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.ga...@huawei.com>
Signed-off-by: Zhichang Yuan <yuanzhich...@hisilicon.com>
Signed-off-by: Gabriele Paoloni <gabriele.paol...@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 @@
+/*
+ * ACPI support for indirect-IO bus.
+ *
+ * Copyright (C) 2017 HiSilicon Limited, All Rights Reserved.
+ * Author: Gabriele Paoloni <gabriele.paol...@huawei.com>
+ * Author: Zhichang Yuan <yuanzhich...@hisilicon.com>
+ * Author: John Garry <john.ga...@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.
+ */
+
+#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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