| Message ID | 1364374682-8547-4-git-send-email-andriy.shevchenko@linux.intel.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On Wed, Mar 27, 2013 at 10:57:59AM +0200, Andy Shevchenko wrote: > Since we have CSRT only to get additional DMA controller resources, let's get > rid of drivers/acpi/csrt.c and move its logic inside ACPI DMA helpers code. > > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> > Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> for such a patch git format-patch -M is your friend. It generates patch to show file movement. It helps review greatly if you just move the file and then do additions on second patch, as diffstat tells me some changes have been done. > @@ -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. > + */ > > +/** > + * 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; where are you getting the base_request_line, i didnt see anything for this in ACPI spec? > + > + 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; > + 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) { > mutex_unlock(&acpi_dma_lock); > return chan; > } > diff --git a/include/linux/acpi_dma.h b/include/linux/acpi_dma.h > index d09deab..fb02980 100644 > --- a/include/linux/acpi_dma.h > +++ b/include/linux/acpi_dma.h > @@ -37,6 +37,8 @@ struct acpi_dma_spec { > * @dev: struct device of this controller > * @acpi_dma_xlate: callback function to find a suitable channel > * @data: private data used by a callback function > + * @base_request_line: first supported request line (CSRT) > + * @end_request_line: last supported request line (CSRT) okay here it is, can you add the width here as well > */ > struct acpi_dma { > struct list_head dma_controllers; > @@ -44,6 +46,8 @@ struct acpi_dma { > struct dma_chan *(*acpi_dma_xlate) > (struct acpi_dma_spec *, struct acpi_dma *); > void *data; > + unsigned short base_request_line; > + unsigned short end_request_line; how do you define these two? > }; > > /* Used with acpi_dma_simple_xlate() */ > -- > 1.8.2.rc0.22.gb3600c3 > -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sat, Mar 30, 2013 at 03:03:50AM +0530, Vinod Koul wrote: > On Wed, Mar 27, 2013 at 10:57:59AM +0200, Andy Shevchenko wrote: > > Since we have CSRT only to get additional DMA controller resources, let's get > > rid of drivers/acpi/csrt.c and move its logic inside ACPI DMA helpers code. > > > > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > > Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> > > Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > for such a patch git format-patch -M is your friend. It generates patch to show > file movement. It helps review greatly if you just move the file and then do > additions on second patch, as diffstat tells me some changes have been done. OK, thanks for the tip. We will use -M with the next revision. > > @@ -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. > > + */ > > > > +/** > > + * 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; > where are you getting the base_request_line, i didnt see anything for this in > ACPI spec? It comes from the CSRT table. In this same patch there is a function acpi_dma_parse_resource_group() that extracts it. If you check the kerneldoc of this function (acpi_dma_update_dma_spec()) it says this: 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. So this patch series is actually the "controller-specific OS driver". And we use CSRT table to extract the request line range for a given controller. > > + 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; > > + 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) { > > mutex_unlock(&acpi_dma_lock); > > return chan; > > } > > diff --git a/include/linux/acpi_dma.h b/include/linux/acpi_dma.h > > index d09deab..fb02980 100644 > > --- a/include/linux/acpi_dma.h > > +++ b/include/linux/acpi_dma.h > > @@ -37,6 +37,8 @@ struct acpi_dma_spec { > > * @dev: struct device of this controller > > * @acpi_dma_xlate: callback function to find a suitable channel > > * @data: private data used by a callback function > > + * @base_request_line: first supported request line (CSRT) > > + * @end_request_line: last supported request line (CSRT) > okay here it is, can you add the width here as well You mean the width from FixedDMA descriptor? If yes, then I think it does not belong here. This stuff is for controllers and FixedDMA belongs to the clients. It can be differrent for each FixedDMA descriptor for each client (although we have only seen 32-bit widhts currently). > > */ > > struct acpi_dma { > > struct list_head dma_controllers; > > @@ -44,6 +46,8 @@ struct acpi_dma { > > struct dma_chan *(*acpi_dma_xlate) > > (struct acpi_dma_spec *, struct acpi_dma *); > > void *data; > > + unsigned short base_request_line; > > + unsigned short end_request_line; > how do you define these two? It is the range of request lines assigned for each controller, if that is what you asked. In ACPI 5 it is the request line in FixedDMA descriptor that is used to locate the right controller. The request line should be unique accross the platform. > > }; > > > > /* Used with acpi_dma_simple_xlate() */ > > -- > > 1.8.2.rc0.22.gb3600c3 > > -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sat, 2013-03-30 at 03:03 +0530, Vinod Koul wrote: > On Wed, Mar 27, 2013 at 10:57:59AM +0200, Andy Shevchenko wrote: > > Since we have CSRT only to get additional DMA controller resources, let's get > > rid of drivers/acpi/csrt.c and move its logic inside ACPI DMA helpers code. > > > > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > > Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> > > Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > for such a patch git format-patch -M is your friend. It generates patch to show > file movement. It helps review greatly if you just move the file and then do > additions on second patch, as diffstat tells me some changes have been done. It obviously will not help. We are not creating new file, but moving (quite partially) contents from one file to the _existing_ one.
diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile index ecb743b..6050c80 100644 --- a/drivers/acpi/Makefile +++ b/drivers/acpi/Makefile @@ -38,7 +38,6 @@ acpi-y += processor_core.o acpi-y += ec.o acpi-$(CONFIG_ACPI_DOCK) += dock.o acpi-y += pci_root.o pci_link.o pci_irq.o -acpi-y += csrt.o acpi-$(CONFIG_X86_INTEL_LPSS) += acpi_lpss.o acpi-y += acpi_platform.o acpi-y += power.o diff --git a/drivers/acpi/csrt.c b/drivers/acpi/csrt.c deleted file mode 100644 index 5c15a91..0000000 --- a/drivers/acpi/csrt.c +++ /dev/null @@ -1,159 +0,0 @@ -/* - * Support for Core System Resources Table (CSRT) - * - * Copyright (C) 2013, Intel Corporation - * Authors: Mika Westerberg <mika.westerberg@linux.intel.com> - * Andy Shevchenko <andriy.shevchenko@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 - * published by the Free Software Foundation. - */ - -#define pr_fmt(fmt) "ACPI: CSRT: " fmt - -#include <linux/acpi.h> -#include <linux/device.h> -#include <linux/kernel.h> -#include <linux/module.h> -#include <linux/platform_device.h> -#include <linux/sizes.h> - -ACPI_MODULE_NAME("CSRT"); - -static int __init acpi_csrt_parse_shared_info(struct platform_device *pdev, - const struct acpi_csrt_group *grp) -{ - const struct acpi_csrt_shared_info *si; - struct resource res[3]; - size_t nres; - int ret; - - memset(res, 0, sizeof(res)); - nres = 0; - - si = (const struct acpi_csrt_shared_info *)&grp[1]; - /* - * The peripherals that are listed on CSRT typically support only - * 32-bit addresses so we only use the low part of MMIO base for - * now. - */ - if (!si->mmio_base_high && si->mmio_base_low) { - /* - * There is no size of the memory resource in shared_info - * so we assume that it is 4k here. - */ - res[nres].start = si->mmio_base_low; - res[nres].end = res[0].start + SZ_4K - 1; - res[nres++].flags = IORESOURCE_MEM; - } - - if (si->gsi_interrupt) { - int irq = acpi_register_gsi(NULL, si->gsi_interrupt, - si->interrupt_mode, - si->interrupt_polarity); - res[nres].start = irq; - res[nres].end = irq; - res[nres++].flags = IORESOURCE_IRQ; - } - - if (si->base_request_line || si->num_handshake_signals) { - /* - * We pass the driver a DMA resource describing the range - * of request lines the device supports. - */ - res[nres].start = si->base_request_line; - res[nres].end = res[nres].start + si->num_handshake_signals - 1; - res[nres++].flags = IORESOURCE_DMA; - } - - ret = platform_device_add_resources(pdev, res, nres); - if (ret) { - if (si->gsi_interrupt) - acpi_unregister_gsi(si->gsi_interrupt); - return ret; - } - - return 0; -} - -static int __init -acpi_csrt_parse_resource_group(const struct acpi_csrt_group *grp) -{ - struct platform_device *pdev; - char vendor[5], name[16]; - int ret, i; - - vendor[0] = grp->vendor_id; - vendor[1] = grp->vendor_id >> 8; - vendor[2] = grp->vendor_id >> 16; - vendor[3] = grp->vendor_id >> 24; - vendor[4] = '\0'; - - if (grp->shared_info_length != sizeof(struct acpi_csrt_shared_info)) - return -ENODEV; - - snprintf(name, sizeof(name), "%s%04X", vendor, grp->device_id); - pdev = platform_device_alloc(name, PLATFORM_DEVID_AUTO); - if (!pdev) - return -ENOMEM; - - /* Add resources based on the shared info */ - ret = acpi_csrt_parse_shared_info(pdev, grp); - if (ret) - goto fail; - - ret = platform_device_add(pdev); - if (ret) - goto fail; - - for (i = 0; i < pdev->num_resources; i++) - dev_dbg(&pdev->dev, "%pR\n", &pdev->resource[i]); - - return 0; - -fail: - platform_device_put(pdev); - return ret; -} - -/* - * 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 present these devices as normal platform devices that don't have ACPI - * IDs or handle. The platform device name will be something like - * <VENDOR><DEVID>.<n>.auto for example: INTL9C06.0.auto. - */ -void __init acpi_csrt_init(void) -{ - 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) - pr_warn("failed to get the CSRT table\n"); - return; - } - - pr_debug("parsing CSRT table for devices\n"); - - grp = (struct acpi_csrt_group *)(csrt + 1); - end = (struct acpi_csrt_group *)((void *)csrt + csrt->header.length); - - while (grp < end) { - ret = acpi_csrt_parse_resource_group(grp); - if (ret) { - pr_warn("error in parsing resource group: %d\n", ret); - return; - } - - grp = (struct acpi_csrt_group *)((void *)grp + grp->length); - } -} diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h index 6f1afd9..297cbf4 100644 --- a/drivers/acpi/internal.h +++ b/drivers/acpi/internal.h @@ -35,7 +35,6 @@ void acpi_pci_link_init(void); void acpi_pci_root_hp_init(void); void acpi_platform_init(void); int acpi_sysfs_init(void); -void acpi_csrt_init(void); #ifdef CONFIG_ACPI_CONTAINER void acpi_container_init(void); #else diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index d7f3c8b..6742aa1 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -2042,7 +2042,6 @@ int __init acpi_scan_init(void) acpi_pci_link_init(); acpi_platform_init(); acpi_lpss_init(); - acpi_csrt_init(); acpi_container_init(); acpi_pci_slot_init(); acpi_memory_hotplug_init(); diff --git a/drivers/dma/acpi-dma.c b/drivers/dma/acpi-dma.c index af4626e..2b41df9 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; + 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) { mutex_unlock(&acpi_dma_lock); return chan; } diff --git a/include/linux/acpi_dma.h b/include/linux/acpi_dma.h index d09deab..fb02980 100644 --- a/include/linux/acpi_dma.h +++ b/include/linux/acpi_dma.h @@ -37,6 +37,8 @@ struct acpi_dma_spec { * @dev: struct device of this controller * @acpi_dma_xlate: callback function to find a suitable channel * @data: private data used by a callback function + * @base_request_line: first supported request line (CSRT) + * @end_request_line: last supported request line (CSRT) */ struct acpi_dma { struct list_head dma_controllers; @@ -44,6 +46,8 @@ struct acpi_dma { struct dma_chan *(*acpi_dma_xlate) (struct acpi_dma_spec *, struct acpi_dma *); void *data; + unsigned short base_request_line; + unsigned short end_request_line; }; /* Used with acpi_dma_simple_xlate() */