| Message ID | 20241214043510.3795984-1-guoren@kernel.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | riscv: Add riscv_force_qspinlock for early_param | expand |
Hi Guo, On 14/12/2024 05:35, guoren@kernel.org wrote: > From: Guo Ren <guoren@linux.alibaba.com> > > When CONFIG_RISCV_COMBO_SPINLOCKS is enabled, permit qspinlock > force enabled. See the Kconfig entry for RISCV_COMBO_SPINLOCKS. > > Signed-off-by: Guo Ren <guoren@linux.alibaba.com> > Signed-off-by: Guo Ren <guoren@kernel.org> > --- > Documentation/admin-guide/kernel-parameters.txt | 5 +++++ > arch/riscv/kernel/setup.c | 13 ++++++++++++- > 2 files changed, 17 insertions(+), 1 deletion(-) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index 3872bc6ec49d..43d0df2922b2 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -5887,6 +5887,11 @@ > [KNL] Disable ring 3 MONITOR/MWAIT feature on supported > CPUs. > > + riscv_force_qspinlock [RISCV, EARLY] > + When CONFIG_RISCV_COMBO_SPINLOCKS is enabled, permit > + qspinlock force enabled. See the Kconfig entry for > + RISCV_COMBO_SPINLOCKS. > + > riscv_isa_fallback [RISCV,EARLY] > When CONFIG_RISCV_ISA_FALLBACK is not enabled, permit > falling back to detecting extension support by parsing > diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c > index 45010e71df86..74b13bc64c9c 100644 > --- a/arch/riscv/kernel/setup.c > +++ b/arch/riscv/kernel/setup.c > @@ -247,6 +247,15 @@ static void __init parse_dtb(void) > #if defined(CONFIG_RISCV_COMBO_SPINLOCKS) > DEFINE_STATIC_KEY_TRUE(qspinlock_key); > EXPORT_SYMBOL(qspinlock_key); > + > +static bool force_qspinlock; > + > +static int __init riscv_force_qspinlock(char *p) > +{ > + force_qspinlock = true; > + return 0; > +} > +early_param("riscv_force_qspinlock", riscv_force_qspinlock); > #endif > > static void __init riscv_spinlock_init(void) > @@ -267,7 +276,9 @@ static void __init riscv_spinlock_init(void) > using_ext = "using Ziccrse"; > } > #if defined(CONFIG_RISCV_COMBO_SPINLOCKS) > - else { > + else if (force_qspinlock) { > + using_ext = "force"; > + } else { > static_branch_disable(&qspinlock_key); > pr_info("Ticket spinlock: enabled\n"); > return; What's the use case for this early param? To me that implies that a platform may have another extension which would allow the usage of qspinlock, so why not listing it in riscv_spinlock_init() instead? Thanks, Alex
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 3872bc6ec49d..43d0df2922b2 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -5887,6 +5887,11 @@ [KNL] Disable ring 3 MONITOR/MWAIT feature on supported CPUs. + riscv_force_qspinlock [RISCV, EARLY] + When CONFIG_RISCV_COMBO_SPINLOCKS is enabled, permit + qspinlock force enabled. See the Kconfig entry for + RISCV_COMBO_SPINLOCKS. + riscv_isa_fallback [RISCV,EARLY] When CONFIG_RISCV_ISA_FALLBACK is not enabled, permit falling back to detecting extension support by parsing diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c index 45010e71df86..74b13bc64c9c 100644 --- a/arch/riscv/kernel/setup.c +++ b/arch/riscv/kernel/setup.c @@ -247,6 +247,15 @@ static void __init parse_dtb(void) #if defined(CONFIG_RISCV_COMBO_SPINLOCKS) DEFINE_STATIC_KEY_TRUE(qspinlock_key); EXPORT_SYMBOL(qspinlock_key); + +static bool force_qspinlock; + +static int __init riscv_force_qspinlock(char *p) +{ + force_qspinlock = true; + return 0; +} +early_param("riscv_force_qspinlock", riscv_force_qspinlock); #endif static void __init riscv_spinlock_init(void) @@ -267,7 +276,9 @@ static void __init riscv_spinlock_init(void) using_ext = "using Ziccrse"; } #if defined(CONFIG_RISCV_COMBO_SPINLOCKS) - else { + else if (force_qspinlock) { + using_ext = "force"; + } else { static_branch_disable(&qspinlock_key); pr_info("Ticket spinlock: enabled\n"); return;