static const char
ucode_path[] __maybe_unused = "kernel/x86/microcode/AuthenticAMD.bin";
-static size_t compute_container_size(u8 *data, u32 total_size)
-{
- size_t size = 0;
- u32 *header = (u32 *)data;
-
- if (header[0] != UCODE_MAGIC ||
- header[1] != UCODE_EQUIV_CPU_TABLE_TYPE || /* type */
- header[2] == 0) /* size */
- return size;
-
- size = header[2] + CONTAINER_HDR_SZ;
- total_size -= size;
- data += size;
-
- while (total_size) {
- u16 patch_size;
-
- header = (u32 *)data;
-
- if (header[0] != UCODE_UCODE_TYPE)
- break;
-
- /*
- * Sanity-check patch size.
- */
- patch_size = header[1];
- if (patch_size > PATCH_MAX_SIZE)
- break;
-
- size += patch_size + SECTION_HDR_SIZE;
- data += patch_size + SECTION_HDR_SIZE;
- total_size -= patch_size + SECTION_HDR_SIZE;
- }
-
- return size;
-}
-
static u16 find_equiv_id(struct equiv_cpu_entry *equiv_table, u32 sig)
{
for (; equiv_table && equiv_table->installed_cpu; equiv_table++) {
* This scans the ucode blob for the proper container as we can have multiple
* containers glued together. Returns the equivalence ID from the equivalence
* table or 0 if none found.
+ * Returns the amount of bytes consumed while scanning. @desc contains all the
+ * data we're going to use in later stages of the application.
*/
-static u16
-find_proper_container(u8 *ucode, size_t size, struct cont_desc *desc)
+static ssize_t parse_container(u8 *ucode, ssize_t size, struct cont_desc *desc)
{
- struct cont_desc ret = { 0 };
- u32 eax, ebx, ecx, edx;
struct equiv_cpu_entry *eq;
- int offset, left;
- u16 eq_id = 0;
- u32 *header;
- u8 *data;
+ ssize_t orig_size = size;
+ u32 *hdr = (u32 *)ucode;
+ u32 eax, ebx, ecx, edx;
+ u16 eq_id;
+ u8 *buf;
- data = ucode;
- left = size;
- header = (u32 *)data;
+ /* Am I looking at an equivalence table header? */
+ if (hdr[0] != UCODE_MAGIC ||
+ hdr[1] != UCODE_EQUIV_CPU_TABLE_TYPE ||
+ hdr[2] == 0) {
+ desc->eq_id = 0;
+ return CONTAINER_HDR_SZ;
+ }
+ buf = ucode;
- /* find equiv cpu table */
- if (header[0] != UCODE_MAGIC ||
- header[1] != UCODE_EQUIV_CPU_TABLE_TYPE || /* type */
- header[2] == 0) /* size */
- return eq_id;
+ eq = (struct equiv_cpu_entry *)(buf + CONTAINER_HDR_SZ);
- eax = 0x00000001;
+ eax = 1;
ecx = 0;
native_cpuid(&eax, &ebx, &ecx, &edx);
- while (left > 0) {
- eq = (struct equiv_cpu_entry *)(data + CONTAINER_HDR_SZ);
-
- ret.data = data;
+ /* Find the equivalence ID of our CPU in this table: */
+ eq_id = find_equiv_id(eq, eax);
- /* Advance past the container header */
- offset = header[2] + CONTAINER_HDR_SZ;
- data += offset;
- left -= offset;
+ buf += hdr[2] + CONTAINER_HDR_SZ;
+ size -= hdr[2] + CONTAINER_HDR_SZ;
- eq_id = find_equiv_id(eq, eax);
- if (eq_id) {
- ret.size = compute_container_size(ret.data, left + offset);
+ /*
+ * Scan through the rest of the container to find where it ends. We do
+ * some basic sanity-checking too.
+ */
+ while (size > 0) {
+ struct microcode_amd *mc;
+ u32 patch_size;
- /*
- * truncate how much we need to iterate over in the
- * ucode update loop below
- */
- left = ret.size - offset;
+ hdr = (u32 *)buf;
- *desc = ret;
- return eq_id;
- }
+ if (hdr[0] != UCODE_UCODE_TYPE)
+ break;
- /*
- * support multiple container files appended together. if this
- * one does not have a matching equivalent cpu entry, we fast
- * forward to the next container file.
- */
- while (left > 0) {
- header = (u32 *)data;
+ /* Sanity-check patch size. */
+ patch_size = hdr[1];
+ if (patch_size > PATCH_MAX_SIZE)
+ break;
- if (header[0] == UCODE_MAGIC &&
- header[1] == UCODE_EQUIV_CPU_TABLE_TYPE)
- break;
+ /* Skip patch section header: */
+ buf += SECTION_HDR_SIZE;
+ size -= SECTION_HDR_SIZE;
- offset = header[1] + SECTION_HDR_SIZE;
- data += offset;
- left -= offset;
+ mc = (struct microcode_amd *)buf;
+ if (eq_id == mc->hdr.processor_rev_id) {
+ desc->psize = patch_size;
+ desc->mc = mc;
}
- /* mark where the next microcode container file starts */
- offset = data - (u8 *)ucode;
- ucode = data;
+ buf += patch_size;
+ size -= patch_size;
}
- return eq_id;
+ /*
+ * If we have found a patch (desc->mc), it means we're looking at the
+ * container which has a patch for this CPU so return 0 to mean, @ucode
+ * already points to the proper container. Otherwise, we return the size
+ * we scanned so that we can advance to the next container in the
+ * buffer.
+ */
+ if (desc->mc) {
+ desc->eq_id = eq_id;
+ desc->data = ucode;
+ desc->size = orig_size - size;
+
+ return 0;
+ }
+
+ return orig_size - size;
+}
+
+/*
+ * Scan the ucode blob for the proper container as we can have multiple
+ * containers glued together.
+ */
+static void scan_containers(u8 *ucode, size_t size, struct cont_desc *desc)
+{
+ ssize_t rem = size;
+
+ while (rem >= 0) {
+ ssize_t s = parse_container(ucode, rem, desc);
+ if (!s)
+ return;
+
+ ucode += s;
+ rem -= s;
+ }
}
static int __apply_microcode_amd(struct microcode_amd *mc)
* load_microcode_amd() to save equivalent cpu table and microcode patches in
* kernel heap memory.
*
- * Returns true if container found (sets @ret_cont), false otherwise.
+ * Returns true if container found (sets @desc), false otherwise.
*/
static bool apply_microcode_early_amd(void *ucode, size_t size, bool save_patch,
- struct cont_desc *desc)
+ struct cont_desc *ret_desc)
{
+ struct cont_desc desc = { 0 };
u8 (*patch)[PATCH_MAX_SIZE];
- u32 rev, *header, *new_rev;
- struct cont_desc ret;
- int offset, left;
- u16 eq_id = 0;
- u8 *data;
+ struct microcode_amd *mc;
+ u32 rev, *new_rev;
+ bool ret = false;
#ifdef CONFIG_X86_32
new_rev = (u32 *)__pa_nodebug(&ucode_new_rev);
if (check_current_patch_level(&rev, true))
return false;
- eq_id = find_proper_container(ucode, size, &ret);
- if (!eq_id)
- return false;
-
- this_equiv_id = eq_id;
- header = (u32 *)ret.data;
-
- /* We're pointing to an equiv table, skip over it. */
- data = ret.data + header[2] + CONTAINER_HDR_SZ;
- left = ret.size - (header[2] + CONTAINER_HDR_SZ);
-
- while (left > 0) {
- struct microcode_amd *mc;
-
- header = (u32 *)data;
- if (header[0] != UCODE_UCODE_TYPE || /* type */
- header[1] == 0) /* size */
- break;
+ scan_containers(ucode, size, &desc);
+ if (!desc.eq_id)
+ return ret;
- mc = (struct microcode_amd *)(data + SECTION_HDR_SIZE);
+ this_equiv_id = desc.eq_id;
- if (eq_id == mc->hdr.processor_rev_id && rev < mc->hdr.patch_id) {
+ mc = desc.mc;
+ if (!mc)
+ return ret;
- if (!__apply_microcode_amd(mc)) {
- rev = mc->hdr.patch_id;
- *new_rev = rev;
+ if (rev >= mc->hdr.patch_id)
+ return ret;
- if (save_patch)
- memcpy(patch, mc, min_t(u32, header[1], PATCH_MAX_SIZE));
- }
- }
+ if (!__apply_microcode_amd(mc)) {
+ *new_rev = mc->hdr.patch_id;
+ ret = true;
- offset = header[1] + SECTION_HDR_SIZE;
- data += offset;
- left -= offset;
+ if (save_patch)
+ memcpy(patch, mc, min_t(u32, desc.psize, PATCH_MAX_SIZE));
}
- if (desc)
- *desc = ret;
+ if (ret_desc)
+ *ret_desc = desc;
- return true;
+ return ret;
}
static bool get_builtin_microcode(struct cpio_data *cp, unsigned int family)
}
if (!apply_microcode_early_amd(cp.data, cp.size, false, &cont)) {
+ cont.data = NULL;
cont.size = -1;
return;
}
{
enum ucode_state ret;
int retval = 0;
- u16 eq_id;
if (!cont.data) {
if (IS_ENABLED(CONFIG_X86_32) && (cont.size != -1)) {
return -EINVAL;
}
- eq_id = find_proper_container(cp.data, cp.size, &cont);
- if (!eq_id) {
+ scan_containers(cp.data, cp.size, &cont);
+ if (!cont.eq_id) {
cont.size = -1;
return -EINVAL;
}