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>,
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lkml <linux-kernel@vger.kernel.org>,
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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 10/12] swiotlb: Add restricted DMA pool initialization
Date: Thu, 24 Jun 2021 23:55:24 +0800 [thread overview]
Message-ID: <20210624155526.2775863-11-tientzu@chromium.org> (raw)
In-Reply-To: <20210624155526.2775863-1-tientzu@chromium.org>
Add the initialization function to create restricted DMA pools from
matching reserved-memory nodes.
Regardless of swiotlb setting, the restricted DMA pool is preferred if
available.
The restricted DMA pools provide 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 a way to lock down the memory access, e.g., MPU.
Signed-off-by: Claire Chang <tientzu@chromium.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Stefano Stabellini <sstabellini@kernel.org>
Tested-by: Will Deacon <will@kernel.org>
---
include/linux/swiotlb.h | 3 +-
kernel/dma/Kconfig | 14 ++++++++
kernel/dma/swiotlb.c | 76 +++++++++++++++++++++++++++++++++++++++++
3 files changed, 92 insertions(+), 1 deletion(-)
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index 3b9454d1e498..39284ff2a6cd 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -73,7 +73,8 @@ extern enum swiotlb_force swiotlb_force;
* range check to see if the memory was in fact allocated by this
* API.
* @nslabs: The number of IO TLB blocks (in groups of 64) between @start and
- * @end. This is command line adjustable via setup_io_tlb_npages.
+ * @end. For default swiotlb, this is command line adjustable via
+ * setup_io_tlb_npages.
* @used: The number of used IO TLB block.
* @list: The free list describing the number of free entries available
* from each index.
diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig
index 77b405508743..3e961dc39634 100644
--- a/kernel/dma/Kconfig
+++ b/kernel/dma/Kconfig
@@ -80,6 +80,20 @@ config SWIOTLB
bool
select NEED_DMA_MAP_STATE
+config DMA_RESTRICTED_POOL
+ bool "DMA Restricted Pool"
+ depends on OF && OF_RESERVED_MEM
+ select SWIOTLB
+ help
+ This enables support for restricted DMA pools which provide a level of
+ DMA memory protection on systems with limited hardware protection
+ capabilities, such as those lacking an IOMMU.
+
+ For more information see
+ <Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt>
+ and <kernel/dma/swiotlb.c>.
+ If unsure, say "n".
+
#
# Should be selected if we can mmap non-coherent mappings to userspace.
# The only thing that is really required is a way to set an uncached bit
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 6a7c6e30eb4b..3baf49c9b766 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -39,6 +39,13 @@
#ifdef CONFIG_DEBUG_FS
#include <linux/debugfs.h>
#endif
+#ifdef CONFIG_DMA_RESTRICTED_POOL
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/of_reserved_mem.h>
+#include <linux/slab.h>
+#endif
#include <asm/io.h>
#include <asm/dma.h>
@@ -737,4 +744,73 @@ bool swiotlb_free(struct device *dev, struct page *page, size_t size)
return true;
}
+static int rmem_swiotlb_device_init(struct reserved_mem *rmem,
+ struct device *dev)
+{
+ struct io_tlb_mem *mem = rmem->priv;
+ unsigned long nslabs = rmem->size >> IO_TLB_SHIFT;
+
+ /*
+ * Since multiple devices can share the same pool, the private data,
+ * io_tlb_mem struct, will be initialized by the first device attached
+ * to it.
+ */
+ if (!mem) {
+ mem = kzalloc(struct_size(mem, slots, nslabs), GFP_KERNEL);
+ if (!mem)
+ return -ENOMEM;
+
+ set_memory_decrypted((unsigned long)phys_to_virt(rmem->base),
+ rmem->size >> PAGE_SHIFT);
+ swiotlb_init_io_tlb_mem(mem, rmem->base, nslabs, false);
+ mem->force_bounce = true;
+ mem->for_alloc = true;
+
+ rmem->priv = mem;
+
+ if (IS_ENABLED(CONFIG_DEBUG_FS)) {
+ mem->debugfs =
+ debugfs_create_dir(rmem->name, debugfs_dir);
+ swiotlb_create_debugfs_files(mem);
+ }
+ }
+
+ dev->dma_io_tlb_mem = mem;
+
+ return 0;
+}
+
+static void rmem_swiotlb_device_release(struct reserved_mem *rmem,
+ struct device *dev)
+{
+ dev->dma_io_tlb_mem = io_tlb_default_mem;
+}
+
+static const struct reserved_mem_ops rmem_swiotlb_ops = {
+ .device_init = rmem_swiotlb_device_init,
+ .device_release = rmem_swiotlb_device_release,
+};
+
+static int __init rmem_swiotlb_setup(struct reserved_mem *rmem)
+{
+ unsigned long node = rmem->fdt_node;
+
+ if (of_get_flat_dt_prop(node, "reusable", NULL) ||
+ of_get_flat_dt_prop(node, "linux,cma-default", NULL) ||
+ of_get_flat_dt_prop(node, "linux,dma-default", NULL) ||
+ of_get_flat_dt_prop(node, "no-map", NULL))
+ return -EINVAL;
+
+ if (PageHighMem(pfn_to_page(PHYS_PFN(rmem->base)))) {
+ pr_err("Restricted DMA pool must be accessible within the linear mapping.");
+ return -EINVAL;
+ }
+
+ rmem->ops = &rmem_swiotlb_ops;
+ pr_info("Reserved memory: created restricted DMA pool at %pa, size %ld MiB\n",
+ &rmem->base, (unsigned long)rmem->size / SZ_1M);
+ return 0;
+}
+
+RESERVEDMEM_OF_DECLARE(dma, "restricted-dma-pool", rmem_swiotlb_setup);
#endif /* CONFIG_DMA_RESTRICTED_POOL */
--
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 ` Claire Chang [this message]
2021-08-24 14:26 ` [PATCH v15 10/12] swiotlb: Add restricted DMA pool initialization Guenter Roeck
2021-08-27 3:50 ` Claire Chang
2021-08-27 6:58 ` Andy Shevchenko
2021-06-24 15:55 ` [PATCH v15 11/12] dt-bindings: of: Add restricted DMA pool Claire Chang
2021-06-24 15:55 ` [PATCH v15 12/12] of: Add plumbing for " 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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