Re: [PATCH RFC 12/13] dmaengine: sdxi: Add Kconfig and Makefile

[kernel test robot <lkp@intel.com>]

Hi Nathan,

[This is a private test report for your RFC patch.]
kernel test robot noticed the following build errors:

[auto build test ERROR on c17b750b3ad9f45f2b6f7e6f7f4679844244f0b9]

url:    https://github.com/intel-lab-lkp/linux/commits/Nathan-Lynch-via-B4-Relay/PCI-Add-SNIA-SDXI-accelerator-sub-class/20250906-025019
base:   c17b750b3ad9f45f2b6f7e6f7f4679844244f0b9
patch link:    https://lore.kernel.org/r/20250905-sdxi-base-v1-12-d0341a1292ba%40amd.com
patch subject: [PATCH RFC 12/13] dmaengine: sdxi: Add Kconfig and Makefile
config: hexagon-allmodconfig (https://download.01.org/0day-ci/archive/20250908/202509081310.SsgvmgVR-lkp@intel.com/config)
compiler: clang version 17.0.6 (https://github.com/llvm/llvm-project 6009708b4367171ccdbf4b5905cb6a803753fe18)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250908/202509081310.SsgvmgVR-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202509081310.SsgvmgVR-lkp@intel.com/

All error/warnings (new ones prefixed by >>):

>> drivers/dma/sdxi/dma.c:78:20: warning: result of comparison of constant 4294967296 with expression of type 'size_t' (aka 'unsigned int') is always false [-Wtautological-constant-out-of-range-compare]
      78 |         if (sdxi_cmd->len > MAX_DMA_COPY_BYTES)
         |             ~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~
   1 warning generated.
--
>> drivers/dma/sdxi/enqueue.c:115:19: error: invalid operand for instruction
     115 |                         bool success = cmpxchg(Write_Index,
         |                                        ^
   include/linux/atomic/atomic-instrumented.h:4788:2: note: expanded from macro 'cmpxchg'
    4788 |         raw_cmpxchg(__ai_ptr, __VA_ARGS__); \
         |         ^
   include/linux/atomic/atomic-arch-fallback.h:55:21: note: expanded from macro 'raw_cmpxchg'
      55 | #define raw_cmpxchg arch_cmpxchg
         |                     ^
   arch/hexagon/include/asm/cmpxchg.h:62:3: note: expanded from macro 'arch_cmpxchg'
      62 |                 "1:     %0 = memw_locked(%1);\n"                \
         |                 ^
   <inline asm>:1:12: note: instantiated into assembly here
       1 |         1:      r5:4 = memw_locked(r23);
         |                        ^
>> drivers/dma/sdxi/enqueue.c:115:19: error: invalid operand for instruction
     115 |                         bool success = cmpxchg(Write_Index,
         |                                        ^
   include/linux/atomic/atomic-instrumented.h:4788:2: note: expanded from macro 'cmpxchg'
    4788 |         raw_cmpxchg(__ai_ptr, __VA_ARGS__); \
         |         ^
   include/linux/atomic/atomic-arch-fallback.h:55:21: note: expanded from macro 'raw_cmpxchg'
      55 | #define raw_cmpxchg arch_cmpxchg
         |                     ^
   arch/hexagon/include/asm/cmpxchg.h:65:4: note: expanded from macro 'arch_cmpxchg'
      65 |                 "       memw_locked(%1,p0) = %3;\n"             \
         |                  ^
   <inline asm>:4:24: note: instantiated into assembly here
       4 |         memw_locked(r23,p0) = r9:8;
         |                               ^
   2 errors generated.
--
>> drivers/dma/sdxi/descriptor_kunit.c:34:19: warning: implicit conversion from 'unsigned long long' to 'size_t' (aka 'unsigned int') changes value from 4294967297 to 1 [-Wconstant-conversion]
      34 |         copy.len = SZ_4G + 1;
         |                  ~ ~~~~~~^~~
   drivers/dma/sdxi/descriptor_kunit.c:42:13: warning: implicit conversion from 'unsigned long long' to 'size_t' (aka 'unsigned int') changes value from 4294967296 to 0 [-Wconstant-conversion]
      42 |         copy.len = SZ_4G;
         |                  ~ ^~~~~
   include/linux/sizes.h:54:18: note: expanded from macro 'SZ_4G'
      54 | #define SZ_4G                           _AC(0x100000000, ULL)
         |                                         ^~~~~~~~~~~~~~~~~~~~~
   include/uapi/linux/const.h:21:18: note: expanded from macro '_AC'
      21 | #define _AC(X,Y)        __AC(X,Y)
         |                         ^~~~~~~~~
   include/uapi/linux/const.h:20:20: note: expanded from macro '__AC'
      20 | #define __AC(X,Y)       (X##Y)
         |                          ^~~~
   <scratch space>:71:1: note: expanded from here
      71 | 0x100000000ULL
         | ^~~~~~~~~~~~~~
   2 warnings generated.


vim +115 drivers/dma/sdxi/enqueue.c

65c648c037296d4 Nathan Lynch 2025-09-05   83  
65c648c037296d4 Nathan Lynch 2025-09-05   84  int sdxi_enqueue(const __le64 *enq_entries,                 /* Ptr to entries to enqueue */
65c648c037296d4 Nathan Lynch 2025-09-05   85  		 u64 enq_num,                               /* Number of entries to enqueue */
65c648c037296d4 Nathan Lynch 2025-09-05   86  		 __le64 *ring_base,                         /* Ptr to ring location */
65c648c037296d4 Nathan Lynch 2025-09-05   87  		 u64 ring_size,                             /* (Ring Size in bytes)/64 */
65c648c037296d4 Nathan Lynch 2025-09-05   88  		 __le64 const volatile * const Read_Index,  /* Ptr to Read_Index location */
65c648c037296d4 Nathan Lynch 2025-09-05   89  		 __le64 volatile * const Write_Index,       /* Ptr to Write_Index location */
65c648c037296d4 Nathan Lynch 2025-09-05   90  		 __le64 __iomem *Door_Bell)                 /* Ptr to Ring Doorbell location */
65c648c037296d4 Nathan Lynch 2025-09-05   91  {
65c648c037296d4 Nathan Lynch 2025-09-05   92  	u64 old_write_idx;
65c648c037296d4 Nathan Lynch 2025-09-05   93  	u64 new_idx;
65c648c037296d4 Nathan Lynch 2025-09-05   94  
65c648c037296d4 Nathan Lynch 2025-09-05   95  	while (true) {
65c648c037296d4 Nathan Lynch 2025-09-05   96  		u64 read_idx;
65c648c037296d4 Nathan Lynch 2025-09-05   97  
65c648c037296d4 Nathan Lynch 2025-09-05   98  		read_idx = le64_to_cpu(READ_ONCE(*Read_Index));
65c648c037296d4 Nathan Lynch 2025-09-05   99  		dma_rmb();  /* Get Read_Index before Write_Index to always get consistent values */
65c648c037296d4 Nathan Lynch 2025-09-05  100  		old_write_idx = le64_to_cpu(READ_ONCE(*Write_Index));
65c648c037296d4 Nathan Lynch 2025-09-05  101  
65c648c037296d4 Nathan Lynch 2025-09-05  102  		if (read_idx > old_write_idx) {
65c648c037296d4 Nathan Lynch 2025-09-05  103  			/* Only happens if Write_Index wraps or ring has bad setup */
65c648c037296d4 Nathan Lynch 2025-09-05  104  			return -EIO;
65c648c037296d4 Nathan Lynch 2025-09-05  105  		}
65c648c037296d4 Nathan Lynch 2025-09-05  106  
65c648c037296d4 Nathan Lynch 2025-09-05  107  		new_idx = old_write_idx + enq_num;
65c648c037296d4 Nathan Lynch 2025-09-05  108  		if (new_idx - read_idx > ring_size) {
65c648c037296d4 Nathan Lynch 2025-09-05  109  			cpu_relax();
65c648c037296d4 Nathan Lynch 2025-09-05  110  			continue;  /* Not enough free entries, try again */
65c648c037296d4 Nathan Lynch 2025-09-05  111  		}
65c648c037296d4 Nathan Lynch 2025-09-05  112  
65c648c037296d4 Nathan Lynch 2025-09-05  113  		if (SDXI_MULTI_PRODUCER) {
65c648c037296d4 Nathan Lynch 2025-09-05  114  			/* Try to atomically update Write_Index. */
65c648c037296d4 Nathan Lynch 2025-09-05 @115  			bool success = cmpxchg(Write_Index,

-- 
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