On book3s/64, the only user of hugepd is hash in 4k mode.
All other setups (hash-64, radix-4, radix-64) use leaf PMD/PUD.
Rework hash-4k to use contiguous PMD and PUD instead.
In that setup there are only two huge page sizes: 16M and 16G.
16M sits at PMD level and 16G at PUD level.
pte_update doesn't know page size, lets use the same trick as
hpte_need_flush() to get page size from segment properties. That's not
the most efficient way but let's do that until callers of pte_update()
provide page size instead of just a huge flag.
Link: https://lkml.kernel.org/r/7448f60a9b3efd396595f4f735d1e0babc5ae379.1719928057.git.christophe.leroy@csgroup.eu
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
e500 supports many page sizes among which the following size are
implemented in the kernel at the time being: 4M, 16M, 64M, 256M, 1G.
On e500, TLB miss for hugepages is exclusively handled by SW even on e6500
which has HW assistance for 4k pages, so there are no constraints like on
the 8xx.
On e500/32, all are at PGD/PMD level and can be handled as cont-PMD.
On e500/64, smaller ones are on PMD while bigger ones are on PUD. Again,
they can easily be handled as cont-PMD and cont-PUD instead of hugepd.
On e500/32, use the pagesize bits in PTE to know if it is a PMD or a leaf
entry. This works because the pagesize bits are in the last 12 bits and
page tables are 4k aligned.
On e500/64, use highest bit which is always 1 on PxD (Because PxD contains
virtual address of a kernel memory) and always 0 on PTEs because not all
bits of RPN are used/possible.
Link: https://lkml.kernel.org/r/dd085987816ed2a0c70adb7e34966cb833fc03e1.1719928057.git.christophe.leroy@csgroup.eu
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Use PTE page size bits to encode hugepage size with the following format
corresponding to the values expected in bits 52-55 in MAS1 register.
Those bits are called TSIZE:
0001 4 Kbyte
0010 16 Kbyte
0011 64 Kbyte
0100 256 Kbyte
0101 1 Mbyte
0110 4 Mbyte
0111 16 Mbyte
1000 64 Mbyte
1001 256 Mbyte
1010 1 Gbyte
1011 4 Gbyte
1100 16 Gbyte
1101 64 Gbyte
1110 256 Gbyte
1111 1 Tbyte
It corresponds to shift value minus 10 with lowest bit removed.
It is not the value expected in the PTE in that field, but only e6500
performs HW based TLB loading and the e6500 reference manual explicitely
says that this field is ignored.
Also add pte_huge_size() which will be used later.
Link: https://lkml.kernel.org/r/6f7ce82fa8c381d55f65342d77060fc55802e612.1719928057.git.christophe.leroy@csgroup.eu
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
