[PATCH v3 17/46] perf/x86/intel/cmt: add uflag CMT_UF_NOLAZY_RMID

[David Carrillo-Cisneros]

This uflag allows user to specify that a rmid must be allocated at monr's
initialization or fail otherwise.

For this to work we split __pmonr_apply_uflags into reserve and apply
modes. The reserve mode will try to reserve a free rmid, and if successful,
the apply mode can proceed using the rmid previously reserved.

Signed-off-by: David Carrillo-Cisneros 
---
 arch/x86/events/intel/cmt.c | 116 +++-
 arch/x86/events/intel/cmt.h |   5 +-
 2 files changed, 109 insertions(+), 12 deletions(-)

diff --git a/arch/x86/events/intel/cmt.c b/arch/x86/events/intel/cmt.c
index 9421a3e..3883cb4 100644
--- a/arch/x86/events/intel/cmt.c
+++ b/arch/x86/events/intel/cmt.c
@@ -33,7 +33,8 @@ static unsigned int __min_max_rmid;   /* minimum max_rmid 
across all pkgs. */
 static struct monr *monr_hrchy_root;
 
 /* Flags for root monr and all its pmonrs while being monitored. */
-static enum cmt_user_flags root_monr_uflags = CMT_UF_HAS_USER;
+static enum cmt_user_flags root_monr_uflags =
+   CMT_UF_HAS_USER | CMT_UF_NOLAZY_RMID;
 
 /* Auxiliar flags */
 static enum cmt_user_flags *pkg_uflags_zeroes;
@@ -414,6 +415,7 @@ static void monr_dealloc(struct monr *monr)
u16 p, nr_pkgs = topology_max_packages();
 
if (WARN_ON_ONCE(monr->nr_has_user) ||
+   WARN_ON_ONCE(monr->nr_nolazy_rmid) ||
WARN_ON_ONCE(monr->mon_events))
return;
 
@@ -478,11 +480,28 @@ static enum cmt_user_flags pmonr_uflags(struct pmonr 
*pmonr)
return monr->uflags | monr->pkg_uflags[pmonr->pkgd->pkgid];
 }
 
+/*
+ * Callable in two modes:
+ *   1) @reserve == true: will check if uflags are applicable and store in
+ *   @res_rmid the "reserved" rmid.
+ *   2) @reserve == false: will apply pmonr_uflags using the rmid stored in
+ *   @res_rmid rmid (if any). Cannot fail.
+ */
 static int __pmonr_apply_uflags(struct pmonr *pmonr,
-   enum cmt_user_flags pmonr_uflags)
+   enum cmt_user_flags pmonr_uflags, bool reserve, u32 *res_rmid)
 {
+   struct pkg_data *pkgd = pmonr->pkgd;
+   u32 free_rmid;
+
+   if (WARN_ON_ONCE(!res_rmid))
+   return -EINVAL;
+   if (WARN_ON_ONCE(reserve && *res_rmid != INVALID_RMID))
+   return -EINVAL;
+
if (!(pmonr_uflags & CMT_UF_HAS_USER)) {
if (pmonr->state != PMONR_OFF) {
+   if (reserve)
+   return 0;
pmonr_to_unused(pmonr);
pmonr_unused_to_off(pmonr);
}
@@ -492,8 +511,40 @@ static int __pmonr_apply_uflags(struct pmonr *pmonr,
if (monr_is_root(pmonr->monr) && (~pmonr_uflags & root_monr_uflags))
return -EINVAL;
 
-   if (pmonr->state == PMONR_OFF)
-   pmonr_to_unused(pmonr);
+   if (pmonr->state == PMONR_OFF) {
+   if (!reserve)
+   pmonr_to_unused(pmonr);
+   }
+   if (pmonr->state == PMONR_ACTIVE)
+   return 0;
+   if (!(pmonr_uflags & CMT_UF_NOLAZY_RMID))
+   return 0;
+   if (pmonr->state == PMONR_DEP_DIRTY) {
+   if (!reserve)
+   pmonr_dep_dirty_to_active(pmonr);
+   return 0;
+   }
+
+   /*
+* At this point pmonr is in either Unused or Dep_Idle state and
+* needs a rmid to transition to Active.
+*/
+   if (reserve) {
+   free_rmid = find_first_bit(pkgd->free_rmids, CMT_MAX_NR_RMIDS);
+   if (free_rmid == CMT_MAX_NR_RMIDS)
+   return -ENOSPC;
+   *res_rmid = free_rmid;
+   __clear_bit(*res_rmid, pkgd->free_rmids);
+   return 0;
+   }
+
+   /* both cases use the reserved rmid. */
+   if (pmonr->state == PMONR_UNUSED) {
+   pmonr_unused_to_active(pmonr, *res_rmid);
+   } else {
+   WARN_ON_ONCE(pmonr->state != PMONR_DEP_IDLE);
+   pmonr_dep_idle_to_active(pmonr, *res_rmid);
+   }
 
return 0;
 }
@@ -514,7 +565,10 @@ static bool monr_has_user(struct monr *monr)
   pkg_uflags_has_user(monr->pkg_uflags);
 }
 
-static int __monr_apply_uflags(struct monr *monr, enum cmt_user_flags *puflags)
+static int __monr_apply_uflags(struct monr *monr,
+  enum cmt_user_flags *puflags,
+  bool reserve,
+  u32 *res_rmids)
 {
enum cmt_user_flags pmonr_uflags;
struct pkg_data *pkgd = NULL;
@@ -526,7 +580,10 @@ static int __monr_apply_uflags(struct monr *monr, enum 
cmt_user_flags *puflags)
pmonr_uflags = monr->uflags |
(puflags ? puflags[p] : monr->pkg_uflags[p]);
pmonr = pkgd_pmonr(pkgd, monr);
-   err = __pmonr_apply_uflags(pmonr, pmonr_uflags);
+   err = __pmonr_apply_uflags(pmonr, pmonr_uflags,
+ 

[PATCH v3 17/46] perf/x86/intel/cmt: add uflag CMT_UF_NOLAZY_RMID

[David Carrillo-Cisneros]

This uflag allows user to specify that a rmid must be allocated at monr's
initialization or fail otherwise.

For this to work we split __pmonr_apply_uflags into reserve and apply
modes. The reserve mode will try to reserve a free rmid, and if successful,
the apply mode can proceed using the rmid previously reserved.

Signed-off-by: David Carrillo-Cisneros 
---
 arch/x86/events/intel/cmt.c | 116 +++-
 arch/x86/events/intel/cmt.h |   5 +-
 2 files changed, 109 insertions(+), 12 deletions(-)

diff --git a/arch/x86/events/intel/cmt.c b/arch/x86/events/intel/cmt.c
index 9421a3e..3883cb4 100644
--- a/arch/x86/events/intel/cmt.c
+++ b/arch/x86/events/intel/cmt.c
@@ -33,7 +33,8 @@ static unsigned int __min_max_rmid;   /* minimum max_rmid 
across all pkgs. */
 static struct monr *monr_hrchy_root;
 
 /* Flags for root monr and all its pmonrs while being monitored. */
-static enum cmt_user_flags root_monr_uflags = CMT_UF_HAS_USER;
+static enum cmt_user_flags root_monr_uflags =
+   CMT_UF_HAS_USER | CMT_UF_NOLAZY_RMID;
 
 /* Auxiliar flags */
 static enum cmt_user_flags *pkg_uflags_zeroes;
@@ -414,6 +415,7 @@ static void monr_dealloc(struct monr *monr)
u16 p, nr_pkgs = topology_max_packages();
 
if (WARN_ON_ONCE(monr->nr_has_user) ||
+   WARN_ON_ONCE(monr->nr_nolazy_rmid) ||
WARN_ON_ONCE(monr->mon_events))
return;
 
@@ -478,11 +480,28 @@ static enum cmt_user_flags pmonr_uflags(struct pmonr 
*pmonr)
return monr->uflags | monr->pkg_uflags[pmonr->pkgd->pkgid];
 }
 
+/*
+ * Callable in two modes:
+ *   1) @reserve == true: will check if uflags are applicable and store in
+ *   @res_rmid the "reserved" rmid.
+ *   2) @reserve == false: will apply pmonr_uflags using the rmid stored in
+ *   @res_rmid rmid (if any). Cannot fail.
+ */
 static int __pmonr_apply_uflags(struct pmonr *pmonr,
-   enum cmt_user_flags pmonr_uflags)
+   enum cmt_user_flags pmonr_uflags, bool reserve, u32 *res_rmid)
 {
+   struct pkg_data *pkgd = pmonr->pkgd;
+   u32 free_rmid;
+
+   if (WARN_ON_ONCE(!res_rmid))
+   return -EINVAL;
+   if (WARN_ON_ONCE(reserve && *res_rmid != INVALID_RMID))
+   return -EINVAL;
+
if (!(pmonr_uflags & CMT_UF_HAS_USER)) {
if (pmonr->state != PMONR_OFF) {
+   if (reserve)
+   return 0;
pmonr_to_unused(pmonr);
pmonr_unused_to_off(pmonr);
}
@@ -492,8 +511,40 @@ static int __pmonr_apply_uflags(struct pmonr *pmonr,
if (monr_is_root(pmonr->monr) && (~pmonr_uflags & root_monr_uflags))
return -EINVAL;
 
-   if (pmonr->state == PMONR_OFF)
-   pmonr_to_unused(pmonr);
+   if (pmonr->state == PMONR_OFF) {
+   if (!reserve)
+   pmonr_to_unused(pmonr);
+   }
+   if (pmonr->state == PMONR_ACTIVE)
+   return 0;
+   if (!(pmonr_uflags & CMT_UF_NOLAZY_RMID))
+   return 0;
+   if (pmonr->state == PMONR_DEP_DIRTY) {
+   if (!reserve)
+   pmonr_dep_dirty_to_active(pmonr);
+   return 0;
+   }
+
+   /*
+* At this point pmonr is in either Unused or Dep_Idle state and
+* needs a rmid to transition to Active.
+*/
+   if (reserve) {
+   free_rmid = find_first_bit(pkgd->free_rmids, CMT_MAX_NR_RMIDS);
+   if (free_rmid == CMT_MAX_NR_RMIDS)
+   return -ENOSPC;
+   *res_rmid = free_rmid;
+   __clear_bit(*res_rmid, pkgd->free_rmids);
+   return 0;
+   }
+
+   /* both cases use the reserved rmid. */
+   if (pmonr->state == PMONR_UNUSED) {
+   pmonr_unused_to_active(pmonr, *res_rmid);
+   } else {
+   WARN_ON_ONCE(pmonr->state != PMONR_DEP_IDLE);
+   pmonr_dep_idle_to_active(pmonr, *res_rmid);
+   }
 
return 0;
 }
@@ -514,7 +565,10 @@ static bool monr_has_user(struct monr *monr)
   pkg_uflags_has_user(monr->pkg_uflags);
 }
 
-static int __monr_apply_uflags(struct monr *monr, enum cmt_user_flags *puflags)
+static int __monr_apply_uflags(struct monr *monr,
+  enum cmt_user_flags *puflags,
+  bool reserve,
+  u32 *res_rmids)
 {
enum cmt_user_flags pmonr_uflags;
struct pkg_data *pkgd = NULL;
@@ -526,7 +580,10 @@ static int __monr_apply_uflags(struct monr *monr, enum 
cmt_user_flags *puflags)
pmonr_uflags = monr->uflags |
(puflags ? puflags[p] : monr->pkg_uflags[p]);
pmonr = pkgd_pmonr(pkgd, monr);
-   err = __pmonr_apply_uflags(pmonr, pmonr_uflags);
+   err = __pmonr_apply_uflags(pmonr, pmonr_uflags,
+