linux/arch/powerpc
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>
2017-12-20 18:57:22 +11:00
..
boot powerpc/boot: Only build CPM code when necessary 2017-12-11 13:03:31 +11:00
configs powerpc/configs: Enable I2C_CHARDEV for pseries and powernv 2017-10-22 12:08:31 +02:00
crypto License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
include powerpc: Free up four 64K PTE bits in 64K backed HPTE pages 2017-12-20 18:57:22 +11:00
kernel powerpc/pci: Separate SR-IOV Calls 2017-12-11 13:03:35 +11:00
kvm * x86 bugfixes: APIC, nested virtualization, IOAPIC 2017-11-30 08:15:19 -08:00
lib powerpc/modules: Don't try to restore r2 after a sibling call 2017-12-11 13:03:29 +11:00
math-emu License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mm powerpc: Free up four 64K PTE bits in 64K backed HPTE pages 2017-12-20 18:57:22 +11:00
net powerpc updates for 4.15 2017-11-16 12:47:46 -08:00
oprofile treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
perf powerpc fixes for 4.15 #2 2017-11-24 19:40:12 -10:00
platforms PCI/IOV: Add pci_vf_drivers_autoprobe() interface 2017-12-11 13:03:36 +11:00
purgatory License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
sysdev powerpc: Use pr_warn instead of pr_warning 2017-12-04 11:54:34 +11:00
tools License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xmon powerpc updates for 4.15 2017-11-16 12:47:46 -08:00
Kconfig powerpc updates for 4.15 2017-11-16 12:47:46 -08:00
Kconfig.debug powerpc updates for 4.15 2017-11-16 12:47:46 -08:00
Makefile powerpc/modules: Fix alignment of .toc section in kernel modules 2017-12-11 13:03:35 +11:00
Makefile.postlink License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00