[PATCH v3 1/2] dma: acpi-dma: parse CSRT to extract additional resources

From: Andy Shevchenko
Date: Wed May 08 2013 - 04:56:46 EST

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@xxxxxxxxxxxxxxx>
Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
drivers/acpi/Makefile | 1 -
drivers/acpi/csrt.c | 159 ------------------------------------------
drivers/acpi/internal.h | 1 -
drivers/acpi/scan.c | 1 -
drivers/dma/acpi-dma.c | 172 +++++++++++++++++++++++++++++++++++++++++++++-
include/linux/acpi_dma.h | 4 ++
6 files changed, 173 insertions(+), 165 deletions(-)
delete mode 100644 drivers/acpi/csrt.c

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@xxxxxxxxxxxxxxx>
- * Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
- *
- * 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 fe158fd..aacc08f 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_memory_hotplug_init();

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@xxxxxxxxxxxxxxx>
+ * Authors: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
+ * Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
*
* 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;
}

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() */
--
1.7.10.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/