[Xen-devel] [RFC 04/16] x86: implement data structure of MBA.

[Yi Sun <yi.y.sun@xxxxxxxxxxxxxxx>]

This patch implements main data structures of MBA.

Like CAT features, MBA HW info has cos_max which means the max cos
registers number, and thrtl_max which means the max throttle value
(delay value). It also have a flag to represent if the throttle
value is linear or not.

One COS register of MBA stores a throttle value for one or more
domains. That means the transaction time between L2 cache and next
level memory will be delayed.

Signed-off-by: Yi Sun <yi.y.sun@xxxxxxxxxxxxxxx>
---
 xen/arch/x86/psr.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/xen/arch/x86/psr.c b/xen/arch/x86/psr.c
index 2c69cc0..58d3555 100644
--- a/xen/arch/x86/psr.c
+++ b/xen/arch/x86/psr.c
@@ -27,17 +27,23 @@
  * - CDP         Code and Data Prioritization
  * - COS/CLOS    Class of Service. Also mean COS registers.
  * - COS_MAX     Max number of COS for the feature (minus 1)
+ * - MBA         Memory Bandwidth Allocation
  * - MSRs        Machine Specific Registers
  * - PSR         Intel Platform Shared Resource
+ * - THRTL_MAX   Max throttle value (delay value) of MBA
  */
 
 #define PSR_CMT        (1<<0)
 #define PSR_CAT        (1<<1)
 #define PSR_CDP        (1<<2)
+#define PSR_MBA        (1<<3)
 
 #define CAT_CBM_LEN_MASK 0x1f
 #define CAT_COS_MAX_MASK 0xffff
 
+/* Linear bit. */
+#define MBA_LINEAR     (1<<2)
+
 /*
  * Per SDM 17.17.3.3 'Cache Allocation Technology: Cache Mask Configuration',
  * the MSRs range from 0C90H through 0D0FH (inclusive), enables support for
@@ -79,6 +85,14 @@ enum psr_feat_type {
     PSR_SOCKET_L3_CAT = 0,
     PSR_SOCKET_L3_CDP,
     PSR_SOCKET_L2_CAT,
+    PSR_SOCKET_MBA    = 16,
+};
+
+/* MBA HW info data structure. */
+struct psr_mba_hw_info {
+    unsigned int thrtl_max;
+    unsigned int cos_max;
+    unsigned int linear;
 };
 
 /* CAT/CDP HW info data structure. */
@@ -93,6 +107,7 @@ struct feat_hw_info {
         struct psr_cat_hw_info l3_cat_info;
         struct psr_cat_hw_info l3_cdp_info;
         struct psr_cat_hw_info l2_cat_info;
+        struct psr_mba_hw_info mba_info;
     };
 };
 
-- 
1.9.1


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