Re: [PATCH 1/7] mm/mm_init.c: remove the useless dma_reserve

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

Hi Baoquan,

kernel test robot noticed the following build errors:

[auto build test ERROR on powerpc/next]
[also build test ERROR on powerpc/fixes linus/master v6.9-rc1]
[cannot apply to akpm-mm/mm-everything next-20240326]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Baoquan-He/mm-mm_init-c-remove-the-useless-dma_reserve/20240325-230756
base:   https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
patch link:    https://lore.kernel.org/r/20240325150459.1045407-2-bhe%40redhat.com
patch subject: [PATCH 1/7] mm/mm_init.c: remove the useless dma_reserve
config: x86_64-rhel-8.3 (https://download.01.org/0day-ci/archive/20240326/202403261645.M4PkWdmb-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240326/202403261645.M4PkWdmb-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/202403261645.M4PkWdmb-lkp@intel.com/

All errors (new ones prefixed by >>):

   arch/x86/mm/init.c: In function 'memblock_find_dma_reserve':
>> arch/x86/mm/init.c:1036:9: error: implicit declaration of function 'set_dma_reserve'; did you mean 'get_dma_residue'? [-Werror=implicit-function-declaration]
    1036 |         set_dma_reserve(nr_pages - nr_free_pages);
         |         ^~~~~~~~~~~~~~~
         |         get_dma_residue
   cc1: some warnings being treated as errors


vim +1036 arch/x86/mm/init.c

176239153049a0 Pekka Enberg 2011-11-01   992  
4270fd8b4c27f0 Ingo Molnar  2017-01-28   993  /*
4270fd8b4c27f0 Ingo Molnar  2017-01-28   994   * Calculate the precise size of the DMA zone (first 16 MB of RAM),
4270fd8b4c27f0 Ingo Molnar  2017-01-28   995   * and pass it to the MM layer - to help it set zone watermarks more
4270fd8b4c27f0 Ingo Molnar  2017-01-28   996   * accurately.
4270fd8b4c27f0 Ingo Molnar  2017-01-28   997   *
4270fd8b4c27f0 Ingo Molnar  2017-01-28   998   * Done on 64-bit systems only for the time being, although 32-bit systems
4270fd8b4c27f0 Ingo Molnar  2017-01-28   999   * might benefit from this as well.
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1000   */
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1001  void __init memblock_find_dma_reserve(void)
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1002  {
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1003  #ifdef CONFIG_X86_64
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1004  	u64 nr_pages = 0, nr_free_pages = 0;
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1005  	unsigned long start_pfn, end_pfn;
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1006  	phys_addr_t start_addr, end_addr;
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1007  	int i;
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1008  	u64 u;
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1009  
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1010  	/*
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1011  	 * Iterate over all memory ranges (free and reserved ones alike),
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1012  	 * to calculate the total number of pages in the first 16 MB of RAM:
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1013  	 */
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1014  	nr_pages = 0;
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1015  	for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, NULL) {
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1016  		start_pfn = min(start_pfn, MAX_DMA_PFN);
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1017  		end_pfn   = min(end_pfn,   MAX_DMA_PFN);
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1018  
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1019  		nr_pages += end_pfn - start_pfn;
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1020  	}
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1021  
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1022  	/*
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1023  	 * Iterate over free memory ranges to calculate the number of free
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1024  	 * pages in the DMA zone, while not counting potential partial
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1025  	 * pages at the beginning or the end of the range:
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1026  	 */
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1027  	nr_free_pages = 0;
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1028  	for_each_free_mem_range(u, NUMA_NO_NODE, MEMBLOCK_NONE, &start_addr, &end_addr, NULL) {
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1029  		start_pfn = min_t(unsigned long, PFN_UP(start_addr), MAX_DMA_PFN);
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1030  		end_pfn   = min_t(unsigned long, PFN_DOWN(end_addr), MAX_DMA_PFN);
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1031  
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1032  		if (start_pfn < end_pfn)
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1033  			nr_free_pages += end_pfn - start_pfn;
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1034  	}
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1035  
4270fd8b4c27f0 Ingo Molnar  2017-01-28 @1036  	set_dma_reserve(nr_pages - nr_free_pages);
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1037  #endif
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1038  }
4270fd8b4c27f0 Ingo Molnar  2017-01-28  1039  

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