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 <lorenzo.pieralisi@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>
Tested-by: Hanjun Guo <hanjun.guo@linaro.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Hanjun Guo <hanjun.guo@linaro.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Tomasz Nowicki <tn@semihalf.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index 47bace8eafb657129466bcab600785709630d85e..e0d2e6e6e40caf03b7c1bf4712664071e433becf 100644 (file)
--- 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 80698d3c5febdfcc2175e92a6d33cfdbae729242..93b00cf4eb3922d541a43d200ce73d5d414f6c3f 100644 (file)
--- 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 dcb2b601e15222b0ba9f7850a446df25a58ccd30..77e08099e55404b53225e71f7bd0b9ca34caec4a 100644 (file)
--- 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; }