CONFIG_PPC_STD_MMU_64 indicates support for the "standard" powerpc MMU
on 64-bit CPUs. The "standard" MMU refers to the hash page table MMU
found in "server" processors, from IBM mainly.
Currently CONFIG_PPC_STD_MMU_64 is == CONFIG_PPC_BOOK3S_64. While it's
annoying to have two symbols that always have the same value, it's not
quite annoying enough to bother removing one.
However with the arrival of Power9, we now have the situation where
CONFIG_PPC_STD_MMU_64 is enabled, but the kernel is running using the
Radix MMU - *not* the "standard" MMU. So it is now actively confusing
to use it, because it implies that code is disabled or inactive when
the Radix MMU is in use, however that is not necessarily true.
So s/CONFIG_PPC_STD_MMU_64/CONFIG_PPC_BOOK3S_64/, and do some minor
formatting updates of some of the affected lines.
This will be a pain for backports, but c'est la vie.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Two single characters (line breaks) should be put into a sequence.
Thus use the corresponding function "seq_putc".
This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The check in hpte_find() should be < and not <= for PAGE_OFFSET
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The current behaviour of the hash table dump assumes that memory is contiguous
and iterates from the start of memory to (start + size of memory). When memory
isn't physically contiguous, this doesn't work.
If memory exists at 0-5 GB and 6-10 GB then the current approach will check if
entries exist in the hash table from 0GB to 9GB. This patch changes the
behaviour to iterate over any holes up to the end of memory.
Fixes: 1515ab9321 ("powerpc/mm: Dump hash table")
Signed-off-by: Rashmica Gupta <rashmica.g@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Useful to be able to dump the kernel hash page table to check
which pages are hashed along with their sizes and other details.
Add a debugfs file to check the hash page table. If radix is enabled
(and so there is no hash page table) then this file doesn't exist. To
use this the PPC_PTDUMP config option must be selected.
Signed-off-by: Rashmica Gupta <rashmicy@gmail.com>
[mpe: Fix build with SPARSEMEM_VMEMMAP=n & PSERIES=n]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
