integ/kernel/kernel-rt/centos/patches/Fix-cacheinfo-compilation-issues-for-3.10.patch

From 8eea2ba32882bcbcaf10588c99f7fec0104e9854 Mon Sep 17 00:00:00 2001
Message-Id: <8eea2ba32882bcbcaf10588c99f7fec0104e9854.1528226387.git.Jim.Somerville@windriver.com>
In-Reply-To: <c8270e79f6b7008fde44b8d5aa6314d8cf89d3ed.1528226387.git.Jim.Somerville@windriver.com>
References: <c8270e79f6b7008fde44b8d5aa6314d8cf89d3ed.1528226387.git.Jim.Somerville@windriver.com>
From: Alex Kozyrev <alex.kozyrev@windriver.com>
Date: Wed, 19 Jul 2017 02:25:15 -0500
Subject: [PATCH 20/32] Fix cacheinfo compilation issues for 3.10

Had to revert commit 7cc277b489b4fe91f42eb596b282879c2d13152e:
"Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs. No functional change."
There is no hotplug state machine in 3.10 kernel.
Also implemented cpumap_print_to_pagebuf() function in place.

Signed-off-by: Jim Somerville <Jim.Somerville@windriver.com>
---
 drivers/base/cacheinfo.c | 65 ++++++++++++++++++++++++++++++++++++------------
 1 file changed, 49 insertions(+), 16 deletions(-)

diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c
index eb3af27..c924f7e 100644
--- a/drivers/base/cacheinfo.c
+++ b/drivers/base/cacheinfo.c
@@ -383,7 +383,12 @@ static ssize_t shared_cpumap_show_func(struct device *dev, bool list, char *buf)
 	struct cacheinfo *this_leaf = dev_get_drvdata(dev);
 	const struct cpumask *mask = &this_leaf->shared_cpu_map;
 
-	return cpumap_print_to_pagebuf(list, buf, mask);
+	int len = list?
+		cpulist_scnprintf(buf, PAGE_SIZE-2, mask) :
+		cpumask_scnprintf(buf, PAGE_SIZE-2, mask);
+	buf[len++] = '\n';
+	buf[len] = '\0';
+	return len;
 }
 
 static ssize_t shared_cpu_map_show(struct device *dev,
@@ -633,30 +638,58 @@ err:
 	return rc;
 }
 
-static int cacheinfo_cpu_online(unsigned int cpu)
+static void cache_remove_dev(unsigned int cpu)
 {
-	int rc = detect_cache_attributes(cpu);
+	if (!cpumask_test_cpu(cpu, &cache_dev_map))
+		return;
+	cpumask_clear_cpu(cpu, &cache_dev_map);
 
-	if (rc)
-		return rc;
-	rc = cache_add_dev(cpu);
-	if (rc)
-		free_cache_attributes(cpu);
-	return rc;
+	cpu_cache_sysfs_exit(cpu);
 }
 
-static int cacheinfo_cpu_pre_down(unsigned int cpu)
+static int cacheinfo_cpu_callback(struct notifier_block *nfb,
+				  unsigned long action, void *hcpu)
 {
-	if (cpumask_test_and_clear_cpu(cpu, &cache_dev_map))
-		cpu_cache_sysfs_exit(cpu);
+	unsigned int cpu = (unsigned long)hcpu;
+	int rc = 0;
 
-	free_cache_attributes(cpu);
-	return 0;
+	switch (action & ~CPU_TASKS_FROZEN) {
+	case CPU_ONLINE:
+		rc = detect_cache_attributes(cpu);
+		if (!rc)
+			rc = cache_add_dev(cpu);
+		break;
+	case CPU_DEAD:
+		cache_remove_dev(cpu);
+		if (per_cpu_cacheinfo(cpu))
+			free_cache_attributes(cpu);
+		break;
+	}
+	return notifier_from_errno(rc);
 }
 
 static int __init cacheinfo_sysfs_init(void)
 {
-	return cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "base/cacheinfo:online",
-				 cacheinfo_cpu_online, cacheinfo_cpu_pre_down);
+	int cpu, rc = 0;
+
+	cpu_notifier_register_begin();
+
+	for_each_online_cpu(cpu) {
+		rc = detect_cache_attributes(cpu);
+		if (rc)
+			goto out;
+		rc = cache_add_dev(cpu);
+		if (rc) {
+			free_cache_attributes(cpu);
+			pr_err("error populating cacheinfo..cpu%d\n", cpu);
+			goto out;
+		}
+	}
+	__hotcpu_notifier(cacheinfo_cpu_callback, 0);
+
+out:
+	cpu_notifier_register_done();
+	return rc;
 }
+
 device_initcall(cacheinfo_sysfs_init);
-- 
1.8.3.1