Re: [RFC 10/10] mm: Remove pXX_devmap

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

Hi Alistair,

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

[auto build test ERROR on ffc253263a1375a65fa6c9f62a893e9767fbebfa]

url:    https://github.com/intel-lab-lkp/linux/commits/Alistair-Popple/mm-gup-c-Remove-redundant-check-for-PCI-P2PDMA-page/20240411-085933
base:   ffc253263a1375a65fa6c9f62a893e9767fbebfa
patch link:    https://lore.kernel.org/r/93e3772f172918a3c489d803f7580309c3a42fff.1712796818.git-series.apopple%40nvidia.com
patch subject: [RFC 10/10] mm: Remove pXX_devmap
config: arm64-allnoconfig (https://download.01.org/0day-ci/archive/20240412/202404120852.dCFQbBaU-lkp@intel.com/config)
compiler: aarch64-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240412/202404120852.dCFQbBaU-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/202404120852.dCFQbBaU-lkp@intel.com/

All errors (new ones prefixed by >>):

   mm/memory.c: In function 'insert_pfn':
>> mm/memory.c:2161:25: error: implicit declaration of function 'pte_mkdevmap'; did you mean 'pfn_t_devmap'? [-Werror=implicit-function-declaration]
    2161 |                 entry = pte_mkdevmap(pfn_t_pte(pfn, prot));
         |                         ^~~~~~~~~~~~
         |                         pfn_t_devmap
   mm/memory.c:2161:25: error: incompatible types when assigning to type 'pte_t' from type 'int'
   cc1: some warnings being treated as errors


vim +2161 mm/memory.c

a667d7456f189e Souptick Joarder 2019-05-13  2123  
9b5a8e00d479bb Matthew Wilcox   2018-10-26  2124  static vm_fault_t insert_pfn(struct vm_area_struct *vma, unsigned long addr,
b2770da6425406 Ross Zwisler     2017-09-06  2125  			pfn_t pfn, pgprot_t prot, bool mkwrite)
423bad600443c5 Nicholas Piggin  2008-04-28  2126  {
423bad600443c5 Nicholas Piggin  2008-04-28  2127  	struct mm_struct *mm = vma->vm_mm;
423bad600443c5 Nicholas Piggin  2008-04-28  2128  	pte_t *pte, entry;
423bad600443c5 Nicholas Piggin  2008-04-28  2129  	spinlock_t *ptl;
423bad600443c5 Nicholas Piggin  2008-04-28  2130  
423bad600443c5 Nicholas Piggin  2008-04-28  2131  	pte = get_locked_pte(mm, addr, &ptl);
423bad600443c5 Nicholas Piggin  2008-04-28  2132  	if (!pte)
9b5a8e00d479bb Matthew Wilcox   2018-10-26  2133  		return VM_FAULT_OOM;
c33c794828f212 Ryan Roberts     2023-06-12  2134  	entry = ptep_get(pte);
c33c794828f212 Ryan Roberts     2023-06-12  2135  	if (!pte_none(entry)) {
b2770da6425406 Ross Zwisler     2017-09-06  2136  		if (mkwrite) {
b2770da6425406 Ross Zwisler     2017-09-06  2137  			/*
b2770da6425406 Ross Zwisler     2017-09-06  2138  			 * For read faults on private mappings the PFN passed
b2770da6425406 Ross Zwisler     2017-09-06  2139  			 * in may not match the PFN we have mapped if the
b2770da6425406 Ross Zwisler     2017-09-06  2140  			 * mapped PFN is a writeable COW page.  In the mkwrite
b2770da6425406 Ross Zwisler     2017-09-06  2141  			 * case we are creating a writable PTE for a shared
f2c57d91b0d96a Jan Kara         2018-10-30  2142  			 * mapping and we expect the PFNs to match. If they
f2c57d91b0d96a Jan Kara         2018-10-30  2143  			 * don't match, we are likely racing with block
f2c57d91b0d96a Jan Kara         2018-10-30  2144  			 * allocation and mapping invalidation so just skip the
f2c57d91b0d96a Jan Kara         2018-10-30  2145  			 * update.
b2770da6425406 Ross Zwisler     2017-09-06  2146  			 */
c33c794828f212 Ryan Roberts     2023-06-12  2147  			if (pte_pfn(entry) != pfn_t_to_pfn(pfn)) {
c33c794828f212 Ryan Roberts     2023-06-12  2148  				WARN_ON_ONCE(!is_zero_pfn(pte_pfn(entry)));
423bad600443c5 Nicholas Piggin  2008-04-28  2149  				goto out_unlock;
f2c57d91b0d96a Jan Kara         2018-10-30  2150  			}
c33c794828f212 Ryan Roberts     2023-06-12  2151  			entry = pte_mkyoung(entry);
cae85cb8add35f Jan Kara         2019-03-28  2152  			entry = maybe_mkwrite(pte_mkdirty(entry), vma);
cae85cb8add35f Jan Kara         2019-03-28  2153  			if (ptep_set_access_flags(vma, addr, pte, entry, 1))
cae85cb8add35f Jan Kara         2019-03-28  2154  				update_mmu_cache(vma, addr, pte);
cae85cb8add35f Jan Kara         2019-03-28  2155  		}
b2770da6425406 Ross Zwisler     2017-09-06  2156  		goto out_unlock;
b2770da6425406 Ross Zwisler     2017-09-06  2157  	}
423bad600443c5 Nicholas Piggin  2008-04-28  2158  
423bad600443c5 Nicholas Piggin  2008-04-28  2159  	/* Ok, finally just insert the thing.. */
01c8f1c44b83a0 Dan Williams     2016-01-15  2160  	if (pfn_t_devmap(pfn))
01c8f1c44b83a0 Dan Williams     2016-01-15 @2161  		entry = pte_mkdevmap(pfn_t_pte(pfn, prot));
01c8f1c44b83a0 Dan Williams     2016-01-15  2162  	else
01c8f1c44b83a0 Dan Williams     2016-01-15  2163  		entry = pte_mkspecial(pfn_t_pte(pfn, prot));
b2770da6425406 Ross Zwisler     2017-09-06  2164  
b2770da6425406 Ross Zwisler     2017-09-06  2165  	if (mkwrite) {
b2770da6425406 Ross Zwisler     2017-09-06  2166  		entry = pte_mkyoung(entry);
b2770da6425406 Ross Zwisler     2017-09-06  2167  		entry = maybe_mkwrite(pte_mkdirty(entry), vma);
b2770da6425406 Ross Zwisler     2017-09-06  2168  	}
b2770da6425406 Ross Zwisler     2017-09-06  2169  
423bad600443c5 Nicholas Piggin  2008-04-28  2170  	set_pte_at(mm, addr, pte, entry);
4b3073e1c53a25 Russell King     2009-12-18  2171  	update_mmu_cache(vma, addr, pte); /* XXX: why not for insert_page? */
423bad600443c5 Nicholas Piggin  2008-04-28  2172  
423bad600443c5 Nicholas Piggin  2008-04-28  2173  out_unlock:
423bad600443c5 Nicholas Piggin  2008-04-28  2174  	pte_unmap_unlock(pte, ptl);
9b5a8e00d479bb Matthew Wilcox   2018-10-26  2175  	return VM_FAULT_NOPAGE;
423bad600443c5 Nicholas Piggin  2008-04-28  2176  }
423bad600443c5 Nicholas Piggin  2008-04-28  2177  

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