lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
 
Hash Suite for Android: free password hash cracker in your pocket
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:   Tue, 4 Apr 2017 18:00:32 +0530
From:   Sricharan R <sricharan@...eaurora.org>
To:     Robin Murphy <robin.murphy@....com>, will.deacon@....com,
        joro@...tes.org, lorenzo.pieralisi@....com,
        iommu@...ts.linux-foundation.org,
        linux-arm-kernel@...ts.infradead.org,
        linux-arm-msm@...r.kernel.org, m.szyprowski@...sung.com,
        bhelgaas@...gle.com, linux-pci@...r.kernel.org,
        linux-acpi@...r.kernel.org, tn@...ihalf.com, hanjun.guo@...aro.org,
        okaya@...eaurora.org, robh+dt@...nel.org, frowand.list@...il.com,
        devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
        sudeep.holla@....com, rjw@...ysocki.net, lenb@...nel.org,
        catalin.marinas@....com, arnd@...db.de, linux-arch@...r.kernel.org,
        gregkh@...uxfoundation.org
Subject: Re: [PATCH V10 07/12] of/acpi: Configure dma operations at probe time
 for platform/amba/pci bus devices

Hi Robin,

On 4/4/2017 5:47 PM, Robin Murphy wrote:
> On 04/04/17 11:18, Sricharan R wrote:
>> Configuring DMA ops at probe time will allow deferring device probe when
>> the IOMMU isn't available yet. The dma_configure for the device is
>> now called from the generic device_attach callback just before the
>> bus/driver probe is called. This way, configuring the DMA ops for the
>> device would be called at the same place for all bus_types, hence the
>> deferred probing mechanism should work for all buses as well.
>>
>> pci_bus_add_devices    (platform/amba)(_device_create/driver_register)
>>        |                         |
>> pci_bus_add_device     (device_add/driver_register)
>>        |                         |
>> device_attach           device_initial_probe
>>        |                         |
>> __device_attach_driver    __device_attach_driver
>>        |
>> driver_probe_device
>>        |
>> really_probe
>>        |
>> dma_configure
>>
>> Similarly on the device/driver_unregister path __device_release_driver is
>> called which inturn calls dma_deconfigure.
>>
>> This patch changes the dma ops configuration to probe time for
>> both OF and ACPI based platform/amba/pci bus devices.
>
> Reviewed-by: Robin Murphy <robin.murphy@....com>
>
> It's possible we could subsume {of,acpi}_dma_deconfigure() into
> dma_deconfigure() entirely in future if it becomes clear that neither of
> them will ever need to do anything firmware-specific, but I think for
> now it's probably safer to keep the current symmetry - calling
> arch_teardown_dma_ops() twice is benign (and even if it weren't, I'd say
> it really should be!)
>

Ya, calling it twice should cause no harm. If nothing firmware specific
gets added this could simply be put in deconfigure itself in future.
Thanks for all the reviews !!

Regards,
  Sricharan



> Robin.
>
>> Tested-by: Marek Szyprowski <m.szyprowski@...sung.com>
>> Tested-by: Hanjun Guo <hanjun.guo@...aro.org>
>> Acked-by: Bjorn Helgaas <bhelgaas@...gle.com> (drivers/pci part)
>> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
>> Signed-off-by: Sricharan R <sricharan@...eaurora.org>
>> ---
>>
>>  [V10] Added dummy dma_(de)configure functions in case
>>        of !CONFIG_HAS_DMA to avoid build breaks.
>>
>>  drivers/acpi/glue.c         |  5 -----
>>  drivers/base/dd.c           |  9 +++++++++
>>  drivers/base/dma-mapping.c  | 40 ++++++++++++++++++++++++++++++++++++++++
>>  drivers/of/platform.c       |  5 +----
>>  drivers/pci/probe.c         | 28 ----------------------------
>>  include/linux/dma-mapping.h | 12 ++++++++++++
>>  6 files changed, 62 insertions(+), 37 deletions(-)
>>
>> diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c
>> index fb19e1c..c05f241 100644
>> --- a/drivers/acpi/glue.c
>> +++ b/drivers/acpi/glue.c
>> @@ -176,7 +176,6 @@ int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
>>  	struct list_head *physnode_list;
>>  	unsigned int node_id;
>>  	int retval = -EINVAL;
>> -	enum dev_dma_attr attr;
>>
>>  	if (has_acpi_companion(dev)) {
>>  		if (acpi_dev) {
>> @@ -233,10 +232,6 @@ int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
>>  	if (!has_acpi_companion(dev))
>>  		ACPI_COMPANION_SET(dev, acpi_dev);
>>
>> -	attr = acpi_get_dma_attr(acpi_dev);
>> -	if (attr != DEV_DMA_NOT_SUPPORTED)
>> -		acpi_dma_configure(dev, attr);
>> -
>>  	acpi_physnode_link_name(physical_node_name, node_id);
>>  	retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
>>  				   physical_node_name);
>> diff --git a/drivers/base/dd.c b/drivers/base/dd.c
>> index a1fbf55..4882f06 100644
>> --- a/drivers/base/dd.c
>> +++ b/drivers/base/dd.c
>> @@ -19,6 +19,7 @@
>>
>>  #include <linux/device.h>
>>  #include <linux/delay.h>
>> +#include <linux/dma-mapping.h>
>>  #include <linux/module.h>
>>  #include <linux/kthread.h>
>>  #include <linux/wait.h>
>> @@ -356,6 +357,10 @@ static int really_probe(struct device *dev, struct device_driver *drv)
>>  	if (ret)
>>  		goto pinctrl_bind_failed;
>>
>> +	ret = dma_configure(dev);
>> +	if (ret)
>> +		goto dma_failed;
>> +
>>  	if (driver_sysfs_add(dev)) {
>>  		printk(KERN_ERR "%s: driver_sysfs_add(%s) failed\n",
>>  			__func__, dev_name(dev));
>> @@ -417,6 +422,8 @@ static int really_probe(struct device *dev, struct device_driver *drv)
>>  	goto done;
>>
>>  probe_failed:
>> +	dma_deconfigure(dev);
>> +dma_failed:
>>  	if (dev->bus)
>>  		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
>>  					     BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
>> @@ -826,6 +833,8 @@ static void __device_release_driver(struct device *dev, struct device *parent)
>>  			drv->remove(dev);
>>
>>  		device_links_driver_cleanup(dev);
>> +		dma_deconfigure(dev);
>> +
>>  		devres_release_all(dev);
>>  		dev->driver = NULL;
>>  		dev_set_drvdata(dev, NULL);
>> diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
>> index efd71cf..449b948 100644
>> --- a/drivers/base/dma-mapping.c
>> +++ b/drivers/base/dma-mapping.c
>> @@ -7,9 +7,11 @@
>>   * This file is released under the GPLv2.
>>   */
>>
>> +#include <linux/acpi.h>
>>  #include <linux/dma-mapping.h>
>>  #include <linux/export.h>
>>  #include <linux/gfp.h>
>> +#include <linux/of_device.h>
>>  #include <linux/slab.h>
>>  #include <linux/vmalloc.h>
>>
>> @@ -341,3 +343,41 @@ void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags)
>>  	vunmap(cpu_addr);
>>  }
>>  #endif
>> +
>> +/*
>> + * Common configuration to enable DMA API use for a device
>> + */
>> +#include <linux/pci.h>
>> +
>> +int dma_configure(struct device *dev)
>> +{
>> +	struct device *bridge = NULL, *dma_dev = dev;
>> +	enum dev_dma_attr attr;
>> +
>> +	if (dev_is_pci(dev)) {
>> +		bridge = pci_get_host_bridge_device(to_pci_dev(dev));
>> +		dma_dev = bridge;
>> +		if (IS_ENABLED(CONFIG_OF) && dma_dev->parent &&
>> +		    dma_dev->parent->of_node)
>> +			dma_dev = dma_dev->parent;
>> +	}
>> +
>> +	if (dma_dev->of_node) {
>> +		of_dma_configure(dev, dma_dev->of_node);
>> +	} else if (has_acpi_companion(dma_dev)) {
>> +		attr = acpi_get_dma_attr(to_acpi_device_node(dma_dev->fwnode));
>> +		if (attr != DEV_DMA_NOT_SUPPORTED)
>> +			acpi_dma_configure(dev, attr);
>> +	}
>> +
>> +	if (bridge)
>> +		pci_put_host_bridge_device(bridge);
>> +
>> +	return 0;
>> +}
>> +
>> +void dma_deconfigure(struct device *dev)
>> +{
>> +	of_dma_deconfigure(dev);
>> +	acpi_dma_deconfigure(dev);
>> +}
>> diff --git a/drivers/of/platform.c b/drivers/of/platform.c
>> index 5344db5..2aa4ebb 100644
>> --- a/drivers/of/platform.c
>> +++ b/drivers/of/platform.c
>> @@ -22,6 +22,7 @@
>>  #include <linux/slab.h>
>>  #include <linux/of_address.h>
>>  #include <linux/of_device.h>
>> +#include <linux/of_iommu.h>
>>  #include <linux/of_irq.h>
>>  #include <linux/of_platform.h>
>>  #include <linux/platform_device.h>
>> @@ -186,11 +187,9 @@ static struct platform_device *of_platform_device_create_pdata(
>>
>>  	dev->dev.bus = &platform_bus_type;
>>  	dev->dev.platform_data = platform_data;
>> -	of_dma_configure(&dev->dev, dev->dev.of_node);
>>  	of_msi_configure(&dev->dev, dev->dev.of_node);
>>
>>  	if (of_device_add(dev) != 0) {
>> -		of_dma_deconfigure(&dev->dev);
>>  		platform_device_put(dev);
>>  		goto err_clear_flag;
>>  	}
>> @@ -248,7 +247,6 @@ static struct amba_device *of_amba_device_create(struct device_node *node,
>>  		dev_set_name(&dev->dev, "%s", bus_id);
>>  	else
>>  		of_device_make_bus_id(&dev->dev);
>> -	of_dma_configure(&dev->dev, dev->dev.of_node);
>>
>>  	/* Allow the HW Peripheral ID to be overridden */
>>  	prop = of_get_property(node, "arm,primecell-periphid", NULL);
>> @@ -542,7 +540,6 @@ static int of_platform_device_destroy(struct device *dev, void *data)
>>  		amba_device_unregister(to_amba_device(dev));
>>  #endif
>>
>> -	of_dma_deconfigure(dev);
>>  	of_node_clear_flag(dev->of_node, OF_POPULATED);
>>  	of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
>>  	return 0;
>> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
>> index dfc9a27..5a8dd43 100644
>> --- a/drivers/pci/probe.c
>> +++ b/drivers/pci/probe.c
>> @@ -1893,33 +1893,6 @@ static void pci_set_msi_domain(struct pci_dev *dev)
>>  	dev_set_msi_domain(&dev->dev, d);
>>  }
>>
>> -/**
>> - * pci_dma_configure - Setup DMA configuration
>> - * @dev: ptr to pci_dev struct of the PCI device
>> - *
>> - * Function to update PCI devices's DMA configuration using the same
>> - * info from the OF node or ACPI node of host bridge's parent (if any).
>> - */
>> -static void pci_dma_configure(struct pci_dev *dev)
>> -{
>> -	struct device *bridge = pci_get_host_bridge_device(dev);
>> -
>> -	if (IS_ENABLED(CONFIG_OF) &&
>> -		bridge->parent && bridge->parent->of_node) {
>> -			of_dma_configure(&dev->dev, bridge->parent->of_node);
>> -	} else if (has_acpi_companion(bridge)) {
>> -		struct acpi_device *adev = to_acpi_device_node(bridge->fwnode);
>> -		enum dev_dma_attr attr = acpi_get_dma_attr(adev);
>> -
>> -		if (attr == DEV_DMA_NOT_SUPPORTED)
>> -			dev_warn(&dev->dev, "DMA not supported.\n");
>> -		else
>> -			acpi_dma_configure(&dev->dev, attr);
>> -	}
>> -
>> -	pci_put_host_bridge_device(bridge);
>> -}
>> -
>>  void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
>>  {
>>  	int ret;
>> @@ -1933,7 +1906,6 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
>>  	dev->dev.dma_mask = &dev->dma_mask;
>>  	dev->dev.dma_parms = &dev->dma_parms;
>>  	dev->dev.coherent_dma_mask = 0xffffffffull;
>> -	pci_dma_configure(dev);
>>
>>  	pci_set_dma_max_seg_size(dev, 65536);
>>  	pci_set_dma_seg_boundary(dev, 0xffffffff);
>> diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
>> index 0977317..4f3eece 100644
>> --- a/include/linux/dma-mapping.h
>> +++ b/include/linux/dma-mapping.h
>> @@ -728,6 +728,18 @@ void *dma_mark_declared_memory_occupied(struct device *dev,
>>  }
>>  #endif /* CONFIG_HAVE_GENERIC_DMA_COHERENT */
>>
>> +#ifdef CONFIG_HAS_DMA
>> +int dma_configure(struct device *dev);
>> +void dma_deconfigure(struct device *dev);
>> +#else
>> +static inline int dma_configure(struct device *dev)
>> +{
>> +	return 0;
>> +}
>> +
>> +static inline void dma_deconfigure(struct device *dev) {}
>> +#endif
>> +
>>  /*
>>   * Managed DMA API
>>   */
>>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in
> the body of a message to majordomo@...r.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>

-- 
"QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

Powered by blists - more mailing lists