diff options
| author | Nicholas Piggin <npiggin@gmail.com> | 2017-10-24 21:44:44 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-11-10 22:11:35 +1100 |
| commit | 1696d0fb7fcd18160c9cc92a3f2b2d68e6923dd8 (patch) | |
| tree | 1f2788739eba799f1a06e5d5ec17328b758d27c0 /arch/powerpc/kernel | |
| parent | 339a3293f4e493a6c40f71e4faab0c8389174313 (diff) | |
| download | linux-1696d0fb7fcd18160c9cc92a3f2b2d68e6923dd8.tar.bz2 | |
powerpc/64: Set DSCR default initially from SPR
Take the DSCR value set by firmware as the dscr_default value,
rather than zero.
POWER9 recommends DSCR default to a non-zero value.
Signed-off-by: From: Nicholas Piggin <npiggin@gmail.com>
[mpe: Make record_spr_defaults() __init]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kernel')
| -rw-r--r-- | arch/powerpc/kernel/setup.h | 6 | ||||
| -rw-r--r-- | arch/powerpc/kernel/setup_64.c | 9 | ||||
| -rw-r--r-- | arch/powerpc/kernel/sysfs.c | 11 |
3 files changed, 26 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/setup.h b/arch/powerpc/kernel/setup.h index cfba134b3024..21c18071d9d5 100644 --- a/arch/powerpc/kernel/setup.h +++ b/arch/powerpc/kernel/setup.h @@ -45,6 +45,12 @@ void emergency_stack_init(void); static inline void emergency_stack_init(void) { }; #endif +#ifdef CONFIG_PPC64 +void record_spr_defaults(void); +#else +static inline void record_spr_defaults(void) { }; +#endif + /* * Having this in kvm_ppc.h makes include dependencies too * tricky to solve for setup-common.c so have it here. diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c index 87b4fe75fd45..8956a9856604 100644 --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -69,6 +69,8 @@ #include <asm/opal.h> #include <asm/cputhreads.h> +#include "setup.h" + #ifdef DEBUG #define DBG(fmt...) udbg_printf(fmt) #else @@ -317,6 +319,13 @@ void __init early_setup(unsigned long dt_ptr) early_init_mmu(); /* + * After firmware and early platform setup code has set things up, + * we note the SPR values for configurable control/performance + * registers, and use those as initial defaults. + */ + record_spr_defaults(); + + /* * At this point, we can let interrupts switch to virtual mode * (the MMU has been setup), so adjust the MSR in the PACA to * have IR and DR set and enable AIL if it exists diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c index 4437c70c7c2b..b8d4a1dac39f 100644 --- a/arch/powerpc/kernel/sysfs.c +++ b/arch/powerpc/kernel/sysfs.c @@ -590,6 +590,17 @@ static void sysfs_create_dscr_default(void) if (cpu_has_feature(CPU_FTR_DSCR)) err = device_create_file(cpu_subsys.dev_root, &dev_attr_dscr_default); } + +void __init record_spr_defaults(void) +{ + int cpu; + + if (cpu_has_feature(CPU_FTR_DSCR)) { + dscr_default = mfspr(SPRN_DSCR); + for (cpu = 0; cpu < nr_cpu_ids; cpu++) + paca[cpu].dscr_default = dscr_default; + } +} #endif /* CONFIG_PPC64 */ #ifdef HAS_PPC_PMC_PA6T |