[PATCH v2 1/1] dmaengine: fsl-qdma: add __iomem and struct in union to fix sparse warning

[Frank Li <Frank.Li@nxp.com>]

Fix below sparse warnings.

drivers/dma/fsl-qdma.c:645:50: sparse: warning: incorrect type in argument 2 (different address spaces)
drivers/dma/fsl-qdma.c:645:50: sparse:    expected void [noderef] __iomem *addr
drivers/dma/fsl-qdma.c:645:50: sparse:    got void

drivers/dma/fsl-qdma.c:387:15: sparse: sparse: restricted __le32 degrades to integer
drivers/dma/fsl-qdma.c:390:19: sparse:     expected restricted __le64 [usertype] data
drivers/dma/fsl-qdma.c:392:13: sparse:     expected unsigned int [assigned] [usertype] cmd

QDMA decriptor have below 3 kind formats. (little endian)

Compound Command Descriptor Format
  ┌──────┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┐
  │Offset│3│3│2│2│2│2│2│2│2│2│2│2│1│1│1│1│1│1│1│1│1│1│ │ │ │ │ │ │ │ │ │ │
  │      │1│0│9│8│7│6│5│4│3│2│1│0│9│8│7│6│5│4│3│2│1│0│9│8│7│6│5│4│3│2│1│0│
  ├──────┼─┴─┼─┴─┴─┼─┴─┴─┼─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┼─┴─┴─┴─┴─┴─┴─┴─┤
  │ 0x0C │DD │  -  │QUEUE│             -                 │      ADDR     │
  ├──────┼───┴─────┴─────┴───────────────────────────────┴───────────────┤
  │ 0x08 │                       ADDR                                    │
  ├──────┼─────┬─────────────────┬───────────────────────────────────────┤
  │ 0x04 │ FMT │    OFFSET       │                   -                   │
  ├──────┼─┬─┬─┴─────────────────┴───────────────────────┬───────────────┤
  │      │ │S│                                           │               │
  │ 0x00 │-│E│                   -                       │    STATUS     │
  │      │ │R│                                           │               │
  └──────┴─┴─┴───────────────────────────────────────────┴───────────────┘

Compound S/G Table Entry Format
 ┌──────┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┐
 │Offset│3│3│2│2│2│2│2│2│2│2│2│2│1│1│1│1│1│1│1│1│1│1│ │ │ │ │ │ │ │ │ │ │
 │      │1│0│9│8│7│6│5│4│3│2│1│0│9│8│7│6│5│4│3│2│1│0│9│8│7│6│5│4│3│2│1│0│
 ├──────┼─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┼─┴─┴─┴─┴─┴─┴─┴─┤
 │ 0x0C │                      -                        │    ADDR       │
 ├──────┼───────────────────────────────────────────────┴───────────────┤
 │ 0x08 │                          ADDR                                 │
 ├──────┼─┬─┬───────────────────────────────────────────────────────────┤
 │ 0x04 │E│F│                    LENGTH                                 │
 ├──────┼─┴─┴─────────────────────────────────┬─────────────────────────┤
 │ 0x00 │              -                      │        OFFSET           │
 └──────┴─────────────────────────────────────┴─────────────────────────┘

Source/Destination Descriptor Format
  ┌──────┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┐
  │Offset│3│3│2│2│2│2│2│2│2│2│2│2│1│1│1│1│1│1│1│1│1│1│ │ │ │ │ │ │ │ │ │ │
  │      │1│0│9│8│7│6│5│4│3│2│1│0│9│8│7│6│5│4│3│2│1│0│9│8│7│6│5│4│3│2│1│0│
  ├──────┼─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┤
  │ 0x0C │                            CMD                                │
  ├──────┼───────────────────────────────────────────────────────────────┤
  │ 0x08 │                             -                                 │
  ├──────┼───────────────┬───────────────────────┬───────────────────────┤
  │ 0x04 │       -       │         S[D]SS        │        S[D]SD         │
  ├──────┼───────────────┴───────────────────────┴───────────────────────┤
  │ 0x00 │                             -                                 │
  └──────┴───────────────────────────────────────────────────────────────┘

Previous code use 64bit 'data' map to 0x8 and 0xC. In little endian system
CMD is high part of 64bit 'data'. It is correct by left shift 32. But in
big endian system, shift left 32 will write to 0x8 position. Sparse detect
this problem.

Add below field ot match 'Source/Destination Descriptor Format'.
struct {
	__le32 __reserved2;
	__le32 cmd;
} __packed;

Using ddf(sdf)->cmd save to correct posistion regardless endian.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202402081929.mggOTHaZ-lkp@intel.com/
Signed-off-by: Frank Li <Frank.Li@nxp.com>
---

Notes:
    Change from v1 to v2
    - update commit message to show why add 'cmd'
    
    fsl-edma-common.c's build warning should not cause by this driver. which is
    difference drivers. This driver will not use any code related with
    fsl-edma-common.c.

 drivers/dma/fsl-qdma.c | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/drivers/dma/fsl-qdma.c b/drivers/dma/fsl-qdma.c
index 1e3bf6f30f784..5005e138fc239 100644
--- a/drivers/dma/fsl-qdma.c
+++ b/drivers/dma/fsl-qdma.c
@@ -161,6 +161,10 @@ struct fsl_qdma_format {
 			u8 __reserved1[2];
 			u8 cfg8b_w1;
 		} __packed;
+		struct {
+			__le32 __reserved2;
+			__le32 cmd;
+		} __packed;
 		__le64 data;
 	};
 } __packed;
@@ -355,7 +359,6 @@ static void fsl_qdma_free_chan_resources(struct dma_chan *chan)
 static void fsl_qdma_comp_fill_memcpy(struct fsl_qdma_comp *fsl_comp,
 				      dma_addr_t dst, dma_addr_t src, u32 len)
 {
-	u32 cmd;
 	struct fsl_qdma_format *sdf, *ddf;
 	struct fsl_qdma_format *ccdf, *csgf_desc, *csgf_src, *csgf_dest;
 
@@ -384,15 +387,11 @@ static void fsl_qdma_comp_fill_memcpy(struct fsl_qdma_comp *fsl_comp,
 	/* This entry is the last entry. */
 	qdma_csgf_set_f(csgf_dest, len);
 	/* Descriptor Buffer */
-	cmd = cpu_to_le32(FSL_QDMA_CMD_RWTTYPE <<
-			  FSL_QDMA_CMD_RWTTYPE_OFFSET) |
-			  FSL_QDMA_CMD_PF;
-	sdf->data = QDMA_SDDF_CMD(cmd);
-
-	cmd = cpu_to_le32(FSL_QDMA_CMD_RWTTYPE <<
-			  FSL_QDMA_CMD_RWTTYPE_OFFSET);
-	cmd |= cpu_to_le32(FSL_QDMA_CMD_LWC << FSL_QDMA_CMD_LWC_OFFSET);
-	ddf->data = QDMA_SDDF_CMD(cmd);
+	sdf->cmd = cpu_to_le32((FSL_QDMA_CMD_RWTTYPE << FSL_QDMA_CMD_RWTTYPE_OFFSET) |
+			       FSL_QDMA_CMD_PF);
+
+	ddf->cmd = cpu_to_le32((FSL_QDMA_CMD_RWTTYPE << FSL_QDMA_CMD_RWTTYPE_OFFSET) |
+			       (FSL_QDMA_CMD_LWC << FSL_QDMA_CMD_LWC_OFFSET));
 }
 
 /*
@@ -626,7 +625,7 @@ static int fsl_qdma_halt(struct fsl_qdma_engine *fsl_qdma)
 
 static int
 fsl_qdma_queue_transfer_complete(struct fsl_qdma_engine *fsl_qdma,
-				 void *block,
+				 __iomem void *block,
 				 int id)
 {
 	bool duplicate;
-- 
2.34.1