From b2fb366425ceb85dca56afa538257ec5a2c4f6d1 Mon Sep 17 00:00:00 2001 From: Mitchel Humpherys Date: Fri, 6 Jan 2017 18:58:11 +0530 Subject: common: DMA-mapping: add DMA_ATTR_PRIVILEGED attribute This patch adds the DMA_ATTR_PRIVILEGED attribute to the DMA-mapping subsystem. Some advanced peripherals such as remote processors and GPUs perform accesses to DMA buffers in both privileged "supervisor" and unprivileged "user" modes. This attribute is used to indicate to the DMA-mapping subsystem that the buffer is fully accessible at the elevated privilege level (and ideally inaccessible or at least read-only at the lesser-privileged levels). Cc: linux-doc@vger.kernel.org Reviewed-by: Robin Murphy Tested-by: Robin Murphy Acked-by: Will Deacon Signed-off-by: Mitchel Humpherys Signed-off-by: Will Deacon --- Documentation/DMA-attributes.txt | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'Documentation') diff --git a/Documentation/DMA-attributes.txt b/Documentation/DMA-attributes.txt index 98bf7ac29aad..44c6bc496eee 100644 --- a/Documentation/DMA-attributes.txt +++ b/Documentation/DMA-attributes.txt @@ -143,3 +143,13 @@ So, this provides a way for drivers to avoid those error messages on calls where allocation failures are not a problem, and shouldn't bother the logs. NOTE: At the moment DMA_ATTR_NO_WARN is only implemented on PowerPC. + +DMA_ATTR_PRIVILEGED +------------------------------ + +Some advanced peripherals such as remote processors and GPUs perform +accesses to DMA buffers in both privileged "supervisor" and unprivileged +"user" modes. This attribute is used to indicate to the DMA-mapping +subsystem that the buffer is fully accessible at the elevated privilege +level (and ideally inaccessible or at least read-only at the +lesser-privileged levels). -- cgit v1.2.3 From bc7d12b91bd35477fd650c4d72b61239de9d9066 Mon Sep 17 00:00:00 2001 From: Eric Auger Date: Thu, 19 Jan 2017 20:57:52 +0000 Subject: iommu: Implement reserved_regions iommu-group sysfs file A new iommu-group sysfs attribute file is introduced. It contains the list of reserved regions for the iommu-group. Each reserved region is described on a separate line: - first field is the start IOVA address, - second is the end IOVA address, - third is the type. Signed-off-by: Eric Auger Tested-by: Tomasz Nowicki Tested-by: Bharat Bhushan Signed-off-by: Will Deacon --- .../ABI/testing/sysfs-kernel-iommu_groups | 12 ++++++++ drivers/iommu/iommu.c | 36 ++++++++++++++++++++++ 2 files changed, 48 insertions(+) (limited to 'Documentation') diff --git a/Documentation/ABI/testing/sysfs-kernel-iommu_groups b/Documentation/ABI/testing/sysfs-kernel-iommu_groups index 9b31556cfdda..35c64e00b35c 100644 --- a/Documentation/ABI/testing/sysfs-kernel-iommu_groups +++ b/Documentation/ABI/testing/sysfs-kernel-iommu_groups @@ -12,3 +12,15 @@ Description: /sys/kernel/iommu_groups/ contains a number of sub- file if the IOMMU driver has chosen to register a more common name for the group. Users: + +What: /sys/kernel/iommu_groups/reserved_regions +Date: January 2017 +KernelVersion: v4.11 +Contact: Eric Auger +Description: /sys/kernel/iommu_groups/reserved_regions list IOVA + regions that are reserved. Not necessarily all + reserved regions are listed. This is typically used to + output direct-mapped, MSI, non mappable regions. Each + region is described on a single line: the 1st field is + the base IOVA, the second is the end IOVA and the third + field describes the type of the region. diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 640056ba46c2..f4a176e56e39 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -68,6 +68,12 @@ struct iommu_group_attribute { const char *buf, size_t count); }; +static const char * const iommu_group_resv_type_string[] = { + [IOMMU_RESV_DIRECT] = "direct", + [IOMMU_RESV_RESERVED] = "reserved", + [IOMMU_RESV_MSI] = "msi", +}; + #define IOMMU_GROUP_ATTR(_name, _mode, _show, _store) \ struct iommu_group_attribute iommu_group_attr_##_name = \ __ATTR(_name, _mode, _show, _store) @@ -231,8 +237,33 @@ int iommu_get_group_resv_regions(struct iommu_group *group, } EXPORT_SYMBOL_GPL(iommu_get_group_resv_regions); +static ssize_t iommu_group_show_resv_regions(struct iommu_group *group, + char *buf) +{ + struct iommu_resv_region *region, *next; + struct list_head group_resv_regions; + char *str = buf; + + INIT_LIST_HEAD(&group_resv_regions); + iommu_get_group_resv_regions(group, &group_resv_regions); + + list_for_each_entry_safe(region, next, &group_resv_regions, list) { + str += sprintf(str, "0x%016llx 0x%016llx %s\n", + (long long int)region->start, + (long long int)(region->start + + region->length - 1), + iommu_group_resv_type_string[region->type]); + kfree(region); + } + + return (str - buf); +} + static IOMMU_GROUP_ATTR(name, S_IRUGO, iommu_group_show_name, NULL); +static IOMMU_GROUP_ATTR(reserved_regions, 0444, + iommu_group_show_resv_regions, NULL); + static void iommu_group_release(struct kobject *kobj) { struct iommu_group *group = to_iommu_group(kobj); @@ -310,6 +341,11 @@ struct iommu_group *iommu_group_alloc(void) */ kobject_put(&group->kobj); + ret = iommu_group_create_file(group, + &iommu_group_attr_reserved_regions); + if (ret) + return ERR_PTR(ret); + pr_debug("Allocated group %d\n", group->id); return group; -- cgit v1.2.3