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Subject[tip: sched/core] cpuidle, xenpv: Make more PARAVIRT_XXL noinstr clean
The following commit has been merged into the sched/core branch of tip:

Commit-ID: 10a099405fdf96c3205ae775abf19fcd301b31b4
Gitweb: https://git.kernel.org/tip/10a099405fdf96c3205ae775abf19fcd301b31b4
Author: Peter Zijlstra <peterz@infradead.org>
AuthorDate: Thu, 12 Jan 2023 20:43:44 +01:00
Committer: Ingo Molnar <mingo@kernel.org>
CommitterDate: Fri, 13 Jan 2023 11:48:16 +01:00

cpuidle, xenpv: Make more PARAVIRT_XXL noinstr clean

objtool found a few cases where this code called out into instrumented
code:

vmlinux.o: warning: objtool: acpi_idle_enter_s2idle+0xde: call to wbinvd() leaves .noinstr.text section
vmlinux.o: warning: objtool: default_idle+0x4: call to arch_safe_halt() leaves .noinstr.text section
vmlinux.o: warning: objtool: xen_safe_halt+0xa: call to HYPERVISOR_sched_op.constprop.0() leaves .noinstr.text section

Solve this by:

- marking arch_safe_halt(), wbinvd(), native_wbinvd() and
HYPERVISOR_sched_op() as __always_inline().

- Explicitly uninlining xen_safe_halt() and pv_native_wbinvd() [they were
already uninlined by the compiler on use as function pointers] and
annotating them as 'noinstr'.

- Annotating pv_native_safe_halt() as 'noinstr'.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Srivatsa S. Bhat (VMware) <srivatsa@csail.mit.edu>
Reviewed-by: Juergen Gross <jgross@suse.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230112195541.171918174@infradead.org
---
arch/x86/include/asm/paravirt.h | 6 ++++--
arch/x86/include/asm/special_insns.h | 4 ++--
arch/x86/include/asm/xen/hypercall.h | 2 +-
arch/x86/kernel/paravirt.c | 14 ++++++++++++--
arch/x86/xen/enlighten_pv.c | 2 +-
arch/x86/xen/irq.c | 2 +-
6 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index 73e9522..86c9d83 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -168,7 +168,7 @@ static inline void __write_cr4(unsigned long x)
PVOP_VCALL1(cpu.write_cr4, x);
}

-static inline void arch_safe_halt(void)
+static __always_inline void arch_safe_halt(void)
{
PVOP_VCALL0(irq.safe_halt);
}
@@ -178,7 +178,9 @@ static inline void halt(void)
PVOP_VCALL0(irq.halt);
}

-static inline void wbinvd(void)
+extern noinstr void pv_native_wbinvd(void);
+
+static __always_inline void wbinvd(void)
{
PVOP_ALT_VCALL0(cpu.wbinvd, "wbinvd", ALT_NOT(X86_FEATURE_XENPV));
}
diff --git a/arch/x86/include/asm/special_insns.h b/arch/x86/include/asm/special_insns.h
index 54621e7..f358a23 100644
--- a/arch/x86/include/asm/special_insns.h
+++ b/arch/x86/include/asm/special_insns.h
@@ -115,7 +115,7 @@ static inline void wrpkru(u32 pkru)
}
#endif

-static inline void native_wbinvd(void)
+static __always_inline void native_wbinvd(void)
{
asm volatile("wbinvd": : :"memory");
}
@@ -179,7 +179,7 @@ static inline void __write_cr4(unsigned long x)
native_write_cr4(x);
}

-static inline void wbinvd(void)
+static __always_inline void wbinvd(void)
{
native_wbinvd();
}
diff --git a/arch/x86/include/asm/xen/hypercall.h b/arch/x86/include/asm/xen/hypercall.h
index e5e0fe1..a2dd249 100644
--- a/arch/x86/include/asm/xen/hypercall.h
+++ b/arch/x86/include/asm/xen/hypercall.h
@@ -382,7 +382,7 @@ MULTI_stack_switch(struct multicall_entry *mcl,
}
#endif

-static inline int
+static __always_inline int
HYPERVISOR_sched_op(int cmd, void *arg)
{
return _hypercall2(int, sched_op, cmd, arg);
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index 327757a..5bf4f0b 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -216,6 +216,11 @@ static noinstr void pv_native_set_debugreg(int regno, unsigned long val)
native_set_debugreg(regno, val);
}

+noinstr void pv_native_wbinvd(void)
+{
+ native_wbinvd();
+}
+
static noinstr void pv_native_irq_enable(void)
{
native_irq_enable();
@@ -225,6 +230,11 @@ static noinstr void pv_native_irq_disable(void)
{
native_irq_disable();
}
+
+static noinstr void pv_native_safe_halt(void)
+{
+ native_safe_halt();
+}
#endif

enum paravirt_lazy_mode paravirt_get_lazy_mode(void)
@@ -256,7 +266,7 @@ struct paravirt_patch_template pv_ops = {
.cpu.read_cr0 = native_read_cr0,
.cpu.write_cr0 = native_write_cr0,
.cpu.write_cr4 = native_write_cr4,
- .cpu.wbinvd = native_wbinvd,
+ .cpu.wbinvd = pv_native_wbinvd,
.cpu.read_msr = native_read_msr,
.cpu.write_msr = native_write_msr,
.cpu.read_msr_safe = native_read_msr_safe,
@@ -290,7 +300,7 @@ struct paravirt_patch_template pv_ops = {
.irq.save_fl = __PV_IS_CALLEE_SAVE(native_save_fl),
.irq.irq_disable = __PV_IS_CALLEE_SAVE(pv_native_irq_disable),
.irq.irq_enable = __PV_IS_CALLEE_SAVE(pv_native_irq_enable),
- .irq.safe_halt = native_safe_halt,
+ .irq.safe_halt = pv_native_safe_halt,
.irq.halt = native_halt,
#endif /* CONFIG_PARAVIRT_XXL */

diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index 5b13796..5cacd48 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -1068,7 +1068,7 @@ static const typeof(pv_ops) xen_cpu_ops __initconst = {

.write_cr4 = xen_write_cr4,

- .wbinvd = native_wbinvd,
+ .wbinvd = pv_native_wbinvd,

.read_msr = xen_read_msr,
.write_msr = xen_write_msr,
diff --git a/arch/x86/xen/irq.c b/arch/x86/xen/irq.c
index 06c3c2f..6092fea 100644
--- a/arch/x86/xen/irq.c
+++ b/arch/x86/xen/irq.c
@@ -24,7 +24,7 @@ noinstr void xen_force_evtchn_callback(void)
(void)HYPERVISOR_xen_version(0, NULL);
}

-static void xen_safe_halt(void)
+static noinstr void xen_safe_halt(void)
{
/* Blocking includes an implicit local_irq_enable(). */
if (HYPERVISOR_sched_op(SCHEDOP_block, NULL) != 0)
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