[PATCH 1/3] arm64/boot: Move init_pgdir[] into __pi_ namespace

[kernel test robot]

Hi Ard,

kernel test robot noticed the following build errors:

[auto build test ERROR on soc/for-next]
[also build test ERROR on linus/master v6.15-rc5 next-20250505]
[cannot apply to arm64/for-next/core kvmarm/next]
[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/Ard-Biesheuvel/arm64-boot-Move-init_pgdir-into-__pi_-namespace/20250503-192534
base:   https://git.kernel.org/pub/scm/linux/kernel/git/soc/soc.git for-next
patch link:    https://lore.kernel.org/r/20250503112137.1962910-6-ardb%2Bgit%40google.com
patch subject: [PATCH 1/3] arm64/boot: Move init_pgdir[] into __pi_ namespace
config: arm64-randconfig-001-20250505 (https://download.01.org/0day-ci/archive/20250505/202505052102.U2NQHrS4-lkp@intel.com/config)
compiler: clang version 21.0.0git (https://github.com/llvm/llvm-project f819f46284f2a79790038e1f6649172789734ae8)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250505/202505052102.U2NQHrS4-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 at intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202505052102.U2NQHrS4-lkp@intel.com/

All errors (new ones prefixed by >>):

>> arch/arm64/kernel/pi/map_kernel.c:191:30: error: use of undeclared identifier 'init_pg_end'
     191 |         memset(init_pg_dir, 0, (u64)init_pg_end - (u64)init_pg_dir);
         |                                     ^
   arch/arm64/kernel/pi/map_kernel.c:222:30: error: use of undeclared identifier 'init_pg_end'
     222 |         memset(__bss_start, 0, (u64)init_pg_end - (u64)__bss_start);
         |                                     ^
   2 errors generated.


vim +/init_pg_end +191 arch/arm64/kernel/pi/map_kernel.c

9684ec186f8fadd Ard Biesheuvel 2024-02-14  158  
9684ec186f8fadd Ard Biesheuvel 2024-02-14  159  static void __init remap_idmap_for_lpa2(void)
9684ec186f8fadd Ard Biesheuvel 2024-02-14  160  {
9684ec186f8fadd Ard Biesheuvel 2024-02-14  161  	/* clear the bits that change meaning once LPA2 is turned on */
9684ec186f8fadd Ard Biesheuvel 2024-02-14  162  	pteval_t mask = PTE_SHARED;
9684ec186f8fadd Ard Biesheuvel 2024-02-14  163  
9684ec186f8fadd Ard Biesheuvel 2024-02-14  164  	/*
9684ec186f8fadd Ard Biesheuvel 2024-02-14  165  	 * We have to clear bits [9:8] in all block or page descriptors in the
9684ec186f8fadd Ard Biesheuvel 2024-02-14  166  	 * initial ID map, as otherwise they will be (mis)interpreted as
9684ec186f8fadd Ard Biesheuvel 2024-02-14  167  	 * physical address bits once we flick the LPA2 switch (TCR.DS). Since
9684ec186f8fadd Ard Biesheuvel 2024-02-14  168  	 * we cannot manipulate live descriptors in that way without creating
9684ec186f8fadd Ard Biesheuvel 2024-02-14  169  	 * potential TLB conflicts, let's create another temporary ID map in a
9684ec186f8fadd Ard Biesheuvel 2024-02-14  170  	 * LPA2 compatible fashion, and update the initial ID map while running
9684ec186f8fadd Ard Biesheuvel 2024-02-14  171  	 * from that.
9684ec186f8fadd Ard Biesheuvel 2024-02-14  172  	 */
9684ec186f8fadd Ard Biesheuvel 2024-02-14  173  	create_init_idmap(init_pg_dir, mask);
9684ec186f8fadd Ard Biesheuvel 2024-02-14  174  	dsb(ishst);
9684ec186f8fadd Ard Biesheuvel 2024-02-14  175  	set_ttbr0_for_lpa2((u64)init_pg_dir);
9684ec186f8fadd Ard Biesheuvel 2024-02-14  176  
9684ec186f8fadd Ard Biesheuvel 2024-02-14  177  	/*
9684ec186f8fadd Ard Biesheuvel 2024-02-14  178  	 * Recreate the initial ID map with the same granularity as before.
9684ec186f8fadd Ard Biesheuvel 2024-02-14  179  	 * Don't bother with the FDT, we no longer need it after this.
9684ec186f8fadd Ard Biesheuvel 2024-02-14  180  	 */
9684ec186f8fadd Ard Biesheuvel 2024-02-14  181  	memset(init_idmap_pg_dir, 0,
ecc54006f158ae0 Zenghui Yu     2024-06-21  182  	       (u64)init_idmap_pg_end - (u64)init_idmap_pg_dir);
9684ec186f8fadd Ard Biesheuvel 2024-02-14  183  
9684ec186f8fadd Ard Biesheuvel 2024-02-14  184  	create_init_idmap(init_idmap_pg_dir, mask);
9684ec186f8fadd Ard Biesheuvel 2024-02-14  185  	dsb(ishst);
9684ec186f8fadd Ard Biesheuvel 2024-02-14  186  
9684ec186f8fadd Ard Biesheuvel 2024-02-14  187  	/* switch back to the updated initial ID map */
9684ec186f8fadd Ard Biesheuvel 2024-02-14  188  	set_ttbr0_for_lpa2((u64)init_idmap_pg_dir);
9684ec186f8fadd Ard Biesheuvel 2024-02-14  189  
9684ec186f8fadd Ard Biesheuvel 2024-02-14  190  	/* wipe the temporary ID map from memory */
9684ec186f8fadd Ard Biesheuvel 2024-02-14 @191  	memset(init_pg_dir, 0, (u64)init_pg_end - (u64)init_pg_dir);
9684ec186f8fadd Ard Biesheuvel 2024-02-14  192  }
9684ec186f8fadd Ard Biesheuvel 2024-02-14  193  

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