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-rw-r--r--drivers/dma/acpi-dma.c172
1 files changed, 169 insertions, 3 deletions
diff --git a/drivers/dma/acpi-dma.c b/drivers/dma/acpi-dma.c
index ba6fc62..5a18f82 100644
--- a/drivers/dma/acpi-dma.c
+++ b/drivers/dma/acpi-dma.c
@@ -4,7 +4,8 @@
* Based on of-dma.c
*
* Copyright (C) 2013, Intel Corporation
- * Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
+ * Authors: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
+ * Mika Westerberg <mika.westerberg@linux.intel.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
@@ -16,6 +17,7 @@
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/slab.h>
+#include <linux/ioport.h>
#include <linux/acpi.h>
#include <linux/acpi_dma.h>
@@ -23,6 +25,117 @@ static LIST_HEAD(acpi_dma_list);
static DEFINE_MUTEX(acpi_dma_lock);
/**
+ * acpi_dma_parse_resource_group - match device and parse resource group
+ * @grp: CSRT resource group
+ * @adev: ACPI device to match with
+ * @adma: struct acpi_dma of the given DMA controller
+ *
+ * Returns 1 on success, 0 when no information is available, or appropriate
+ * errno value on error.
+ *
+ * In order to match a device from DSDT table to the corresponding CSRT device
+ * we use MMIO address and IRQ.
+ */
+static int acpi_dma_parse_resource_group(const struct acpi_csrt_group *grp,
+ struct acpi_device *adev, struct acpi_dma *adma)
+{
+ const struct acpi_csrt_shared_info *si;
+ struct list_head resource_list;
+ struct resource_list_entry *rentry;
+ resource_size_t mem = 0, irq = 0;
+ u32 vendor_id;
+ int ret;
+
+ if (grp->shared_info_length != sizeof(struct acpi_csrt_shared_info))
+ return -ENODEV;
+
+ INIT_LIST_HEAD(&resource_list);
+ ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
+ if (ret <= 0)
+ return 0;
+
+ list_for_each_entry(rentry, &resource_list, node) {
+ if (resource_type(&rentry->res) == IORESOURCE_MEM)
+ mem = rentry->res.start;
+ else if (resource_type(&rentry->res) == IORESOURCE_IRQ)
+ irq = rentry->res.start;
+ }
+
+ acpi_dev_free_resource_list(&resource_list);
+
+ /* Consider initial zero values as resource not found */
+ if (mem == 0 && irq == 0)
+ return 0;
+
+ si = (const struct acpi_csrt_shared_info *)&grp[1];
+
+ /* Match device by MMIO and IRQ */
+ if (si->mmio_base_low != mem || si->gsi_interrupt != irq)
+ return 0;
+
+ vendor_id = le32_to_cpu(grp->vendor_id);
+ dev_dbg(&adev->dev, "matches with %.4s%04X (rev %u)\n",
+ (char *)&vendor_id, grp->device_id, grp->revision);
+
+ /* Check if the request line range is available */
+ if (si->base_request_line == 0 && si->num_handshake_signals == 0)
+ return 0;
+
+ adma->base_request_line = si->base_request_line;
+ adma->end_request_line = si->base_request_line +
+ si->num_handshake_signals - 1;
+
+ dev_dbg(&adev->dev, "request line base: 0x%04x end: 0x%04x\n",
+ adma->base_request_line, adma->end_request_line);
+
+ return 1;
+}
+
+/**
+ * acpi_dma_parse_csrt - parse CSRT to exctract additional DMA resources
+ * @adev: ACPI device to match with
+ * @adma: struct acpi_dma of the given DMA controller
+ *
+ * CSRT or Core System Resources Table is a proprietary ACPI table
+ * introduced by Microsoft. This table can contain devices that are not in
+ * the system DSDT table. In particular DMA controllers might be described
+ * here.
+ *
+ * We are using this table to get the request line range of the specific DMA
+ * controller to be used later.
+ *
+ */
+static void acpi_dma_parse_csrt(struct acpi_device *adev, struct acpi_dma *adma)
+{
+ struct acpi_csrt_group *grp, *end;
+ struct acpi_table_csrt *csrt;
+ acpi_status status;
+ int ret;
+
+ status = acpi_get_table(ACPI_SIG_CSRT, 0,
+ (struct acpi_table_header **)&csrt);
+ if (ACPI_FAILURE(status)) {
+ if (status != AE_NOT_FOUND)
+ dev_warn(&adev->dev, "failed to get the CSRT table\n");
+ return;
+ }
+
+ grp = (struct acpi_csrt_group *)(csrt + 1);
+ end = (struct acpi_csrt_group *)((void *)csrt + csrt->header.length);
+
+ while (grp < end) {
+ ret = acpi_dma_parse_resource_group(grp, adev, adma);
+ if (ret < 0) {
+ dev_warn(&adev->dev,
+ "error in parsing resource group\n");
+ return;
+ }
+
+ grp = (struct acpi_csrt_group *)((void *)grp + grp->length);
+ }
+}
+
+/**
* acpi_dma_controller_register - Register a DMA controller to ACPI DMA helpers
* @dev: struct device of DMA controller
* @acpi_dma_xlate: translation function which converts a dma specifier
@@ -61,6 +174,8 @@ int acpi_dma_controller_register(struct device *dev,
adma->acpi_dma_xlate = acpi_dma_xlate;
adma->data = data;
+ acpi_dma_parse_csrt(adev, adma);
+
/* Now queue acpi_dma controller structure in list */
mutex_lock(&acpi_dma_lock);
list_add_tail(&adma->dma_controllers, &acpi_dma_list);
@@ -149,6 +264,45 @@ void devm_acpi_dma_controller_free(struct device *dev)
}
EXPORT_SYMBOL_GPL(devm_acpi_dma_controller_free);
+/**
+ * acpi_dma_update_dma_spec - prepare dma specifier to pass to translation function
+ * @adma: struct acpi_dma of DMA controller
+ * @dma_spec: dma specifier to update
+ *
+ * Returns 0, if no information is avaiable, -1 on mismatch, and 1 otherwise.
+ *
+ * Accordingly to ACPI 5.0 Specification Table 6-170 "Fixed DMA Resource
+ * Descriptor":
+ * DMA Request Line bits is a platform-relative number uniquely
+ * identifying the request line assigned. Request line-to-Controller
+ * mapping is done in a controller-specific OS driver.
+ * That's why we can safely adjust slave_id when the appropriate controller is
+ * found.
+ */
+static int acpi_dma_update_dma_spec(struct acpi_dma *adma,
+ struct acpi_dma_spec *dma_spec)
+{
+ /* Set link to the DMA controller device */
+ dma_spec->dev = adma->dev;
+
+ /* Check if the request line range is available */
+ if (adma->base_request_line == 0 && adma->end_request_line == 0)
+ return 0;
+
+ /* Check if slave_id falls to the range */
+ if (dma_spec->slave_id < adma->base_request_line ||
+ dma_spec->slave_id > adma->end_request_line)
+ return -1;
+
+ /*
+ * Here we adjust slave_id. It should be a relative number to the base
+ * request line.
+ */
+ dma_spec->slave_id -= adma->base_request_line;
+
+ return 1;
+}
+
struct acpi_dma_parser_data {
struct acpi_dma_spec dma_spec;
size_t index;
@@ -193,6 +347,7 @@ struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev,
struct acpi_device *adev;
struct acpi_dma *adma;
struct dma_chan *chan = NULL;
+ int found;
/* Check if the device was enumerated by ACPI */
if (!dev || !ACPI_HANDLE(dev))
@@ -219,9 +374,20 @@ struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev,
mutex_lock(&acpi_dma_lock);
list_for_each_entry(adma, &acpi_dma_list, dma_controllers) {
- dma_spec->dev = adma->dev;
+ /*
+ * We are not going to call translation function if slave_id
+ * doesn't fall to the request range.
+ */
+ found = acpi_dma_update_dma_spec(adma, dma_spec);
+ if (found < 0)
+ continue;
chan = adma->acpi_dma_xlate(dma_spec, adma);
- if (chan)
+ /*
+ * Try to get a channel only from the DMA controller that
+ * matches the slave_id. See acpi_dma_update_dma_spec()
+ * description for the details.
+ */
+ if (found > 0 || chan)
break;
}
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