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// SPDX-License-Identifier: GPL-2.0-only
/*
* ACPI helpers for DMA request / controller
*
* Based on of-dma.c
*
* Copyright (C) 2013, Intel Corporation
* Authors: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
* Mika Westerberg <mika.westerberg@linux.intel.com>
*/
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/kernel.h>
#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>
#include <linux/property.h>
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
*
* In order to match a device from DSDT table to the corresponding CSRT device
* we use MMIO address and IRQ.
*
* Return:
* 1 on success, 0 when no information is available, or appropriate errno value
* on error.
*/
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_entry *rentry;
resource_size_t mem = 0, irq = 0;
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 != lower_32_bits(mem) ||
si->mmio_base_high != upper_32_bits(mem) ||
si->gsi_interrupt != irq)
return 0;
dev_dbg(&adev->dev, "matches with %.4s%04X (rev %u)\n",
(char *)&grp->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;
/* Set up DMA mask based on value from CSRT */
ret = dma_coerce_mask_and_coherent(&adev->dev,
DMA_BIT_MASK(si->dma_address_width));
if (ret)
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
* into a dma_chan structure
* @data: pointer to controller specific data to be used by
* translation function
*
* Allocated memory should be freed with appropriate acpi_dma_controller_free()
* call.
*
* Return:
* 0 on success or appropriate errno value on error.
*/
int acpi_dma_controller_register(struct device *dev,
struct dma_chan *(*acpi_dma_xlate)
(struct acpi_dma_spec *, struct acpi_dma *),
void *data)
{
struct acpi_device *adev;
struct acpi_dma *adma;
if (!dev || !acpi_dma_xlate)
return -EINVAL;
/* Check if the device was enumerated by ACPI */
adev = ACPI_COMPANION(dev);
if (!adev)
return -EINVAL;
adma = kzalloc(sizeof(*adma), GFP_KERNEL);
if (!adma)
return -ENOMEM;
adma->dev = 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);
mutex_unlock(&acpi_dma_lock);
return 0;
}
EXPORT_SYMBOL_GPL(acpi_dma_controller_register);
/**
* acpi_dma_controller_free - Remove a DMA controller from ACPI DMA helpers list
* @dev: struct device of DMA controller
*
* Memory allocated by acpi_dma_controller_register() is freed here.
*
* Return:
* 0 on success or appropriate errno value on error.
*/
int acpi_dma_controller_free(struct device *dev)
{
struct acpi_dma *adma;
if (!dev)
return -EINVAL;
mutex_lock(&acpi_dma_lock);
list_for_each_entry(adma, &acpi_dma_list, dma_controllers)
if (adma->dev == dev) {
list_del(&adma->dma_controllers);
mutex_unlock(&acpi_dma_lock);
kfree(adma);
return 0;
}
mutex_unlock(&acpi_dma_lock);
return -ENODEV;
}
EXPORT_SYMBOL_GPL(acpi_dma_controller_free);
static void devm_acpi_dma_release(struct device *dev, void *res)
{
acpi_dma_controller_free(dev);
}
/**
* devm_acpi_dma_controller_register - resource managed acpi_dma_controller_register()
* @dev: device that is registering this DMA controller
* @acpi_dma_xlate: translation function
* @data: pointer to controller specific data
*
* Managed acpi_dma_controller_register(). DMA controller registered by this
* function are automatically freed on driver detach. See
* acpi_dma_controller_register() for more information.
*
* Return:
* 0 on success or appropriate errno value on error.
*/
int devm_acpi_dma_controller_register(struct device *dev,
struct dma_chan *(*acpi_dma_xlate)
(struct acpi_dma_spec *, struct acpi_dma *),
void *data)
{
void *res;
int ret;
res = devres_alloc(devm_acpi_dma_release, 0, GFP_KERNEL);
if (!res)
return -ENOMEM;
ret = acpi_dma_controller_register(dev, acpi_dma_xlate, data);
if (ret) {
devres_free(res);
return ret;
}
devres_add(dev, res);
return 0;
}
EXPORT_SYMBOL_GPL(devm_acpi_dma_controller_register);
/**
* devm_acpi_dma_controller_free - resource managed acpi_dma_controller_free()
* @dev: device that is unregistering as DMA controller
*
* Unregister a DMA controller registered with
* devm_acpi_dma_controller_register(). Normally this function will not need to
* be called and the resource management code will ensure that the resource is
* freed.
*/
void devm_acpi_dma_controller_free(struct device *dev)
{
WARN_ON(devres_release(dev, devm_acpi_dma_release, NULL, NULL));
}
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
*
* 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.
*
* Return:
* 0, if no information is avaiable, -1 on mismatch, and 1 otherwise.
*/
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 &&<
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