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| author | Nicholas Piggin <npiggin@gmail.com> | 2017-05-22 15:53:00 +1000 |
|---|---|---|
| committer | Stewart Smith <stewart@linux.vnet.ibm.com> | 2017-06-06 20:49:06 +1000 |
| commit | 38b0c8454b56a74fe785f0db1d218afa8f6ea478 (patch) | |
| tree | 2371fcb67e716a7cd16016031cd3554d1afddede | |
| parent | 41b14f9452c25f3dd74a8304763a3cc58bff019f (diff) | |
| download | skiboot-38b0c8454b56a74fe785f0db1d218afa8f6ea478.zip skiboot-38b0c8454b56a74fe785f0db1d218afa8f6ea478.tar.gz skiboot-38b0c8454b56a74fe785f0db1d218afa8f6ea478.tar.bz2 | |
cpu: Introduce smt_lowest()
Recent CPUs have introduced a lower SMT priority. This uses the
Linux pattern of executing priority nops in descending order to
get a simple portable way to put the CPU into lowest SMT priority.
Introduce smt_lowest() and use it in place of smt_very_low and
smt_low ; smt_very_low sequences.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>
| -rw-r--r-- | asm/head.S | 6 | ||||
| -rw-r--r-- | core/cpu.c | 2 | ||||
| -rw-r--r-- | core/fast-reboot.c | 6 | ||||
| -rw-r--r-- | include/cpu.h | 3 | ||||
| -rw-r--r-- | include/processor.h | 2 |
5 files changed, 10 insertions, 9 deletions
@@ -398,7 +398,7 @@ secondary_wait: */ LOAD_IMM32(%r3, boot_flag - __head) add %r3,%r3,%r30 -1: smt_very_low +1: smt_lowest lwz %r0,0(%r3) cmpdi %r0,0 beq 1b @@ -416,7 +416,7 @@ secondary_wait: 1: /* Now wait for cpu_secondary_start to be set */ LOAD_ADDR_FROM_TOC(%r3, cpu_secondary_start) -1: smt_very_low +1: smt_lowest ld %r0,0(%r3) cmpdi %r0,0 beq 1b @@ -441,7 +441,7 @@ secondary_wait: /* Not found... what to do ? set some global error ? */ secondary_not_found: - smt_very_low + smt_lowest b . call_relocate: @@ -871,7 +871,7 @@ void cpu_bringup(void) /* Add a callin timeout ? If so, call cpu_remove_node(t). */ while (t->state != cpu_state_active) { - smt_very_low(); + smt_lowest(); sync(); } smt_medium(); diff --git a/core/fast-reboot.c b/core/fast-reboot.c index 41e87e3..b99eb99 100644 --- a/core/fast-reboot.c +++ b/core/fast-reboot.c @@ -488,7 +488,7 @@ void __noreturn fast_reboot_entry(void) if (this_cpu() != boot_cpu) { this_cpu()->state = cpu_state_present; while (!fast_boot_release) { - smt_very_low(); + smt_lowest(); sync(); } smt_medium(); @@ -511,7 +511,7 @@ void __noreturn fast_reboot_entry(void) /* XXX Add a callin timeout ? */ while (cpu->state != cpu_state_present) { - smt_very_low(); + smt_lowest(); sync(); } smt_medium(); @@ -534,7 +534,7 @@ void __noreturn fast_reboot_entry(void) /* XXX Add a callin timeout ? */ while (cpu->state == cpu_state_present) { - smt_very_low(); + smt_lowest(); sync(); } } diff --git a/include/cpu.h b/include/cpu.h index 1e147aa..938492e 100644 --- a/include/cpu.h +++ b/include/cpu.h @@ -121,8 +121,7 @@ extern struct cpu_thread *boot_cpu; static inline void __nomcount cpu_relax(void) { /* Relax a bit to give sibling threads some breathing space */ - smt_low(); - smt_very_low(); + smt_lowest(); asm volatile("nop; nop; nop; nop;\n" "nop; nop; nop; nop;\n" "nop; nop; nop; nop;\n" diff --git a/include/processor.h b/include/processor.h index b98dff8..5906b86 100644 --- a/include/processor.h +++ b/include/processor.h @@ -197,6 +197,7 @@ #define smt_medium_low or 6,6,6 #define smt_extra_high or 7,7,7 #define smt_very_low or 31,31,31 +#define smt_lowest smt_low ; smt_very_low #else /* __ASSEMBLY__ */ @@ -214,6 +215,7 @@ static inline void smt_medium_high(void){ asm volatile("or 5,5,5"); } static inline void smt_medium_low(void) { asm volatile("or 6,6,6"); } static inline void smt_extra_high(void) { asm volatile("or 7,7,7"); } static inline void smt_very_low(void) { asm volatile("or 31,31,31"); } +static inline void smt_lowest(void) { smt_low(); smt_very_low(); } /* * SPR access functions |