Author: cem
Date: Sat May 4 17:35:13 2019
New Revision: 347129
URL: https://svnweb.freebsd.org/changeset/base/347129
Log:
x86: Define pc_monitorbuf as a logical structure
Rather than just accessing it via pointer cast.
No functional change intended.
Discussed with: kib (earlier version)
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D20135
Modified:
head/sys/amd64/include/pcpu.h
head/sys/i386/include/pcpu.h
head/sys/x86/x86/cpu_machdep.c
Modified: head/sys/amd64/include/pcpu.h
==============================================================================
--- head/sys/amd64/include/pcpu.h Sat May 4 16:27:58 2019 (r347128)
+++ head/sys/amd64/include/pcpu.h Sat May 4 17:35:13 2019 (r347129)
@@ -36,6 +36,13 @@
#endif
#define PC_PTI_STACK_SZ 16
+
+struct monitorbuf {
+ int idle_state; /* Used by cpu_idle_mwait. */
+ char padding[128 - (1 * sizeof(int))];
+};
+_Static_assert(sizeof(struct monitorbuf) == 128, "2x cache line");
+
/*
* The SMP parts are setup in pmap.c and locore.s for the BSP, and
* mp_machdep.c sets up the data for the AP's to "see" when they awake.
@@ -44,7 +51,7 @@
* other processors"
*/
#define PCPU_MD_FIELDS \
- char pc_monitorbuf[128] __aligned(128); /* cache line */ \
+ struct monitorbuf pc_monitorbuf __aligned(128); /* cache line */\
struct pcpu *pc_prvspace; /* Self-reference */ \
struct pmap *pc_curpmap; \
struct amd64tss *pc_tssp; /* TSS segment active on CPU */ \
Modified: head/sys/i386/include/pcpu.h
==============================================================================
--- head/sys/i386/include/pcpu.h Sat May 4 16:27:58 2019 (r347128)
+++ head/sys/i386/include/pcpu.h Sat May 4 17:35:13 2019 (r347129)
@@ -41,6 +41,12 @@
#include <sys/_lock.h>
#include <sys/_mutex.h>
+struct monitorbuf {
+ int idle_state; /* Used by cpu_idle_mwait. */
+ char padding[128 - (1 * sizeof(int))];
+};
+_Static_assert(sizeof(struct monitorbuf) == 128, "2x cache line");
+
/*
* The SMP parts are setup in pmap.c and machdep.c for the BSP, and
* pmap.c and mp_machdep.c sets up the data for the AP's to "see" when
@@ -50,7 +56,7 @@
*/
#define PCPU_MD_FIELDS \
- char pc_monitorbuf[128] __aligned(128); /* cache line */ \
+ struct monitorbuf pc_monitorbuf __aligned(128); /* cache line */\
struct pcpu *pc_prvspace; /* Self-reference */ \
struct pmap *pc_curpmap; \
struct segment_descriptor pc_common_tssd; \
Modified: head/sys/x86/x86/cpu_machdep.c
==============================================================================
--- head/sys/x86/x86/cpu_machdep.c Sat May 4 16:27:58 2019 (r347128)
+++ head/sys/x86/x86/cpu_machdep.c Sat May 4 17:35:13 2019 (r347129)
@@ -164,7 +164,7 @@ acpi_cpu_idle_mwait(uint32_t mwait_hint)
* but all Intel CPUs provide hardware coordination.
*/
- state = (int *)PCPU_PTR(monitorbuf);
+ state = &PCPU_PTR(monitorbuf)->idle_state;
KASSERT(atomic_load_int(state) == STATE_SLEEPING,
("cpu_mwait_cx: wrong monitorbuf state"));
atomic_store_int(state, STATE_MWAIT);
@@ -422,7 +422,7 @@ cpu_idle_acpi(sbintime_t sbt)
{
int *state;
- state = (int *)PCPU_PTR(monitorbuf);
+ state = &PCPU_PTR(monitorbuf)->idle_state;
atomic_store_int(state, STATE_SLEEPING);
/* See comments in cpu_idle_hlt(). */
@@ -441,7 +441,7 @@ cpu_idle_hlt(sbintime_t sbt)
{
int *state;
- state = (int *)PCPU_PTR(monitorbuf);
+ state = &PCPU_PTR(monitorbuf)->idle_state;
atomic_store_int(state, STATE_SLEEPING);
/*
@@ -473,7 +473,7 @@ cpu_idle_mwait(sbintime_t sbt)
{
int *state;
- state = (int *)PCPU_PTR(monitorbuf);
+ state = &PCPU_PTR(monitorbuf)->idle_state;
atomic_store_int(state, STATE_MWAIT);
/* See comments in cpu_idle_hlt(). */
@@ -498,7 +498,7 @@ cpu_idle_spin(sbintime_t sbt)
int *state;
int i;
- state = (int *)PCPU_PTR(monitorbuf);
+ state = &PCPU_PTR(monitorbuf)->idle_state;
atomic_store_int(state, STATE_RUNNING);
/*
@@ -598,9 +598,11 @@ SYSCTL_INT(_machdep, OID_AUTO, idle_apl31, CTLFLAG_RW,
int
cpu_idle_wakeup(int cpu)
{
+ struct monitorbuf *mb;
int *state;
- state = (int *)pcpu_find(cpu)->pc_monitorbuf;
+ mb = &pcpu_find(cpu)->pc_monitorbuf;
+ state = &mb->idle_state;
switch (atomic_load_int(state)) {
case STATE_SLEEPING:
return (0);