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

powerpc/vdso: Move cvdso_call macro into gettimeofday.S

2022-02-12T11:47:44Z

Now that gettimeofday.S is unique, move cvdso_call macro into that file which is the only user. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/72720359d4c58e3a3b96dd74952741225faac3de.1642782130.git.christophe.leroy@csgroup.eu

powerpc/vdso: Remove cvdso_call_time macro

2022-02-12T11:47:43Z

cvdso_call_time macro is very similar to cvdso_call macro. Add a call_time argument to cvdso_call which is 0 by default and set to 1 when using cvdso_call to call __c_kernel_time(). Return returned value as is with CR[SO] cleared when it is used for time(). Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/837a260ad86fc1ce297a562c2117fd69be5f7b5c.1642782130.git.christophe.leroy@csgroup.eu

powerpc/vdso: Add support for time namespaces

2021-04-14T13:04:44Z

This patch adds the necessary glue to provide time namespaces. Things are mainly copied from ARM64. __arch_get_timens_vdso_data() calculates timens vdso data position based on the vdso data position, knowing it is the next page in vvar. This avoids having to redo the mflr/bcl/mflr/mtlr dance to locate the page relative to running code position. Signed-off-by: Christophe Leroy Reviewed-by: Vincenzo Frascino # vDSO parts Acked-by: Andrei Vagin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/1a15495f80ec19a87b16cf874dbf7c3fa5ec40fe.1617209142.git.christophe.leroy@csgroup.eu

powerpc/vdso: Fix clock_gettime_fallback for vdso32

2021-01-14T04:56:44Z

The second argument of __kernel_clock_gettime64 points to a struct __kernel_timespec, with 64-bit time_t, so use the clock_gettime64 syscall in the fallback function for the 32-bit VDSO. Similarly, clock_getres_fallback should use the clock_getres_time64 syscall, though it isn't yet called from the 32-bit VDSO. Fixes: d0e3fc69d00d ("powerpc/vdso: Provide __kernel_clock_gettime64() on vdso32") Signed-off-by: Andreas Schwab [chleroy: Moved into a single #ifdef __powerpc64__ block] Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/0c0ab0eb3cc80687c326f76ff0dd5762b8812ecc.1610452505.git.christophe.leroy@csgroup.eu

powerpc/vdso: Remove unused \tmp param in __get_datapage()

2020-12-03T14:01:17Z

The \tmp param is not used anymore, remove it. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/4b13f897dcccce8ae03c031a4598cf26b32e2f1c.1601197618.git.christophe.leroy@csgroup.eu

powerpc/vdso: Provide __kernel_clock_gettime64() on vdso32

2020-12-03T14:01:11Z

Provides __kernel_clock_gettime64() on vdso32. This is the 64 bits version of __kernel_clock_gettime() which is y2038 compliant. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20201126131006.2431205-9-mpe@ellerman.id.au

powerpc/vdso: Save and restore TOC pointer on PPC64

2020-12-03T14:01:10Z

On PPC64, the TOC pointer needs to be saved and restored. Suggested-by: Michael Ellerman Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20201126131006.2431205-7-mpe@ellerman.id.au

powerpc/vdso: Prepare for switching VDSO to generic C implementation.

2020-12-03T14:01:10Z

Prepare for switching VDSO to generic C implementation in following patch. Here, we: - Prepare the helpers to call the C VDSO functions - Prepare the required callbacks for the C VDSO functions - Prepare the clocksource.h files to define VDSO_ARCH_CLOCKMODES - Add the C trampolines to the generic C VDSO functions powerpc is a bit special for VDSO as well as system calls in the way that it requires setting CR SO bit which cannot be done in C. Therefore, entry/exit needs to be performed in ASM. Implementing __arch_get_vdso_data() would clobber the link register, requiring the caller to save it. As the ASM calling function already has to set a stack frame and saves the link register before calling the C vdso function, retriving the vdso data pointer there is lighter. Implement __arch_vdso_capable() and always return true. Provide vdso_shift_ns(), as the generic x >> s gives the following bad result: 18: 35 25 ff e0 addic. r9,r5,-32 1c: 41 80 00 10 blt 2c 20: 7c 64 4c 30 srw r4,r3,r9 24: 38 60 00 00 li r3,0 ... 2c: 54 69 08 3c rlwinm r9,r3,1,0,30 30: 21 45 00 1f subfic r10,r5,31 34: 7c 84 2c 30 srw r4,r4,r5 38: 7d 29 50 30 slw r9,r9,r10 3c: 7c 63 2c 30 srw r3,r3,r5 40: 7d 24 23 78 or r4,r9,r4 In our case the shift is always <= 32. In addition, the upper 32 bits of the result are likely nul. Lets GCC know it, it also optimises the following calculations. With the patch, we get: 0: 21 25 00 20 subfic r9,r5,32 4: 7c 69 48 30 slw r9,r3,r9 8: 7c 84 2c 30 srw r4,r4,r5 c: 7d 24 23 78 or r4,r9,r4 10: 7c 63 2c 30 srw r3,r3,r5 Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20201126131006.2431205-6-mpe@ellerman.id.au