[PULL 010/113] dma: Let dma_memory_read() propagate MemTxResult

[Paolo Bonzini]

From: Philippe Mathieu-Daudé <philmd@redhat.com>

dma_memory_rw_relaxed() returns a MemTxResult type.
Do not discard it, return it to the caller.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Li Qiang <liq3ea@gmail.com>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20201023151923.3243652-7-philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 include/sysemu/dma.h | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/include/sysemu/dma.h b/include/sysemu/dma.h
index 04687d8825..df170047eb 100644
--- a/include/sysemu/dma.h
+++ b/include/sysemu/dma.h
@@ -89,8 +89,9 @@ static inline MemTxResult dma_memory_rw_relaxed(AddressSpace 
*as,
                             buf, len, dir == DMA_DIRECTION_FROM_DEVICE);
 }
 
-static inline int dma_memory_read_relaxed(AddressSpace *as, dma_addr_t addr,
-                                          void *buf, dma_addr_t len)
+static inline MemTxResult dma_memory_read_relaxed(AddressSpace *as,
+                                                  dma_addr_t addr,
+                                                  void *buf, dma_addr_t len)
 {
     return dma_memory_rw_relaxed(as, addr, buf, len, DMA_DIRECTION_TO_DEVICE);
 }
@@ -124,8 +125,20 @@ static inline MemTxResult dma_memory_rw(AddressSpace *as, 
dma_addr_t addr,
     return dma_memory_rw_relaxed(as, addr, buf, len, dir);
 }
 
-static inline int dma_memory_read(AddressSpace *as, dma_addr_t addr,
-                                  void *buf, dma_addr_t len)
+/**
+ * dma_memory_read: Read from an address space from DMA controller.
+ *
+ * Return a MemTxResult indicating whether the operation succeeded
+ * or failed (eg unassigned memory, device rejected the transaction,
+ * IOMMU fault).  Called within RCU critical section.
+ *
+ * @as: #AddressSpace to be accessed
+ * @addr: address within that address space
+ * @buf: buffer with the data transferred
+ * @len: length of the data transferred
+ */
+static inline MemTxResult dma_memory_read(AddressSpace *as, dma_addr_t addr,
+                                          void *buf, dma_addr_t len)
 {
     return dma_memory_rw(as, addr, buf, len, DMA_DIRECTION_TO_DEVICE);
 }
-- 
2.26.2