linux_dsm_epyc7002/drivers/dma/dw/platform.c
Christian Lamparter 7b0c03ecc4 dmaengine: dw-dmac: implement dma protection control setting
This patch adds a new device-tree property that allows to
specify the dma protection control bits for the all of the
DMA controller's channel uniformly.

Setting the "correct" bits can have a huge impact on the
PPC460EX and APM82181 that use this DMA engine in combination
with a DesignWare' SATA-II core (sata_dwc_460ex driver).

In the OpenWrt Forum, the user takimata reported that:
|It seems your patch unleashed the full power of the SATA port.
|Where I was previously hitting a really hard limit at around
|82 MB/s for reading and 27 MB/s for writing, I am now getting this:
|
|root@OpenWrt:/mnt# time dd if=/dev/zero of=tempfile bs=1M count=1024
|1024+0 records in
|1024+0 records out
|real    0m 13.65s
|user    0m 0.01s
|sys     0m 11.89s
|
|root@OpenWrt:/mnt# time dd if=tempfile of=/dev/null bs=1M count=1024
|1024+0 records in
|1024+0 records out
|real    0m 8.41s
|user    0m 0.01s
|sys     0m 4.70s
|
|This means: 121 MB/s reading and 75 MB/s writing!
|
|The drive is a WD Green WD10EARX taken from an older MBL Single.
|I repeated the test a few times with even larger files to rule out
|any caching, I'm still seeing the same great performance. OpenWrt is
|now completely on par with the original MBL firmware's performance.

Another user And.short reported:
|I can report that your fix worked! Boots up fine with two
|drives even with more partitions, and no more reboot on
|concurrent disk access!

A closer look into the sata_dwc_460ex code revealed that
the driver did initally set the correct protection control
bits. However, this feature was lost when the sata_dwc_460ex
driver was converted to the generic DMA driver framework.

BugLink: https://forum.openwrt.org/t/wd-mybook-live-duo-two-disks/16195/55
BugLink: https://forum.openwrt.org/t/wd-mybook-live-duo-two-disks/16195/50
Fixes: 8b3444852a ("sata_dwc_460ex: move to generic DMA driver")
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2018-11-24 20:07:22 +05:30

357 lines
8.5 KiB
C

/*
* Platform driver for the Synopsys DesignWare DMA Controller
*
* Copyright (C) 2007-2008 Atmel Corporation
* Copyright (C) 2010-2011 ST Microelectronics
* Copyright (C) 2013 Intel Corporation
*
* Some parts of this driver are derived from the original dw_dmac.
*
* 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.
*/
#include <linux/module.h>
#include <linux/device.h>
#include <linux/clk.h>
#include <linux/pm_runtime.h>
#include <linux/platform_device.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/of.h>
#include <linux/of_dma.h>
#include <linux/acpi.h>
#include <linux/acpi_dma.h>
#include "internal.h"
#define DRV_NAME "dw_dmac"
static struct dma_chan *dw_dma_of_xlate(struct of_phandle_args *dma_spec,
struct of_dma *ofdma)
{
struct dw_dma *dw = ofdma->of_dma_data;
struct dw_dma_slave slave = {
.dma_dev = dw->dma.dev,
};
dma_cap_mask_t cap;
if (dma_spec->args_count != 3)
return NULL;
slave.src_id = dma_spec->args[0];
slave.dst_id = dma_spec->args[0];
slave.m_master = dma_spec->args[1];
slave.p_master = dma_spec->args[2];
if (WARN_ON(slave.src_id >= DW_DMA_MAX_NR_REQUESTS ||
slave.dst_id >= DW_DMA_MAX_NR_REQUESTS ||
slave.m_master >= dw->pdata->nr_masters ||
slave.p_master >= dw->pdata->nr_masters))
return NULL;
dma_cap_zero(cap);
dma_cap_set(DMA_SLAVE, cap);
/* TODO: there should be a simpler way to do this */
return dma_request_channel(cap, dw_dma_filter, &slave);
}
#ifdef CONFIG_ACPI
static bool dw_dma_acpi_filter(struct dma_chan *chan, void *param)
{
struct acpi_dma_spec *dma_spec = param;
struct dw_dma_slave slave = {
.dma_dev = dma_spec->dev,
.src_id = dma_spec->slave_id,
.dst_id = dma_spec->slave_id,
.m_master = 0,
.p_master = 1,
};
return dw_dma_filter(chan, &slave);
}
static void dw_dma_acpi_controller_register(struct dw_dma *dw)
{
struct device *dev = dw->dma.dev;
struct acpi_dma_filter_info *info;
int ret;
info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
if (!info)
return;
dma_cap_zero(info->dma_cap);
dma_cap_set(DMA_SLAVE, info->dma_cap);
info->filter_fn = dw_dma_acpi_filter;
ret = devm_acpi_dma_controller_register(dev, acpi_dma_simple_xlate,
info);
if (ret)
dev_err(dev, "could not register acpi_dma_controller\n");
}
#else /* !CONFIG_ACPI */
static inline void dw_dma_acpi_controller_register(struct dw_dma *dw) {}
#endif /* !CONFIG_ACPI */
#ifdef CONFIG_OF
static struct dw_dma_platform_data *
dw_dma_parse_dt(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
struct dw_dma_platform_data *pdata;
u32 tmp, arr[DW_DMA_MAX_NR_MASTERS], mb[DW_DMA_MAX_NR_CHANNELS];
u32 nr_masters;
u32 nr_channels;
if (!np) {
dev_err(&pdev->dev, "Missing DT data\n");
return NULL;
}
if (of_property_read_u32(np, "dma-masters", &nr_masters))
return NULL;
if (nr_masters < 1 || nr_masters > DW_DMA_MAX_NR_MASTERS)
return NULL;
if (of_property_read_u32(np, "dma-channels", &nr_channels))
return NULL;
if (nr_channels > DW_DMA_MAX_NR_CHANNELS)
return NULL;
pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
if (!pdata)
return NULL;
pdata->nr_masters = nr_masters;
pdata->nr_channels = nr_channels;
if (of_property_read_bool(np, "is_private"))
pdata->is_private = true;
/*
* All known devices, which use DT for configuration, support
* memory-to-memory transfers. So enable it by default.
*/
pdata->is_memcpy = true;
if (!of_property_read_u32(np, "chan_allocation_order", &tmp))
pdata->chan_allocation_order = (unsigned char)tmp;
if (!of_property_read_u32(np, "chan_priority", &tmp))
pdata->chan_priority = tmp;
if (!of_property_read_u32(np, "block_size", &tmp))
pdata->block_size = tmp;
if (!of_property_read_u32_array(np, "data-width", arr, nr_masters)) {
for (tmp = 0; tmp < nr_masters; tmp++)
pdata->data_width[tmp] = arr[tmp];
} else if (!of_property_read_u32_array(np, "data_width", arr, nr_masters)) {
for (tmp = 0; tmp < nr_masters; tmp++)
pdata->data_width[tmp] = BIT(arr[tmp] & 0x07);
}
if (!of_property_read_u32_array(np, "multi-block", mb, nr_channels)) {
for (tmp = 0; tmp < nr_channels; tmp++)
pdata->multi_block[tmp] = mb[tmp];
} else {
for (tmp = 0; tmp < nr_channels; tmp++)
pdata->multi_block[tmp] = 1;
}
if (!of_property_read_u32(np, "snps,dma-protection-control", &tmp)) {
if (tmp > CHAN_PROTCTL_MASK)
return NULL;
pdata->protctl = tmp;
}
return pdata;
}
#else
static inline struct dw_dma_platform_data *
dw_dma_parse_dt(struct platform_device *pdev)
{
return NULL;
}
#endif
static int dw_probe(struct platform_device *pdev)
{
struct dw_dma_chip *chip;
struct device *dev = &pdev->dev;
struct resource *mem;
const struct dw_dma_platform_data *pdata;
int err;
chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
if (!chip)
return -ENOMEM;
chip->irq = platform_get_irq(pdev, 0);
if (chip->irq < 0)
return chip->irq;
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
chip->regs = devm_ioremap_resource(dev, mem);
if (IS_ERR(chip->regs))
return PTR_ERR(chip->regs);
err = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
if (err)
return err;
pdata = dev_get_platdata(dev);
if (!pdata)
pdata = dw_dma_parse_dt(pdev);
chip->dev = dev;
chip->id = pdev->id;
chip->pdata = pdata;
chip->clk = devm_clk_get(chip->dev, "hclk");
if (IS_ERR(chip->clk))
return PTR_ERR(chip->clk);
err = clk_prepare_enable(chip->clk);
if (err)
return err;
pm_runtime_enable(&pdev->dev);
err = dw_dma_probe(chip);
if (err)
goto err_dw_dma_probe;
platform_set_drvdata(pdev, chip);
if (pdev->dev.of_node) {
err = of_dma_controller_register(pdev->dev.of_node,
dw_dma_of_xlate, chip->dw);
if (err)
dev_err(&pdev->dev,
"could not register of_dma_controller\n");
}
if (ACPI_HANDLE(&pdev->dev))
dw_dma_acpi_controller_register(chip->dw);
return 0;
err_dw_dma_probe:
pm_runtime_disable(&pdev->dev);
clk_disable_unprepare(chip->clk);
return err;
}
static int dw_remove(struct platform_device *pdev)
{
struct dw_dma_chip *chip = platform_get_drvdata(pdev);
if (pdev->dev.of_node)
of_dma_controller_free(pdev->dev.of_node);
dw_dma_remove(chip);
pm_runtime_disable(&pdev->dev);
clk_disable_unprepare(chip->clk);
return 0;
}
static void dw_shutdown(struct platform_device *pdev)
{
struct dw_dma_chip *chip = platform_get_drvdata(pdev);
/*
* We have to call dw_dma_disable() to stop any ongoing transfer. On
* some platforms we can't do that since DMA device is powered off.
* Moreover we have no possibility to check if the platform is affected
* or not. That's why we call pm_runtime_get_sync() / pm_runtime_put()
* unconditionally. On the other hand we can't use
* pm_runtime_suspended() because runtime PM framework is not fully
* used by the driver.
*/
pm_runtime_get_sync(chip->dev);
dw_dma_disable(chip);
pm_runtime_put_sync_suspend(chip->dev);
clk_disable_unprepare(chip->clk);
}
#ifdef CONFIG_OF
static const struct of_device_id dw_dma_of_id_table[] = {
{ .compatible = "snps,dma-spear1340" },
{}
};
MODULE_DEVICE_TABLE(of, dw_dma_of_id_table);
#endif
#ifdef CONFIG_ACPI
static const struct acpi_device_id dw_dma_acpi_id_table[] = {
{ "INTL9C60", 0 },
{ "80862286", 0 },
{ "808622C0", 0 },
{ }
};
MODULE_DEVICE_TABLE(acpi, dw_dma_acpi_id_table);
#endif
#ifdef CONFIG_PM_SLEEP
static int dw_suspend_late(struct device *dev)
{
struct dw_dma_chip *chip = dev_get_drvdata(dev);
dw_dma_disable(chip);
clk_disable_unprepare(chip->clk);
return 0;
}
static int dw_resume_early(struct device *dev)
{
struct dw_dma_chip *chip = dev_get_drvdata(dev);
int ret;
ret = clk_prepare_enable(chip->clk);
if (ret)
return ret;
return dw_dma_enable(chip);
}
#endif /* CONFIG_PM_SLEEP */
static const struct dev_pm_ops dw_dev_pm_ops = {
SET_LATE_SYSTEM_SLEEP_PM_OPS(dw_suspend_late, dw_resume_early)
};
static struct platform_driver dw_driver = {
.probe = dw_probe,
.remove = dw_remove,
.shutdown = dw_shutdown,
.driver = {
.name = DRV_NAME,
.pm = &dw_dev_pm_ops,
.of_match_table = of_match_ptr(dw_dma_of_id_table),
.acpi_match_table = ACPI_PTR(dw_dma_acpi_id_table),
},
};
static int __init dw_init(void)
{
return platform_driver_register(&dw_driver);
}
subsys_initcall(dw_init);
static void __exit dw_exit(void)
{
platform_driver_unregister(&dw_driver);
}
module_exit(dw_exit);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Synopsys DesignWare DMA Controller platform driver");
MODULE_ALIAS("platform:" DRV_NAME);