[tip:x86/cache] x86/intel_rdt: Introduce the Cache Pseudo-Locking modes

From: tip-bot for Reinette Chatre
Date: Tue Jun 19 2018 - 20:21:19 EST


Commit-ID: f438e62bcabd3e616b6280d422c5ba1c70b37f44
Gitweb: https://git.kernel.org/tip/f438e62bcabd3e616b6280d422c5ba1c70b37f44
Author: Reinette Chatre <reinette.chatre@xxxxxxxxx>
AuthorDate: Tue, 29 May 2018 05:57:41 -0700
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Wed, 20 Jun 2018 00:56:33 +0200

x86/intel_rdt: Introduce the Cache Pseudo-Locking modes

The two modes used to manage Cache Pseudo-Locked regions are introduced. A
resource group is assigned "pseudo-locksetup" mode when the user indicates
that this resource group will be used for a Cache Pseudo-Locked
region. When the Cache Pseudo-Locked region has been set up successfully
after the user wrote the requested schemata to the "schemata" file, then
the mode will automatically changed to "pseudo-locked". The user is not
able to modify the mode to "pseudo-locked" by writing "pseudo-locked" to
the "mode" file directly.

Signed-off-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: fenghua.yu@xxxxxxxxx
Cc: tony.luck@xxxxxxxxx
Cc: vikas.shivappa@xxxxxxxxxxxxxxx
Cc: gavin.hindman@xxxxxxxxx
Cc: jithu.joseph@xxxxxxxxx
Cc: dave.hansen@xxxxxxxxx
Cc: hpa@xxxxxxxxx
Link: https://lkml.kernel.org/r/6ab82fb595f4b0ffa305dc204255b921eed51de7.1527593970.git.reinette.chatre@xxxxxxxxx

---
arch/x86/kernel/cpu/intel_rdt.h | 10 ++++++++++
arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 13 +++++++++++--
2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/cpu/intel_rdt.h b/arch/x86/kernel/cpu/intel_rdt.h
index 8bbb047bf37c..bda87f5ef7bc 100644
--- a/arch/x86/kernel/cpu/intel_rdt.h
+++ b/arch/x86/kernel/cpu/intel_rdt.h
@@ -84,15 +84,25 @@ enum rdt_group_type {
* enum rdtgrp_mode - Mode of a RDT resource group
* @RDT_MODE_SHAREABLE: This resource group allows sharing of its allocations
* @RDT_MODE_EXCLUSIVE: No sharing of this resource group's allocations allowed
+ * @RDT_MODE_PSEUDO_LOCKSETUP: Resource group will be used for Pseudo-Locking
+ * @RDT_MODE_PSEUDO_LOCKED: No sharing of this resource group's allocations
+ * allowed AND the allocations are Cache Pseudo-Locked
*
* The mode of a resource group enables control over the allowed overlap
* between allocations associated with different resource groups (classes
* of service). User is able to modify the mode of a resource group by
* writing to the "mode" resctrl file associated with the resource group.
+ *
+ * The "shareable", "exclusive", and "pseudo-locksetup" modes are set by
+ * writing the appropriate text to the "mode" file. A resource group enters
+ * "pseudo-locked" mode after the schemata is written while the resource
+ * group is in "pseudo-locksetup" mode.
*/
enum rdtgrp_mode {
RDT_MODE_SHAREABLE = 0,
RDT_MODE_EXCLUSIVE,
+ RDT_MODE_PSEUDO_LOCKSETUP,
+ RDT_MODE_PSEUDO_LOCKED,

/* Must be last */
RDT_NUM_MODES,
diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
index 7d63380abe02..9e69f4dbc686 100644
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -161,8 +161,10 @@ enum rdtgrp_mode rdtgroup_mode_by_closid(int closid)
}

static const char * const rdt_mode_str[] = {
- [RDT_MODE_SHAREABLE] = "shareable",
- [RDT_MODE_EXCLUSIVE] = "exclusive",
+ [RDT_MODE_SHAREABLE] = "shareable",
+ [RDT_MODE_EXCLUSIVE] = "exclusive",
+ [RDT_MODE_PSEUDO_LOCKSETUP] = "pseudo-locksetup",
+ [RDT_MODE_PSEUDO_LOCKED] = "pseudo-locked",
};

/**
@@ -759,6 +761,13 @@ static int rdt_bit_usage_show(struct kernfs_open_file *of,
case RDT_MODE_EXCLUSIVE:
exclusive |= *ctrl;
break;
+ /*
+ * Temporarily handle pseudo-locking enums
+ * to silence compile warnings until handling
+ * added in later patches.
+ */
+ case RDT_MODE_PSEUDO_LOCKSETUP:
+ case RDT_MODE_PSEUDO_LOCKED:
case RDT_NUM_MODES:
WARN(1,
"invalid mode for closid %d\n", i);