Today, PAGE_NONE is defined as a page not having _PAGE_USER.
In some circunstances, when the CPU supports it, it might be
better to be able to flag a page with NO ACCESS.
In a following patch, the 8xx will switch user access being flagged
in the PMD, therefore it will not be possible anymore to use
_PAGE_USER as a way to flag a page with no access.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
commit ac29c64089 ("powerpc/mm: Replace _PAGE_USER with
_PAGE_PRIVILEGED") introduced _PAGE_PRIVILEGED for BOOK3S/64
This patch generalises _PAGE_PRIVILEGED for all CPUs, allowing
to have either _PAGE_PRIVILEGED or _PAGE_USER or both.
PPC_8xx has a _PAGE_SHARED flag which is set for and only for
all non user pages. Lets rename it _PAGE_PRIVILEGED to remove
confusion as it has nothing to do with Linux shared pages.
On BookE, there's a _PAGE_BAP_SR which has to be set for kernel
pages: defining _PAGE_PRIVILEGED as _PAGE_BAP_SR will make
this generic
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The H_PAGE_F_SECOND,H_PAGE_F_GIX are not in the 64K main-PTE.
capture these changes in the dump pte report.
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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 page table dump code doesn't know about huge pages, so currently
it crashes (or walks random memory, usually leading to a crash), if it
finds a huge page. On Book3S we only see huge pages in the Linux page
tables when we're using the P9 Radix MMU.
Teaching the code to properly handle huge pages is a bit more involved,
so for now just prevent the crash.
Cc: stable@vger.kernel.org # v4.10+
Fixes: 8eb07b1870 ("powerpc/mm: Dump linux pagetables")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Page table dump debugfs file is named 'kernel_page_tables' on
all other architectures implementing it, while is is named
'kernel_pagetables' on powerpc. This patch renames it.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
On some targets, _PAGE_RW is 0 and this is _PAGE_RO which is used.
There is also _PAGE_SHARED that is missing.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
On PPC32 (eg. mpc885_ads_defconfig), page table dump compilation fails as
follows. This is because the memory layout is slightly different on PPC32. This
patch adapts it.
arch/powerpc/mm/dump_linuxpagetables.c: In function 'walk_pagetables':
arch/powerpc/mm/dump_linuxpagetables.c:369:10: error: 'KERN_VIRT_START' undeclared (first use in this function)
...
Fixes: 8eb07b1870 ("powerpc/mm: Dump linux pagetables")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The current page table dumper scans the Linux page tables and coalesces mappings
with adjacent virtual addresses and similar PTE flags. This behaviour is
somewhat broken when you consider the IOREMAP space where entirely unrelated
mappings will appear to be virtually contiguous. This patch modifies the range
coalescing so that only ranges that are both physically and virtually contiguous
are combined. This patch also adds to the dump output the physical address at
the start of each range.
Fixes: 8eb07b1870 ("powerpc/mm: Dump linux pagetables")
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
[mpe: Print the physicall address with 0x like the other addresses]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
On Book3s we have two PTE flags used to mark cache-inhibited mappings:
_PAGE_TOLERANT and _PAGE_NON_IDEMPOTENT. Currently the kernel page table dumper
only looks at the generic _PAGE_NO_CACHE which is defined to be _PAGE_TOLERANT.
This patch modifies the dumper so both flags are shown in the dump.
Fixes: 8eb07b1870 ("powerpc/mm: Dump linux pagetables")
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In the recent commit 1515ab9321 ("powerpc/mm: Dump hash table") we
added code to dump the hage page table. Currently this can be selected
to build on any platform. However it breaks the build if we're building
for a non-Book3S platform, because none of the hash page table related
defines and so on exist. So restrict it to building only on Book3S.
Similarly in commit 8eb07b1870 ("powerpc/mm: Dump linux pagetables")
we added code to dump the Linux page tables, which uses some constants
which are only defined on Book3S - so guard those with an #ifdef.
Fixes: 1515ab9321 ("powerpc/mm: Dump hash table")
Fixes: 8eb07b1870 ("powerpc/mm: Dump linux pagetables")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Useful to be able to dump the kernels page tables to check permissions
and memory types - derived from arm64's implementation.
Add a debugfs file to check the page tables. To use this the PPC_PTDUMP
config option must be selected.
Signed-off-by: Rashmica Gupta <rashmicy@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Christophe Leroy