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ACPI: Make acpi_dma_configure() DMA regions aware

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Current ACPI DMA configuration set-up device DMA capabilities through
kernel defaults that do not take into account platform specific DMA
configurations reported by firmware.

By leveraging the ACPI acpi_dev_get_dma_resources() API, add code
in acpi_dma_configure() to retrieve the DMA regions to correctly
set-up PCI devices DMA parameters.

Rework the ACPI IORT kernel API to make sure they can accommodate
the DMA set-up required by firmware. By making PCI devices DMA set-up
ACPI IORT specific, the kernel is shielded from unwanted regressions
that could be triggered by parsing DMA resources on arches that were
previously ignoring them (ie x86/ia64), leaving kernel behaviour
unchanged on those arches.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Tested-by: Nate Watterson <nwatters@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Lorenzo Pieralisi 2017-08-07 11:29:49 +01:00 committed by Rafael J. Wysocki
parent c04ac679c6
commit 7ad4263980
3 changed files with 42 additions and 12 deletions
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37
drivers/acpi/arm64/iort.c
View file

@ -681,12 +681,17 @@ static const struct iommu_ops *iort_iommu_xlate(struct device *dev,
}
/**
* iort_set_dma_mask - Set-up dma mask for a device.
* iort_dma_setup() - Set-up device DMA parameters.
*
* @dev: device to configure
* @dma_addr: device DMA address result pointer
* @size: DMA range size result pointer
*/
void iort_set_dma_mask(struct device *dev)
void iort_dma_setup(struct device *dev, u64 *dma_addr, u64 *dma_size)
{
u64 mask, dmaaddr = 0, size = 0, offset = 0;
int ret, msb;
/*
* Set default coherent_dma_mask to 32 bit. Drivers are expected to
* setup the correct supported mask.
@ -700,6 +705,34 @@ void iort_set_dma_mask(struct device *dev)
*/
if (!dev->dma_mask)
dev->dma_mask = &dev->coherent_dma_mask;
size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1);
if (dev_is_pci(dev)) {
ret = acpi_dma_get_range(dev, &dmaaddr, &offset, &size);
if (!ret) {
msb = fls64(dmaaddr + size - 1);
/*
* Round-up to the power-of-two mask or set
* the mask to the whole 64-bit address space
* in case the DMA region covers the full
* memory window.
*/
mask = msb == 64 ? U64_MAX : (1ULL << msb) - 1;
/*
* Limit coherent and dma mask based on size
* retrieved from firmware.
*/
dev->coherent_dma_mask = mask;
*dev->dma_mask = mask;
}
}
*dma_addr = dmaaddr;
*dma_size = size;
dev->dma_pfn_offset = PFN_DOWN(offset);
dev_dbg(dev, "dma_pfn_offset(%#08llx)\n", offset);
}
/**

12
drivers/acpi/scan.c
View file

@ -1446,20 +1446,16 @@ int acpi_dma_get_range(struct device *dev, u64 *dma_addr, u64 *offset,
int acpi_dma_configure(struct device *dev, enum dev_dma_attr attr)
{
const struct iommu_ops *iommu;
u64 size;
u64 dma_addr = 0, size = 0;
iort_set_dma_mask(dev);
iort_dma_setup(dev, &dma_addr, &size);
iommu = iort_iommu_configure(dev);
if (IS_ERR(iommu) && PTR_ERR(iommu) == -EPROBE_DEFER)
return -EPROBE_DEFER;
size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1);
/*
* Assume dma valid range starts at 0 and covers the whole
* coherent_dma_mask.
*/
arch_setup_dma_ops(dev, 0, size, iommu, attr == DEV_DMA_COHERENT);
arch_setup_dma_ops(dev, dma_addr, size,
iommu, attr == DEV_DMA_COHERENT);
return 0;
}

5
include/linux/acpi_iort.h
View file

@ -36,7 +36,7 @@ struct irq_domain *iort_get_device_domain(struct device *dev, u32 req_id);
void acpi_configure_pmsi_domain(struct device *dev);
int iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id);
/* IOMMU interface */
void iort_set_dma_mask(struct device *dev);
void iort_dma_setup(struct device *dev, u64 *dma_addr, u64 *size);
const struct iommu_ops *iort_iommu_configure(struct device *dev);
#else
static inline void acpi_iort_init(void) { }
@ -47,7 +47,8 @@ static inline struct irq_domain *iort_get_device_domain(struct device *dev,
{ return NULL; }
static inline void acpi_configure_pmsi_domain(struct device *dev) { }
/* IOMMU interface */
static inline void iort_set_dma_mask(struct device *dev) { }
static inline void iort_dma_setup(struct device *dev, u64 *dma_addr,
u64 *size) { }
static inline
const struct iommu_ops *iort_iommu_configure(struct device *dev)
{ return NULL; }