[PATCH 1/2] sparc64: Add a new hypercall CPU_POKE

From: Vijay Kumar
Date: Sat Jul 08 2017 - 16:24:34 EST


This adds a new hypercall CPU_POKE for quickly waking up an idle CPU.
CPU POKE should only be sent to valid non-local CPUs.

Signed-off-by: Rob Gardner <rob.gardner@xxxxxxxxxx>
Signed-off-by: Vijay Kumar <vijay.ac.kumar@xxxxxxxxxx>
Reviewed-by: Anthony Yznaga <anthony.yznaga@xxxxxxxxxx>
---
arch/sparc/include/asm/hypervisor.h | 18 ++++++++++++++++++
arch/sparc/kernel/hvcalls.S | 11 +++++++++++
2 files changed, 29 insertions(+), 0 deletions(-)

diff --git a/arch/sparc/include/asm/hypervisor.h b/arch/sparc/include/asm/hypervisor.h
index 73cb897..3dc9215 100644
--- a/arch/sparc/include/asm/hypervisor.h
+++ b/arch/sparc/include/asm/hypervisor.h
@@ -298,6 +298,24 @@ unsigned long sun4v_cpu_start(unsigned long cpuid,
unsigned long sun4v_cpu_yield(void);
#endif

+/* cpu_poke()
+ * TRAP: HV_FAST_TRAP
+ * FUNCTION: HV_FAST_CPU_POKE
+ * RET0: status
+ * ERRORS: ENOCPU cpuid refers to a CPU that does not exist
+ * EINVAL cpuid is current CPU
+ *
+ * Poke CPU cpuid. If the target CPU is currently suspended having
+ * invoked the cpu-yield service, that vCPU will be resumed.
+ * Poke interrupts may only be sent to valid, non-local CPUs.
+ * It is not legal to poke the current vCPU.
+ */
+#define HV_FAST_CPU_POKE 0x13
+
+#ifndef __ASSEMBLY__
+unsigned long sun4v_cpu_poke(unsigned long cpuid);
+#endif
+
/* cpu_qconf()
* TRAP: HV_FAST_TRAP
* FUNCTION: HV_FAST_CPU_QCONF
diff --git a/arch/sparc/kernel/hvcalls.S b/arch/sparc/kernel/hvcalls.S
index 4116ee5..e57007f 100644
--- a/arch/sparc/kernel/hvcalls.S
+++ b/arch/sparc/kernel/hvcalls.S
@@ -106,6 +106,17 @@ ENTRY(sun4v_cpu_yield)
nop
ENDPROC(sun4v_cpu_yield)

+ /* %o0: cpuid
+ *
+ * returns %o0: status
+ */
+ENTRY(sun4v_cpu_poke)
+ mov HV_FAST_CPU_POKE, %o5
+ ta HV_FAST_TRAP
+ retl
+ nop
+ENDPROC(sun4v_cpu_poke)
+
/* %o0: type
* %o1: queue paddr
* %o2: num queue entries
--
1.7.1