platform/x86/intel/ifs: Gen2 scan image loading

Scan image loading flow for newer IFS generations are slightly different
from that of current generation. In newer schemes, loading need not be
done once for each socket as was done in gen0.

Also the width of NUM_CHUNKS bitfield in SCAN_HASHES_STATUS MSR has
increased from 8 -> 16 bits. Similarly there are width differences for
CHUNK_AUTHENTICATION_STATUS too.

Further the parameter to AUTHENTICATE_AND_COPY_CHUNK is passed
differently in newer generations.

Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: Pengfei Xu <pengfei.xu@intel.com>
Link: https://lore.kernel.org/r/20231005195137.3117166-4-jithu.joseph@intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

1 files changed, 110 insertions, 2 deletions

diff --git a/drivers/platform/x86/intel/ifs/load.c b/drivers/platform/x86/intel/ifs/load.c
index 851c97cc6a6b..6b827247945b 100644
--- a/drivers/platform/x86/intel/ifs/load.c
+++ b/drivers/platform/x86/intel/ifs/load.c
@@ -2,6 +2,7 @@
 /* Copyright(c) 2022 Intel Corporation. */
 
 #include <linux/firmware.h>
+#include <linux/sizes.h>
 #include <asm/cpu.h>
 #include <asm/microcode.h>
 
@@ -26,6 +27,11 @@ union meta_data {
 
 #define IFS_HEADER_SIZE	(sizeof(struct microcode_header_intel))
 #define META_TYPE_IFS	1
+#define INVALIDATE_STRIDE	0x1UL
+#define IFS_GEN_STRIDE_AWARE	2
+#define AUTH_INTERRUPTED_ERROR	5
+#define IFS_AUTH_RETRY_CT	10
+
 static  struct microcode_header_intel *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 */
@@ -44,7 +50,10 @@ static const char * const scan_hash_status[] = {
 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"
+	[2] = "Chunk authentication error. The hash of chunk did not match expected value",
+	[3] = "Reserved",
+	[4] = "Chunk outside the current stride",
+	[5] = "Authentication flow interrupted",
 };
 
 #define MC_HEADER_META_TYPE_END		(0)
@@ -154,6 +163,102 @@ done:
 	complete(&ifs_done);
 }
 
+static int get_num_chunks(int gen, union ifs_scan_hashes_status_gen2 status)
+{
+	return gen >= IFS_GEN_STRIDE_AWARE ? status.chunks_in_stride : status.num_chunks;
+}
+
+static bool need_copy_scan_hashes(struct ifs_data *ifsd)
+{
+	return !ifsd->loaded ||
+		ifsd->generation < IFS_GEN_STRIDE_AWARE ||
+		ifsd->loaded_version != ifs_header_ptr->rev;
+}
+
+static int copy_hashes_authenticate_chunks_gen2(struct device *dev)
+{
+	union ifs_scan_hashes_status_gen2 hashes_status;
+	union ifs_chunks_auth_status_gen2 chunk_status;
+	u32 err_code, valid_chunks, total_chunks;
+	int i, num_chunks, chunk_size;
+	union meta_data *ifs_meta;
+	int starting_chunk_nr;
+	struct ifs_data *ifsd;
+	u64 linear_addr, base;
+	u64 chunk_table[2];
+	int retry_count;
+
+	ifsd = ifs_get_data(dev);
+
+	if (need_copy_scan_hashes(ifsd)) {
+		wrmsrl(MSR_COPY_SCAN_HASHES, ifs_hash_ptr);
+		rdmsrl(MSR_SCAN_HASHES_STATUS, hashes_status.data);
+
+		/* enumerate the scan image information */
+		chunk_size = hashes_status.chunk_size * SZ_1K;
+		err_code = hashes_status.error_code;
+
+		num_chunks = get_num_chunks(ifsd->generation, hashes_status);
+
+		if (!hashes_status.valid) {
+			hashcopy_err_message(dev, err_code);
+			return -EIO;
+		}
+		ifsd->loaded_version = ifs_header_ptr->rev;
+		ifsd->chunk_size = chunk_size;
+	} else {
+		num_chunks = ifsd->valid_chunks;
+		chunk_size = ifsd->chunk_size;
+	}
+
+	if (ifsd->generation >= IFS_GEN_STRIDE_AWARE) {
+		wrmsrl(MSR_SAF_CTRL, INVALIDATE_STRIDE);
+		rdmsrl(MSR_CHUNKS_AUTHENTICATION_STATUS, chunk_status.data);
+		if (chunk_status.valid_chunks != 0) {
+			dev_err(dev, "Couldn't invalidate installed stride - %d\n",
+				chunk_status.valid_chunks);
+			return -EIO;
+		}
+	}
+
+	base = ifs_test_image_ptr;
+	ifs_meta = (union meta_data *)find_meta_data(ifs_header_ptr, META_TYPE_IFS);
+	starting_chunk_nr = ifs_meta->starting_chunk;
+
+	/* scan data authentication and copy chunks to secured memory */
+	for (i = 0; i < num_chunks; i++) {
+		retry_count = IFS_AUTH_RETRY_CT;
+		linear_addr = base + i * chunk_size;
+
+		chunk_table[0] = starting_chunk_nr + i;
+		chunk_table[1] = linear_addr;
+		do {
+			wrmsrl(MSR_AUTHENTICATE_AND_COPY_CHUNK, (u64)chunk_table);
+			rdmsrl(MSR_CHUNKS_AUTHENTICATION_STATUS, chunk_status.data);
+			err_code = chunk_status.error_code;
+		} while (err_code == AUTH_INTERRUPTED_ERROR && --retry_count);
+
+		if (err_code) {
+			ifsd->loading_error = true;
+			auth_err_message(dev, err_code);
+			return -EIO;
+		}
+	}
+
+	valid_chunks = chunk_status.valid_chunks;
+	total_chunks = chunk_status.total_chunks;
+
+	if (valid_chunks != total_chunks) {
+		ifsd->loading_error = true;
+		dev_err(dev, "Couldn't authenticate all the chunks. Authenticated %d total %d.\n",
+			valid_chunks, total_chunks);
+		return -EIO;
+	}
+	ifsd->valid_chunks = valid_chunks;
+
+	return 0;
+}
+
 static int validate_ifs_metadata(struct device *dev)
 {
 	struct ifs_data *ifsd = ifs_get_data(dev);
@@ -206,7 +311,9 @@ static int scan_chunks_sanity_check(struct device *dev)
 		return ret;
 
 	ifsd->loading_error = false;
-	ifsd->loaded_version = ifs_header_ptr->rev;
+
+	if (ifsd->generation > 0)
+		return copy_hashes_authenticate_chunks_gen2(dev);
 
 	/* copy the scan hash and authenticate per package */
 	cpus_read_lock();
@@ -226,6 +333,7 @@ static int scan_chunks_sanity_check(struct device *dev)
 		ifs_pkg_auth[curr_pkg] = 1;
 	}
 	ret = 0;
+	ifsd->loaded_version = ifs_header_ptr->rev;
 out:
 	cpus_read_unlock();