From 18b709beb503bfc9a96a2e4b93d3cae4f5b17df0 Mon Sep 17 00:00:00 2001 From: Lorenzo Pieralisi Date: Tue, 6 Dec 2016 14:20:11 +0000 Subject: [PATCH] ACPI/IORT: Make dma masks set-up IORT specific The introduction of acpi_dma_configure() allows to configure DMA and related IOMMU for any device that is DMA capable. To achieve that goal it ensures DMA masks are set-up to sane default values before proceeding with IOMMU and DMA ops configuration. On x86/ia64 systems, through acpi_bind_one(), acpi_dma_configure() is called for every device that has an ACPI companion, in that every device is considered DMA capable on x86/ia64 systems (ie acpi_get_dma_attr() API), which has the side effect of initializing dma masks also for pseudo-devices (eg CPUs and memory nodes) and potentially for devices whose dma masks were not set-up before the acpi_dma_configure() API was introduced, which may have noxious side effects. Therefore, in preparation for IORT firmware specific DMA masks set-up, wrap the default DMA masks set-up in acpi_dma_configure() inside an IORT specific wrapper that reverts to a NOP on x86/ia64 systems, restoring the default expected behaviour on x86/ia64 systems and keeping DMA default masks set-up on IORT based (ie ARM) arch configurations. Signed-off-by: Lorenzo Pieralisi Acked-by: Will Deacon Acked-by: Rafael J. Wysocki Reviewed-by: Hanjun Guo Tested-by: Hanjun Guo Cc: Will Deacon Cc: Hanjun Guo Cc: Bjorn Helgaas Cc: Robin Murphy Cc: Tomasz Nowicki Cc: Joerg Roedel Cc: "Rafael J. Wysocki" Cc: Sricharan R Signed-off-by: Joerg Roedel --- drivers/acpi/arm64/iort.c | 22 ++++++++++++++++++++++ drivers/acpi/scan.c | 14 +------------- include/linux/acpi_iort.h | 2 ++ 3 files changed, 25 insertions(+), 13 deletions(-) diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c index 47bace8eafb6..e0d2e6e6e40c 100644 --- a/drivers/acpi/arm64/iort.c +++ b/drivers/acpi/arm64/iort.c @@ -546,6 +546,28 @@ static const struct iommu_ops *iort_iommu_xlate(struct device *dev, return ret ? NULL : ops; } +/** + * iort_set_dma_mask - Set-up dma mask for a device. + * + * @dev: device to configure + */ +void iort_set_dma_mask(struct device *dev) +{ + /* + * Set default coherent_dma_mask to 32 bit. Drivers are expected to + * setup the correct supported mask. + */ + if (!dev->coherent_dma_mask) + dev->coherent_dma_mask = DMA_BIT_MASK(32); + + /* + * Set it to coherent_dma_mask by default if the architecture + * code has not set it. + */ + if (!dev->dma_mask) + dev->dma_mask = &dev->coherent_dma_mask; +} + /** * iort_iommu_configure - Set-up IOMMU configuration for a device. * diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 80698d3c5feb..93b00cf4eb39 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -1380,19 +1380,7 @@ void acpi_dma_configure(struct device *dev, enum dev_dma_attr attr) { const struct iommu_ops *iommu; - /* - * Set default coherent_dma_mask to 32 bit. Drivers are expected to - * setup the correct supported mask. - */ - if (!dev->coherent_dma_mask) - dev->coherent_dma_mask = DMA_BIT_MASK(32); - - /* - * Set it to coherent_dma_mask by default if the architecture - * code has not set it. - */ - if (!dev->dma_mask) - dev->dma_mask = &dev->coherent_dma_mask; + iort_set_dma_mask(dev); iommu = iort_iommu_configure(dev); diff --git a/include/linux/acpi_iort.h b/include/linux/acpi_iort.h index dcb2b601e152..77e08099e554 100644 --- a/include/linux/acpi_iort.h +++ b/include/linux/acpi_iort.h @@ -35,6 +35,7 @@ bool iort_node_match(u8 type); u32 iort_msi_map_rid(struct device *dev, u32 req_id); struct irq_domain *iort_get_device_domain(struct device *dev, u32 req_id); /* IOMMU interface */ +void iort_set_dma_mask(struct device *dev); const struct iommu_ops *iort_iommu_configure(struct device *dev); #else static inline void acpi_iort_init(void) { } @@ -45,6 +46,7 @@ static inline struct irq_domain *iort_get_device_domain(struct device *dev, u32 req_id) { return NULL; } /* IOMMU interface */ +static inline void iort_set_dma_mask(struct device *dev) { } static inline const struct iommu_ops *iort_iommu_configure(struct device *dev) { return NULL; } -- 2.39.5