[Xen-devel] [PATCH v10 14/25] x86: refactor psr: CDP: implement CPU init and free flow.

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

This patch implements the CPU init and free flow for CDP including L3 CDP
initialization callback function. The flow is almost same as L3 CAT.

Signed-off-by: Yi Sun <yi.y.sun@xxxxxxxxxxxxxxx>
---
v10:
    - fix comment.
      (suggested by Jan Beulich)
    - use swith in 'cat_init_feature' to handle different feature types.
      (suggested by Jan Beulich)
    - changes about 'props'.
      (suggested by Jan Beulich)
    - restore MSRs to default value when cpu online.
      (suggested by Jan Beulich)
    - remove feat_mask.
      (suggested by Jan Beulich)
v9:
    - modify commit message to describe flow clearer.
    - handle cpu offline and online again case to read MSRs registers values
      back and save them into cos array to make user can get real data.
    - modify error handling process in 'psr_cpu_prepare' to reduce redundant
      codes.
    - modify 'get_cdp_data' and 'get_cdp_code' to make them standard.
      (suggested by Roger Pau and Jan Beulich)
    - encapsulate CDP operations into 'cat_init_feature' to reduce redundant
      codes.
      (suggested by Roger Pau)
    - reuse 'cat_get_cos_max' for CDP.
      (suggested by Roger Pau)
    - handle 'PSR_CDP' in psr_presmp_init to make init work can be done when
      there is only 'psr=cdp' in cmdline.
    - remove unnecessary comment.
      (suggested by Jan Beulich)
    - move CDP related codes in 'cpu_init_work' into 'psr_cpu_init'.
      (suggested by Jan Beulich)
    - add codes to handle CDP's 'cos_num'.
      (suggested by Jan Beulich)
    - fix coding style issue.
      (suggested by Jan Beulich)
    - do not free resources when allocation fails in 'psr_cpu_prepare'.
      (suggested by Jan Beulich)
    - changes about 'uint64_t' to 'uint32_t'.
      (suggested by Jan Beulich)
v7:
    - initialize 'l3_cdp'.
      (suggested by Konrad Rzeszutek Wilk)
v6:
    - use 'cpuid_leaf'.
      (suggested by Konrad Rzeszutek Wilk and Jan Beulich)
v5:
    - remove codes to free 'feat_l3_cdp' in 'free_feature'.
      (suggested by Jan Beulich)
    - encapsulate cpuid registers into 'struct cpuid_leaf_regs'.
      (suggested by Jan Beulich)
    - print socket info when 'opt_cpu_info' is true.
      (suggested by Jan Beulich)
    - rename 'l3_cdp_get_max_cos_max' to 'l3_cdp_get_cos_max'.
      (suggested by Jan Beulich)
    - rename 'dat[]' to 'data[]'.
      (suggested by Jan Beulich)
    - move 'cpu_prepare_work' contents into 'psr_cpu_prepare'.
      (suggested by Jan Beulich)
v4:
    - create this patch to make codes easier to understand.
      (suggested by Jan Beulich)
---
 xen/arch/x86/psr.c | 84 ++++++++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 76 insertions(+), 8 deletions(-)

diff --git a/xen/arch/x86/psr.c b/xen/arch/x86/psr.c
index 0f57676..58970fa 100644
--- a/xen/arch/x86/psr.c
+++ b/xen/arch/x86/psr.c
@@ -144,11 +144,28 @@ static DEFINE_PER_CPU(struct psr_assoc, psr_assoc);
  * array creation. It is used to transiently store a spare node.
  */
 static struct feat_node *feat_l3_cat;
+static struct feat_node *feat_l3_cdp;
 
 /* Common functions */
 #define cat_default_val(len) (0xffffffff >> (32 - (len)))
 
 /*
+ * get_cdp_data - get DATA COS register value from input COS ID.
+ * @feat:        the feature node.
+ * @cos:         the COS ID.
+ */
+#define get_cdp_data(feat, cos)              \
+            ( (feat)->cos_reg_val[(cos) * 2] )
+
+/*
+ * get_cdp_code - get CODE COS register value from input COS ID.
+ * @feat:        the feature node.
+ * @cos:         the COS ID.
+ */
+#define get_cdp_code(feat, cos)              \
+            ( (feat)->cos_reg_val[(cos) * 2 + 1] )
+
+/*
  * Use this function to check if any allocation feature has been enabled
  * in cmdline.
  */
@@ -283,6 +300,37 @@ static void cat_init_feature(const struct cpuid_leaf *regs,
 
         break;
 
+    case PSR_SOCKET_L3_CDP:
+    {
+        unsigned long val;
+
+        /* Cut half of cos_max when CDP is enabled. */
+        feat->props->cos_max >>= 1;
+
+        /* We only write mask1 since mask0 is always all ones by default. */
+        wrmsrl(MSR_IA32_PSR_L3_MASK(1), cat_default_val(feat->props->cbm_len));
+        rdmsrl(MSR_IA32_PSR_L3_QOS_CFG, val);
+        wrmsrl(MSR_IA32_PSR_L3_QOS_CFG, val | (1 << 
PSR_L3_QOS_CDP_ENABLE_BIT));
+
+        /* cos=0 is reserved as default cbm(all bits within cbm_len are 1). */
+        get_cdp_code(feat, 0) = cat_default_val(feat->props->cbm_len);
+        get_cdp_data(feat, 0) = cat_default_val(feat->props->cbm_len);
+
+        /*
+         * To handle cpu offline and then online case, we need restore MSRs to
+         * default values.
+         */
+        for ( i = 1; i <= feat->props->cos_max; i++ )
+        {
+            wrmsrl(MSR_IA32_PSR_L3_MASK_DATA(i), get_cdp_data(feat, 0));
+            wrmsrl(MSR_IA32_PSR_L3_MASK_CODE(i), get_cdp_code(feat, 0));
+            get_cdp_code(feat, i) = get_cdp_code(feat, 0);
+            get_cdp_data(feat, i) = get_cdp_data(feat, 0);
+        }
+
+        break;
+    }
+
     default:
         return;
     }
@@ -294,8 +342,9 @@ static void cat_init_feature(const struct cpuid_leaf *regs,
     if ( !opt_cpu_info )
         return;
 
-    printk(XENLOG_INFO "%s CAT: enabled on socket %u, cos_max:%u, 
cbm_len:%u\n",
-           ((type == PSR_SOCKET_L3_CAT) ? "L3" : "L2"),
+    printk(XENLOG_INFO "%s: enabled on socket %u, cos_max:%u, cbm_len:%u\n",
+           ((type == PSR_SOCKET_L3_CDP) ? "CDP" :
+            ((type == PSR_SOCKET_L3_CAT) ? "L3 CAT": "L2 CAT")),
            socket, feat->props->cos_max, feat->props->cbm_len);
 }
 
@@ -336,6 +385,11 @@ static struct feat_props l3_cat_props = {
     .write_msr = l3_cat_write_msr,
 };
 
+/* L3 CDP ops */
+static struct feat_props l3_cdp_props = {
+    .cos_num = 2,
+};
+
 static void __init parse_psr_bool(char *s, char *value, char *feature,
                                   unsigned int mask)
 {
@@ -1161,6 +1215,10 @@ static int psr_cpu_prepare(void)
          (feat_l3_cat = xzalloc(struct feat_node)) == NULL )
         return -ENOMEM;
 
+    if ( feat_l3_cdp == NULL &&
+         (feat_l3_cdp = xzalloc(struct feat_node)) == NULL )
+        return -ENOMEM;
+
     return 0;
 }
 
@@ -1193,11 +1251,21 @@ static void psr_cpu_init(void)
     {
         cpuid_count_leaf(PSR_CPUID_LEVEL_CAT, 1, &regs);
 
-        feat = feat_l3_cat;
-        feat_l3_cat = NULL;
-        feat->props = &l3_cat_props;
-
-        cat_init_feature(&regs, feat, info, PSR_SOCKET_L3_CAT);
+        if ( (regs.c & PSR_CAT_CDP_CAPABILITY) && (opt_psr & PSR_CDP) &&
+             !info->features[PSR_SOCKET_L3_CDP] )
+        {
+            feat = feat_l3_cdp;
+            feat_l3_cdp = NULL;
+            feat->props = &l3_cdp_props;
+            cat_init_feature(&regs, feat, info, PSR_SOCKET_L3_CDP);
+        }
+        else
+        {
+            feat = feat_l3_cat;
+            feat_l3_cat = NULL;
+            feat->props = &l3_cat_props;
+            cat_init_feature(&regs, feat, info, PSR_SOCKET_L3_CAT);
+        }
     }
 
  assoc_init:
@@ -1257,7 +1325,7 @@ static int __init psr_presmp_init(void)
     if ( (opt_psr & PSR_CMT) && opt_rmid_max )
         init_psr_cmt(opt_rmid_max);
 
-    if ( opt_psr & PSR_CAT )
+    if ( opt_psr & (PSR_CAT | PSR_CDP) )
         init_psr();
 
     if ( psr_cpu_prepare() )
-- 
1.9.1


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