 12/08/17 01:02, Khuong Dinh wrote:
> This patch makes pci-xgene-msi driver ACPI-aware and provides
> MSI capability for X-Gene v1 PCIe controllers in ACPI boot mode.
>
> Signed-off-by: Khuong Dinh <kdinh@apm.com>
> [Take over from Duc Dang]
> Acked-by: Marc Zyngier <marc.zyngier@arm.com>

Given that the patch has changed very substantially, this Ack is no
longer valid.

> ---
> v3:
> - Input X-Gene MSI base address for irq_domain_alloc_fwnode
> - Add a hook to enforce X-Gene MSI be probed prior acpi_bus_scan happens
> v2:
> - Verify with BIOS version 3.06.25 and 3.07.09
> v1:
> - Initial version
> ---
> drivers/acpi/Makefile | 2 +-
> drivers/acpi/acpi_msi.c | 74 ++++++++++++++++++++++++++++++++++++++
> drivers/acpi/internal.h | 1 +
> drivers/acpi/scan.c | 1 +
> drivers/pci/host/pci-xgene-msi.c | 36 +++++++++++++++++--
> 5 files changed, 110 insertions(+), 4 deletions(-)
> create mode 100644 drivers/acpi/acpi_msi.c
>
> diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
> index b1aacfc..c15f5cd 100644
> --- a/drivers/acpi/Makefile
> +++ b/drivers/acpi/Makefile
> @@ -40,7 +40,7 @@ acpi-y += ec.o
> acpi-$(CONFIG_ACPI_DOCK) += dock.o
> acpi-y += pci_root.o pci_link.o pci_irq.o
> obj-$(CONFIG_ACPI_MCFG) += pci_mcfg.o
> -acpi-y += acpi_lpss.o acpi_apd.o
> +acpi-y += acpi_lpss.o acpi_apd.o acpi_msi.o
> acpi-y += acpi_platform.o
> acpi-y += acpi_pnp.o
> acpi-$(CONFIG_ARM_AMBA) += acpi_amba.o
> diff --git a/drivers/acpi/acpi_msi.c b/drivers/acpi/acpi_msi.c
> new file mode 100644
> index 0000000..c2f8d26
> --- /dev/null
> +++ b/drivers/acpi/acpi_msi.c
> @@ -0,0 +1,74 @@
> +/*
> + * Enforce MSI driver loaded by PCIe controller driver
> + *
> + * Copyright (c) 2017, MACOM Technology Solutions Corporation
> + * Author: Khuong Dinh <kdinh@apm.com>
> + *
> + * 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.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/acpi.h>
> +#include "internal.h"
> +
> +static acpi_status acpi_create_msi_device(acpi_handle handle, u32 Level,
> + void *context, void **retval)
> +{
> + struct acpi_device *device = NULL;
> + int type = ACPI_BUS_TYPE_DEVICE;
> + unsigned long long sta;
> + acpi_status status;
> + int ret = 0;
> +
> + acpi_bus_get_device(handle, &device);
> + status = acpi_bus_get_status_handle(handle, &sta);
> + if (ACPI_FAILURE(status))
> + sta = 0;
> +
> + device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
> + if (!device)
> + return -ENOMEM;
> +
> + acpi_init_device_object(device, handle, type, sta);
> + ret = acpi_device_add(device, NULL);
> + if (ret)
> + return ret;

Hello, memory leak.

> + device->parent = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
> + INIT_LIST_HEAD(&device->parent->physical_node_list);
> +
> + acpi_device_add_finalize(device);
> +
> + ret = device_attach(&device->dev);
> + if (ret < 0)
> + return ret;

And another one.

> +
> + acpi_create_platform_device(device, NULL);
> + acpi_device_set_enumerated(device);
> +
> + return ret;
> +}
> +
> +static const struct acpi_device_id acpi_msi_device_ids[] = {
> + {"APMC0D0E", 0},

Isn't this an APM-specific thing? Is that supposed to be populated by
all MSI controller drivers? If so, this would better be served by a
separate linker section.

> + { }
> +};
> +
> +int __init acpi_msi_init(void)
> +{
> + acpi_status status;
> + int ret = 0;
> +
> + status = acpi_get_devices(acpi_msi_device_ids[0].id,
> + acpi_create_msi_device, NULL, NULL);
> + if (ACPI_FAILURE(status))
> + ret = -ENODEV;
> +
> + return ret;
> +}

Overall, this part should be a separate patch, and you should start by
explaining what it does exactly. Because so far, all I can see is that
it pre-populates random ACPI device structures, and that definitely seem
fishy to me.

> diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
> index 58dd7ab..3da50d3 100644
> --- a/drivers/acpi/internal.h
> +++ b/drivers/acpi/internal.h
> @@ -80,6 +80,7 @@ int acpi_scan_add_handler_with_hotplug(struct acpi_scan_handler *handler,
> void acpi_lpss_init(void);
>
> void acpi_apd_init(void);
> +int acpi_msi_init(void);
>
> acpi_status acpi_hotplug_schedule(struct acpi_device *adev, u32 src);
> bool acpi_queue_hotplug_work(struct work_struct *work);
> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> index 3389729..8ec4d39 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -2029,6 +2029,7 @@ int __init acpi_scan_init(void)
> acpi_status status;
> struct acpi_table_stao *stao_ptr;
>
> + acpi_msi_init();
> acpi_pci_root_init();
> acpi_pci_link_init();
> acpi_processor_init();
> diff --git a/drivers/pci/host/pci-xgene-msi.c b/drivers/pci/host/pci-xgene-msi.c
> index f1b633b..b1768a1 100644
> --- a/drivers/pci/host/pci-xgene-msi.c
> +++ b/drivers/pci/host/pci-xgene-msi.c
> @@ -24,6 +24,7 @@
> #include <linux/pci.h>
> #include <linux/platform_device.h>
> #include <linux/of_pci.h>
> +#include <linux/acpi.h>
>
> #define MSI_IR0 0x000000
> #define MSI_INT0 0x800000
> @@ -39,7 +40,7 @@ struct xgene_msi_group {
> };
>
> struct xgene_msi {
> - struct device_node *node;
> + struct fwnode_handle *fwnode;
> struct irq_domain *inner_domain;
> struct irq_domain *msi_domain;
> u64 msi_addr;
> @@ -249,6 +250,13 @@ static void xgene_irq_domain_free(struct irq_domain *domain,
> .free = xgene_irq_domain_free,
> };
>
> +#ifdef CONFIG_ACPI
> +static struct fwnode_handle *xgene_msi_get_fwnode(struct device *dev)
> +{
> + return xgene_msi_ctrl.fwnode;
> +}
> +#endif
> +
> static int xgene_allocate_domains(struct xgene_msi *msi)
> {
> msi->inner_domain = irq_domain_add_linear(NULL, NR_MSI_VEC,
> @@ -256,7 +264,7 @@ static int xgene_allocate_domains(struct xgene_msi *msi)
> if (!msi->inner_domain)
> return -ENOMEM;
>
> - msi->msi_domain = pci_msi_create_irq_domain(of_node_to_fwnode(msi->node),
> + msi->msi_domain = pci_msi_create_irq_domain(msi->fwnode,
> &xgene_msi_domain_info,
> msi->inner_domain);
>
> @@ -265,6 +273,9 @@ static int xgene_allocate_domains(struct xgene_msi *msi)
> return -ENOMEM;
> }
>
> +#ifdef CONFIG_ACPI
> + pci_msi_register_fwnode_provider(&xgene_msi_get_fwnode);
> +#endif
> return 0;
> }
>
> @@ -449,6 +460,13 @@ static int xgene_msi_hwirq_free(unsigned int cpu)
> {},
> };
>
> +#ifdef CONFIG_ACPI
> +static const struct acpi_device_id xgene_msi_acpi_ids[] = {
> + {"APMC0D0E", 0},
> + { },
> +};
> +#endif
> +
> static int xgene_msi_probe(struct platform_device *pdev)
> {
> struct resource *res;
> @@ -469,7 +487,18 @@ static int xgene_msi_probe(struct platform_device *pdev)
> goto error;
> }
> xgene_msi->msi_addr = res->start;
> - xgene_msi->node = pdev->dev.of_node;
> +
> + xgene_msi->fwnode = of_node_to_fwnode(pdev->dev.of_node);
> + if (!xgene_msi->fwnode) {
> + xgene_msi->fwnode =
> + irq_domain_alloc_fwnode((void *)xgene_msi->msi_addr);
> + if (!xgene_msi->fwnode) {
> + dev_err(&pdev->dev, "Failed to create fwnode\n");
> + rc = ENOMEM;
> + goto error;
> + }
> + }
> +
> xgene_msi->num_cpus = num_possible_cpus();
>
> rc = xgene_msi_init_allocator(xgene_msi);
> @@ -540,6 +569,7 @@ static int xgene_msi_probe(struct platform_device *pdev)
> .driver = {
> .name = "xgene-msi",
> .of_match_table = xgene_msi_match_table,
> + .acpi_match_table = ACPI_PTR(xgene_msi_acpi_ids),
> },
> .probe = xgene_msi_probe,
> .remove = xgene_msi_remove,
>

Thanks,

M.
--
Jazz is not dead. It just smells funny...