[patch 3/3] x86: cache_info: Kill the atomic allocation in amd_init_l3_cache()

[Thomas Gleixner <tglx@linutronix.de>]

[-- Attachment #1: x86-amd-nb-kill-atomic-allocation.patch --]
[-- Type: text/plain, Size: 7853 bytes --]

It's not a good reason to allocate memory in the smp function call
just because someone thought it's the most conveniant place.

The AMD L3 data is coupled to the northbridge info by a pointer to the
corresponding north bridge data. So allocating it with the northbridge
data and referencing the northbridge in the cache_info code instead
uses less memory and gets rid of that atomic allocation hack in the
smp function call.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 arch/x86/include/asm/amd_nb.h         |    6 ++
 arch/x86/kernel/cpu/intel_cacheinfo.c |   74 +++++++++++-----------------------
 2 files changed, 32 insertions(+), 48 deletions(-)

Index: linux-2.6/arch/x86/include/asm/amd_nb.h
===================================================================
--- linux-2.6.orig/arch/x86/include/asm/amd_nb.h
+++ linux-2.6/arch/x86/include/asm/amd_nb.h
@@ -19,9 +19,15 @@ extern int amd_numa_init(void);
 extern int amd_get_subcaches(int);
 extern int amd_set_subcaches(int, int);
 
+struct amd_l3_cache {
+	unsigned indices;
+	u8	 subcaches[4];
+};
+
 struct amd_northbridge {
 	struct pci_dev *misc;
 	struct pci_dev *link;
+	struct amd_l3_cache l3_cache;
 };
 
 struct amd_northbridge_info {
Index: linux-2.6/arch/x86/kernel/cpu/intel_cacheinfo.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/intel_cacheinfo.c
+++ linux-2.6/arch/x86/kernel/cpu/intel_cacheinfo.c
@@ -151,18 +151,12 @@ union _cpuid4_leaf_ecx {
 	u32 full;
 };
 
-struct amd_l3_cache {
-	struct	 amd_northbridge *nb;
-	unsigned indices;
-	u8	 subcaches[4];
-};
-
 struct _cpuid4_info_regs {
 	union _cpuid4_leaf_eax eax;
 	union _cpuid4_leaf_ebx ebx;
 	union _cpuid4_leaf_ecx ecx;
 	unsigned long size;
-	struct amd_l3_cache *l3;
+	struct amd_northbridge *nb;
 };
 
 struct _cpuid4_info {
@@ -309,12 +303,13 @@ struct _cache_attr {
 /*
  * L3 cache descriptors
  */
-static void __cpuinit amd_calc_l3_indices(struct amd_l3_cache *l3)
+static void __cpuinit amd_calc_l3_indices(struct amd_northbridge *nb)
 {
+	struct amd_l3_cache *l3 = &nb->l3_cache;
 	unsigned int sc0, sc1, sc2, sc3;
 	u32 val = 0;
 
-	pci_read_config_dword(l3->nb->misc, 0x1C4, &val);
+	pci_read_config_dword(nb->misc, 0x1C4, &val);
 
 	/* calculate subcache sizes */
 	l3->subcaches[0] = sc0 = !(val & BIT(0));
@@ -328,33 +323,16 @@ static void __cpuinit amd_calc_l3_indice
 static void __cpuinit amd_init_l3_cache(struct _cpuid4_info_regs *this_leaf,
 					int index)
 {
-	static struct amd_l3_cache *__cpuinitdata l3_caches;
 	int node;
 
 	/* only for L3, and not in virtualized environments */
-	if (index < 3 || amd_nb_num() == 0)
+	if (index < 3)
 		return;
 
-	/*
-	 * Strictly speaking, the amount in @size below is leaked since it is
-	 * never freed but this is done only on shutdown so it doesn't matter.
-	 */
-	if (!l3_caches) {
-		int size = amd_nb_num() * sizeof(struct amd_l3_cache);
-
-		l3_caches = kzalloc(size, GFP_ATOMIC);
-		if (!l3_caches)
-			return;
-	}
-
 	node = amd_get_nb_id(smp_processor_id());
-
-	if (!l3_caches[node].nb) {
-		l3_caches[node].nb = node_to_amd_nb(node);
-		amd_calc_l3_indices(&l3_caches[node]);
-	}
-
-	this_leaf->l3 = &l3_caches[node];
+	this_leaf->nb = node_to_amd_nb(node);
+	if (this_leaf->nb && !this_leaf->nb->l3_cache.indices)
+		amd_calc_l3_indices(this_leaf->nb);
 }
 
 /*
@@ -364,11 +342,11 @@ static void __cpuinit amd_init_l3_cache(
  *
  * @returns: the disabled index if used or negative value if slot free.
  */
-int amd_get_l3_disable_slot(struct amd_l3_cache *l3, unsigned slot)
+int amd_get_l3_disable_slot(struct amd_northbridge *nb, unsigned slot)
 {
 	unsigned int reg = 0;
 
-	pci_read_config_dword(l3->nb->misc, 0x1BC + slot * 4, &reg);
+	pci_read_config_dword(nb->misc, 0x1BC + slot * 4, &reg);
 
 	/* check whether this slot is activated already */
 	if (reg & (3UL << 30))
@@ -382,10 +360,10 @@ static ssize_t show_cache_disable(struct
 {
 	int index;
 
-	if (!this_leaf->base.l3 || !amd_nb_has_feature(AMD_NB_L3_INDEX_DISABLE))
+	if (!this_leaf->base.nb || !amd_nb_has_feature(AMD_NB_L3_INDEX_DISABLE))
 		return -EINVAL;
 
-	index = amd_get_l3_disable_slot(this_leaf->base.l3, slot);
+	index = amd_get_l3_disable_slot(this_leaf->base.nb, slot);
 	if (index >= 0)
 		return sprintf(buf, "%d\n", index);
 
@@ -402,7 +380,7 @@ show_cache_disable_##slot(struct _cpuid4
 SHOW_CACHE_DISABLE(0)
 SHOW_CACHE_DISABLE(1)
 
-static void amd_l3_disable_index(struct amd_l3_cache *l3, int cpu,
+static void amd_l3_disable_index(struct amd_northbridge *nb, int cpu,
 				 unsigned slot, unsigned long idx)
 {
 	int i;
@@ -415,10 +393,10 @@ static void amd_l3_disable_index(struct 
 	for (i = 0; i < 4; i++) {
 		u32 reg = idx | (i << 20);
 
-		if (!l3->subcaches[i])
+		if (!nb->l3_cache.subcaches[i])
 			continue;
 
-		pci_write_config_dword(l3->nb->misc, 0x1BC + slot * 4, reg);
+		pci_write_config_dword(nb->misc, 0x1BC + slot * 4, reg);
 
 		/*
 		 * We need to WBINVD on a core on the node containing the L3
@@ -428,7 +406,7 @@ static void amd_l3_disable_index(struct 
 		wbinvd_on_cpu(cpu);
 
 		reg |= BIT(31);
-		pci_write_config_dword(l3->nb->misc, 0x1BC + slot * 4, reg);
+		pci_write_config_dword(nb->misc, 0x1BC + slot * 4, reg);
 	}
 }
 
@@ -442,24 +420,24 @@ static void amd_l3_disable_index(struct 
  *
  * @return: 0 on success, error status on failure
  */
-int amd_set_l3_disable_slot(struct amd_l3_cache *l3, int cpu, unsigned slot,
+int amd_set_l3_disable_slot(struct amd_northbridge *nb, int cpu, unsigned slot,
 			    unsigned long index)
 {
 	int ret = 0;
 
 	/*  check if @slot is already used or the index is already disabled */
-	ret = amd_get_l3_disable_slot(l3, slot);
+	ret = amd_get_l3_disable_slot(nb, slot);
 	if (ret >= 0)
 		return -EINVAL;
 
-	if (index > l3->indices)
+	if (index > nb->l3_cache.indices)
 		return -EINVAL;
 
 	/* check whether the other slot has disabled the same index already */
-	if (index == amd_get_l3_disable_slot(l3, !slot))
+	if (index == amd_get_l3_disable_slot(nb, !slot))
 		return -EINVAL;
 
-	amd_l3_disable_index(l3, cpu, slot, index);
+	amd_l3_disable_index(nb, cpu, slot, index);
 
 	return 0;
 }
@@ -474,7 +452,7 @@ static ssize_t store_cache_disable(struc
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
-	if (!this_leaf->base.l3 || !amd_nb_has_feature(AMD_NB_L3_INDEX_DISABLE))
+	if (!this_leaf->base.nb || !amd_nb_has_feature(AMD_NB_L3_INDEX_DISABLE))
 		return -EINVAL;
 
 	cpu = cpumask_first(to_cpumask(this_leaf->shared_cpu_map));
@@ -482,7 +460,7 @@ static ssize_t store_cache_disable(struc
 	if (strict_strtoul(buf, 10, &val) < 0)
 		return -EINVAL;
 
-	err = amd_set_l3_disable_slot(this_leaf->base.l3, cpu, slot, val);
+	err = amd_set_l3_disable_slot(this_leaf->base.nb, cpu, slot, val);
 	if (err) {
 		if (err == -EEXIST)
 			printk(KERN_WARNING "L3 disable slot %d in use!\n",
@@ -511,7 +489,7 @@ static struct _cache_attr cache_disable_
 static ssize_t
 show_subcaches(struct _cpuid4_info *this_leaf, char *buf, unsigned int cpu)
 {
-	if (!this_leaf->base.l3 || !amd_nb_has_feature(AMD_NB_L3_PARTITIONING))
+	if (!this_leaf->base.nb || !amd_nb_has_feature(AMD_NB_L3_PARTITIONING))
 		return -EINVAL;
 
 	return sprintf(buf, "%x\n", amd_get_subcaches(cpu));
@@ -526,7 +504,7 @@ store_subcaches(struct _cpuid4_info *thi
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
-	if (!this_leaf->base.l3 || !amd_nb_has_feature(AMD_NB_L3_PARTITIONING))
+	if (!this_leaf->base.nb || !amd_nb_has_feature(AMD_NB_L3_PARTITIONING))
 		return -EINVAL;
 
 	if (strict_strtoul(buf, 16, &val) < 0)
@@ -1118,7 +1096,7 @@ static int __cpuinit cache_add_dev(struc
 
 		ktype_cache.default_attrs = default_attrs;
 #ifdef CONFIG_AMD_NB
-		if (this_leaf->base.l3)
+		if (this_leaf->base.nb)
 			ktype_cache.default_attrs = amd_l3_attrs();
 #endif
 		retval = kobject_init_and_add(&(this_object->kobj),