linux-stable/arch
Athira Rajeev 1cade527f6 powerpc/perf: BHRB control to disable BHRB logic when not used
PowerISA v3.1 has few updates for the Branch History Rolling
Buffer(BHRB).

BHRB disable is controlled via Monitor Mode Control Register A (MMCRA)
bit, namely "BHRB Recording Disable (BHRBRD)". This field controls
whether BHRB entries are written when BHRB recording is enabled by
other bits. This patch implements support for this BHRB disable bit.
By setting 0b1 to this bit will disable the BHRB and by setting 0b0 to
this bit will have BHRB enabled. This addresses backward
compatibility (for older OS), since this bit will be cleared and
hardware will be writing to BHRB by default.

This patch addresses changes to set MMCRA (BHRBRD) at boot for
power10 (there by the core will run faster) and enable this feature
only on runtime ie, on explicit need from user. Also save/restore
MMCRA in the restore path of state-loss idle state to make sure we
keep BHRB disabled if it was not enabled on request at runtime.

Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1594996707-3727-12-git-send-email-atrajeev@linux.vnet.ibm.com
2020-07-22 21:56:42 +10:00
..
alpha Kbuild updates for v5.8 (2nd) 2020-06-13 13:29:16 -07:00
arc treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
arm maccess: make get_kernel_nofault() check for minimal type compatibility 2020-06-18 12:10:37 -07:00
arm64 Kbuild fixes for v5.8 2020-06-21 12:44:52 -07:00
c6x This time around we have 4 lines of diff in the core framework, removing a 2020-06-10 11:42:19 -07:00
csky maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault 2020-06-17 10:57:41 -07:00
h8300 This time around we have 4 lines of diff in the core framework, removing a 2020-06-10 11:42:19 -07:00
hexagon treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
ia64 Merge branch 'hch' (maccess patches from Christoph Hellwig) 2020-06-18 12:35:51 -07:00
m68k Kbuild updates for v5.8 (2nd) 2020-06-13 13:29:16 -07:00
microblaze mmap locking API: convert mmap_sem comments 2020-06-09 09:39:14 -07:00
mips maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault 2020-06-17 10:57:41 -07:00
nds32 maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault 2020-06-17 10:57:41 -07:00
nios2 nios2 update for v5.8-rc1 2020-06-12 11:55:11 -07:00
openrisc OpenRISC updates for 5.8 2020-06-13 10:54:09 -07:00
parisc maccess: make get_kernel_nofault() check for minimal type compatibility 2020-06-18 12:10:37 -07:00
powerpc powerpc/perf: BHRB control to disable BHRB logic when not used 2020-07-22 21:56:42 +10:00
riscv RISC-V Fixes for 5.8-rc2 2020-06-20 12:14:29 -07:00
s390 s390 fixes for 5.8-rc2 2020-06-20 12:31:08 -07:00
sh maccess: rename probe_kernel_address to get_kernel_nofault 2020-06-18 11:14:40 -07:00
sparc treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
um maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault 2020-06-17 10:57:41 -07:00
unicore32 This time around we have 4 lines of diff in the core framework, removing a 2020-06-10 11:42:19 -07:00
x86 Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2020-06-20 19:18:27 -07:00
xtensa mmap locking API: convert mmap_sem API comments 2020-06-09 09:39:14 -07:00
.gitignore
Kconfig treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00