Initialising the suppport for EFI runtime services requires us to
allocate a pgd off the back of an early_initcall. On systems where the
PGD_SIZE is smaller than PAGE_SIZE (e.g. 64k pages and 48-bit VA), the
pgd_cache isn't initialised at this stage, and we panic with a NULL
dereference during boot:
Unable to handle kernel NULL pointer dereference at virtual address 00000000
__create_mapping.isra.5+0x84/0x350
create_pgd_mapping+0x20/0x28
efi_create_mapping+0x5c/0x6c
arm_enable_runtime_services+0x154/0x1e4
do_one_initcall+0x8c/0x190
kernel_init_freeable+0x84/0x1ec
kernel_init+0x10/0xe0
ret_from_fork+0x10/0x50
This patch fixes the problem by initialising the pgd_cache earlier, in
the pgtable_cache_init callback, which sounds suspiciously like what it
was intended for.
Reported-by: Dennis Chen <dennis.chen@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
39b5be9b42