From: Borislav Petkov <[email protected]> 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 <[email protected]> --- arch/x86/kernel/microcode_amd.c | 67 ++++++++++++++++++++++++++++++++++++++++- 1 file changed, 66 insertions(+), 1 deletion(-) 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); -- 1.7.11.rc1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
