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authorBorislav Petkov <borislav.petkov@amd.com>2012-08-01 15:38:18 +0200
committerH. Peter Anvin <hpa@linux.intel.com>2012-08-22 16:16:21 -0700
commita3eb3b4da106a23b5d41bf915726172e31654a65 (patch)
treeeb8192823f4b15184eb631902aa785bb8195fbe7
parentc96d2c0905cc48e34f2b37b775b59932c416b343 (diff)
downloadlinux-linaro-stable-a3eb3b4da106a23b5d41bf915726172e31654a65.tar.gz
x86, microcode, AMD: Add a small, per-family patches cache
This is a trivial cache which collects all ucode patches for the current family of CPUs on the system. If a newer patch appears due to the container file being updated in userspace, we replace our cached version with the new one. Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> Link: http://lkml.kernel.org/r/1344361461-10076-12-git-send-email-bp@amd64.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
-rw-r--r--arch/x86/kernel/microcode_amd.c67
1 files changed, 66 insertions, 1 deletions
diff --git a/arch/x86/kernel/microcode_amd.c b/arch/x86/kernel/microcode_amd.c
index 03ed5af7053d..cacdc9a5ee49 100644
--- a/arch/x86/kernel/microcode_amd.c
+++ b/arch/x86/kernel/microcode_amd.c
@@ -78,12 +78,22 @@ static struct equiv_cpu_entry *equiv_cpu_table;
/* page-sized ucode patch buffer */
void *patch;
+struct ucode_patch {
+ struct list_head plist;
+ void *data;
+ u32 patch_id;
+ u16 equiv_cpu;
+};
+
+static LIST_HEAD(pcache);
+
static u16 find_equiv_id(unsigned int cpu)
{
struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
int i = 0;
- BUG_ON(equiv_cpu_table == NULL);
+ if (!equiv_cpu_table)
+ return 0;
while (equiv_cpu_table[i].installed_cpu != 0) {
if (uci->cpu_sig.sig == equiv_cpu_table[i].installed_cpu)
@@ -108,6 +118,61 @@ static u32 find_cpu_family_by_equiv_cpu(u16 equiv_cpu)
return 0;
}
+/*
+ * a small, trivial cache of per-family ucode patches
+ */
+static struct ucode_patch *cache_find_patch(u16 equiv_cpu)
+{
+ struct ucode_patch *p;
+
+ list_for_each_entry(p, &pcache, plist)
+ if (p->equiv_cpu == equiv_cpu)
+ return p;
+ return NULL;
+}
+
+static void update_cache(struct ucode_patch *new_patch)
+{
+ struct ucode_patch *p;
+
+ list_for_each_entry(p, &pcache, plist) {
+ if (p->equiv_cpu == new_patch->equiv_cpu) {
+ if (p->patch_id >= new_patch->patch_id)
+ /* we already have the latest patch */
+ return;
+
+ list_replace(&p->plist, &new_patch->plist);
+ kfree(p->data);
+ kfree(p);
+ return;
+ }
+ }
+ /* no patch found, add it */
+ list_add_tail(&new_patch->plist, &pcache);
+}
+
+static void free_cache(void)
+{
+ struct ucode_patch *p;
+
+ list_for_each_entry_reverse(p, &pcache, plist) {
+ __list_del(p->plist.prev, p->plist.next);
+ kfree(p->data);
+ kfree(p);
+ }
+}
+
+static struct ucode_patch *find_patch(unsigned int cpu)
+{
+ u16 equiv_id;
+
+ equiv_id = find_equiv_id(cpu);
+ if (!equiv_id)
+ return NULL;
+
+ return cache_find_patch(equiv_id);
+}
+
static int collect_cpu_info_amd(int cpu, struct cpu_signature *csig)
{
struct cpuinfo_x86 *c = &cpu_data(cpu);