[PATCH V8 5/6] ACPI: Support the probing on the devices which apply indirect-IO

[zhichang.yuan]

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. To access the I/O
peripherals, an indirect-IO mechanism is introduced to mapped the host-local
I/O to system logical/fake PIO similar the PCI MMIO on architectures where no
separate I/O space exists. Just as PCI MMIO, the host I/O range should be
registered before probing the downstream devices and set up the I/O mapping.
But current ACPI bus probing doesn't support these indirect-IO hosts/devices.

This patch introdueces a new ACPI handler for this device category. Through the
handler attach callback, the indirect-IO hosts I/O registration is done and
all peripherals' I/O resources are translated into logic/fake PIO before
starting the enumeration.

Signed-off-by: zhichang.yuan <yuanzhichang@xxxxxxxxxxxxx>
Signed-off-by: Gabriele Paoloni <gabriele.paoloni@xxxxxxxxxx>
---
 drivers/acpi/Makefile          |   1 +
 drivers/acpi/acpi_indirectio.c | 344 +++++++++++++++++++++++++++++++++++++++++
 drivers/acpi/internal.h        |   5 +
 drivers/acpi/scan.c            |   1 +
 4 files changed, 351 insertions(+)
 create mode 100644 drivers/acpi/acpi_indirectio.c

diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index a391bbc..10e5f2b 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -57,6 +57,7 @@ acpi-$(CONFIG_ACPI_PROCFS_POWER) += cm_sbs.o
 acpi-y				+= acpi_lpat.o
 acpi-$(CONFIG_ACPI_GENERIC_GSI) += irq.o
 acpi-$(CONFIG_ACPI_WATCHDOG)	+= acpi_watchdog.o
+acpi-$(CONFIG_INDIRECT_PIO)	+= acpi_indirectio.o
 
 # These are (potentially) separate modules
 
diff --git a/drivers/acpi/acpi_indirectio.c b/drivers/acpi/acpi_indirectio.c
new file mode 100644
index 0000000..c8c80b5
--- /dev/null
+++ b/drivers/acpi/acpi_indirectio.c
@@ -0,0 +1,344 @@
+/*
+ * ACPI support for indirect-IO bus.
+ *
+ * Copyright (C) 2017 Hisilicon Limited, All Rights Reserved.
+ * Author: Zhichang Yuan <yuanzhichang@xxxxxxxxxxxxx>
+ *
+ * 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/platform_device.h>
+#include <linux/logic_pio.h>
+
+#include "internal.h"
+
+ACPI_MODULE_NAME("indirect IO");
+
+#define INDIRECT_IO_INFO(desc) ((unsigned long)&desc)
+
+struct lpc_private_data {
+	resource_size_t io_size;
+	resource_size_t io_start;
+};
+
+struct indirectio_device_desc {
+	void *pdata; /* device relevant info data */
+	int (*pre_setup)(struct acpi_device *adev, void *pdata);
+};
+
+static struct lpc_private_data lpc_data = {
+	.io_size = LPC_BUS_IO_SIZE,
+	.io_start = LPC_MIN_BUS_RANGE,
+};
+
+static inline bool acpi_logicio_supported_resource(struct acpi_resource *res)
+{
+	switch (res->type) {
+	case ACPI_RESOURCE_TYPE_ADDRESS32:
+	case ACPI_RESOURCE_TYPE_ADDRESS64:
+		return true;
+	}
+	return false;
+}
+
+static acpi_status acpi_count_logiciores(struct acpi_resource *res,
+					   void *data)
+{
+	int *res_cnt = data;
+
+	if (acpi_logicio_supported_resource(res) &&
+		!acpi_dev_filter_resource_type(res, IORESOURCE_IO))
+		(*res_cnt)++;
+
+	return AE_OK;
+}
+
+static acpi_status acpi_read_one_logiciores(struct acpi_resource *res,
+		void *data)
+{
+	struct acpi_resource **resource = data;
+
+	if (acpi_logicio_supported_resource(res) &&
+		!acpi_dev_filter_resource_type(res, IORESOURCE_IO)) {
+		memcpy((*resource), res, sizeof(struct acpi_resource));
+		(*resource)->length = sizeof(struct acpi_resource);
+		(*resource)->type = res->type;
+		(*resource)++;
+	}
+
+	return AE_OK;
+}
+
+static acpi_status
+acpi_build_logiciores_template(struct acpi_device *adev,
+			struct acpi_buffer *buffer)
+{
+	acpi_handle handle = adev->handle;
+	struct acpi_resource *resource;
+	acpi_status status;
+	int res_cnt = 0;
+
+	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
+				     acpi_count_logiciores, &res_cnt);
+	if (ACPI_FAILURE(status) || !res_cnt) {
+		dev_err(&adev->dev, "can't evaluate _CRS: %d\n", status);
+		return -EINVAL;
+	}
+
+	buffer->length = sizeof(struct acpi_resource) * (res_cnt + 1) + 1;
+	buffer->pointer = kzalloc(buffer->length - 1, GFP_KERNEL);
+	if (!buffer->pointer)
+		return -ENOMEM;
+
+	resource = (struct acpi_resource *)buffer->pointer;
+	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
+				     acpi_read_one_logiciores, &resource);
+	if (ACPI_FAILURE(status)) {
+		kfree(buffer->pointer);
+		dev_err(&adev->dev, "can't evaluate _CRS: %d\n", status);
+		return -EINVAL;
+	}
+
+	resource->type = ACPI_RESOURCE_TYPE_END_TAG;
+	resource->length = sizeof(struct acpi_resource);
+
+	return 0;
+}
+
+static int acpi_translate_logiciores(struct acpi_device *adev,
+		struct acpi_device *host, struct acpi_buffer *buffer)
+{
+	int res_cnt = (buffer->length - 1) / sizeof(struct acpi_resource) - 1;
+	struct acpi_resource *resource = buffer->pointer;
+	struct acpi_resource_address64 addr;
+	unsigned long sys_port;
+	struct device *dev = &adev->dev;
+
+	/* only one I/O resource now */
+	if (res_cnt != 1) {
+		dev_err(dev, "encode %d resources whose type is(%d)!\n",
+			res_cnt, resource->type);
+		return -EINVAL;
+	}
+
+	if (ACPI_FAILURE(acpi_resource_to_address64(resource, &addr))) {
+		dev_err(dev, "convert acpi resource(%d) as addr64 FAIL!\n",
+			resource->type);
+		return -EFAULT;
+	}
+
+	/* For indirect-IO, addr length must be fixed. (>0, 0/1, 0/1)(0,0,0) */
+	if (addr.min_address_fixed != addr.max_address_fixed) {
+		dev_warn(dev, "variable I/O resource is invalid!\n");
+		return -EINVAL;
+	}
+
+	dev_info(dev, "CRS IO: len=0x%llx [0x%llx - 0x%llx]\n",
+			addr.address.address_length, addr.address.minimum,
+			addr.address.maximum);
+	sys_port = logic_pio_trans_hwaddr(&host->fwnode, addr.address.minimum);
+	if (sys_port == -1) {
+		dev_err(dev, "translate bus-addr(0x%llx) fail!\n",
+			addr.address.minimum);
+		return -EFAULT;
+	}
+
+	switch (resource->type) {
+	case ACPI_RESOURCE_TYPE_ADDRESS32:
+	{
+		struct acpi_resource_address32 *out_res;
+
+		out_res = &resource->data.address32;
+		if (!addr.address.address_length)
+			addr.address.address_length = out_res->address.maximum -
+				out_res->address.minimum + 1;
+		out_res->address.minimum = sys_port;
+		out_res->address.maximum = sys_port +
+				addr.address.address_length - 1;
+		out_res->address.address_length = addr.address.address_length;
+
+		dev_info(dev, "_SRS 32IO: [0x%x - 0x%x] len = 0x%x\n",
+			out_res->address.minimum,
+			out_res->address.maximum,
+			out_res->address.address_length);
+
+		break;
+	}
+
+	case ACPI_RESOURCE_TYPE_ADDRESS64:
+	{
+		struct acpi_resource_address64 *out_res;
+
+		out_res = &resource->data.address64;
+		if (!addr.address.address_length)
+			addr.address.address_length = out_res->address.maximum -
+				out_res->address.minimum + 1;
+		out_res->address.minimum = sys_port;
+		out_res->address.maximum = sys_port +
+				addr.address.address_length - 1;
+		out_res->address.address_length = addr.address.address_length;
+
+		dev_info(dev, "_SRS 64IO: [0x%llx - 0x%llx] len = 0x%llx\n",
+			out_res->address.minimum,
+			out_res->address.maximum,
+			out_res->address.address_length);
+
+		break;
+	}
+
+	default:
+		return -EINVAL;
+
+	}
+
+	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.
+ *
+ * @adev: the device node to be updated the I/O resource;
+ * @host: the device node where 'adev' is attached, which can be not
+ *	the parent of 'adev';
+ *
+ * return 0 when successful, negative is for failure.
+ */
+static int acpi_set_logicio_resource(struct device *child,
+		struct device *hostdev)
+{
+	struct acpi_device *adev;
+	struct acpi_device *host;
+	struct acpi_buffer buffer;
+	acpi_status status;
+	int ret;
+
+	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;
+	}
+
+	/* read the _CRS and convert as acpi_buffer */
+	status = acpi_build_logiciores_template(adev, &buffer);
+	if (ACPI_FAILURE(status)) {
+		dev_warn(child, "Failure evaluating %s\n", METHOD_NAME__CRS);
+		return -ENODEV;
+	}
+
+	/* translate the I/O resources */
+	ret = acpi_translate_logiciores(adev, host, &buffer);
+	if (ret) {
+		kfree(buffer.pointer);
+		dev_err(child, "Translate I/O range FAIL!\n");
+		return ret;
+	}
+
+	/* set current resource... */
+	status = acpi_set_current_resources(adev->handle, &buffer);
+	kfree(buffer.pointer);
+	if (ACPI_FAILURE(status)) {
+		dev_err(child, "Error evaluating _SRS (0x%x)\n", status);
+		ret = -EIO;
+	}
+
+	return ret;
+}
+
+static int lpc_host_io_setup(struct acpi_device *adev, void *pdata)
+{
+	struct logic_pio_hwaddr *range, *tmprange;
+	struct lpc_private_data *lpc_private;
+	struct acpi_device *child;
+
+	lpc_private = (struct lpc_private_data *)pdata;
+	range = kzalloc(sizeof(*range), GFP_KERNEL);
+	if (!range)
+		return -ENOMEM;
+	range->fwnode = &adev->fwnode;
+	range->flags = PIO_INDIRECT;
+	range->size = lpc_private->io_size;
+	range->hw_start = lpc_private->io_start;
+
+	tmprange = logic_pio_register_range(range, 1);
+	if (tmprange != range) {
+		kfree(range);
+		if (IS_ERR(tmprange))
+			return -EFAULT;
+	}
+
+	/* For hisilpc, only care about the sons of host. */
+	list_for_each_entry(child, &adev->children, node) {
+		int ret;
+
+		ret = acpi_set_logicio_resource(&child->dev, &adev->dev);
+		if (ret) {
+			dev_err(&child->dev, "set resource failed..\n");
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static const struct indirectio_device_desc lpc_host_desc = {
+	.pdata = &lpc_data,
+	.pre_setup = lpc_host_io_setup,
+};
+
+/* All the host devices which apply indirect-IO can be listed here. */
+static const struct acpi_device_id acpi_indirect_host_id[] = {
+	{"HISI0191", INDIRECT_IO_INFO(lpc_host_desc)},
+	{""},
+};
+
+static int acpi_indirectio_attach(struct acpi_device *adev,
+				const struct acpi_device_id *id)
+{
+	struct indirectio_device_desc *hostdata;
+	struct platform_device *pdev;
+	int ret;
+
+	hostdata = (struct indirectio_device_desc *)id->driver_data;
+	if (!hostdata || !hostdata->pre_setup)
+		return -EINVAL;
+
+	ret = hostdata->pre_setup(adev, hostdata->pdata);
+	if (!ret) {
+		pdev = acpi_create_platform_device(adev, NULL);
+		if (IS_ERR_OR_NULL(pdev)) {
+			dev_err(&adev->dev, "Create platform device for host FAIL!\n");
+			return -EFAULT;
+		}
+		acpi_device_set_enumerated(adev);
+		ret = 1;
+	}
+
+	return ret;
+}
+
+
+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 f159001..b11412d 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 1926918..eda79ce 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -2033,6 +2033,7 @@ int __init acpi_scan_init(void)
 	acpi_int340x_thermal_init();
 	acpi_amba_init();
 	acpi_watchdog_init();
+	acpi_indirectio_scan_init();
 
 	acpi_scan_add_handler(&generic_device_handler);
 
-- 
1.9.1