arm64/mpam: resctrl: Update closid alloc and free process with bitmap

hulk inclusion
category: feature
feature: ARM MPAM support
bugzilla: 48265
CVE: NA

--------------------------------

Replace u32 bitmask with bitmap for closid allocation, it's because closid
may be too large to use 32 bits.

This also support cdp, when cdp is enabled, closid will be assigned twice
once time, giving closid to code LxCache and closid+1 to data LxDATA, so
do free process.
Signed-off-by: NWang ShaoBo <bobo.shaobowang@huawei.com>
Reviewed-by: NXiongfeng Wang <wangxiongfeng2@huawei.com>
Reviewed-by: NCheng Jian <cj.chengjian@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

arch/arm64/include/asm/mpam.h

@@ -168,10 +168,7 @@ do {   \
 		__result = as_hw_t(__name, __closid); \
 } while (0)
 
-static inline bool is_resctrl_cdp_enabled(void)
-{
-	return 0;
-}
+bool is_resctrl_cdp_enabled(void);
 
 #define hw_alloc_times_validate(__name, __times, __flag) \
 do {   \
@@ -269,7 +266,7 @@ int resctrl_group_mondata_show(struct seq_file *m, void *arg);
 void rmdir_mondata_subdir_allrdtgrp(struct resctrl_resource *r,
 				    unsigned int dom_id);
 
-void closid_init(void);
+int closid_init(void);
 int closid_alloc(void);
 void closid_free(int closid);
 

arch/arm64/include/asm/resctrl.h

@@ -91,10 +91,18 @@ static inline void free_mon_id(u32 id)
 }
 
 void pmg_init(void);
-static inline void resctrl_id_init(void)
+static inline int resctrl_id_init(void)
 {
-	closid_init();
+	int ret;
+
+	ret = closid_init();
+	if (ret)
+		goto out;
+
 	pmg_init();
+
+out:
+	return ret;
 }
 
 static inline int resctrl_id_alloc(void)
@@ -136,4 +144,6 @@ int resctrl_group_init_alloc(struct rdtgroup *rdtgrp);
 struct resctrl_resource *
 mpam_resctrl_get_resource(enum resctrl_resource_level level);
 
+#define RESCTRL_MAX_CLOSID 32
+
 #endif /* _ASM_ARM64_RESCTRL_H */

arch/arm64/kernel/mpam/mpam_resctrl.c

@@ -102,6 +102,11 @@ void mpam_resctrl_clear_default_cpu(unsigned int cpu)
 	cpumask_clear_cpu(cpu, &resctrl_group_default.cpu_mask);
 }
 
+bool is_resctrl_cdp_enabled(void)
+{
+	return !!resctrl_cdp_enabled;
+}
+
 static void
 mpam_resctrl_update_component_cfg(struct resctrl_resource *r,
 	struct rdt_domain *d, struct list_head *opt_list, u32 partid);
@@ -443,8 +448,8 @@ static int common_wrmon(struct rdt_domain *d, struct rdtgroup *g, bool enable)
 }
 
 /*
- * Trivial allocator for CLOSIDs. Since h/w only supports a small number,
- * we can keep a bitmap of free CLOSIDs in a single integer.
+ * Notifing resctrl_id_init() should be called after calling parse_
+ * resctrl_group_fs_options() to guarantee resctrl_cdp_enabled() active.
  *
  * Using a global CLOSID across all resources has some advantages and
  * some drawbacks:
@@ -457,35 +462,64 @@ static int common_wrmon(struct rdt_domain *d, struct rdtgroup *g, bool enable)
  * - Our choices on how to configure each resource become progressively more
  *   limited as the number of resources grows.
  */
-static int closid_free_map;
 
-void closid_init(void)
+static unsigned long *closid_free_map;
+static int num_closid;
+
+int closid_init(void)
 {
-	int num_closid = INT_MAX;
+	int pos;
+	u32 times, flag;
+
+	if (closid_free_map)
+		kfree(closid_free_map);
 
 	num_closid = mpam_sysprops_num_partid();
+	num_closid = min(num_closid, RESCTRL_MAX_CLOSID);
+
+	hw_alloc_times_validate(clos, times, flag);
+
+	if (flag)
+		num_closid = rounddown(num_closid, 2);
+
+	closid_free_map = bitmap_zalloc(num_closid, GFP_KERNEL);
+	if (!closid_free_map)
+		return -ENOMEM;
 
-	closid_free_map = BIT_MASK(num_closid) - 1;
+	bitmap_set(closid_free_map, 0, num_closid);
 
 	/* CLOSID 0 is always reserved for the default group */
-	closid_free_map &= ~1;
-}
+	pos = find_first_bit(closid_free_map, num_closid);
+	bitmap_clear(closid_free_map, pos, times);
 
+	return 0;
+}
+/*
+ * If cdp enabled, allocate two closid once time, then return first
+ * allocated id.
+ */
 int closid_alloc(void)
 {
-	u32 closid = ffs(closid_free_map);
+	int pos;
+	u32 times, flag;
+
+	hw_alloc_times_validate(clos, times, flag);
 
-	if (closid == 0)
+	pos = find_first_bit(closid_free_map, num_closid);
+	if (pos == num_closid)
 		return -ENOSPC;
-	closid--;
-	closid_free_map &= ~(1 << closid);
 
-	return closid;
+	bitmap_clear(closid_free_map, pos, times);
+
+	return pos;
 }
 
 void closid_free(int closid)
 {
-	closid_free_map |= 1 << closid;
+	u32 times, flag;
+
+	hw_alloc_times_validate(clos, times, flag);
+	bitmap_set(closid_free_map, closid, times);
 }
 
 /*

fs/resctrlfs.c

@@ -341,7 +341,9 @@ static int resctrl_get_tree(struct fs_context *fc)
 	if (ret)
 		goto out;
 #endif
-	resctrl_id_init();
+	ret = resctrl_id_init();
+	if (ret)
+		goto out;
 
 	ret = resctrl_group_create_info_dir(resctrl_group_default.kn);
 	if (ret)