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SubjectRe: [PATCH v12 7/9] ACPI: Translate the I/O range of non-MMIO devices before scanning
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On 04/02/2018 07:45, Rafael J. Wysocki wrote:
> On Tue, Jan 23, 2018 at 5:36 PM, John Garry <john.garry@huawei.com> 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 Rafael,

Thanks for checking.

> The changelog is somewhat dry for a patch adding over 300 lines of new
> code and a new file for that matter.

Will add more. Indeed MFD is not even mentioned.

>
>> Signed-off-by: John Garry <john.garry@huawei.com>
>> Signed-off-by: Zhichang Yuan <yuanzhichang@hisilicon.com>
>> Signed-off-by: Gabriele Paoloni <gabriele.paoloni@huawei.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 @@
>
> SPDX license identifier here?

Will fix. I also need to fixup the other new files in the patchset.

>
>> +/*
>> + * ACPI support for indirect-IO bus.
>> + *
>> + * Copyright (C) 2017 HiSilicon Limited, All Rights Reserved.
>> + * Author: Gabriele Paoloni <gabriele.paoloni@huawei.com>
>> + * Author: Zhichang Yuan <yuanzhichang@hisilicon.com>
>> + * Author: John Garry <john.garry@huawei.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.
>
> And then you can skip the above.
>
> Also I would like to see some description of what's there in this file
> to appear here.

Sure.

>
>> + */
>> +
>> +#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 {
>
> Why don't you use a consistent naming convention and call this
> acpi_indirect_io_device_desc (and analogously everywhere above and
> below)?

Right, I can correct the file to have consistent symbol prefixes.

>
>> + 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) {
>
> Would if (sysp_port < 0) not work here?

I don't think so because sys_port is an unsigned value. I should change
this if statement to use -1UL.

>
>> + dev_err(dev, "translate bus-addr(0x%llx) fail!\n",
>> + resource->start);
>
> That's not a very informative message. What are users expected to do
> in response to seeing it?

Right, the user generally would not be able to decipher this, so I
should add some more info on what the fallout will be.

>
>> + 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.
>> + */
>
> The above should be a proper kerneldoc comment.
>
>> +int acpi_indirectio_set_logicio_res(struct device *child,

This should actually be static, so I think we can avoid the kerneldoc
comment?

>> + 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]);
>
> You don't need to break this line as far as I'm concerned.

This is just to keep checkpatch happy. I could move the complete
function call to a single line. And also shortening some symbols will help.

>
>> + if (ret) {
>> + kfree(resources);
>> + dev_err(child,
>> + "Translate I/O range failed (%d)!\n",
>> + ret);
>
> And this too.

Again, just appeasing checkpatch

>
>> + return ret;
>> + }
>> + }
>> + }
>> + *res = resources;
>> + *num_res = count;
>> +
>> + return ret;
>> +}
>> +
>> +int
>
> Don't break the line here, please.

Alright, will do. I thought that this was an accepted style when the
arguments list is quite long.

>
>> +acpi_indirectio_pre_setup(struct acpi_device *adev,
>> + struct acpi_indirectio_host_data *pdata)
>
> As a non-static function, this requires a kerneldoc comment.

In fact this should be static. I should have fixed these already.

>
> In particular, the comment should describe who and when is expected to
> call this function (and which also applies to the comment preceding
> the previous function).
>
> Apparently, they both need to be called before the initial namespace
> scan for the acpi_indirectio_attach() below to work, right?
>

Right, this needs to be prior to device enumeration in the ACPI namespace.

>> +{
>> + 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 = {
>
> acpi_indirect_io_handler?

sure

>
>> + .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);
>>
>> --
>> 1.9.1
>>

Thank you,
John


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