From: Vincent Donnefort <vdonnefort@google.com>
To: catalin.marinas@arm.com, will@kernel.org, rppt@kernel.org,
akpm@linux-foundation.org, m.szyprowski@samsung.com,
jenswi@kernel.org, robh@kernel.org, krzk+dt@kernel.org,
conor+dt@kernel.org
Cc: mark.rutland@arm.com, robin.murphy@arm.com, hch@lst.de,
ryan.roberts@arm.com, sumit.garg@kernel.org,
sudeep.holla@kernel.org, ardb@kernel.org,
thierry.reding@kernel.org, david@kernel.org,
danielmentz@google.com, linux-arm-kernel@lists.infradead.org,
linux-mm@kvack.org, iommu@lists.linux.dev,
op-tee@lists.trustedfirmware.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org,
Vincent Donnefort <vdonnefort@google.com>
Subject: [PATCH v3 7/8] arm64: Add support for lendable-dma-pool
Date: Wed, 11 Nov 2026 11:07:37 +0000 [thread overview]
Message-ID: <20261111110738.872947-8-vdonnefort@google.com> (raw)
In-Reply-To: <20261111110738.872947-1-vdonnefort@google.com>
Even when the linear map uses block mappings, regions marked with
MEMBLOCK_PTEMAP are mapped at page granularity and can be modified at
runtime. Implement the architecture hooks for the lendable-dma-pool to
force the last-level mappings, validate ranges and update the direct
mapping.
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
---
arch/arm64/Kconfig | 1 +
arch/arm64/include/asm/set_memory.h | 2 +
arch/arm64/mm/dma-mapping.c | 71 +++++++++++++++++++++++++++++
arch/arm64/mm/pageattr.c | 56 ++++++++++++++++++-----
4 files changed, 118 insertions(+), 12 deletions(-)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 1075bc661833..34fe7a7eea82 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -117,6 +117,7 @@ config ARM64
select DYNAMIC_FTRACE if FUNCTION_TRACER
select DMA_BOUNCE_UNALIGNED_KMALLOC
select DMA_DIRECT_REMAP
+ select DMA_LENDABLE if DMA_CMA
select EDAC_SUPPORT
select FRAME_POINTER
select FUNCTION_ALIGNMENT_4B
diff --git a/arch/arm64/include/asm/set_memory.h b/arch/arm64/include/asm/set_memory.h
index b6ec938703d6..ec8bbb59e51f 100644
--- a/arch/arm64/include/asm/set_memory.h
+++ b/arch/arm64/include/asm/set_memory.h
@@ -17,6 +17,8 @@ int set_memory_valid(unsigned long addr, int numpages, int enable);
int set_direct_map_invalid_noflush(struct page *page, unsigned int numpages);
int set_direct_map_default_noflush(struct page *page, unsigned int numpages);
+int __set_direct_map_invalid_noflush(struct page *page, unsigned int numpages);
+int __set_direct_map_default_noflush(struct page *page, unsigned int numpages);
bool kernel_page_present(struct page *page);
int set_memory_encrypted(unsigned long addr, int numpages);
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index 7f6f2f40dba2..c324e9826ce2 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -7,9 +7,13 @@
#include <linux/gfp.h>
#include <linux/cache.h>
#include <linux/dma-map-ops.h>
+#include <linux/kernel.h>
+#include <linux/memblock.h>
#include <xen/xen.h>
#include <asm/cacheflush.h>
+#include <asm/set_memory.h>
+#include <asm/tlbflush.h>
#include <asm/xen/xen-ops.h>
void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
@@ -38,6 +42,73 @@ void arch_dma_prep_coherent(struct page *page, size_t size)
dcache_clean_poc(start, start + size);
}
+#ifdef CONFIG_DMA_LENDABLE
+int __init arch_dma_mark_lendable(phys_addr_t base, phys_addr_t size)
+{
+ if (!PAGE_ALIGNED(base | size))
+ return -EINVAL;
+
+ return memblock_mark_ptemap(base, size);
+}
+
+bool __init arch_dma_is_lendable(struct page *page, unsigned int nr_pages)
+{
+ return direct_map_is_ptemap(page, nr_pages);
+}
+
+int arch_dma_zap_direct_map(struct page *page, unsigned int nr_pages,
+ bool from_lendable)
+{
+ unsigned long start = (unsigned long)page_address(page);
+ unsigned long end = start + ((unsigned long)nr_pages << PAGE_SHIFT);
+ int ret;
+
+ /*
+ * arch_dma_prep_coherent() only cleans as normal DMA buffers retain a
+ * cacheable linear-map alias. Since that alias is being removed here,
+ * also invalidate to make sure they can't be evicted later on while the
+ * memory is secured.
+ */
+ dcache_clean_inval_poc(start, end);
+
+ if (from_lendable) {
+ ret = __set_direct_map_invalid_noflush(page, nr_pages);
+ } else {
+ might_sleep();
+ ret = set_direct_map_invalid_noflush(page, nr_pages);
+ }
+
+ if (ret)
+ return ret;
+
+ flush_tlb_kernel_range(start, end);
+
+ return 0;
+}
+
+int arch_dma_restore_direct_map(struct page *page, unsigned int nr_pages,
+ bool from_lendable)
+{
+ unsigned long start = (unsigned long)page_address(page);
+ unsigned long end = start + ((unsigned long)nr_pages << PAGE_SHIFT);
+ int ret;
+
+ if (from_lendable) {
+ ret = __set_direct_map_default_noflush(page, nr_pages);
+ } else {
+ might_sleep();
+ ret = set_direct_map_default_noflush(page, nr_pages);
+ }
+
+ if (ret)
+ return ret;
+
+ dcache_inval_poc(start, end);
+
+ return 0;
+}
+#endif /* CONFIG_DMA_LENDABLE */
+
void arch_setup_dma_ops(struct device *dev, bool coherent)
{
int cls = cache_line_size_of_cpu();
diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c
index c7662fd2fcb2..467a420af0f5 100644
--- a/arch/arm64/mm/pageattr.c
+++ b/arch/arm64/mm/pageattr.c
@@ -167,8 +167,8 @@ bool __init direct_map_is_ptemap(struct page *page, unsigned int numpages)
NULL, NULL);
}
-static int update_range_prot(unsigned long start, unsigned long size,
- pgprot_t set_mask, pgprot_t clear_mask)
+static int __update_range_prot(unsigned long start, unsigned long size,
+ pgprot_t set_mask, pgprot_t clear_mask)
{
struct page_change_data data;
int ret;
@@ -176,10 +176,6 @@ static int update_range_prot(unsigned long start, unsigned long size,
data.set_mask = set_mask;
data.clear_mask = clear_mask;
- ret = split_kernel_leaf_mapping(start, start + size);
- if (WARN_ON_ONCE(ret))
- return ret;
-
lazy_mmu_mode_enable();
/*
@@ -194,6 +190,18 @@ static int update_range_prot(unsigned long start, unsigned long size,
return ret;
}
+static int update_range_prot(unsigned long start, unsigned long size,
+ pgprot_t set_mask, pgprot_t clear_mask)
+{
+ int ret;
+
+ ret = split_kernel_leaf_mapping(start, start + size);
+ if (WARN_ON_ONCE(ret))
+ return ret;
+
+ return __update_range_prot(start, size, set_mask, clear_mask);
+}
+
static int __change_memory_common(unsigned long start, unsigned long size,
pgprot_t set_mask, pgprot_t clear_mask)
{
@@ -316,28 +324,52 @@ int set_memory_valid(unsigned long addr, int numpages, int enable)
__pgprot(PTE_PRESENT_VALID_KERNEL));
}
-int set_direct_map_invalid_noflush(struct page *page, unsigned int numpages)
+int __set_direct_map_invalid_noflush(struct page *page, unsigned int numpages)
{
pgprot_t clear_mask = __pgprot(PTE_PRESENT_VALID_KERNEL);
pgprot_t set_mask = __pgprot(PTE_PRESENT_INVALID);
+ return __update_range_prot((unsigned long)page_address(page),
+ PAGE_SIZE * numpages, set_mask, clear_mask);
+}
+
+int set_direct_map_invalid_noflush(struct page *page, unsigned int numpages)
+{
+ unsigned long start = (unsigned long)page_address(page);
+ int ret;
+
if (!can_set_direct_map())
return 0;
- return update_range_prot((unsigned long)page_address(page),
- PAGE_SIZE * numpages, set_mask, clear_mask);
+ ret = split_kernel_leaf_mapping(start, start + PAGE_SIZE * numpages);
+ if (WARN_ON_ONCE(ret))
+ return ret;
+
+ return __set_direct_map_invalid_noflush(page, numpages);
}
-int set_direct_map_default_noflush(struct page *page, unsigned int numpages)
+int __set_direct_map_default_noflush(struct page *page, unsigned int numpages)
{
pgprot_t set_mask = __pgprot(PTE_PRESENT_VALID_KERNEL | PTE_WRITE);
pgprot_t clear_mask = __pgprot(PTE_PRESENT_INVALID | PTE_RDONLY);
+ return __update_range_prot((unsigned long)page_address(page),
+ PAGE_SIZE * numpages, set_mask, clear_mask);
+}
+
+int set_direct_map_default_noflush(struct page *page, unsigned int numpages)
+{
+ unsigned long start = (unsigned long)page_address(page);
+ int ret;
+
if (!can_set_direct_map())
return 0;
- return update_range_prot((unsigned long)page_address(page),
- PAGE_SIZE * numpages, set_mask, clear_mask);
+ ret = split_kernel_leaf_mapping(start, start + PAGE_SIZE * numpages);
+ if (WARN_ON_ONCE(ret))
+ return ret;
+
+ return __set_direct_map_default_noflush(page, numpages);
}
int __set_memory_enc_dec(unsigned long addr, int numpages, bool encrypt)
--
2.56.0.542.g3ef89b7020-goog
next prev parent reply other threads:[~2026-11-11 11:08 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-11-11 11:07 [PATCH v3 0/8] arm64: Unmap FF-A lent memory from direct map Vincent Donnefort
2026-11-11 11:07 ` [PATCH v3 1/8] memblock: Introduce MEMBLOCK_PTEMAP Vincent Donnefort
2026-11-11 11:07 ` [PATCH v3 2/8] arm64: Add support for MEMBLOCK_PTEMAP Vincent Donnefort
2026-11-11 11:07 ` [PATCH v3 3/8] dma-contiguous: Expose rmem_cma_ops Vincent Donnefort
2026-11-11 11:07 ` [PATCH v3 4/8] dt-bindings: reserved-memory: Add lendable-dma-pool Vincent Donnefort
2026-11-11 11:07 ` [PATCH v3 5/8] dma-mapping: Introduce lendable-dma-pool Vincent Donnefort
2026-11-11 11:07 ` [PATCH v3 6/8] arm64: Introduce direct_map_is_ptemap() Vincent Donnefort
2026-11-11 11:07 ` Vincent Donnefort [this message]
2026-11-11 11:07 ` [PATCH v3 8/8] optee: Add support for lendable-dma-pool Vincent Donnefort
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