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Ram Pai bf9a95f9a6 powerpc: Free up four 64K PTE bits in 64K backed HPTE pages
Rearrange 64K PTE bits to free up bits 3, 4, 5 and 6
in the 64K backed HPTE pages. This along with the earlier
patch will entirely free up the four bits from 64K PTE.
The bit numbers are big-endian as defined in the ISA3.0

This patch does the following change to 64K PTE backed
by 64K HPTE.

H_PAGE_F_SECOND (S) which occupied bit 4 moves to the
	second part of the pte to bit 60.
H_PAGE_F_GIX (G,I,X) which occupied bit 5, 6 and 7 also
	moves to the second part of the pte to bit 61,
 	62, 63, 64 respectively

since bit 7 is now freed up, we move H_PAGE_BUSY (B) from
bit 9 to bit 7.

The second part of the PTE will hold
(H_PAGE_F_SECOND|H_PAGE_F_GIX) at bit 60,61,62,63.
NOTE: None of the bits in the secondary PTE were not used
by 64k-HPTE backed PTE.

Before the patch, the 64K HPTE backed 64k PTE format was
as follows

 0 1 2 3 4  5  6  7  8 9 10...........................63
 : : : : :  :  :  :  : : :                            :
 v v v v v  v  v  v  v v v                            v

,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-,
|x|x|x| |S |G |I |X |x|B| |x|x|................|x|x|x|x| <- primary pte
'_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_'
| | | | |  |  |  |  | | | | |..................| | | | | <- secondary pte
'_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_'

After the patch, the 64k HPTE backed 64k PTE format is
as follows

 0 1 2 3 4  5  6  7  8 9 10...........................63
 : : : : :  :  :  :  : : :                            :
 v v v v v  v  v  v  v v v                            v

,-,-,-,-,--,--,--,--,-,-,-,-,-,------------------,-,-,-,
|x|x|x| |  |  |  |B |x| | |x|x|................|.|.|.|.| <- primary pte
'_'_'_'_'__'__'__'__'_'_'_'_'_'________________'_'_'_'_'
| | | | |  |  |  |  | | | | |..................|S|G|I|X| <- secondary pte
'_'_'_'_'__'__'__'__'_'_'_'_'__________________'_'_'_'_'

The above PTE changes is applicable to hugetlbpages aswell.

The patch does the following code changes:

a) moves the H_PAGE_F_SECOND and H_PAGE_F_GIX to 4k PTE
	header since it is no more needed b the 64k PTEs.
b) abstracts out __real_pte() and __rpte_to_hidx() so the
	caller need not know the bit location of the slot.
c) moves the slot bits to the secondary pte.

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>
History 2017-12-20 18:57:22 +11:00
arch powerpc: Free up four 64K PTE bits in 64K backed HPTE pages 2017-12-20 18:57:22 +11:00
block Merge branch 'for-linus' of git://git.kernel.dk/linux-block 2017-12-01 08:05:45 -05:00
certs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2017-11-28 16:22:10 -08:00
Documentation hwmon fixes for v4.15-rc2 2017-12-03 10:46:16 -05:00
drivers PCI/IOV: Add pci_vf_drivers_autoprobe() interface 2017-12-11 13:03:36 +11:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs NFS client fixes for Linux 4.15-rc2 2017-12-01 20:04:20 -05:00
include PCI/IOV: Add pci_vf_drivers_autoprobe() interface 2017-12-11 13:03:36 +11:00
init EXPERT Kconfig menu: fix broken EXPERT menu 2017-11-17 16:10:05 -08:00
ipc Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
kernel Merge branch 'for-linus' of git://git.kernel.dk/linux-block 2017-12-01 08:05:45 -05:00
lib RISC-V Cleanups and ABI Fixes for 4.15-rc2 2017-12-01 19:39:12 -05:00
mm Merge branch 'for-linus' of git://git.kernel.dk/linux-block 2017-12-01 08:05:45 -05:00
net NFS client fixes for Linux 4.15-rc2 2017-12-01 20:04:20 -05:00
samples kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
scripts Merge branch 'akpm' (patches from Andrew) 2017-11-29 19:12:44 -08:00
security bug fixes: 2017-11-30 18:56:41 -05:00
sound Revert "ALSA: usb-audio: Fix potential zero-division at parsing FU" 2017-11-28 09:34:36 -08:00
tools selftests/powerpc: Fix build errors in powerpc ptrace selftests 2017-12-11 13:03:37 +11:00
usr initramfs: fix initramfs rebuilds w/ compression after disabling 2017-11-03 07:39:19 -07:00
virt * x86 bugfixes: APIC, nested virtualization, IOAPIC 2017-11-30 08:15:19 -08:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Add hch to .get_maintainer.ignore 2015-08-21 14:30:10 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Kbuild misc updates for v4.15 2017-11-17 17:51:33 -08:00
.mailmap Add Jason Gunthorpe as co-maintainer of the RDMA stack 2017-11-17 09:36:18 -08:00
COPYING [PATCH] update FSF address in COPYING 2005-09-10 10:06:29 -07:00
CREDITS MAINTAINERS: update TPM driver infrastructure changes 2017-11-09 17:58:40 -08:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
MAINTAINERS hwmon fixes for v4.15-rc2 2017-12-03 10:46:16 -05:00
Makefile Linux 4.15-rc2 2017-12-03 11:01:47 -05:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.