kernel/arch/powerpc/include/asm/vdso/timebase.h, branch linux-6.2.y

powerpc: Change CONFIG_E500 to CONFIG_PPC_E500

2022-09-26T13:00:13Z

It will be used outside arch/powerpc, make it clear its a powerpc configuration item. And we already have CONFIG_PPC_E500MC, so that will make it more consistent. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/e63b22083c11c4300f4a82d3123a46e5fdd54fa6.1663606876.git.christophe.leroy@csgroup.eu

powerpc/time: Remove get_tbl()

2021-02-11T12:35:13Z

There are no more users of get_tbl(). Remove it. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/dd0368bfd497ffe06b31ee1b5f2ebf7760e30900.1612866360.git.christophe.leroy@csgroup.eu

powerpc/time: Force inlining of get_tb()

2020-12-21T11:06:10Z

Force inlining of get_tb() in order to avoid getting following function in vdso32, leading to suboptimal performance in clock_gettime() 00000688 <.get_tb>: 688: 7c 6d 42 a6 mftbu r3 68c: 7c 8c 42 a6 mftb r4 690: 7d 2d 42 a6 mftbu r9 694: 7c 03 48 40 cmplw r3,r9 698: 40 e2 ff f0 bne+ 688 <.get_tb> 69c: 4e 80 00 20 blr Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/df05d53eed1210cf1aa76d1fb44aa0fab29c018e.1608488286.git.christophe.leroy@csgroup.eu

powerpc/time: Fix mftb()/get_tb() for use with the compat VDSO

2020-12-03T14:01:10Z

When we're building the compat VDSO we are building 32-bit code but in the context of a 64-bit kernel configuration. To make this work we need to be careful in some places when using ifdefs to differentiate between CONFIG_PPC64 and __powerpc64__. CONFIG_PPC64 indicates the kernel we're building is 64-bit, but it doesn't tell us that we're currently building 64-bit code - we could be building 32-bit code for the compat VDSO. On the other hand __powerpc64__ tells us that we are currently building 64-bit code (and therefore we must also be building a 64-bit kernel). In the case of get_tb() we want to use the 32-bit code sequence regardless of whether the kernel we're building for is 64-bit or 32-bit, what matters is the word size of the current object. So we need to check __powerpc64__ to decide if we use mftb() or the mftbu()/mftb() sequence. For mftb() the logic for CPU_FTR_CELL_TB_BUG only makes sense if we're building 64-bit code, so guard that with a __powerpc64__ check. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20201126131006.2431205-4-mpe@ellerman.id.au

powerpc/time: Move timebase functions into new asm/vdso/timebase.h

2020-12-03T14:01:10Z

In order to easily use get_tb() from C VDSO, move timebase functions into a new header named asm/vdso/timebase.h Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20201126131006.2431205-3-mpe@ellerman.id.au