[Xen-devel] [PATCH v4 04/24] x86: refactor psr: implement CPU init and free flow.

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

This patch implements the CPU init and free flow including L3 CAT
initialization and feature list free.

Per this patch, you can see how callback functions work and how the
feature list is handled.

Signed-off-by: Yi Sun <yi.y.sun@xxxxxxxxxxxxxxx>
---
 xen/arch/x86/psr.c | 179 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 176 insertions(+), 3 deletions(-)

diff --git a/xen/arch/x86/psr.c b/xen/arch/x86/psr.c
index 49a4598..fa9bc32 100644
--- a/xen/arch/x86/psr.c
+++ b/xen/arch/x86/psr.c
@@ -35,6 +35,9 @@
 #define PSR_CAT        (1<<1)
 #define PSR_CDP        (1<<2)
 
+#define CAT_CBM_LEN_MASK 0x1f
+#define CAT_COS_MAX_MASK 0xffff
+
 /*
  * Per SDM 17.17.3.3 'Cache Allocation Technology: Cache Mask Configuration',
  * the MSRs range from 0C90H through 0D0FH (inclusive), enables support for
@@ -141,11 +144,79 @@ struct psr_assoc {
 
 struct psr_cmt *__read_mostly psr_cmt;
 
+static struct psr_socket_info *__read_mostly socket_info;
+
 static unsigned int opt_psr;
 static unsigned int __initdata opt_rmid_max = 255;
+static unsigned int __read_mostly opt_cos_max = MAX_COS_REG_CNT;
 static uint64_t rmid_mask;
 static DEFINE_PER_CPU(struct psr_assoc, psr_assoc);
 
+/* Declare feature list entry. */
+static struct feat_node *feat_l3_cat;
+
+/* Common functions. */
+static void free_feature(struct psr_socket_info *info)
+{
+    struct feat_node *feat_tmp;
+
+    if ( !info )
+        return;
+
+    list_for_each_entry(feat_tmp, &info->feat_list, list)
+    {
+        clear_bit(feat_tmp->feature, &info->feat_mask);
+        list_del(&feat_tmp->list);
+        xfree(feat_tmp);
+    }
+
+    /* Free feature which are not added into feat_list. */
+    if ( feat_l3_cat )
+    {
+        xfree(feat_l3_cat);
+        feat_l3_cat = NULL;
+    }
+}
+
+/* L3 CAT callback functions implementation. */
+static void l3_cat_init_feature(unsigned int eax, unsigned int ebx,
+                                unsigned int ecx, unsigned int edx,
+                                struct feat_node *feat,
+                                struct psr_socket_info *info)
+{
+    struct psr_cat_hw_info l3_cat;
+    unsigned int socket;
+
+    /* No valid value so do not enable feature. */
+    if ( !eax || !edx )
+        return;
+
+    l3_cat.cbm_len = (eax & CAT_CBM_LEN_MASK) + 1;
+    l3_cat.cos_max = min(opt_cos_max, edx & CAT_COS_MAX_MASK);
+
+    /* cos=0 is reserved as default cbm(all ones). */
+    feat->cos_reg_val[0] = (1ull << l3_cat.cbm_len) - 1;
+
+    feat->feature = PSR_SOCKET_L3_CAT;
+    __set_bit(PSR_SOCKET_L3_CAT, &info->feat_mask);
+
+    feat->info.l3_cat_info = l3_cat;
+
+    info->nr_feat++;
+
+    /* Add this feature into list. */
+    list_add_tail(&feat->list, &info->feat_list);
+
+    socket = cpu_to_socket(smp_processor_id());
+    printk(XENLOG_INFO "L3 CAT: enabled on socket %u, cos_max:%u, 
cbm_len:%u\n",
+           socket, feat->info.l3_cat_info.cos_max,
+           feat->info.l3_cat_info.cbm_len);
+}
+
+struct feat_ops l3_cat_ops = {
+    .init_feature = l3_cat_init_feature,
+};
+
 static void __init parse_psr_bool(char *s, char *value, char *feature,
                                   unsigned int mask)
 {
@@ -185,6 +256,9 @@ static void __init parse_psr_param(char *s)
         if ( val_str && !strcmp(s, "rmid_max") )
             opt_rmid_max = simple_strtoul(val_str, NULL, 0);
 
+        if ( val_str && !strcmp(s, "cos_max") )
+            opt_cos_max = simple_strtoul(val_str, NULL, 0);
+
         s = ss + 1;
     } while ( ss );
 }
@@ -340,18 +414,113 @@ void psr_domain_free(struct domain *d)
     psr_free_rmid(d);
 }
 
-static int psr_cpu_prepare(unsigned int cpu)
+static int cpu_prepare_work(unsigned int cpu)
 {
+    if ( !socket_info )
+        return 0;
+
+    /* Malloc memory for the global feature head here. */
+    if ( feat_l3_cat == NULL &&
+         (feat_l3_cat = xzalloc(struct feat_node)) == NULL )
+        return -ENOMEM;
+
     return 0;
 }
 
+static void cpu_init_work(void)
+{
+    unsigned int eax, ebx, ecx, edx;
+    struct psr_socket_info *info;
+    unsigned int socket;
+    unsigned int cpu = smp_processor_id();
+    const struct cpuinfo_x86 *c = cpu_data + cpu;
+    struct feat_node *feat_tmp;
+
+    if ( !cpu_has(c, X86_FEATURE_PQE) || c->cpuid_level < PSR_CPUID_LEVEL_CAT )
+        return;
+
+    socket = cpu_to_socket(cpu);
+    info = socket_info + socket;
+    if ( info->feat_mask )
+        return;
+
+    spin_lock_init(&info->ref_lock);
+
+    cpuid_count(PSR_CPUID_LEVEL_CAT, 0, &eax, &ebx, &ecx, &edx);
+    if ( ebx & PSR_RESOURCE_TYPE_L3 )
+    {
+        cpuid_count(PSR_CPUID_LEVEL_CAT, 1, &eax, &ebx, &ecx, &edx);
+
+        feat_tmp = feat_l3_cat;
+        feat_l3_cat = NULL;
+        feat_tmp->ops = l3_cat_ops;
+
+        feat_tmp->ops.init_feature(eax, ebx, ecx, edx, feat_tmp, info);
+    }
+}
+
+static void cpu_fini_work(unsigned int cpu)
+{
+    unsigned int socket = cpu_to_socket(cpu);
+
+    if ( !socket_cpumask[socket] || cpumask_empty(socket_cpumask[socket]) )
+    {
+        struct psr_socket_info *info = socket_info + socket;
+
+        free_feature(info);
+    }
+}
+
+static void __init init_psr(void)
+{
+    unsigned int i;
+
+    if ( opt_cos_max < 1 )
+    {
+        printk(XENLOG_INFO "CAT: disabled, cos_max is too small\n");
+        return;
+    }
+
+    socket_info = xzalloc_array(struct psr_socket_info, nr_sockets);
+
+    if ( !socket_info )
+    {
+        printk(XENLOG_INFO "Fail to alloc socket_info!\n");
+        return;
+    }
+
+    for ( i = 0; i < nr_sockets; i++ )
+        INIT_LIST_HEAD(&socket_info[i].feat_list);
+}
+
+static void __init psr_free(void)
+{
+    unsigned int i;
+
+    for ( i = 0; i < nr_sockets; i++ )
+        free_feature(&socket_info[i]);
+
+    xfree(socket_info);
+    socket_info = NULL;
+}
+
+static int psr_cpu_prepare(unsigned int cpu)
+{
+    return cpu_prepare_work(cpu);
+}
+
 static void psr_cpu_init(void)
 {
+    if ( socket_info )
+        cpu_init_work();
+
     psr_assoc_init();
 }
 
 static void psr_cpu_fini(unsigned int cpu)
 {
+    if ( socket_info )
+        cpu_fini_work(cpu);
     return;
 }
 
@@ -393,10 +562,14 @@ static int __init psr_presmp_init(void)
     if ( (opt_psr & PSR_CMT) && opt_rmid_max )
         init_psr_cmt(opt_rmid_max);
 
-    psr_cpu_prepare(0);
+    if ( opt_psr & PSR_CAT )
+        init_psr();
+
+    if ( psr_cpu_prepare(0) )
+        psr_free();
 
     psr_cpu_init();
-    if ( psr_cmt_enabled() )
+    if ( psr_cmt_enabled() || socket_info )
         register_cpu_notifier(&cpu_nfb);
 
     return 0;
-- 
1.9.1


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