linux-kernel - [PATCH v2 16/33] x86/intel_rdt: Class of service and capacity bitmask management for CDP

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Date:   Thu,  8 Sep 2016 02:57:10 -0700
From:   "Fenghua Yu" <fenghua.yu@...el.com>
To:     "Thomas Gleixner" <tglx@...utronix.de>,
        "H. Peter Anvin" <h.peter.anvin@...el.com>,
        "Ingo Molnar" <mingo@...e.hu>, "Tony Luck" <tony.luck@...el.com>,
        "Peter Zijlstra" <peterz@...radead.org>,
        "Tejun Heo" <tj@...nel.org>, "Borislav Petkov" <bp@...e.de>,
        "Stephane Eranian" <eranian@...gle.com>,
        "Marcelo Tosatti" <mtosatti@...hat.com>,
        "David Carrillo-Cisneros" <davidcc@...gle.com>,
        "Shaohua Li" <shli@...com>,
        "Ravi V Shankar" <ravi.v.shankar@...el.com>,
        "Vikas Shivappa" <vikas.shivappa@...ux.intel.com>,
        "Sai Prakhya" <sai.praneeth.prakhya@...el.com>
Cc:     "linux-kernel" <linux-kernel@...r.kernel.org>,
        "x86" <x86@...nel.org>, Fenghua Yu <fenghua.yu@...el.com>
Subject: [PATCH v2 16/33] x86/intel_rdt: Class of service and capacity bitmask management for CDP

From: Vikas Shivappa <vikas.shivappa@...ux.intel.com>

Add support to manage CLOSid(CLass Of Service id) and capacity
bitmask(cbm) for code data prioritization(CDP).

Closid management includes changes to allocating, freeing closid and
closid_get and closid_put and changes to closid availability map during
CDP set up. CDP has a separate cbm for code and data.

Each closid is mapped to a (dcache_cbm, icache_cbm) pair when cdp mode
is enabled.

Signed-off-by: Vikas Shivappa <vikas.shivappa@...ux.intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@...el.com>
Reviewed-by: Tony Luck <tony.luck@...el.com>
---
 arch/x86/kernel/cpu/intel_rdt.c | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/cpu/intel_rdt.c b/arch/x86/kernel/cpu/intel_rdt.c
index e0f23b6..9cee3fe 100644
--- a/arch/x86/kernel/cpu/intel_rdt.c
+++ b/arch/x86/kernel/cpu/intel_rdt.c
@@ -27,7 +27,13 @@
 #include <asm/intel_rdt.h>
 
 /*
- * cctable maintains 1:1 mapping between CLOSid and cache bitmask.
+ * During cache alloc mode cctable maintains 1:1 mapping between
+ * CLOSid and cache bitmask.
+ *
+ * During CDP mode, the cctable maintains a 1:2 mapping between the closid
+ * and (dcache_cbm, icache_cbm) pair.
+ * index of a dcache_cbm for CLOSid 'n' = n << 1.
+ * index of a icache_cbm for CLOSid 'n' = n << 1 + 1
  */
 static struct clos_cbm_table *cctable;
 /*
@@ -50,6 +56,13 @@ bool cdp_enabled;
 
 #define __DCBM_TABLE_INDEX(x)	(x << 1)
 #define __ICBM_TABLE_INDEX(x)	((x << 1) + 1)
+#define __DCBM_MSR_INDEX(x)			\
+	CBM_FROM_INDEX(__DCBM_TABLE_INDEX(x))
+#define __ICBM_MSR_INDEX(x)			\
+	CBM_FROM_INDEX(__ICBM_TABLE_INDEX(x))
+
+#define DCBM_TABLE_INDEX(x)	(x << cdp_enabled)
+#define ICBM_TABLE_INDEX(x)	((x << cdp_enabled) + cdp_enabled)
 
 struct rdt_remote_data {
 	int msr;
@@ -107,9 +120,12 @@ void __intel_rdt_sched_in(void *dummy)
 	state->closid = 0;
 }
 
+/*
+ * When cdp mode is enabled, refcnt is maintained in the dcache_cbm entry.
+ */
 static inline void closid_get(u32 closid)
 {
-	struct clos_cbm_table *cct = &cctable[closid];
+	struct clos_cbm_table *cct = &cctable[DCBM_TABLE_INDEX(closid)];
 
 	lockdep_assert_held(&rdtgroup_mutex);
 
@@ -139,7 +155,7 @@ static int closid_alloc(u32 *closid)
 static inline void closid_free(u32 closid)
 {
 	clear_bit(closid, cconfig.closmap);
-	cctable[closid].cbm = 0;
+	cctable[DCBM_TABLE_INDEX(closid)].cbm = 0;
 
 	if (WARN_ON(!cconfig.closids_used))
 		return;
@@ -149,7 +165,7 @@ static inline void closid_free(u32 closid)
 
 static void closid_put(u32 closid)
 {
-	struct clos_cbm_table *cct = &cctable[closid];
+	struct clos_cbm_table *cct = &cctable[DCBM_TABLE_INDEX(closid)];
 
 	lockdep_assert_held(&rdtgroup_mutex);
 	if (WARN_ON(!cct->clos_refcnt))
-- 
2.5.0