Date:   Thu, 1 Feb 2018 11:32:50 +0000
From:   John Garry <john.garry@...wei.com>
To:     <mika.westerberg@...ux.intel.com>, <rafael@...nel.org>,
        <lorenzo.pieralisi@....com>, <rjw@...ysocki.net>
CC:     <robh+dt@...nel.org>, <bhelgaas@...gle.com>, <arnd@...db.de>,
        <mark.rutland@....com>, <olof@...om.net>, <hanjun.guo@...aro.org>,
        <dann.frazier@...onical.com>, <benh@...nel.crashing.org>,
        <linux-kernel@...r.kernel.org>, <linux-acpi@...r.kernel.org>,
        <linuxarm@...wei.com>, <linux-pci@...r.kernel.org>,
        <minyard@....org>, <devicetree@...r.kernel.org>,
        <linux-arch@...r.kernel.org>, <rdunlap@...radead.org>
Subject: Re: [PATCH v12 7/9] ACPI: Translate the I/O range of non-MMIO devices
 before scanning

On 23/01/2018 16:36, John Garry wrote:
> On some platforms(such as Hip06/Hip07), the legacy ISA/LPC devices access
> I/O with some special host-local I/O ports known on x86. As their I/O space
> are not memory mapped like PCI/PCIE MMIO host bridges, this patch is meant
> to support a new class of I/O host controllers where the local IO ports of
> the children devices are translated into the Indirect I/O address space.
>
> Through the handler attach callback, all the I/O translations are done
> before starting the enumeration on children devices and the translated
> addresses are replaced in the children resources.
>

Hi Lorenzo, Rafael, Mika,

I would really appreciate if you could have a look at this patch.

The current solution here is to scan the ACPI devices under these 
indirectIO hosts and create MFDs for the children.

I think another solution - which you may prefer - is to avoid adding 
this scan handler (and all this other scan code) and add a check like 
acpi_is_serial_bus_slave() [which checks the device parent versus a list 
of known indirectIO hosts] to not enumerate these children, and do it 
from the LLDD host probe instead (https://lkml.org/lkml/2017/6/16/250)

John

> Signed-off-by: John Garry <john.garry@...wei.com>
> Signed-off-by: Zhichang Yuan <yuanzhichang@...ilicon.com>
> Signed-off-by: Gabriele Paoloni <gabriele.paoloni@...wei.com>
> ---
>  drivers/acpi/arm64/Makefile          |   1 +
>  drivers/acpi/arm64/acpi_indirectio.c | 273 +++++++++++++++++++++++++++++++++++
>  drivers/acpi/internal.h              |   5 +
>  drivers/acpi/scan.c                  |   1 +
>  4 files changed, 280 insertions(+)
>  create mode 100644 drivers/acpi/arm64/acpi_indirectio.c
>
> diff --git a/drivers/acpi/arm64/Makefile b/drivers/acpi/arm64/Makefile
> index 1017def..f4a7f46 100644
> --- a/drivers/acpi/arm64/Makefile
> +++ b/drivers/acpi/arm64/Makefile
> @@ -1,2 +1,3 @@
>  obj-$(CONFIG_ACPI_IORT) 	+= iort.o
>  obj-$(CONFIG_ACPI_GTDT) 	+= gtdt.o
> +obj-$(CONFIG_INDIRECT_PIO)	+= acpi_indirectio.o
> diff --git a/drivers/acpi/arm64/acpi_indirectio.c b/drivers/acpi/arm64/acpi_indirectio.c
> new file mode 100644
> index 0000000..2649f57
> --- /dev/null
> +++ b/drivers/acpi/arm64/acpi_indirectio.c
> @@ -0,0 +1,273 @@
> +/*
> + * ACPI support for indirect-IO bus.
> + *
> + * Copyright (C) 2017 HiSilicon Limited, All Rights Reserved.
> + * Author: Gabriele Paoloni <gabriele.paoloni@...wei.com>
> + * Author: Zhichang Yuan <yuanzhichang@...ilicon.com>
> + * Author: John Garry <john.garry@...wei.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <linux/acpi.h>
> +#include <linux/logic_pio.h>
> +#include <linux/mfd/core.h>
> +#include <linux/platform_device.h>
> +
> +ACPI_MODULE_NAME("indirect IO");
> +
> +#define ACPI_INDIRECTIO_NAME_LENGTH 255
> +
> +#define INDIRECT_IO_INFO(desc) ((unsigned long)&desc)
> +
> +struct acpi_indirectio_mfd_cell {
> +	struct mfd_cell_acpi_match acpi_match;
> +	char name[ACPI_INDIRECTIO_NAME_LENGTH];
> +	char pnpid[ACPI_INDIRECTIO_NAME_LENGTH];
> +};
> +
> +struct acpi_indirectio_host_data {
> +	resource_size_t io_size;
> +	resource_size_t io_start;
> +};
> +
> +struct acpi_indirectio_device_desc {
> +	struct acpi_indirectio_host_data pdata; /* device relevant info data */
> +	int (*pre_setup)(struct acpi_device *adev,
> +			 struct acpi_indirectio_host_data *pdata);
> +};
> +
> +static int acpi_translate_logicio_res(struct acpi_device *adev,
> +		struct acpi_device *host, struct resource *resource)
> +{
> +	unsigned long sys_port;
> +	struct device *dev = &adev->dev;
> +	resource_size_t length = resource->end - resource->start;
> +
> +	sys_port = logic_pio_trans_hwaddr(&host->fwnode, resource->start,
> +					length);
> +
> +	if (sys_port == -1) {
> +		dev_err(dev, "translate bus-addr(0x%llx) fail!\n",
> +			resource->start);
> +		return -EFAULT;
> +	}
> +
> +	resource->start = sys_port;
> +	resource->end = sys_port + length;
> +
> +	return 0;
> +}
> +
> +/*
> + * update/set the current I/O resource of the designated device node.
> + * after this calling, the enumeration can be started as the I/O resource
> + * had been translated to logicial I/O from bus-local I/O.
> + *
> + * @child: the device node to be updated the I/O resource;
> + * @hostdev: the device node where 'adev' is attached, which can be not
> + *  the parent of 'adev';
> + * @res: double pointer to be set to the address of the updated resources
> + * @num_res: address of the variable to contain the number of updated resources
> + *
> + * return 0 when successful, negative is for failure.
> + */
> +int acpi_indirectio_set_logicio_res(struct device *child,
> +					 struct device *hostdev,
> +					 const struct resource **res,
> +					 int *num_res)
> +{
> +	struct acpi_device *adev;
> +	struct acpi_device *host;
> +	struct resource_entry *rentry;
> +	LIST_HEAD(resource_list);
> +	struct resource *resources = NULL;
> +	int count;
> +	int i;
> +	int ret = -EIO;
> +
> +	if (!child || !hostdev)
> +		return -EINVAL;
> +
> +	host = to_acpi_device(hostdev);
> +	adev = to_acpi_device(child);
> +
> +	/* check the device state */
> +	if (!adev->status.present) {
> +		dev_info(child, "ACPI: device is not present!\n");
> +		return 0;
> +	}
> +	/* whether the child had been enumerated? */
> +	if (acpi_device_enumerated(adev)) {
> +		dev_info(child, "ACPI: had been enumerated!\n");
> +		return 0;
> +	}
> +
> +	count = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
> +	if (count <= 0) {
> +		dev_err(&adev->dev, "failed to get ACPI resources\n");
> +		return count ? count : -EIO;
> +	}
> +
> +	resources = kcalloc(count, sizeof(struct resource), GFP_KERNEL);
> +	if (!resources) {
> +		acpi_dev_free_resource_list(&resource_list);
> +		return -ENOMEM;
> +	}
> +	count = 0;
> +	list_for_each_entry(rentry, &resource_list, node)
> +		resources[count++] = *rentry->res;
> +
> +	acpi_dev_free_resource_list(&resource_list);
> +
> +	/* translate the I/O resources */
> +	for (i = 0; i < count; i++) {
> +		if (resources[i].flags & IORESOURCE_IO) {
> +			ret = acpi_translate_logicio_res(adev, host,
> +							&resources[i]);
> +			if (ret) {
> +				kfree(resources);
> +				dev_err(child,
> +					"Translate I/O range failed (%d)!\n",
> +					ret);
> +				return ret;
> +			}
> +		}
> +	}
> +	*res = resources;
> +	*num_res = count;
> +
> +	return ret;
> +}
> +
> +int
> +acpi_indirectio_pre_setup(struct acpi_device *adev,
> +			  struct acpi_indirectio_host_data *pdata)
> +{
> +	struct platform_device *pdev;
> +	struct mfd_cell *mfd_cells;
> +	struct logic_pio_hwaddr *range;
> +	struct acpi_device *child;
> +	struct acpi_indirectio_mfd_cell *acpi_indirectio_mfd_cells;
> +	int size, ret, count = 0, cell_num = 0;
> +
> +	range = kzalloc(sizeof(*range), GFP_KERNEL);
> +	if (!range)
> +		return -ENOMEM;
> +	range->fwnode = &adev->fwnode;
> +	range->flags = PIO_INDIRECT;
> +	range->size = pdata->io_size;
> +	range->hw_start = pdata->io_start;
> +
> +	ret = logic_pio_register_range(range);
> +	if (ret)
> +		goto free_range;
> +
> +	list_for_each_entry(child, &adev->children, node)
> +		cell_num++;
> +
> +	/* allocate the mfd cells */
> +	size = sizeof(*mfd_cells) + sizeof(*acpi_indirectio_mfd_cells);
> +	mfd_cells = kcalloc(cell_num, size, GFP_KERNEL);
> +	if (!mfd_cells) {
> +		ret = -ENOMEM;
> +		goto free_range;
> +	}
> +
> +	acpi_indirectio_mfd_cells = (struct acpi_indirectio_mfd_cell *)
> +					&mfd_cells[cell_num];
> +	/* Only consider the children of the host */
> +	list_for_each_entry(child, &adev->children, node) {
> +		struct mfd_cell *mfd_cell = &mfd_cells[count];
> +		struct acpi_indirectio_mfd_cell *acpi_indirectio_mfd_cell =
> +					&acpi_indirectio_mfd_cells[count];
> +		const struct mfd_cell_acpi_match *acpi_match =
> +					&acpi_indirectio_mfd_cell->acpi_match;
> +		char *name = &acpi_indirectio_mfd_cell[count].name[0];
> +		char *pnpid = &acpi_indirectio_mfd_cell[count].pnpid[0];
> +		struct mfd_cell_acpi_match match = {
> +				.pnpid = pnpid,
> +		};
> +
> +		snprintf(name, ACPI_INDIRECTIO_NAME_LENGTH, "indirect-io-%s",
> +			 acpi_device_hid(child));
> +		snprintf(pnpid, ACPI_INDIRECTIO_NAME_LENGTH, "%s",
> +			 acpi_device_hid(child));
> +
> +		memcpy((void *)acpi_match, (void *)&match, sizeof(*acpi_match));
> +		mfd_cell->name = name;
> +		mfd_cell->acpi_match = acpi_match;
> +
> +		ret =
> +		acpi_indirectio_set_logicio_res(&child->dev,
> +						&adev->dev,
> +						&mfd_cell->resources,
> +						&mfd_cell->num_resources);
> +		if (ret) {
> +			dev_err(&child->dev, "set resource failed (%d)\n", ret);
> +			goto free_mfd_res;
> +		}
> +		count++;
> +	}
> +
> +	pdev = acpi_create_platform_device(adev, NULL);
> +	if (IS_ERR_OR_NULL(pdev)) {
> +		dev_err(&adev->dev, "Create platform device for host failed!\n");
> +		ret = PTR_ERR(pdev);
> +		goto free_mfd_res;
> +	}
> +	acpi_device_set_enumerated(adev);
> +
> +	ret = mfd_add_devices(&pdev->dev, PLATFORM_DEVID_NONE,
> +			mfd_cells, cell_num, NULL, 0, NULL);
> +	if (ret) {
> +		dev_err(&pdev->dev, "failed to add mfd cells (%d)\n", ret);
> +		goto free_mfd_res;
> +	}
> +
> +	return ret;
> +
> +free_mfd_res:
> +	while (cell_num--)
> +		kfree(mfd_cells[cell_num].resources);
> +	kfree(mfd_cells);
> +free_range:
> +	kfree(range);
> +
> +	return ret;
> +}
> +
> +/* All the host devices which apply indirect-IO can be listed here. */
> +static const struct acpi_device_id acpi_indirect_host_id[] = {
> +	{""},
> +};
> +
> +static int acpi_indirectio_attach(struct acpi_device *adev,
> +				const struct acpi_device_id *id)
> +{
> +	struct acpi_indirectio_device_desc *hostdata;
> +	int ret;
> +
> +	hostdata = (struct acpi_indirectio_device_desc *)id->driver_data;
> +	if (!hostdata || !hostdata->pre_setup)
> +		return -EINVAL;
> +
> +	ret = hostdata->pre_setup(adev, &hostdata->pdata);
> +
> +	if (ret < 0)
> +		return ret;
> +
> +	return 1;
> +}
> +
> +static struct acpi_scan_handler acpi_indirect_handler = {
> +	.ids = acpi_indirect_host_id,
> +	.attach = acpi_indirectio_attach,
> +};
> +
> +void __init acpi_indirectio_scan_init(void)
> +{
> +	acpi_scan_add_handler(&acpi_indirect_handler);
> +}
> diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
> index 1d0a501..d6b1a95 100644
> --- a/drivers/acpi/internal.h
> +++ b/drivers/acpi/internal.h
> @@ -31,6 +31,11 @@
>  void acpi_platform_init(void);
>  void acpi_pnp_init(void);
>  void acpi_int340x_thermal_init(void);
> +#ifdef CONFIG_INDIRECT_PIO
> +void acpi_indirectio_scan_init(void);
> +#else
> +static inline void acpi_indirectio_scan_init(void) {}
> +#endif
>  #ifdef CONFIG_ARM_AMBA
>  void acpi_amba_init(void);
>  #else
> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> index b0fe527..8ea6f69 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -2141,6 +2141,7 @@ int __init acpi_scan_init(void)
>  	acpi_amba_init();
>  	acpi_watchdog_init();
>  	acpi_init_lpit();
> +	acpi_indirectio_scan_init();
>
>  	acpi_scan_add_handler(&generic_device_handler);
>
>

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