[RFC PATCH v3 13/13] drivers: acpi: iort: introduce iort_iommu_configure
From: Lorenzo Pieralisi <hidden>
Date: 2016-08-11 08:45:01
Also in:
linux-acpi, linux-iommu, linux-pci, lkml
On Wed, Aug 03, 2016 at 10:19:43AM -0400, nwatters at codeaurora.org wrote: [...]
quoted
+const struct iommu_ops *iort_iommu_configure(struct device *dev) +{ + struct acpi_iort_node *node, *parent; + struct fwnode_handle *iort_fwnode; + u32 rid = 0, devid = 0;Since this routine maps the RID space of a device to the StreamID space of its parent smmu, would you consider renaming the devid variable to some form of sid or streamid?quoted
+ + if (dev_is_pci(dev)) { + struct pci_bus *bus = to_pci_dev(dev)->bus; + + pci_for_each_dma_alias(to_pci_dev(dev), __get_pci_rid, + &rid); + + node = iort_scan_node(ACPI_IORT_NODE_PCI_ROOT_COMPLEX, + iort_match_node_callback, &bus->dev); + } else { + node = iort_scan_node(ACPI_IORT_NODE_NAMED_COMPONENT, + iort_match_node_callback, dev); + } + + if (!node) + return NULL; + + parent = iort_node_map_rid(node, rid, &devid, IORT_IOMMU_TYPE); + if (parent) { + iort_fwnode = iort_get_fwnode(parent); + if (iort_fwnode) { + arm_smmu_iort_xlate(dev, devid, iort_fwnode);What about named components with multiple stream ids? Since establishing the relationship between a named component and its parent smmu is already dependent on there being an appropriate mapping of rid 0, it stands to reason that all of the stream ids for a named component could be enumerated by mapping increasing rid values until the output parent no longer matches that returned for rid 0.
I have reworked the code since for named component it makes no sense to carry out a mapping that depends on an input id given that we do not have one. Instead what we will do is the same thing DT does (ie "iommus" property), namely walk the array of single mappings for a given named component (that do not depend on the input rid, there is not any) and add them to the translation as we find them. Ergo, mappings that are not single mappings are pretty much useless for named components (for the time being), and I won't allow them. Thoughts ? Lorenzo
quoted hunk ↗ jump to hunk
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+ return fwspec_iommu_get_ops(iort_fwnode); + } + } + + return NULL; +}It should be noted that while trying out the approach described above, I noticed that each of the smmu attached named components described in my iort were ending up with an extra stream id. The culprit appears to be that the range checking in iort_id_map() is overly permissive on the upper bounds. For example, mappings with input_base=N and id_count=1 were matching both N and N+1. The following change fixed the issue.@@ -296,7 +296,7 @@ iort_id_map(struct acpi_iort_id_mapping *map, u8type, u32 rid_in, u32 *rid_out) } if (rid_in < map->input_base || - (rid_in > map->input_base + map->id_count)) + (rid_in >= map->input_base + map->id_count)) return -ENXIO; *rid_out = map->output_base + (rid_in - map->input_base);quoted
+ static void acpi_smmu_v3_register_irq(int hwirq, const char *name, struct resource *res) {diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index b4b9064..de28825 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c@@ -7,6 +7,7 @@#include <linux/slab.h> #include <linux/kernel.h> #include <linux/acpi.h> +#include <linux/iort.h> #include <linux/signal.h> #include <linux/kthread.h> #include <linux/dmi.h>@@ -1365,11 +1366,15 @@ enum dev_dma_attr acpi_get_dma_attr(structacpi_device *adev) */ void acpi_dma_configure(struct device *dev, enum dev_dma_attr attr) { + const struct iommu_ops *iommu; + + iommu = iort_iommu_configure(dev); + /* * Assume dma valid range starts at 0 and covers the whole * coherent_dma_mask. */ - arch_setup_dma_ops(dev, 0, dev->coherent_dma_mask + 1, NULL, + arch_setup_dma_ops(dev, 0, dev->coherent_dma_mask + 1, iommu, attr == DEV_DMA_COHERENT);If dev has a matching named component iort entry with a non-zero value for memory_address_limit, why not use that as the size input to arch_setup_dma_ops?quoted
}diff --git a/include/linux/iort.h b/include/linux/iort.h index 18e6836..bbe08ef 100644 --- a/include/linux/iort.h +++ b/include/linux/iort.h@@ -34,6 +34,8 @@ struct irq_domain *iort_get_device_domain(structdevice *dev, u32 req_id); /* IOMMU interface */ int iort_add_smmu_platform_device(struct fwnode_handle *fwnode, struct acpi_iort_node *node); + +const struct iommu_ops *iort_iommu_configure(struct device *dev); #else static inline bool iort_node_match(u8 type) { return false; } static inline void iort_table_detect(void) { }@@ -48,6 +50,8 @@ iort_add_smmu_platform_device(structfwnode_handle *fwnode, { return -ENODEV; } +static inline const struct iommu_ops * +iort_iommu_configure(struct device *dev) { return NULL; } #endif #define IORT_ACPI_DECLARE(name, table_id, fn) \-- Qualcomm Datacenter Technologies, Inc. on behalf of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.