[PATCH v5 20/21] nvmem: layouts: Add ONIE tlv layout driver

Michael Walle
2022-12-06T20:19:26Z

From: Miquel Raynal <miquel.raynal@bootlin.com>

This layout applies on top of any non volatile storage device containing
an ONIE table factory flashed. This table follows the tlv
(type-length-value) organization described in the link below. We cannot
afford using regular parsers because the content of these tables is
manufacturer specific and must be dynamically discovered.

Link: https://opencomputeproject.github.io/onie/design-spec/hw_requirements.html
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
changes since v4:
- none

changes since v3:
- don't use kfree()
- fix typo, s/no/on/

changes since v2:
- new patch

drivers/nvmem/layouts/Kconfig | 9 ++
drivers/nvmem/layouts/Makefile | 1 +
drivers/nvmem/layouts/onie-tlv.c | 244 +++++++++++++++++++++++++++++++
3 files changed, 254 insertions(+)
create mode 100644 drivers/nvmem/layouts/onie-tlv.c

diff --git a/drivers/nvmem/layouts/Kconfig b/drivers/nvmem/layouts/Kconfig
index 75082f6b471d..9ad50474cb77 100644
--- a/drivers/nvmem/layouts/Kconfig
+++ b/drivers/nvmem/layouts/Kconfig
@@ -11,4 +11,13 @@ config NVMEM_LAYOUT_SL28_VPD

If unsure, say N.

+config NVMEM_LAYOUT_ONIE_TLV
+ bool "ONIE tlv support"
+ select CRC32
+ help
+ Say Y here if you want to support the Open Compute Project ONIE
+ Type-Length-Value standard table.
+
+ If unsure, say N.
+
endmenu
diff --git a/drivers/nvmem/layouts/Makefile b/drivers/nvmem/layouts/Makefile
index fc617b9e87d0..2974bd7d33ed 100644
--- a/drivers/nvmem/layouts/Makefile
+++ b/drivers/nvmem/layouts/Makefile
@@ -4,3 +4,4 @@
#

obj-$(CONFIG_NVMEM_LAYOUT_SL28_VPD) += sl28vpd.o
+obj-$(CONFIG_NVMEM_LAYOUT_ONIE_TLV) += onie-tlv.o
diff --git a/drivers/nvmem/layouts/onie-tlv.c b/drivers/nvmem/layouts/onie-tlv.c
new file mode 100644
index 000000000000..074c7c700845
--- /dev/null
+++ b/drivers/nvmem/layouts/onie-tlv.c
@@ -0,0 +1,244 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ONIE tlv NVMEM cells provider
+ *
+ * Copyright (C) 2022 Open Compute Group ONIE
+ * Author: Miquel Raynal <miquel.raynal@bootlin.com>
+ * Based on the nvmem driver written by: Vadym Kochan <vadym.kochan@plvision.eu>
+ * Inspired by the first layout written by: Rafał Miłecki <rafal@milecki.pl>
+ */
+
+#include <linux/crc32.h>
+#include <linux/etherdevice.h>
+#include <linux/nvmem-consumer.h>
+#include <linux/nvmem-provider.h>
+#include <linux/of.h>
+
+#define ONIE_TLV_MAX_LEN 2048
+#define ONIE_TLV_CRC_FIELD_SZ 6
+#define ONIE_TLV_CRC_SZ 4
+#define ONIE_TLV_HDR_ID "TlvInfo"
+
+struct onie_tlv_hdr {
+ u8 id[8];
+ u8 version;
+ __be16 data_len;
+} __packed;
+
+struct onie_tlv {
+ u8 type;
+ u8 len;
+} __packed;
+
+static const char *onie_tlv_cell_name(u8 type)
+{
+ switch (type) {
+ case 0x21:
+ return "product-name";
+ case 0x22:
+ return "part-number";
+ case 0x23:
+ return "serial-number";
+ case 0x24:
+ return "mac-address";
+ case 0x25:
+ return "manufacture-date";
+ case 0x26:
+ return "device-version";
+ case 0x27:
+ return "label-revision";
+ case 0x28:
+ return "platforn-name";
+ case 0x29:
+ return "onie-version";
+ case 0x2A:
+ return "num-macs";
+ case 0x2B:
+ return "manufacturer";
+ case 0x2C:
+ return "country-code";
+ case 0x2D:
+ return "vendor";
+ case 0x2E:
+ return "diag-version";
+ case 0x2F:
+ return "service-tag";
+ case 0xFD:
+ return "vendor-extension";
+ case 0xFE:
+ return "crc32";
+ default:
+ break;
+ }
+
+ return NULL;
+}
+
+static int onie_tlv_mac_read_cb(void *priv, const char *id, int index,
+ unsigned int offset, void *buf,
+ size_t bytes)
+{
+ eth_addr_add(buf, index);
+
+ return 0;
+}
+
+static nvmem_cell_post_process_t onie_tlv_read_cb(u8 type, u8 *buf)
+{
+ switch (type) {
+ case 0x24:
+ return &onie_tlv_mac_read_cb;
+ default:
+ break;
+ }
+
+ return NULL;
+}
+
+static int onie_tlv_add_cells(struct device *dev, struct nvmem_device *nvmem,
+ size_t data_len, u8 *data)
+{
+ struct nvmem_cell_info cell = {};
+ struct device_node *layout;
+ struct onie_tlv tlv;
+ unsigned int hdr_len = sizeof(struct onie_tlv_hdr);
+ unsigned int offset = 0;
+ int ret;
+
+ layout = of_nvmem_layout_get_container(nvmem);
+ if (!layout)
+ return -ENOENT;
+
+ while (offset < data_len) {
+ memcpy(&tlv, data + offset, sizeof(tlv));
+ if (offset + tlv.len >= data_len) {
+ dev_err(dev, "Out of bounds field (0x%x bytes at 0x%x)\n",
+ tlv.len, hdr_len + offset);
+ break;
+ }
+
+ cell.name = onie_tlv_cell_name(tlv.type);
+ if (!cell.name)
+ continue;
+
+ cell.offset = hdr_len + offset + sizeof(tlv.type) + sizeof(tlv.len);
+ cell.bytes = tlv.len;
+ cell.np = of_get_child_by_name(layout, cell.name);
+ cell.read_post_process = onie_tlv_read_cb(tlv.type, data + offset + sizeof(tlv));
+
+ ret = nvmem_add_one_cell(nvmem, &cell);
+ if (ret) {
+ of_node_put(layout);
+ return ret;
+ }
+
+ offset += sizeof(tlv) + tlv.len;
+ }
+
+ of_node_put(layout);
+
+ return 0;
+}
+
+static bool onie_tlv_hdr_is_valid(struct device *dev, struct onie_tlv_hdr *hdr)
+{
+ if (memcmp(hdr->id, ONIE_TLV_HDR_ID, sizeof(hdr->id))) {
+ dev_err(dev, "Invalid header\n");
+ return false;
+ }
+
+ if (hdr->version != 0x1) {
+ dev_err(dev, "Invalid version number\n");
+ return false;
+ }
+
+ return true;
+}
+
+static bool onie_tlv_crc_is_valid(struct device *dev, size_t table_len, u8 *table)
+{
+ struct onie_tlv crc_hdr;
+ u32 read_crc, calc_crc;
+ __be32 crc_be;
+
+ memcpy(&crc_hdr, table + table_len - ONIE_TLV_CRC_FIELD_SZ, sizeof(crc_hdr));
+ if (crc_hdr.type != 0xfe || crc_hdr.len != ONIE_TLV_CRC_SZ) {
+ dev_err(dev, "Invalid CRC field\n");
+ return false;
+ }
+
+ /* The table contains a JAMCRC, which is XOR'ed compared to the original
+ * CRC32 implementation as known in the Ethernet world.
+ */
+ memcpy(&crc_be, table + table_len - ONIE_TLV_CRC_SZ, ONIE_TLV_CRC_SZ);
+ read_crc = be32_to_cpu(crc_be);
+ calc_crc = crc32(~0, table, table_len - ONIE_TLV_CRC_SZ) ^ 0xFFFFFFFF;
+ if (read_crc != calc_crc) {
+ dev_err(dev, "Invalid CRC read: 0x%08x, expected: 0x%08x\n",
+ read_crc, calc_crc);
+ return false;
+ }
+
+ return true;
+}
+
+static int onie_tlv_parse_table(struct device *dev, struct nvmem_device *nvmem,
+ struct nvmem_layout *layout)
+{
+ struct onie_tlv_hdr hdr;
+ size_t table_len, data_len, hdr_len;
+ u8 *table, *data;
+ int ret;
+
+ ret = nvmem_device_read(nvmem, 0, sizeof(hdr), &hdr);
+ if (ret < 0)
+ return ret;
+
+ if (!onie_tlv_hdr_is_valid(dev, &hdr)) {
+ dev_err(dev, "Invalid ONIE TLV header\n");
+ return -EINVAL;
+ }
+
+ hdr_len = sizeof(hdr.id) + sizeof(hdr.version) + sizeof(hdr.data_len);
+ data_len = be16_to_cpu(hdr.data_len);
+ table_len = hdr_len + data_len;
+ if (table_len > ONIE_TLV_MAX_LEN) {
+ dev_err(dev, "Invalid ONIE TLV data length\n");
+ return -EINVAL;
+ }
+
+ table = devm_kmalloc(dev, table_len, GFP_KERNEL);
+ if (!table)
+ return -ENOMEM;
+
+ ret = nvmem_device_read(nvmem, 0, table_len, table);
+ if (ret != table_len)
+ return ret;
+
+ if (!onie_tlv_crc_is_valid(dev, table_len, table))
+ return -EINVAL;
+
+ data = table + hdr_len;
+ ret = onie_tlv_add_cells(dev, nvmem, data_len, data);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static const struct of_device_id onie_tlv_of_match_table[] = {
+ { .compatible = "onie,tlv-layout", },
+ {},
+};
+
+static struct nvmem_layout onie_tlv_layout = {
+ .name = "ONIE tlv layout",
+ .of_match_table = onie_tlv_of_match_table,
+ .add_cells = onie_tlv_parse_table,
+};
+
+static int __init onie_tlv_init(void)
+{
+ return nvmem_layout_register(&onie_tlv_layout);
+}
+subsys_initcall(onie_tlv_init);