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linux/drivers/iommu/dma-iommu.h
Robin Murphy b67483b3c4 iommu/dma: Centralise iommu_setup_dma_ops()
It's somewhat hard to see, but arm64's arch_setup_dma_ops() should only
ever call iommu_setup_dma_ops() after a successful iommu_probe_device(),
which means there should be no harm in achieving the same order of
operations by running it off the back of iommu_probe_device() itself.
This then puts it in line with the x86 and s390 .probe_finalize bodges,
letting us pull it all into the main flow properly. As a bonus this lets
us fold in and de-scope the PCI workaround setup as well.

At this point we can also then pull the call up inside the group mutex,
and avoid having to think about whether iommu_group_store_type() could
theoretically race and free the domain if iommu_setup_dma_ops() ran just
*before* iommu_device_use_default_domain() claims it... Furthermore we
replace one .probe_finalize call completely, since the only remaining
implementations are now one which only needs to run once for the initial
boot-time probe, and two which themselves render that path unreachable.

This leaves us a big step closer to realistically being able to unpick
the variety of different things that iommu_setup_dma_ops() has been
muddling together, and further streamline iommu-dma into core API flows
in future.

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com> # For Intel IOMMU
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/bebea331c1d688b34d9862eefd5ede47503961b8.1713523152.git.robin.murphy@arm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2024-04-26 12:07:26 +02:00

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C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2014-2015 ARM Ltd.
*/
#ifndef __DMA_IOMMU_H
#define __DMA_IOMMU_H
#include <linux/iommu.h>
#ifdef CONFIG_IOMMU_DMA
void iommu_setup_dma_ops(struct device *dev);
int iommu_get_dma_cookie(struct iommu_domain *domain);
void iommu_put_dma_cookie(struct iommu_domain *domain);
int iommu_dma_init_fq(struct iommu_domain *domain);
void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list);
extern bool iommu_dma_forcedac;
#else /* CONFIG_IOMMU_DMA */
static inline void iommu_setup_dma_ops(struct device *dev)
{
}
static inline int iommu_dma_init_fq(struct iommu_domain *domain)
{
return -EINVAL;
}
static inline int iommu_get_dma_cookie(struct iommu_domain *domain)
{
return -ENODEV;
}
static inline void iommu_put_dma_cookie(struct iommu_domain *domain)
{
}
static inline void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list)
{
}
#endif /* CONFIG_IOMMU_DMA */
#endif /* __DMA_IOMMU_H */