[PATCH] ACPI: add support for CSRT table

[PATCH] ACPI: add support for CSRT table

[Mika Westerberg]

Core System Resources Table (CSRT) is a proprietary ACPI table that
contains resources for certain devices that are not found in the DSDT
table. Typically a shared DMA controller might be found here.

This patch adds support for this table. We go through all entries in the
table and make platform devices of them. The resources from the table are
passed with the platform device.

There is one special resource in the table and it is the DMA request line
base and number of request lines. This information might be needed by the
DMA controller driver as it needs to map the ACPI DMA request line number
to the actual request line understood by the hardware. This range is passed
as IORESOURCE_DMA resource.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
 drivers/acpi/Makefile |    1 +
 drivers/acpi/csrt.c   |  156 +++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 157 insertions(+)
 create mode 100644 drivers/acpi/csrt.c

diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index 4ee2e75..474fcfe 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -38,6 +38,7 @@ 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-y				+= acpi_platform.o
 acpi-y				+= power.o
 acpi-y				+= event.o
diff --git a/drivers/acpi/csrt.c b/drivers/acpi/csrt.c
new file mode 100644
index 0000000..94665f9
--- /dev/null
+++ b/drivers/acpi/csrt.c
@@ -0,0 +1,156 @@
+/*
+ * 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];
+	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 = (resource_size_t)si->mmio_base_high << 32
+				| 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.
+ */
+static int __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)
+			return -ENOENT;
+		return -EINVAL;
+	}
+
+	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)
+			return ret;
+
+		grp = (struct acpi_csrt_group *)((void *)grp + grp->length);
+	}
+
+	return 0;
+}
+subsys_initcall(acpi_csrt_init);
-- 
1.7.10.4

Re: [PATCH] ACPI: add support for CSRT table

[Rafael J. Wysocki]

On Monday, January 14, 2013 11:51:51 AM Mika Westerberg wrote:
> Core System Resources Table (CSRT) is a proprietary ACPI table that
> contains resources for certain devices that are not found in the DSDT
> table. Typically a shared DMA controller might be found here.
> 
> This patch adds support for this table. We go through all entries in the
> table and make platform devices of them. The resources from the table are
> passed with the platform device.
> 
> There is one special resource in the table and it is the DMA request line
> base and number of request lines. This information might be needed by the
> DMA controller driver as it needs to map the ACPI DMA request line number
> to the actual request line understood by the hardware. This range is passed
> as IORESOURCE_DMA resource.

I have a question: Who's going to bind to those platform devices created
by the code in this patch and how exactly this is going to happen?

Rafael


> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
> ---
>  drivers/acpi/Makefile |    1 +
>  drivers/acpi/csrt.c   |  156 +++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 157 insertions(+)
>  create mode 100644 drivers/acpi/csrt.c
> 
> diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
> index 4ee2e75..474fcfe 100644
> --- a/drivers/acpi/Makefile
> +++ b/drivers/acpi/Makefile
> @@ -38,6 +38,7 @@ 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-y				+= acpi_platform.o
>  acpi-y				+= power.o
>  acpi-y				+= event.o
> diff --git a/drivers/acpi/csrt.c b/drivers/acpi/csrt.c
> new file mode 100644
> index 0000000..94665f9
> --- /dev/null
> +++ b/drivers/acpi/csrt.c
> @@ -0,0 +1,156 @@
> +/*
> + * 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];
> +	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 = (resource_size_t)si->mmio_base_high << 32
> +				| 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.
> + */
> +static int __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)
> +			return -ENOENT;
> +		return -EINVAL;
> +	}
> +
> +	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)
> +			return ret;
> +
> +		grp = (struct acpi_csrt_group *)((void *)grp + grp->length);
> +	}
> +
> +	return 0;
> +}
> +subsys_initcall(acpi_csrt_init);
> 
-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.

Re: [PATCH] ACPI: add support for CSRT table

[Mika Westerberg]

On Wed, Jan 16, 2013 at 12:35:56AM +0100, Rafael J. Wysocki wrote:
> On Monday, January 14, 2013 11:51:51 AM Mika Westerberg wrote:
> > Core System Resources Table (CSRT) is a proprietary ACPI table that
> > contains resources for certain devices that are not found in the DSDT
> > table. Typically a shared DMA controller might be found here.
> > 
> > This patch adds support for this table. We go through all entries in the
> > table and make platform devices of them. The resources from the table are
> > passed with the platform device.
> > 
> > There is one special resource in the table and it is the DMA request line
> > base and number of request lines. This information might be needed by the
> > DMA controller driver as it needs to map the ACPI DMA request line number
> > to the actual request line understood by the hardware. This range is passed
> > as IORESOURCE_DMA resource.
> 
> I have a question: Who's going to bind to those platform devices created
> by the code in this patch and how exactly this is going to happen?

Typically it is the DMA driver (but not limited to that). It is supposed to
work so that either the driver name (in the platform driver struct) matches
the device name in the CSRT or like with the dw_dmac case we do something
like:

/* The platform device created is "INTL9C60.0.auto" */

static const struct platform_device_id dw_dma_ids[] = {
        { "INTL9C60", 0 },
	{ }
}

static struct platform_driver dw_driver = {
	...
	.id_table = dw_dma_ids,
};

Re: [PATCH] ACPI: add support for CSRT table

[Rafael J. Wysocki]

On Wednesday, January 16, 2013 06:42:16 AM Mika Westerberg wrote:
> On Wed, Jan 16, 2013 at 12:35:56AM +0100, Rafael J. Wysocki wrote:
> > On Monday, January 14, 2013 11:51:51 AM Mika Westerberg wrote:
> > > Core System Resources Table (CSRT) is a proprietary ACPI table that
> > > contains resources for certain devices that are not found in the DSDT
> > > table. Typically a shared DMA controller might be found here.
> > > 
> > > This patch adds support for this table. We go through all entries in the
> > > table and make platform devices of them. The resources from the table are
> > > passed with the platform device.
> > > 
> > > There is one special resource in the table and it is the DMA request line
> > > base and number of request lines. This information might be needed by the
> > > DMA controller driver as it needs to map the ACPI DMA request line number
> > > to the actual request line understood by the hardware. This range is passed
> > > as IORESOURCE_DMA resource.
> > 
> > I have a question: Who's going to bind to those platform devices created
> > by the code in this patch and how exactly this is going to happen?
> 
> Typically it is the DMA driver (but not limited to that). It is supposed to
> work so that either the driver name (in the platform driver struct) matches
> the device name in the CSRT or like with the dw_dmac case we do something
> like:
> 
> /* The platform device created is "INTL9C60.0.auto" */
> 
> static const struct platform_device_id dw_dma_ids[] = {
>         { "INTL9C60", 0 },
> 	{ }
> }
> 
> static struct platform_driver dw_driver = {
> 	...
> 	.id_table = dw_dma_ids,
> };

OK, that's fine by me.  Will apply.

Do you want it to go to any particular branch (eg. along with the acpi-scan
changes)?

Rafael


-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.

Re: [PATCH] ACPI: add support for CSRT table

[Mika Westerberg]

On Wed, Jan 16, 2013 at 04:05:13PM +0100, Rafael J. Wysocki wrote:
> On Wednesday, January 16, 2013 06:42:16 AM Mika Westerberg wrote:
> > On Wed, Jan 16, 2013 at 12:35:56AM +0100, Rafael J. Wysocki wrote:
> > > On Monday, January 14, 2013 11:51:51 AM Mika Westerberg wrote:
> > > > Core System Resources Table (CSRT) is a proprietary ACPI table that
> > > > contains resources for certain devices that are not found in the DSDT
> > > > table. Typically a shared DMA controller might be found here.
> > > > 
> > > > This patch adds support for this table. We go through all entries in the
> > > > table and make platform devices of them. The resources from the table are
> > > > passed with the platform device.
> > > > 
> > > > There is one special resource in the table and it is the DMA request line
> > > > base and number of request lines. This information might be needed by the
> > > > DMA controller driver as it needs to map the ACPI DMA request line number
> > > > to the actual request line understood by the hardware. This range is passed
> > > > as IORESOURCE_DMA resource.
> > > 
> > > I have a question: Who's going to bind to those platform devices created
> > > by the code in this patch and how exactly this is going to happen?
> > 
> > Typically it is the DMA driver (but not limited to that). It is supposed to
> > work so that either the driver name (in the platform driver struct) matches
> > the device name in the CSRT or like with the dw_dmac case we do something
> > like:
> > 
> > /* The platform device created is "INTL9C60.0.auto" */
> > 
> > static const struct platform_device_id dw_dma_ids[] = {
> >         { "INTL9C60", 0 },
> > 	{ }
> > }
> > 
> > static struct platform_driver dw_driver = {
> > 	...
> > 	.id_table = dw_dma_ids,
> > };
> 
> OK, that's fine by me.  Will apply.

Thanks!

> Do you want it to go to any particular branch (eg. along with the acpi-scan
> changes)?

This is not dependent on anything so you can pick the branch :-)

[PATCH v2] ACPI: add support for CSRT table

[Mika Westerberg]

Core System Resources Table (CSRT) is a proprietary ACPI table that
contains resources for certain devices that are not found in the DSDT
table. Typically a shared DMA controller might be found here.

This patch adds support for this table. We go through all entries in the
table and make platform devices of them. The resources from the table are
passed with the platform device.

There is one special resource in the table and it is the DMA request line
base and number of request lines. This information might be needed by the
DMA controller driver as it needs to map the ACPI DMA request line number
to the actual request line understood by the hardware. This range is passed
as IORESOURCE_DMA resource.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
We got a report that compiling this as 32-bit gives the following warning:

    drivers/acpi/csrt.c:42:5: warning: left shift count >= width of type [enabled by default]

Since all the CSRT tables we've seen are limited to 32-bit physical
addresses anyway (and the LPSS itself is 32-bit only) we fix this by only
using the low part of the MMIO address for now.

Sorry about the mess.

 drivers/acpi/Makefile |    1 +
 drivers/acpi/csrt.c   |  160 +++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 161 insertions(+)
 create mode 100644 drivers/acpi/csrt.c

diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index 4ee2e75..474fcfe 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -38,6 +38,7 @@ 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-y				+= acpi_platform.o
 acpi-y				+= power.o
 acpi-y				+= event.o
diff --git a/drivers/acpi/csrt.c b/drivers/acpi/csrt.c
new file mode 100644
index 0000000..fe69587
--- /dev/null
+++ b/drivers/acpi/csrt.c
@@ -0,0 +1,160 @@
+/*
+ * 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.
+ */
+static int __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)
+			return -ENOENT;
+		return -EINVAL;
+	}
+
+	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)
+			return ret;
+
+		grp = (struct acpi_csrt_group *)((void *)grp + grp->length);
+	}
+
+	return 0;
+}
+subsys_initcall(acpi_csrt_init);
-- 
1.7.10.4

Re: [PATCH v2] ACPI: add support for CSRT table

[Rafael J. Wysocki]

On Wednesday, January 16, 2013 06:13:43 PM Mika Westerberg wrote:
> Core System Resources Table (CSRT) is a proprietary ACPI table that
> contains resources for certain devices that are not found in the DSDT
> table. Typically a shared DMA controller might be found here.
> 
> This patch adds support for this table. We go through all entries in the
> table and make platform devices of them. The resources from the table are
> passed with the platform device.
> 
> There is one special resource in the table and it is the DMA request line
> base and number of request lines. This information might be needed by the
> DMA controller driver as it needs to map the ACPI DMA request line number
> to the actual request line understood by the hardware. This range is passed
> as IORESOURCE_DMA resource.
> 
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
> ---
> We got a report that compiling this as 32-bit gives the following warning:
> 
>     drivers/acpi/csrt.c:42:5: warning: left shift count >= width of type [enabled by default]
> 
> Since all the CSRT tables we've seen are limited to 32-bit physical
> addresses anyway (and the LPSS itself is 32-bit only) we fix this by only
> using the low part of the MMIO address for now.
> 
> Sorry about the mess.

No biggie.

I was about to apply this, but I started to wonder ->

> 
>  drivers/acpi/Makefile |    1 +
>  drivers/acpi/csrt.c   |  160 +++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 161 insertions(+)
>  create mode 100644 drivers/acpi/csrt.c
> 
> diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
> index 4ee2e75..474fcfe 100644
> --- a/drivers/acpi/Makefile
> +++ b/drivers/acpi/Makefile
> @@ -38,6 +38,7 @@ 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-y				+= acpi_platform.o
>  acpi-y				+= power.o
>  acpi-y				+= event.o
> diff --git a/drivers/acpi/csrt.c b/drivers/acpi/csrt.c
> new file mode 100644
> index 0000000..fe69587
> --- /dev/null
> +++ b/drivers/acpi/csrt.c
> @@ -0,0 +1,160 @@
> +/*
> + * 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.
> + */
> +static int __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)
> +			return -ENOENT;
> +		return -EINVAL;
> +	}
> +
> +	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)
> +			return ret;
> +
> +		grp = (struct acpi_csrt_group *)((void *)grp + grp->length);
> +	}
> +
> +	return 0;
> +}
> +subsys_initcall(acpi_csrt_init);

-> Do we really need a separate initcall for that?  And what if ACPI is
disabled?

Perhaps it would be better to call acpi_csrt_init() directly from
acpi_init() (or from acpi_scan_init() whichever is more suitable)?

Rafael


-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.

Re: [PATCH v2] ACPI: add support for CSRT table

[Mika Westerberg]

On Thu, Jan 17, 2013 at 12:27:32AM +0100, Rafael J. Wysocki wrote:
> > +static int __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)
> > +			return -ENOENT;
> > +		return -EINVAL;
> > +	}
> > +
> > +	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)
> > +			return ret;
> > +
> > +		grp = (struct acpi_csrt_group *)((void *)grp + grp->length);
> > +	}
> > +
> > +	return 0;
> > +}
> > +subsys_initcall(acpi_csrt_init);
> 
> -> Do we really need a separate initcall for that?  And what if ACPI is
> disabled?

Ah, good point - ACPI can be disabled at runtime as well.

> Perhaps it would be better to call acpi_csrt_init() directly from
> acpi_init() (or from acpi_scan_init() whichever is more suitable)?

Indeed. I'll fix this up and send you a new version soon.

Thanks.