From: Claire Chang <tientzu@chromium.org>
To: Rob Herring <robh+dt@kernel.org>,
mpe@ellerman.id.au, Joerg Roedel <joro@8bytes.org>,
Will Deacon <will@kernel.org>,
Frank Rowand <frowand.list@gmail.com>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
boris.ostrovsky@oracle.com, jgross@suse.com,
Christoph Hellwig <hch@lst.de>,
Marek Szyprowski <m.szyprowski@samsung.com>
Cc: benh@kernel.crashing.org, paulus@samba.org,
"list@263.net:IOMMU DRIVERS" <iommu@lists.linux-foundation.org>,
sstabellini@kernel.org, Robin Murphy <robin.murphy@arm.com>,
grant.likely@arm.com, xypron.glpk@gmx.de,
Thierry Reding <treding@nvidia.com>,
mingo@kernel.org, bauerman@linux.ibm.com, peterz@infradead.org,
Greg KH <gregkh@linuxfoundation.org>,
Saravana Kannan <saravanak@google.com>,
"Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
heikki.krogerus@linux.intel.com,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Randy Dunlap <rdunlap@infradead.org>,
Dan Williams <dan.j.williams@intel.com>,
Bartosz Golaszewski <bgolaszewski@baylibre.com>,
linux-devicetree <devicetree@vger.kernel.org>,
lkml <linux-kernel@vger.kernel.org>,
linuxppc-dev@lists.ozlabs.org, xen-devel@lists.xenproject.org,
Nicolas Boichat <drinkcat@chromium.org>,
Jim Quinlan <james.quinlan@broadcom.com>,
tfiga@chromium.org, bskeggs@redhat.com, bhelgaas@google.com,
chris@chris-wilson.co.uk, tientzu@chromium.org, daniel@ffwll.ch,
airlied@linux.ie, dri-devel@lists.freedesktop.org,
intel-gfx@lists.freedesktop.org, jani.nikula@linux.intel.com,
jxgao@google.com, joonas.lahtinen@linux.intel.com,
linux-pci@vger.kernel.org, maarten.lankhorst@linux.intel.com,
matthew.auld@intel.com, rodrigo.vivi@intel.com,
thomas.hellstrom@linux.intel.com, thomas.lendacky@amd.com,
quic_qiancai@quicinc.com
Subject: [PATCH v15 11/12] dt-bindings: of: Add restricted DMA pool
Date: Thu, 24 Jun 2021 23:55:25 +0800 [thread overview]
Message-ID: <20210624155526.2775863-12-tientzu@chromium.org> (raw)
In-Reply-To: <20210624155526.2775863-1-tientzu@chromium.org>
Introduce the new compatible string, restricted-dma-pool, for restricted
DMA. One can specify the address and length of the restricted DMA memory
region by restricted-dma-pool in the reserved-memory node.
Signed-off-by: Claire Chang <tientzu@chromium.org>
Tested-by: Stefano Stabellini <sstabellini@kernel.org>
Tested-by: Will Deacon <will@kernel.org>
---
.../reserved-memory/reserved-memory.txt | 36 +++++++++++++++++--
1 file changed, 33 insertions(+), 3 deletions(-)
diff --git a/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt b/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
index e8d3096d922c..39b5f4c5a511 100644
--- a/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
+++ b/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
@@ -51,6 +51,23 @@ compatible (optional) - standard definition
used as a shared pool of DMA buffers for a set of devices. It can
be used by an operating system to instantiate the necessary pool
management subsystem if necessary.
+ - restricted-dma-pool: This indicates a region of memory meant to be
+ used as a pool of restricted DMA buffers for a set of devices. The
+ memory region would be the only region accessible to those devices.
+ When using this, the no-map and reusable properties must not be set,
+ so the operating system can create a virtual mapping that will be used
+ for synchronization. The main purpose for restricted DMA is to
+ mitigate the lack of DMA access control on systems without an IOMMU,
+ which could result in the DMA accessing the system memory at
+ unexpected times and/or unexpected addresses, possibly leading to data
+ leakage or corruption. The feature on its own provides a basic level
+ of protection against the DMA overwriting buffer contents at
+ unexpected times. However, to protect against general data leakage and
+ system memory corruption, the system needs to provide way to lock down
+ the memory access, e.g., MPU. Note that since coherent allocation
+ needs remapping, one must set up another device coherent pool by
+ shared-dma-pool and use dma_alloc_from_dev_coherent instead for atomic
+ coherent allocation.
- vendor specific string in the form <vendor>,[<device>-]<usage>
no-map (optional) - empty property
- Indicates the operating system must not create a virtual mapping
@@ -85,10 +102,11 @@ memory-region-names (optional) - a list of names, one for each corresponding
Example
-------
-This example defines 3 contiguous regions are defined for Linux kernel:
+This example defines 4 contiguous regions for Linux kernel:
one default of all device drivers (named linux,cma@72000000 and 64MiB in size),
-one dedicated to the framebuffer device (named framebuffer@78000000, 8MiB), and
-one for multimedia processing (named multimedia-memory@77000000, 64MiB).
+one dedicated to the framebuffer device (named framebuffer@78000000, 8MiB),
+one for multimedia processing (named multimedia-memory@77000000, 64MiB), and
+one for restricted dma pool (named restricted_dma_reserved@0x50000000, 64MiB).
/ {
#address-cells = <1>;
@@ -120,6 +138,11 @@ one for multimedia processing (named multimedia-memory@77000000, 64MiB).
compatible = "acme,multimedia-memory";
reg = <0x77000000 0x4000000>;
};
+
+ restricted_dma_reserved: restricted_dma_reserved {
+ compatible = "restricted-dma-pool";
+ reg = <0x50000000 0x4000000>;
+ };
};
/* ... */
@@ -138,4 +161,11 @@ one for multimedia processing (named multimedia-memory@77000000, 64MiB).
memory-region = <&multimedia_reserved>;
/* ... */
};
+
+ pcie_device: pcie_device@0,0 {
+ reg = <0x83010000 0x0 0x00000000 0x0 0x00100000
+ 0x83010000 0x0 0x00100000 0x0 0x00100000>;
+ memory-region = <&restricted_dma_reserved>;
+ /* ... */
+ };
};
--
2.32.0.288.g62a8d224e6-goog
next prev parent reply other threads:[~2021-06-24 15:57 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-24 15:55 [PATCH v15 00/12] Restricted DMA Claire Chang
2021-06-24 15:55 ` [PATCH v15 01/12] swiotlb: Refactor swiotlb init functions Claire Chang
2021-06-24 15:55 ` [PATCH v15 02/12] swiotlb: Refactor swiotlb_create_debugfs Claire Chang
2021-06-24 15:55 ` [PATCH v15 03/12] swiotlb: Set dev->dma_io_tlb_mem to the swiotlb pool used Claire Chang
2021-06-24 15:55 ` [PATCH v15 04/12] swiotlb: Update is_swiotlb_buffer to add a struct device argument Claire Chang
2021-06-24 15:55 ` [PATCH v15 05/12] swiotlb: Update is_swiotlb_active " Claire Chang
2021-06-24 15:55 ` [PATCH v15 06/12] swiotlb: Use is_swiotlb_force_bounce for swiotlb data bouncing Claire Chang
2021-06-30 1:43 ` Nathan Chancellor
2021-06-30 9:17 ` Claire Chang
2021-06-30 11:43 ` Will Deacon
2021-06-30 15:56 ` Nathan Chancellor
2021-07-01 7:40 ` Will Deacon
2021-07-01 7:52 ` Nathan Chancellor
2021-07-02 13:58 ` Will Deacon
2021-07-02 15:13 ` Robin Murphy
2021-07-03 5:55 ` Nathan Chancellor
2021-07-05 7:29 ` Claire Chang
2021-07-05 18:25 ` Nathan Chancellor
2021-07-05 19:03 ` Will Deacon
2021-07-06 4:48 ` Christoph Hellwig
2021-07-06 13:24 ` Will Deacon
2021-07-06 14:01 ` Robin Murphy
2021-07-06 14:05 ` Christoph Hellwig
2021-07-06 14:46 ` Konrad Rzeszutek Wilk
2021-07-06 16:57 ` Will Deacon
2021-07-06 16:59 ` Konrad Rzeszutek Wilk
2021-07-12 13:56 ` Will Deacon
2021-07-14 0:06 ` Konrad Rzeszutek Wilk
2021-07-06 15:39 ` Robin Murphy
2021-07-06 17:06 ` Will Deacon
2021-07-06 19:14 ` Nathan Chancellor
2021-07-08 16:44 ` Will Deacon
2021-06-24 15:55 ` [PATCH v15 07/12] swiotlb: Move alloc_size to swiotlb_find_slots Claire Chang
2021-06-24 15:55 ` [PATCH v15 08/12] swiotlb: Refactor swiotlb_tbl_unmap_single Claire Chang
2021-06-24 15:55 ` [PATCH v15 09/12] swiotlb: Add restricted DMA alloc/free support Claire Chang
2021-06-24 15:55 ` [PATCH v15 10/12] swiotlb: Add restricted DMA pool initialization Claire Chang
2021-08-24 14:26 ` Guenter Roeck
2021-08-27 3:50 ` Claire Chang
2021-08-27 6:58 ` Andy Shevchenko
2021-06-24 15:55 ` Claire Chang [this message]
2021-06-24 15:55 ` [PATCH v15 12/12] of: Add plumbing for restricted DMA pool Claire Chang
2021-07-02 3:08 ` Guenter Roeck
2021-07-02 11:39 ` Robin Murphy
2021-07-02 13:18 ` Will Deacon
2021-07-02 13:48 ` Guenter Roeck
2021-06-24 19:19 ` [PATCH v15 00/12] Restricted DMA Konrad Rzeszutek Wilk
2021-06-25 0:41 ` Claire Chang
2021-06-25 12:30 ` Will Deacon
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