[PATCH v5 7/9] drm: Add a drm_get_unmapped_area() helper

Tue Mar 3 21:06:39 UTC 2020

Hi "Thomas,

I love your patch! Yet something to improve:

[auto build test ERROR on drm-exynos/exynos-drm-next]
[also build test ERROR on drm-intel/for-linux-next drm-tip/drm-tip linus/master v5.6-rc4 next-20200303]
[cannot apply to tegra-drm/drm/tegra/for-next]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url:    https://github.com/0day-ci/linux/commits/Thomas-Hellstr-m-VMware/Huge-page-table-entries-for-TTM/20200304-022543
base:   https://git.kernel.org/pub/scm/linux/kernel/git/daeinki/drm-exynos.git exynos-drm-next
config: c6x-allyesconfig (attached as .config)
compiler: c6x-elf-gcc (GCC) 7.5.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        GCC_VERSION=7.5.0 make.cross ARCH=c6x 

If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp at intel.com>

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

   drivers/gpu/drm/drm_file.c: In function 'drm_get_unmapped_area':
>> drivers/gpu/drm/drm_file.c:966:20: error: 'struct mm_struct' has no member named 'get_unmapped_area'
     return current->mm->get_unmapped_area(file, uaddr, len, pgoff, flags);
                       ^~
>> drivers/gpu/drm/drm_file.c:967:1: warning: control reaches end of non-void function [-Wreturn-type]
    }
    ^

vim +966 drivers/gpu/drm/drm_file.c

   882	
   883	/**
   884	 * drm_get_unmapped_area() - Get an unused user-space virtual memory area
   885	 * suitable for huge page table entries.
   886	 * @file: The struct file representing the address space being mmap()'d.
   887	 * @uaddr: Start address suggested by user-space.
   888	 * @len: Length of the area.
   889	 * @pgoff: The page offset into the address space.
   890	 * @flags: mmap flags
   891	 * @mgr: The address space manager used by the drm driver. This argument can
   892	 * probably be removed at some point when all drivers use the same
   893	 * address space manager.
   894	 *
   895	 * This function attempts to find an unused user-space virtual memory area
   896	 * that can accommodate the size we want to map, and that is properly
   897	 * aligned to facilitate huge page table entries matching actual
   898	 * huge pages or huge page aligned memory in buffer objects. Buffer objects
   899	 * are assumed to start at huge page boundary pfns (io memory) or be
   900	 * populated by huge pages aligned to the start of the buffer object
   901	 * (system- or coherent memory). Adapted from shmem_get_unmapped_area.
   902	 *
   903	 * Return: aligned user-space address.
   904	 */
   905	unsigned long drm_get_unmapped_area(struct file *file,
   906					    unsigned long uaddr, unsigned long len,
   907					    unsigned long pgoff, unsigned long flags,
   908					    struct drm_vma_offset_manager *mgr)
   909	{
   910		unsigned long addr;
   911		unsigned long inflated_addr;
   912		struct drm_vma_offset_node *node;
   913	
   914		if (len > TASK_SIZE)
   915			return -ENOMEM;
   916	
   917		/*
   918		 * @pgoff is the file page-offset the huge page boundaries of
   919		 * which typically aligns to physical address huge page boundaries.
   920		 * That's not true for DRM, however, where physical address huge
   921		 * page boundaries instead are aligned with the offset from
   922		 * buffer object start. So adjust @pgoff to be the offset from
   923		 * buffer object start.
   924		 */
   925		drm_vma_offset_lock_lookup(mgr);
   926		node = drm_vma_offset_lookup_locked(mgr, pgoff, 1);
   927		if (node)
   928			pgoff -= node->vm_node.start;
   929		drm_vma_offset_unlock_lookup(mgr);
   930	
   931		addr = current->mm->get_unmapped_area(file, uaddr, len, pgoff, flags);
   932		if (IS_ERR_VALUE(addr))
   933			return addr;
   934		if (addr & ~PAGE_MASK)
   935			return addr;
   936		if (addr > TASK_SIZE - len)
   937			return addr;
   938	
   939		if (len < HPAGE_PMD_SIZE)
   940			return addr;
   941		if (flags & MAP_FIXED)
   942			return addr;
   943		/*
   944		 * Our priority is to support MAP_SHARED mapped hugely;
   945		 * and support MAP_PRIVATE mapped hugely too, until it is COWed.
   946		 * But if caller specified an address hint, respect that as before.
   947		 */
   948		if (uaddr)
   949			return addr;
   950	
   951		inflated_addr = drm_addr_inflate(addr, len, pgoff, flags,
   952						 HPAGE_PMD_SIZE);
   953	
   954		if (IS_ENABLED(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD) &&
   955		    len >= HPAGE_PUD_SIZE)
   956			inflated_addr = drm_addr_inflate(inflated_addr, len, pgoff,
   957							 flags, HPAGE_PUD_SIZE);
   958		return inflated_addr;
   959	}
   960	#else /* CONFIG_TRANSPARENT_HUGEPAGE */
   961	unsigned long drm_get_unmapped_area(struct file *file,
   962					    unsigned long uaddr, unsigned long len,
   963					    unsigned long pgoff, unsigned long flags,
   964					    struct drm_vma_offset_manager *mgr)
   965	{
 > 966		return current->mm->get_unmapped_area(file, uaddr, len, pgoff, flags);
 > 967	}

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
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