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To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , arnd@arndb.de, tglx@linutronix.de, vincenzo.frascino@arm.com, luto@kernel.org Date: Mon, 23 Dec 2019 14:31:11 +0000 (UTC) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191223_063115_512317_95C32FFB X-CRM114-Status: GOOD ( 22.62 ) X-Spam-Score: -0.2 (/) X-Spam-Report: SpamAssassin version 3.4.2 on bombadil.infradead.org summary: Content analysis details: (-0.2 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at https://www.dnswl.org/, no trust [93.17.236.30 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature -0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: x86@kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org This is a tentative to switch powerpc/32 vdso to generic C implementation. It will likely not work on 64 bits or even build properly at the moment, hence the RFC status. 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 and fallback needs to be performed in ASM. On powerpc 8xx, performance is degraded by 30-40% for gettime and by 15-20% for getres On a powerpc885 at 132MHz: With current powerpc/32 ASM VDSO: gettimeofday: vdso: 737 nsec/call clock-getres-realtime-coarse: vdso: 3081 nsec/call clock-gettime-realtime-coarse: vdso: 2861 nsec/call clock-getres-realtime: vdso: 475 nsec/call clock-gettime-realtime: vdso: 892 nsec/call clock-getres-boottime: vdso: 2621 nsec/call clock-gettime-boottime: vdso: 3857 nsec/call clock-getres-tai: vdso: 2620 nsec/call clock-gettime-tai: vdso: 3854 nsec/call clock-getres-monotonic-raw: vdso: 2621 nsec/call clock-gettime-monotonic-raw: vdso: 3499 nsec/call clock-getres-monotonic-coarse: vdso: 3083 nsec/call clock-gettime-monotonic-coarse: vdso: 3082 nsec/call clock-getres-monotonic: vdso: 475 nsec/call clock-gettime-monotonic: vdso: 1014 nsec/call Once switched to C implementation: gettimeofday: vdso: 1016 nsec/call clock-getres-realtime-coarse: vdso: 614 nsec/call clock-gettime-realtime-coarse: vdso: 760 nsec/call clock-getres-realtime: vdso: 560 nsec/call clock-gettime-realtime: vdso: 1192 nsec/call clock-getres-boottime: vdso: 560 nsec/call clock-gettime-boottime: vdso: 1194 nsec/call clock-getres-tai: vdso: 560 nsec/call clock-gettime-tai: vdso: 1192 nsec/call clock-getres-monotonic-raw: vdso: 560 nsec/call clock-gettime-monotonic-raw: vdso: 1248 nsec/call clock-getres-monotonic-coarse: vdso: 614 nsec/call clock-gettime-monotonic-coarse: vdso: 760 nsec/call clock-getres-monotonic: vdso: 560 nsec/call clock-gettime-monotonic: vdso: 1192 nsec/call On a powerpc 8321 running at 333MHz With current powerpc/32 ASM VDSO: gettimeofday: vdso: 190 nsec/call clock-getres-realtime-coarse: vdso: 1449 nsec/call clock-gettime-realtime-coarse: vdso: 1352 nsec/call clock-getres-realtime: vdso: 135 nsec/call clock-gettime-realtime: vdso: 244 nsec/call clock-getres-boottime: vdso: 1313 nsec/call clock-gettime-boottime: vdso: 1701 nsec/call clock-getres-tai: vdso: 1268 nsec/call clock-gettime-tai: vdso: 1742 nsec/call clock-getres-monotonic-raw: vdso: 1310 nsec/call clock-gettime-monotonic-raw: vdso: 1584 nsec/call clock-getres-monotonic-coarse: vdso: 1488 nsec/call clock-gettime-monotonic-coarse: vdso: 1503 nsec/call clock-getres-monotonic: vdso: 135 nsec/call clock-gettime-monotonic: vdso: 283 nsec/call Once switched to C implementation: gettimeofday: vdso: 347 nsec/call clock-getres-realtime-coarse: vdso: 169 nsec/call clock-gettime-realtime-coarse: vdso: 271 nsec/call clock-getres-realtime: vdso: 150 nsec/call clock-gettime-realtime: vdso: 383 nsec/call clock-getres-boottime: vdso: 157 nsec/call clock-gettime-boottime: vdso: 377 nsec/call clock-getres-tai: vdso: 150 nsec/call clock-gettime-tai: vdso: 380 nsec/call clock-getres-monotonic-raw: vdso: 153 nsec/call clock-gettime-monotonic-raw: vdso: 407 nsec/call clock-getres-monotonic-coarse: vdso: 169 nsec/call clock-gettime-monotonic-coarse: vdso: 271 nsec/call clock-getres-monotonic: vdso: 153 nsec/call clock-gettime-monotonic: vdso: 377 nsec/call Signed-off-by: Christophe Leroy --- arch/powerpc/Kconfig | 2 + arch/powerpc/include/asm/vdso/gettimeofday.h | 45 +++++ arch/powerpc/include/asm/vdso/vsyscall.h | 27 +++ arch/powerpc/include/asm/vdso_datapage.h | 18 +- arch/powerpc/kernel/asm-offsets.c | 23 +-- arch/powerpc/kernel/time.c | 92 +--------- arch/powerpc/kernel/vdso.c | 19 +- arch/powerpc/kernel/vdso32/Makefile | 19 +- arch/powerpc/kernel/vdso32/gettimeofday.S | 261 ++++----------------------- arch/powerpc/kernel/vdso32/vgettimeofday.c | 32 ++++ 10 files changed, 178 insertions(+), 360 deletions(-) create mode 100644 arch/powerpc/include/asm/vdso/gettimeofday.h create mode 100644 arch/powerpc/include/asm/vdso/vsyscall.h create mode 100644 arch/powerpc/kernel/vdso32/vgettimeofday.c diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 1ec34e16ed65..bd04c68baf91 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -169,6 +169,7 @@ config PPC select GENERIC_STRNCPY_FROM_USER select GENERIC_STRNLEN_USER select GENERIC_TIME_VSYSCALL + select GENERIC_GETTIMEOFDAY select HAVE_ARCH_AUDITSYSCALL select HAVE_ARCH_HUGE_VMAP if PPC_BOOK3S_64 && PPC_RADIX_MMU select HAVE_ARCH_JUMP_LABEL @@ -198,6 +199,7 @@ config PPC select HAVE_FUNCTION_GRAPH_TRACER select HAVE_FUNCTION_TRACER select HAVE_GCC_PLUGINS if GCC_VERSION >= 50200 # plugin support on gcc <= 5.1 is buggy on PPC + select HAVE_GENERIC_VDSO select HAVE_HW_BREAKPOINT if PERF_EVENTS && (PPC_BOOK3S || PPC_8xx) select HAVE_IDE select HAVE_IOREMAP_PROT diff --git a/arch/powerpc/include/asm/vdso/gettimeofday.h b/arch/powerpc/include/asm/vdso/gettimeofday.h new file mode 100644 index 000000000000..e170e12a78bb --- /dev/null +++ b/arch/powerpc/include/asm/vdso/gettimeofday.h @@ -0,0 +1,45 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ASM_VDSO_GETTIMEOFDAY_H +#define __ASM_VDSO_GETTIMEOFDAY_H + +#ifndef __ASSEMBLY__ + +#include +#include +#include + +#define VDSO_HAS_CLOCK_GETRES 1 + +#define VDSO_HAS_TIME 1 + +static __always_inline u64 __arch_get_hw_counter(s32 clock_mode) +{ + /* + * clock_mode == 0 implies that vDSO are enabled otherwise + * fallback on syscall. + */ + if (clock_mode) + return ULLONG_MAX; + + return get_tb() & LLONG_MAX; +} + +/* + * powerpc specific delta calculation. + * + * This variant removes the masking of the subtraction because the + * clocksource mask of all VDSO capable clocksources on powerpc is U64_MAX + * which would result in a pointless operation. The compiler cannot + * optimize it away as the mask comes from the vdso data and is not compile + * time constant. + */ +static __always_inline +u64 vdso_calc_delta(u64 cycles, u64 last, u64 mask, u32 mult) +{ + return (cycles - last) * mult; +} +#define vdso_calc_delta vdso_calc_delta + +#endif /* !__ASSEMBLY__ */ + +#endif /* __ASM_VDSO_GETTIMEOFDAY_H */ diff --git a/arch/powerpc/include/asm/vdso/vsyscall.h b/arch/powerpc/include/asm/vdso/vsyscall.h new file mode 100644 index 000000000000..d12c2298cbb8 --- /dev/null +++ b/arch/powerpc/include/asm/vdso/vsyscall.h @@ -0,0 +1,27 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ASM_VDSO_VSYSCALL_H +#define __ASM_VDSO_VSYSCALL_H + +#ifndef __ASSEMBLY__ + +#include +#include + +extern struct vdso_arch_data *vdso_arch_data; + +/* + * Update the vDSO data page to keep in sync with kernel timekeeping. + */ +static __always_inline +struct vdso_data *__powerpc_get_k_vdso_data(void) +{ + return vdso_arch_data->data; +} +#define __arch_get_k_vdso_data __powerpc_get_k_vdso_data + +/* The asm-generic header needs to be included after the definitions above */ +#include + +#endif /* !__ASSEMBLY__ */ + +#endif /* __ASM_VDSO_VSYSCALL_H */ diff --git a/arch/powerpc/include/asm/vdso_datapage.h b/arch/powerpc/include/asm/vdso_datapage.h index ee5319a6f4e3..6b9424ca91c4 100644 --- a/arch/powerpc/include/asm/vdso_datapage.h +++ b/arch/powerpc/include/asm/vdso_datapage.h @@ -36,6 +36,7 @@ #include #include +#include #define SYSCALL_MAP_SIZE ((NR_syscalls + 31) / 32) @@ -93,20 +94,9 @@ struct vdso_data { /* * And here is the simpler 32 bits version */ -struct vdso_data { - __u64 tb_orig_stamp; /* Timebase at boot 0x30 */ +struct vdso_arch_data { + struct vdso_data data[CS_BASES]; __u64 tb_ticks_per_sec; /* Timebase tics / sec 0x38 */ - __u64 tb_to_xs; /* Inverse of TB to 2^20 0x40 */ - __u64 stamp_xsec; /* 0x48 */ - __u32 tb_update_count; /* Timebase atomicity ctr 0x50 */ - __u32 tz_minuteswest; /* Minutes west of Greenwich 0x58 */ - __u32 tz_dsttime; /* Type of dst correction 0x5C */ - __s32 wtom_clock_sec; /* Wall to monotonic clock */ - __s32 wtom_clock_nsec; - __s32 stamp_xtime_sec; /* xtime seconds as at tb_orig_stamp */ - __s32 stamp_xtime_nsec; /* xtime nsecs as at tb_orig_stamp */ - __u32 stamp_sec_fraction; /* fractional seconds of stamp_xtime */ - __u32 hrtimer_res; /* hrtimer resolution */ __u32 syscall_map_32[SYSCALL_MAP_SIZE]; /* map of syscalls */ __u32 dcache_block_size; /* L1 d-cache block size */ __u32 icache_block_size; /* L1 i-cache block size */ @@ -116,7 +106,7 @@ struct vdso_data { #endif /* CONFIG_PPC64 */ -extern struct vdso_data *vdso_data; +extern struct vdso_arch_data *vdso_arch_data; #else /* __ASSEMBLY__ */ diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c index 3d47aec7becf..5927c9cf9cc7 100644 --- a/arch/powerpc/kernel/asm-offsets.c +++ b/arch/powerpc/kernel/asm-offsets.c @@ -376,23 +376,12 @@ int main(void) #endif /* ! CONFIG_PPC64 */ /* datapage offsets for use by vdso */ - OFFSET(CFG_TB_ORIG_STAMP, vdso_data, tb_orig_stamp); - OFFSET(CFG_TB_TICKS_PER_SEC, vdso_data, tb_ticks_per_sec); - OFFSET(CFG_TB_TO_XS, vdso_data, tb_to_xs); - OFFSET(CFG_TB_UPDATE_COUNT, vdso_data, tb_update_count); - OFFSET(CFG_TZ_MINUTEWEST, vdso_data, tz_minuteswest); - OFFSET(CFG_TZ_DSTTIME, vdso_data, tz_dsttime); - OFFSET(CFG_SYSCALL_MAP32, vdso_data, syscall_map_32); - OFFSET(WTOM_CLOCK_SEC, vdso_data, wtom_clock_sec); - OFFSET(WTOM_CLOCK_NSEC, vdso_data, wtom_clock_nsec); - OFFSET(STAMP_XTIME_SEC, vdso_data, stamp_xtime_sec); - OFFSET(STAMP_XTIME_NSEC, vdso_data, stamp_xtime_nsec); - OFFSET(STAMP_SEC_FRAC, vdso_data, stamp_sec_fraction); - OFFSET(CLOCK_HRTIMER_RES, vdso_data, hrtimer_res); - OFFSET(CFG_ICACHE_BLOCKSZ, vdso_data, icache_block_size); - OFFSET(CFG_DCACHE_BLOCKSZ, vdso_data, dcache_block_size); - OFFSET(CFG_ICACHE_LOGBLOCKSZ, vdso_data, icache_log_block_size); - OFFSET(CFG_DCACHE_LOGBLOCKSZ, vdso_data, dcache_log_block_size); + OFFSET(CFG_TB_TICKS_PER_SEC, vdso_arch_data, tb_ticks_per_sec); + OFFSET(CFG_SYSCALL_MAP32, vdso_arch_data, syscall_map_32); + OFFSET(CFG_ICACHE_BLOCKSZ, vdso_arch_data, icache_block_size); + OFFSET(CFG_DCACHE_BLOCKSZ, vdso_arch_data, dcache_block_size); + OFFSET(CFG_ICACHE_LOGBLOCKSZ, vdso_arch_data, icache_log_block_size); + OFFSET(CFG_DCACHE_LOGBLOCKSZ, vdso_arch_data, dcache_log_block_size); #ifdef CONFIG_PPC64 OFFSET(CFG_SYSCALL_MAP64, vdso_data, syscall_map_64); OFFSET(TVAL64_TV_SEC, __kernel_old_timeval, tv_sec); diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index 1168e8b37e30..e0c8023db42c 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -882,95 +882,6 @@ static notrace u64 timebase_read(struct clocksource *cs) return (u64)get_tb(); } - -void update_vsyscall(struct timekeeper *tk) -{ - struct timespec64 xt; - struct clocksource *clock = tk->tkr_mono.clock; - u32 mult = tk->tkr_mono.mult; - u32 shift = tk->tkr_mono.shift; - u64 cycle_last = tk->tkr_mono.cycle_last; - u64 new_tb_to_xs, new_stamp_xsec; - u64 frac_sec; - - if (clock != &clocksource_timebase) - return; - - xt.tv_sec = tk->xtime_sec; - xt.tv_nsec = (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift); - - /* Make userspace gettimeofday spin until we're done. */ - ++vdso_data->tb_update_count; - smp_mb(); - - /* - * This computes ((2^20 / 1e9) * mult) >> shift as a - * 0.64 fixed-point fraction. - * The computation in the else clause below won't overflow - * (as long as the timebase frequency is >= 1.049 MHz) - * but loses precision because we lose the low bits of the constant - * in the shift. Note that 19342813113834067 ~= 2^(20+64) / 1e9. - * For a shift of 24 the error is about 0.5e-9, or about 0.5ns - * over a second. (Shift values are usually 22, 23 or 24.) - * For high frequency clocks such as the 512MHz timebase clock - * on POWER[6789], the mult value is small (e.g. 32768000) - * and so we can shift the constant by 16 initially - * (295147905179 ~= 2^(20+64-16) / 1e9) and then do the - * remaining shifts after the multiplication, which gives a - * more accurate result (e.g. with mult = 32768000, shift = 24, - * the error is only about 1.2e-12, or 0.7ns over 10 minutes). - */ - if (mult <= 62500000 && clock->shift >= 16) - new_tb_to_xs = ((u64) mult * 295147905179ULL) >> (clock->shift - 16); - else - new_tb_to_xs = (u64) mult * (19342813113834067ULL >> clock->shift); - - /* - * Compute the fractional second in units of 2^-32 seconds. - * The fractional second is tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift - * in nanoseconds, so multiplying that by 2^32 / 1e9 gives - * it in units of 2^-32 seconds. - * We assume shift <= 32 because clocks_calc_mult_shift() - * generates shift values in the range 0 - 32. - */ - frac_sec = tk->tkr_mono.xtime_nsec << (32 - shift); - do_div(frac_sec, NSEC_PER_SEC); - - /* - * Work out new stamp_xsec value for any legacy users of systemcfg. - * stamp_xsec is in units of 2^-20 seconds. - */ - new_stamp_xsec = frac_sec >> 12; - new_stamp_xsec += tk->xtime_sec * XSEC_PER_SEC; - - /* - * tb_update_count is used to allow the userspace gettimeofday code - * to assure itself that it sees a consistent view of the tb_to_xs and - * stamp_xsec variables. It reads the tb_update_count, then reads - * tb_to_xs and stamp_xsec and then reads tb_update_count again. If - * the two values of tb_update_count match and are even then the - * tb_to_xs and stamp_xsec values are consistent. If not, then it - * loops back and reads them again until this criteria is met. - */ - vdso_data->tb_orig_stamp = cycle_last; - vdso_data->stamp_xsec = new_stamp_xsec; - vdso_data->tb_to_xs = new_tb_to_xs; - vdso_data->wtom_clock_sec = tk->wall_to_monotonic.tv_sec; - vdso_data->wtom_clock_nsec = tk->wall_to_monotonic.tv_nsec; - vdso_data->stamp_xtime_sec = xt.tv_sec; - vdso_data->stamp_xtime_nsec = xt.tv_nsec; - vdso_data->stamp_sec_fraction = frac_sec; - vdso_data->hrtimer_res = hrtimer_resolution; - smp_wmb(); - ++(vdso_data->tb_update_count); -} - -void update_vsyscall_tz(void) -{ - vdso_data->tz_minuteswest = sys_tz.tz_minuteswest; - vdso_data->tz_dsttime = sys_tz.tz_dsttime; -} - static void __init clocksource_init(void) { struct clocksource *clock; @@ -1140,8 +1051,7 @@ void __init time_init(void) sys_tz.tz_dsttime = 0; } - vdso_data->tb_update_count = 0; - vdso_data->tb_ticks_per_sec = tb_ticks_per_sec; + vdso_arch_data->tb_ticks_per_sec = tb_ticks_per_sec; /* initialise and enable the large decrementer (if we have one) */ set_decrementer_max(); diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c index eae9ddaecbcf..d1e4f3a3a781 100644 --- a/arch/powerpc/kernel/vdso.c +++ b/arch/powerpc/kernel/vdso.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include @@ -71,10 +72,10 @@ static int vdso_ready; * with it, it will become dynamically allocated */ static union { - struct vdso_data data; + struct vdso_arch_data arch_data; u8 page[PAGE_SIZE]; } vdso_data_store __page_aligned_data; -struct vdso_data *vdso_data = &vdso_data_store.data; +struct vdso_arch_data *vdso_arch_data = &vdso_data_store.arch_data; /* Format of the patch table */ struct vdso_patch_def @@ -661,7 +662,7 @@ static void __init vdso_setup_syscall_map(void) 0x80000000UL >> (i & 0x1f); #else /* CONFIG_PPC64 */ if (sys_call_table[i] != sys_ni_syscall) - vdso_data->syscall_map_32[i >> 5] |= + vdso_arch_data->syscall_map_32[i >> 5] |= 0x80000000UL >> (i & 0x1f); #endif /* CONFIG_PPC64 */ } @@ -729,10 +730,10 @@ static int __init vdso_init(void) vdso64_pages = (&vdso64_end - &vdso64_start) >> PAGE_SHIFT; DBG("vdso64_kbase: %p, 0x%x pages\n", vdso64_kbase, vdso64_pages); #else - vdso_data->dcache_block_size = L1_CACHE_BYTES; - vdso_data->dcache_log_block_size = L1_CACHE_SHIFT; - vdso_data->icache_block_size = L1_CACHE_BYTES; - vdso_data->icache_log_block_size = L1_CACHE_SHIFT; + vdso_arch_data->dcache_block_size = L1_CACHE_BYTES; + vdso_arch_data->dcache_log_block_size = L1_CACHE_SHIFT; + vdso_arch_data->icache_block_size = L1_CACHE_BYTES; + vdso_arch_data->icache_log_block_size = L1_CACHE_SHIFT; #endif /* CONFIG_PPC64 */ @@ -775,7 +776,7 @@ static int __init vdso_init(void) get_page(pg); vdso32_pagelist[i] = pg; } - vdso32_pagelist[i++] = virt_to_page(vdso_data); + vdso32_pagelist[i++] = virt_to_page(vdso_arch_data); vdso32_pagelist[i] = NULL; #endif @@ -792,7 +793,7 @@ static int __init vdso_init(void) vdso64_pagelist[i] = NULL; #endif /* CONFIG_PPC64 */ - get_page(virt_to_page(vdso_data)); + get_page(virt_to_page(vdso_arch_data)); smp_wmb(); vdso_ready = 1; diff --git a/arch/powerpc/kernel/vdso32/Makefile b/arch/powerpc/kernel/vdso32/Makefile index 06f54d947057..09edcd1a2dc7 100644 --- a/arch/powerpc/kernel/vdso32/Makefile +++ b/arch/powerpc/kernel/vdso32/Makefile @@ -2,10 +2,17 @@ # List of files in the vdso, has to be asm only for now +ARCH_REL_TYPE_ABS := R_PPC_JUMP_SLOT|R_PPC_GLOB_DAT|R_PPC_ADDR32|R_PPC_ADDR24|R_PPC_ADDR16|R_PPC_ADDR16_LO|R_PPC_ADDR16_HI|R_PPC_ADDR16_HA|R_PPC_ADDR14|R_PPC_ADDR14_BRTAKEN|R_PPC_ADDR14_BRNTAKEN +include $(srctree)/lib/vdso/Makefile + obj-vdso32-$(CONFIG_PPC64) = getcpu.o obj-vdso32 = sigtramp.o gettimeofday.o datapage.o cacheflush.o note.o \ $(obj-vdso32-y) +ifneq ($(c-gettimeofday-y),) + CFLAGS_vgettimeofday.o += -include $(c-gettimeofday-y) +endif + # Build rules ifdef CROSS32_COMPILE @@ -38,8 +45,8 @@ CPPFLAGS_vdso32.lds += -P -C -Upowerpc $(obj)/vdso32_wrapper.o : $(obj)/vdso32.so # link rule for the .so file, .lds has to be first -$(obj)/vdso32.so.dbg: $(src)/vdso32.lds $(obj-vdso32) FORCE - $(call if_changed,vdso32ld) +$(obj)/vdso32.so.dbg: $(src)/vdso32.lds $(obj-vdso32) $(obj)/vgettimeofday.o FORCE + $(call if_changed,vdso32ld_and_check) # strip rule for the .so file $(obj)/%.so: OBJCOPYFLAGS := -S @@ -49,12 +56,16 @@ $(obj)/%.so: $(obj)/%.so.dbg FORCE # assembly rules for the .S files $(obj-vdso32): %.o: %.S FORCE $(call if_changed_dep,vdso32as) +$(obj)/vgettimeofday.o: %.o: %.c FORCE + $(call if_changed_dep,vdso32cc) # actual build commands -quiet_cmd_vdso32ld = VDSO32L $@ - cmd_vdso32ld = $(VDSOCC) $(c_flags) $(CC32FLAGS) -o $@ -Wl,-T$(filter %.lds,$^) $(filter %.o,$^) +quiet_cmd_vdso32ld_and_check = VDSO32L $@ + cmd_vdso32ld_and_check = $(VDSOCC) $(c_flags) $(CC32FLAGS) -o $@ -Wl,-T$(filter %.lds,$^) $(filter %.o,$^) ; $(cmd_vdso_check) quiet_cmd_vdso32as = VDSO32A $@ cmd_vdso32as = $(VDSOCC) $(a_flags) $(CC32FLAGS) -c -o $@ $< +quiet_cmd_vdso32cc = VDSO32A $@ + cmd_vdso32cc = $(VDSOCC) $(c_flags) $(CC32FLAGS) -c -o $@ $< # install commands for the unstripped file quiet_cmd_vdso_install = INSTALL $@ diff --git a/arch/powerpc/kernel/vdso32/gettimeofday.S b/arch/powerpc/kernel/vdso32/gettimeofday.S index d6c1d331e8cb..d767d0089ad0 100644 --- a/arch/powerpc/kernel/vdso32/gettimeofday.S +++ b/arch/powerpc/kernel/vdso32/gettimeofday.S @@ -13,14 +13,32 @@ #include #include -/* Offset for the low 32-bit part of a field of long type */ -#ifdef CONFIG_PPC64 -#define LOPART 4 -#else -#define LOPART 0 -#endif - .text + +.macro cvdso_call_with_fallback funct, syscall + stwu r1, -16(r1) + mflr r0 + stw r0, 20(r1) + stw r3, 8(r1) + stw r4, 12(r1) + get_datapage r5, r0 + bl \funct + lwz r0, 20(r1) + cmpwi r3, 0 + mtlr r0 + bne- 99f + addi r1, r1, 16 + crclr so + blr +99: + lwz r3, 8(r1) + lwz r4, 12(r1) + li r0, \syscall + addi r1, r1, 16 + sc + blr +.endm + /* * Exact prototype of gettimeofday * @@ -29,31 +47,7 @@ */ V_FUNCTION_BEGIN(__kernel_gettimeofday) .cfi_startproc - mflr r12 - .cfi_register lr,r12 - - mr r10,r3 /* r10 saves tv */ - mr r11,r4 /* r11 saves tz */ - get_datapage r9, r0 - cmplwi r10,0 /* check if tv is NULL */ - beq 3f - lis r7,1000000@ha /* load up USEC_PER_SEC */ - addi r7,r7,1000000@l /* so we get microseconds in r4 */ - bl __do_get_tspec@local /* get sec/usec from tb & kernel */ - stw r3,TVAL32_TV_SEC(r10) - stw r4,TVAL32_TV_USEC(r10) - -3: cmplwi r11,0 /* check if tz is NULL */ - beq 1f - lwz r4,CFG_TZ_MINUTEWEST(r9)/* fill tz */ - lwz r5,CFG_TZ_DSTTIME(r9) - stw r4,TZONE_TZ_MINWEST(r11) - stw r5,TZONE_TZ_DSTTIME(r11) - -1: mtlr r12 - crclr cr0*4+so - li r3,0 - blr + cvdso_call_with_fallback __c_kernel_gettimeofday, __NR_gettimeofday .cfi_endproc V_FUNCTION_END(__kernel_gettimeofday) @@ -65,76 +59,7 @@ V_FUNCTION_END(__kernel_gettimeofday) */ V_FUNCTION_BEGIN(__kernel_clock_gettime) .cfi_startproc - /* Check for supported clock IDs */ - cmpli cr0,r3,CLOCK_REALTIME - cmpli cr1,r3,CLOCK_MONOTONIC - cror cr0*4+eq,cr0*4+eq,cr1*4+eq - bne cr0,99f - - mflr r12 /* r12 saves lr */ - .cfi_register lr,r12 - mr r11,r4 /* r11 saves tp */ - get_datapage r9, r0 - lis r7,NSEC_PER_SEC@h /* want nanoseconds */ - ori r7,r7,NSEC_PER_SEC@l -50: bl __do_get_tspec@local /* get sec/nsec from tb & kernel */ - bne cr1,80f /* not monotonic -> all done */ - - /* - * CLOCK_MONOTONIC - */ - - /* now we must fixup using wall to monotonic. We need to snapshot - * that value and do the counter trick again. Fortunately, we still - * have the counter value in r8 that was returned by __do_get_xsec. - * At this point, r3,r4 contain our sec/nsec values, r5 and r6 - * can be used, r7 contains NSEC_PER_SEC. - */ - - lwz r5,(WTOM_CLOCK_SEC+LOPART)(r9) - lwz r6,WTOM_CLOCK_NSEC(r9) - - /* We now have our offset in r5,r6. We create a fake dependency - * on that value and re-check the counter - */ - or r0,r6,r5 - xor r0,r0,r0 - add r9,r9,r0 - lwz r0,(CFG_TB_UPDATE_COUNT+LOPART)(r9) - cmpl cr0,r8,r0 /* check if updated */ - bne- 50b - - /* Calculate and store result. Note that this mimics the C code, - * which may cause funny results if nsec goes negative... is that - * possible at all ? - */ - add r3,r3,r5 - add r4,r4,r6 - cmpw cr0,r4,r7 - cmpwi cr1,r4,0 - blt 1f - subf r4,r7,r4 - addi r3,r3,1 -1: bge cr1,80f - addi r3,r3,-1 - add r4,r4,r7 - -80: stw r3,TSPC32_TV_SEC(r11) - stw r4,TSPC32_TV_NSEC(r11) - - mtlr r12 - crclr cr0*4+so - li r3,0 - blr - - /* - * syscall fallback - */ -99: - li r0,__NR_clock_gettime - .cfi_restore lr - sc - blr + cvdso_call_with_fallback __c_kernel_clock_gettime, __NR_clock_gettime .cfi_endproc V_FUNCTION_END(__kernel_clock_gettime) @@ -147,32 +72,7 @@ V_FUNCTION_END(__kernel_clock_gettime) */ V_FUNCTION_BEGIN(__kernel_clock_getres) .cfi_startproc - /* Check for supported clock IDs */ - cmpwi cr0,r3,CLOCK_REALTIME - cmpwi cr1,r3,CLOCK_MONOTONIC - cror cr0*4+eq,cr0*4+eq,cr1*4+eq - bne cr0,99f - - mflr r12 - .cfi_register lr,r12 - get_datapage r3, r0 - lwz r5, CLOCK_HRTIMER_RES(r3) - mtlr r12 - li r3,0 - cmpli cr0,r4,0 - crclr cr0*4+so - beqlr - stw r3,TSPC32_TV_SEC(r4) - stw r5,TSPC32_TV_NSEC(r4) - blr - - /* - * syscall fallback - */ -99: - li r0,__NR_clock_getres - sc - blr + cvdso_call_with_fallback __c_kernel_clock_getres, __NR_clock_getres .cfi_endproc V_FUNCTION_END(__kernel_clock_getres) @@ -185,104 +85,15 @@ V_FUNCTION_END(__kernel_clock_getres) */ V_FUNCTION_BEGIN(__kernel_time) .cfi_startproc - mflr r12 - .cfi_register lr,r12 - - mr r11,r3 /* r11 holds t */ - get_datapage r9, r0 - - lwz r3,STAMP_XTIME_SEC+LOPART(r9) - - cmplwi r11,0 /* check if t is NULL */ - beq 2f - stw r3,0(r11) /* store result at *t */ -2: mtlr r12 + stwu r1, -16(r1) + mflr r0 + stw r0, 20(r1) + get_datapage r4, r0 + bl __c_kernel_time + lwz r0, 20(r1) crclr cr0*4+so + mtlr r0 + addi r1, r1, 16 blr .cfi_endproc V_FUNCTION_END(__kernel_time) - -/* - * This is the core of clock_gettime() and gettimeofday(), - * it returns the current time in r3 (seconds) and r4. - * On entry, r7 gives the resolution of r4, either USEC_PER_SEC - * or NSEC_PER_SEC, giving r4 in microseconds or nanoseconds. - * It expects the datapage ptr in r9 and doesn't clobber it. - * It clobbers r0, r5 and r6. - * On return, r8 contains the counter value that can be reused. - * This clobbers cr0 but not any other cr field. - */ -__do_get_tspec: - .cfi_startproc - /* Check for update count & load values. We use the low - * order 32 bits of the update count - */ -1: lwz r8,(CFG_TB_UPDATE_COUNT+LOPART)(r9) - andi. r0,r8,1 /* pending update ? loop */ - bne- 1b - xor r0,r8,r8 /* create dependency */ - add r9,r9,r0 - - /* Load orig stamp (offset to TB) */ - lwz r5,CFG_TB_ORIG_STAMP(r9) - lwz r6,(CFG_TB_ORIG_STAMP+4)(r9) - - /* Get a stable TB value */ -2: MFTBU(r3) - MFTBL(r4) - MFTBU(r0) - cmplw cr0,r3,r0 - bne- 2b - - /* Subtract tb orig stamp and shift left 12 bits. - */ - subfc r4,r6,r4 - subfe r0,r5,r3 - slwi r0,r0,12 - rlwimi. r0,r4,12,20,31 - slwi r4,r4,12 - - /* - * Load scale factor & do multiplication. - * We only use the high 32 bits of the tb_to_xs value. - * Even with a 1GHz timebase clock, the high 32 bits of - * tb_to_xs will be at least 4 million, so the error from - * ignoring the low 32 bits will be no more than 0.25ppm. - * The error will just make the clock run very very slightly - * slow until the next time the kernel updates the VDSO data, - * at which point the clock will catch up to the kernel's value, - * so there is no long-term error accumulation. - */ - lwz r5,CFG_TB_TO_XS(r9) /* load values */ - mulhwu r4,r4,r5 - li r3,0 - - beq+ 4f /* skip high part computation if 0 */ - mulhwu r3,r0,r5 - mullw r5,r0,r5 - addc r4,r4,r5 - addze r3,r3 -4: - /* At this point, we have seconds since the xtime stamp - * as a 32.32 fixed-point number in r3 and r4. - * Load & add the xtime stamp. - */ - lwz r5,STAMP_XTIME_SEC+LOPART(r9) - lwz r6,STAMP_SEC_FRAC(r9) - addc r4,r4,r6 - adde r3,r3,r5 - - /* We create a fake dependency on the result in r3/r4 - * and re-check the counter - */ - or r6,r4,r3 - xor r0,r6,r6 - add r9,r9,r0 - lwz r0,(CFG_TB_UPDATE_COUNT+LOPART)(r9) - cmplw cr0,r8,r0 /* check if updated */ - bne- 1b - - mulhwu r4,r4,r7 /* convert to micro or nanoseconds */ - - blr - .cfi_endproc diff --git a/arch/powerpc/kernel/vdso32/vgettimeofday.c b/arch/powerpc/kernel/vdso32/vgettimeofday.c new file mode 100644 index 000000000000..290b4415bf85 --- /dev/null +++ b/arch/powerpc/kernel/vdso32/vgettimeofday.c @@ -0,0 +1,32 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * ARM64 userspace implementations of gettimeofday() and similar. + * + * Copyright (C) 2018 ARM Limited + * + */ +#include +#include + +int __c_kernel_clock_gettime(clockid_t clock, struct old_timespec32 *ts, + const struct vdso_data *vd) +{ + return __cvdso_clock_gettime32(vd, clock, ts); +} + +int __c_kernel_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz, + const struct vdso_data *vd) +{ + return __cvdso_gettimeofday(vd, tv, tz); +} + +int __c_kernel_clock_getres(clockid_t clock_id, struct old_timespec32 *res, + const struct vdso_data *vd) +{ + return __cvdso_clock_getres_time32(vd, clock_id, res); +} + +time_t __c_kernel_time(time_t *time, const struct vdso_data *vd) +{ + return __cvdso_time(vd, time); +}