1 files changed, 266 insertions, 0 deletions
diff --git a/drivers/platform/x86/intel/ifs/load.c b/drivers/platform/x86/intel/ifs/load.c
new file mode 100644
index 000000000..3e52b4eb1
--- /dev/null
+++ b/drivers/platform/x86/intel/ifs/load.c
@@ -0,0 +1,266 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright(c) 2022 Intel Corporation. */
+
+#include <linux/firmware.h>
+#include <asm/cpu.h>
+#include <linux/slab.h>
+#include <asm/microcode_intel.h>
+
+#include "ifs.h"
+
+struct ifs_header {
+	u32 header_ver;
+	u32 blob_revision;
+	u32 date;
+	u32 processor_sig;
+	u32 check_sum;
+	u32 loader_rev;
+	u32 processor_flags;
+	u32 metadata_size;
+	u32 total_size;
+	u32 fusa_info;
+	u64 reserved;
+};
+
+#define IFS_HEADER_SIZE	(sizeof(struct ifs_header))
+static struct ifs_header *ifs_header_ptr;	/* pointer to the ifs image header */
+static u64 ifs_hash_ptr;			/* Address of ifs metadata (hash) */
+static u64 ifs_test_image_ptr;			/* 256B aligned address of test pattern */
+static DECLARE_COMPLETION(ifs_done);
+
+static const char * const scan_hash_status[] = {
+	[0] = "No error reported",
+	[1] = "Attempt to copy scan hashes when copy already in progress",
+	[2] = "Secure Memory not set up correctly",
+	[3] = "FuSaInfo.ProgramID does not match or ff-mm-ss does not match",
+	[4] = "Reserved",
+	[5] = "Integrity check failed",
+	[6] = "Scan reload or test is in progress"
+};
+
+static const char * const scan_authentication_status[] = {
+	[0] = "No error reported",
+	[1] = "Attempt to authenticate a chunk which is already marked as authentic",
+	[2] = "Chunk authentication error. The hash of chunk did not match expected value"
+};
+
+/*
+ * To copy scan hashes and authenticate test chunks, the initiating cpu must point
+ * to the EDX:EAX to the test image in linear address.
+ * Run wrmsr(MSR_COPY_SCAN_HASHES) for scan hash copy and run wrmsr(MSR_AUTHENTICATE_AND_COPY_CHUNK)
+ * for scan hash copy and test chunk authentication.
+ */
+static void copy_hashes_authenticate_chunks(struct work_struct *work)
+{
+	struct ifs_work *local_work = container_of(work, struct ifs_work, w);
+	union ifs_scan_hashes_status hashes_status;
+	union ifs_chunks_auth_status chunk_status;
+	struct device *dev = local_work->dev;
+	int i, num_chunks, chunk_size;
+	struct ifs_data *ifsd;
+	u64 linear_addr, base;
+	u32 err_code;
+
+	ifsd = ifs_get_data(dev);
+	/* run scan hash copy */
+	wrmsrl(MSR_COPY_SCAN_HASHES, ifs_hash_ptr);
+	rdmsrl(MSR_SCAN_HASHES_STATUS, hashes_status.data);
+
+	/* enumerate the scan image information */
+	num_chunks = hashes_status.num_chunks;
+	chunk_size = hashes_status.chunk_size * 1024;
+	err_code = hashes_status.error_code;
+
+	if (!hashes_status.valid) {
+		ifsd->loading_error = true;
+		if (err_code >= ARRAY_SIZE(scan_hash_status)) {
+			dev_err(dev, "invalid error code 0x%x for hash copy\n", err_code);
+			goto done;
+		}
+		dev_err(dev, "Hash copy error : %s", scan_hash_status[err_code]);
+		goto done;
+	}
+
+	/* base linear address to the scan data */
+	base = ifs_test_image_ptr;
+
+	/* scan data authentication and copy chunks to secured memory */
+	for (i = 0; i < num_chunks; i++) {
+		linear_addr = base + i * chunk_size;
+		linear_addr |= i;
+
+		wrmsrl(MSR_AUTHENTICATE_AND_COPY_CHUNK, linear_addr);
+		rdmsrl(MSR_CHUNKS_AUTHENTICATION_STATUS, chunk_status.data);
+
+		ifsd->valid_chunks = chunk_status.valid_chunks;
+		err_code = chunk_status.error_code;
+
+		if (err_code) {
+			ifsd->loading_error = true;
+			if (err_code >= ARRAY_SIZE(scan_authentication_status)) {
+				dev_err(dev,
+					"invalid error code 0x%x for authentication\n", err_code);
+				goto done;
+			}
+			dev_err(dev, "Chunk authentication error %s\n",
+				scan_authentication_status[err_code]);
+			goto done;
+		}
+	}
+done:
+	complete(&ifs_done);
+}
+
+/*
+ * IFS requires scan chunks authenticated per each socket in the platform.
+ * Once the test chunk is authenticated, it is automatically copied to secured memory
+ * and proceed the authentication for the next chunk.
+ */
+static int scan_chunks_sanity_check(struct device *dev)
+{
+	int metadata_size, curr_pkg, cpu, ret = -ENOMEM;
+	struct ifs_data *ifsd = ifs_get_data(dev);
+	bool *package_authenticated;
+	struct ifs_work local_work;
+	char *test_ptr;
+
+	package_authenticated = kcalloc(topology_max_packages(), sizeof(bool), GFP_KERNEL);
+	if (!package_authenticated)
+		return ret;
+
+	metadata_size = ifs_header_ptr->metadata_size;
+
+	/* Spec says that if the Meta Data Size = 0 then it should be treated as 2000 */
+	if (metadata_size == 0)
+		metadata_size = 2000;
+
+	/* Scan chunk start must be 256 byte aligned */
+	if ((metadata_size + IFS_HEADER_SIZE) % 256) {
+		dev_err(dev, "Scan pattern offset within the binary is not 256 byte aligned\n");
+		return -EINVAL;
+	}
+
+	test_ptr = (char *)ifs_header_ptr + IFS_HEADER_SIZE + metadata_size;
+	ifsd->loading_error = false;
+
+	ifs_test_image_ptr = (u64)test_ptr;
+	ifsd->loaded_version = ifs_header_ptr->blob_revision;
+
+	/* copy the scan hash and authenticate per package */
+	cpus_read_lock();
+	for_each_online_cpu(cpu) {
+		curr_pkg = topology_physical_package_id(cpu);
+		if (package_authenticated[curr_pkg])
+			continue;
+		reinit_completion(&ifs_done);
+		local_work.dev = dev;
+		INIT_WORK_ONSTACK(&local_work.w, copy_hashes_authenticate_chunks);
+		schedule_work_on(cpu, &local_work.w);
+		wait_for_completion(&ifs_done);
+		if (ifsd->loading_error)
+			goto out;
+		package_authenticated[curr_pkg] = 1;
+	}
+	ret = 0;
+out:
+	cpus_read_unlock();
+	kfree(package_authenticated);
+
+	return ret;
+}
+
+static int ifs_sanity_check(struct device *dev,
+			    const struct microcode_header_intel *mc_header)
+{
+	unsigned long total_size, data_size;
+	u32 sum, *mc;
+
+	total_size = get_totalsize(mc_header);
+	data_size = get_datasize(mc_header);
+
+	if ((data_size + MC_HEADER_SIZE > total_size) || (total_size % sizeof(u32))) {
+		dev_err(dev, "bad ifs data file size.\n");
+		return -EINVAL;
+	}
+
+	if (mc_header->ldrver != 1 || mc_header->hdrver != 1) {
+		dev_err(dev, "invalid/unknown ifs update format.\n");
+		return -EINVAL;
+	}
+
+	mc = (u32 *)mc_header;
+	sum = 0;
+	for (int i = 0; i < total_size / sizeof(u32); i++)
+		sum += mc[i];
+
+	if (sum) {
+		dev_err(dev, "bad ifs data checksum, aborting.\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static bool find_ifs_matching_signature(struct device *dev, struct ucode_cpu_info *uci,
+					const struct microcode_header_intel *shdr)
+{
+	unsigned int mc_size;
+
+	mc_size = get_totalsize(shdr);
+
+	if (!mc_size || ifs_sanity_check(dev, shdr) < 0) {
+		dev_err(dev, "ifs sanity check failure\n");
+		return false;
+	}
+
+	if (!intel_cpu_signatures_match(uci->cpu_sig.sig, uci->cpu_sig.pf, shdr->sig, shdr->pf)) {
+		dev_err(dev, "ifs signature, pf not matching\n");
+		return false;
+	}
+
+	return true;
+}
+
+static bool ifs_image_sanity_check(struct device *dev, const struct microcode_header_intel *data)
+{
+	struct ucode_cpu_info uci;
+
+	intel_cpu_collect_info(&uci);
+
+	return find_ifs_matching_signature(dev, &uci, data);
+}
+
+/*
+ * Load ifs image. Before loading ifs module, the ifs image must be located
+ * in /lib/firmware/intel/ifs and named as {family/model/stepping}.{testname}.
+ */
+void ifs_load_firmware(struct device *dev)
+{
+	struct ifs_data *ifsd = ifs_get_data(dev);
+	const struct firmware *fw;
+	char scan_path[32];
+	int ret;
+
+	snprintf(scan_path, sizeof(scan_path), "intel/ifs/%02x-%02x-%02x.scan",
+		 boot_cpu_data.x86, boot_cpu_data.x86_model, boot_cpu_data.x86_stepping);
+
+	ret = request_firmware_direct(&fw, scan_path, dev);
+	if (ret) {
+		dev_err(dev, "ifs file %s load failed\n", scan_path);
+		goto done;
+	}
+
+	if (!ifs_image_sanity_check(dev, (struct microcode_header_intel *)fw->data)) {
+		dev_err(dev, "ifs header sanity check failed\n");
+		goto release;
+	}
+
+	ifs_header_ptr = (struct ifs_header *)fw->data;
+	ifs_hash_ptr = (u64)(ifs_header_ptr + 1);
+
+	ret = scan_chunks_sanity_check(dev);
+release:
+	release_firmware(fw);
+done:
+	ifsd->loaded = (ret == 0);
+}