Merge branch 'dma-mapping-for-next' of https://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux.git

5 files changed, 59 insertions, 16 deletions

diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h
index c249912456f9..daa31a1adf7b 100644
--- a/include/linux/dma-direct.h
+++ b/include/linux/dma-direct.h
@@ -77,6 +77,10 @@ static inline dma_addr_t dma_range_map_max(const struct bus_dma_region *map)
 #ifndef phys_to_dma_unencrypted
 #define phys_to_dma_unencrypted		phys_to_dma
 #endif
+
+#ifndef phys_to_dma_encrypted
+#define phys_to_dma_encrypted		phys_to_dma
+#endif
 #else
 static inline dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
 {
@@ -90,6 +94,12 @@ static inline dma_addr_t phys_to_dma_unencrypted(struct device *dev,
 {
 	return dma_addr_unencrypted(__phys_to_dma(dev, paddr));
 }
+
+static inline dma_addr_t phys_to_dma_encrypted(struct device *dev,
+		phys_addr_t paddr)
+{
+	return dma_addr_encrypted(__phys_to_dma(dev, paddr));
+}
 /*
  * If memory encryption is supported, phys_to_dma will set the memory encryption
  * bit in the DMA address, and dma_to_phys will clear it.
@@ -125,12 +135,20 @@ static inline bool force_dma_unencrypted(struct device *dev)
 #endif /* CONFIG_ARCH_HAS_FORCE_DMA_UNENCRYPTED */
 
 static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size,
-		bool is_ram)
+		bool is_ram, unsigned long attrs)
 {
 	dma_addr_t end = addr + size - 1;
 
 	if (addr == DMA_MAPPING_ERROR)
 		return false;
+	/*
+	 * The DMA address was derived from encrypted RAM, but this device
+	 * requires unencrypted DMA addresses. Treat it as not DMA-capable
+	 * so the caller can fall back to a suitable SWIOTLB pool.
+	 */
+	if (!(attrs & DMA_ATTR_CC_SHARED) && force_dma_unencrypted(dev))
+		return false;
+
 	if (is_ram && !IS_ENABLED(CONFIG_ARCH_DMA_ADDR_T_64BIT) &&
 	    min(addr, end) < phys_to_dma(dev, PFN_PHYS(min_low_pfn)))
 		return false;
diff --git a/include/linux/dma-map-ops.h b/include/linux/dma-map-ops.h
index bcb5b5428aea..8fae2b7deb20 100644
--- a/include/linux/dma-map-ops.h
+++ b/include/linux/dma-map-ops.h
@@ -212,9 +212,10 @@ void *dma_common_pages_remap(struct page **pages, size_t size, pgprot_t prot,
 void dma_common_free_remap(void *cpu_addr, size_t size);
 
 struct page *dma_alloc_from_pool(struct device *dev, size_t size,
-		void **cpu_addr, gfp_t flags,
+		void **cpu_addr, gfp_t flags, unsigned long attrs,
 		bool (*phys_addr_ok)(struct device *, phys_addr_t, size_t));
 bool dma_free_from_pool(struct device *dev, void *start, size_t size);
+bool dma_free_from_pool_page(struct device *dev, struct page *page, size_t size);
 
 int dma_direct_set_offset(struct device *dev, phys_addr_t cpu_start,
 		dma_addr_t dma_start, u64 size);
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index cc0823a99cfd..a3e880649fa4 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -104,6 +104,14 @@
 #define DMA_ATTR_CC_SHARED	(1UL << 13)
 
 /*
+ * __DMA_ATTR_ALLOC_CC_SHARED: Internal DMA-mapping attribute used by
+ * allocation paths that create shared (decrypted) backing pages for
+ * confidential computing guests. Drivers must not pass this attribute to
+ * dma_alloc_attrs().
+ */
+#define __DMA_ATTR_ALLOC_CC_SHARED	(1UL << 14)
+
+/*
  * A dma_addr_t can hold any valid DMA or bus address for the platform.  It can
  * be given to a device to use as a DMA source or target.  It is specific to a
  * given device and there may be a translation between the CPU physical address
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index 3dae0f592063..2a421241b980 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -15,8 +15,7 @@ struct page;
 struct scatterlist;
 
 #define SWIOTLB_VERBOSE	(1 << 0) /* verbose initialization */
-#define SWIOTLB_FORCE	(1 << 1) /* force bounce buffering */
-#define SWIOTLB_ANY	(1 << 2) /* allow any memory for the buffer */
+#define SWIOTLB_ANY	(1 << 1) /* allow any memory for the buffer */
 
 /*
  * Maximum allowable number of contiguous slabs to map,
@@ -32,8 +31,12 @@ struct scatterlist;
 #define IO_TLB_SHIFT 11
 #define IO_TLB_SIZE (1 << IO_TLB_SHIFT)
 
-/* default to 64MB */
-#define IO_TLB_DEFAULT_SIZE (64UL<<20)
+/* compile-time default; overridable via CONFIG_SWIOTLB_DEFAULT_SIZE_MB */
+#ifdef CONFIG_SWIOTLB
+#define IO_TLB_DEFAULT_SIZE ((unsigned long)CONFIG_SWIOTLB_DEFAULT_SIZE_MB << 20)
+#else
+#define IO_TLB_DEFAULT_SIZE (64UL << 20)
+#endif
 
 unsigned long swiotlb_size_or_default(void);
 void __init swiotlb_init_remap(bool addressing_limit, unsigned int flags,
@@ -64,8 +67,9 @@ extern void __init swiotlb_update_mem_attributes(void);
  * @areas:	Array of memory area descriptors.
  * @slots:	Array of slot descriptors.
  * @node:	Member of the IO TLB memory pool list.
- * @rcu:	RCU head for swiotlb_dyn_free().
+ * @dyn_free:	RCU work item used to free the pool from process context.
  * @transient:  %true if transient memory pool.
+ * @cc_shared:	%true if the pool memory is shared for confidential computing.
  */
 struct io_tlb_pool {
 	phys_addr_t start;
@@ -79,8 +83,9 @@ struct io_tlb_pool {
 	struct io_tlb_slot *slots;
 #ifdef CONFIG_SWIOTLB_DYNAMIC
 	struct list_head node;
-	struct rcu_head rcu;
+	struct rcu_work dyn_free;
 	bool transient;
+	bool cc_shared;
 #endif
 };
 
@@ -92,16 +97,17 @@ struct io_tlb_pool {
  * @debugfs:	The dentry to debugfs.
  * @force_bounce: %true if swiotlb bouncing is forced
  * @for_alloc:  %true if the pool is used for memory allocation
+ * @cc_shared:	%true if the pool memory is shared for confidential computing.
  * @can_grow:	%true if more pools can be allocated dynamically.
  * @phys_limit:	Maximum allowed physical address.
  * @lock:	Lock to synchronize changes to the list.
  * @pools:	List of IO TLB memory pool descriptors (if dynamic).
  * @dyn_alloc:	Dynamic IO TLB pool allocation work.
  * @total_used:	The total number of slots in the pool that are currently used
- *		across all areas. Used only for calculating used_hiwater in
- *		debugfs.
- * @used_hiwater: The high water mark for total_used.  Used only for reporting
- *		in debugfs.
+ *		across all areas. Used only for calculating used_hiwater via boot
+ *		parameter swiotlb=track_hiwater and exposed via debugfs.
+ * @used_hiwater: The high water mark for total_used.  Can be enabled at boot
+ *		time via swiotlb=track_hiwater and exposed via debugfs.
  * @transient_nslabs: The total number of slots in all transient pools that
  *		are currently used across all areas.
  */
@@ -111,6 +117,7 @@ struct io_tlb_mem {
 	struct dentry *debugfs;
 	bool force_bounce;
 	bool for_alloc;
+	bool cc_shared;
 #ifdef CONFIG_SWIOTLB_DYNAMIC
 	bool can_grow;
 	u64 phys_limit;
@@ -238,7 +245,7 @@ static inline phys_addr_t default_swiotlb_limit(void)
 
 phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, phys_addr_t phys,
 		size_t mapping_size, unsigned int alloc_aligned_mask,
-		enum dma_data_direction dir, unsigned long attrs);
+		enum dma_data_direction dir, unsigned long *attrs);
 dma_addr_t swiotlb_map(struct device *dev, phys_addr_t phys,
 		size_t size, enum dma_data_direction dir, unsigned long attrs);
 
@@ -282,15 +289,19 @@ static inline void swiotlb_sync_single_for_cpu(struct device *dev,
 extern void swiotlb_print_info(void);
 
 #ifdef CONFIG_DMA_RESTRICTED_POOL
-struct page *swiotlb_alloc(struct device *dev, size_t size);
+struct page *swiotlb_alloc(struct device *dev, size_t size,
+		unsigned long attrs);
 bool swiotlb_free(struct device *dev, struct page *page, size_t size);
+void swiotlb_free_from_pool(struct device *dev,
+		phys_addr_t tlb_addr, struct io_tlb_pool *pool);
 
 static inline bool is_swiotlb_for_alloc(struct device *dev)
 {
 	return dev->dma_io_tlb_mem->for_alloc;
 }
 #else
-static inline struct page *swiotlb_alloc(struct device *dev, size_t size)
+static inline struct page *swiotlb_alloc(struct device *dev, size_t size,
+		unsigned long attrs)
 {
 	return NULL;
 }
@@ -299,6 +310,10 @@ static inline bool swiotlb_free(struct device *dev, struct page *page,
 {
 	return false;
 }
+static inline void swiotlb_free_from_pool(struct device *dev,
+		phys_addr_t tlb_addr, struct io_tlb_pool *pool)
+{
+}
 static inline bool is_swiotlb_for_alloc(struct device *dev)
 {
 	return false;
diff --git a/include/trace/events/dma.h b/include/trace/events/dma.h
index 31c9ddf72c9d..9df02c1511de 100644
--- a/include/trace/events/dma.h
+++ b/include/trace/events/dma.h
@@ -35,7 +35,8 @@ TRACE_DEFINE_ENUM(DMA_NONE);
 		{ DMA_ATTR_MMIO, "MMIO" }, \
 		{ DMA_ATTR_DEBUGGING_IGNORE_CACHELINES, "CACHELINES_OVERLAP" }, \
 		{ DMA_ATTR_REQUIRE_COHERENT, "REQUIRE_COHERENT" }, \
-		{ DMA_ATTR_CC_SHARED, "CC_SHARED" })
+		{ DMA_ATTR_CC_SHARED, "CC_SHARED" }, \
+		{ __DMA_ATTR_ALLOC_CC_SHARED, "ALLOC_CC_SHARED" })
 
 DECLARE_EVENT_CLASS(dma_map,
 	TP_PROTO(struct device *dev, phys_addr_t phys_addr, dma_addr_t dma_addr,