[PATCH 4/9] mci: add RPMB support
Sascha Hauer
s.hauer at pengutronix.de
Wed Mar 12 05:16:19 PDT 2025
This implements the MMC specific part to access RPMB partitions:
- Provide a function to find a RPMB capable eMMC
- partition switching to the RPMB partition
- Dissecting the OP-TEE requests into the correspnding MMC read/write
multiblock commands
For now we only support a single eMMC RPMB partition per board. This is
the 99% case, but there might be systems with multiple eMMCs. The OP-TEE
protocol has a dev_id field to support multiple eMMCs, but OP-TEE itself
currently only supports a single RPMB. This means we really only need to
support one eMMC, but should there be multiple eMMCs on a system we will
need a way for the user to specify which one shall be used. As of now
the first one found will be used.
Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
---
drivers/mci/Kconfig | 3 +
drivers/mci/Makefile | 1 +
drivers/mci/mci-core.c | 24 +++++-
drivers/mci/rpmb.c | 206 +++++++++++++++++++++++++++++++++++++++++++++++++
include/mci.h | 3 +
5 files changed, 236 insertions(+), 1 deletion(-)
diff --git a/drivers/mci/Kconfig b/drivers/mci/Kconfig
index 4641e9cdcd..09648aa771 100644
--- a/drivers/mci/Kconfig
+++ b/drivers/mci/Kconfig
@@ -68,6 +68,9 @@ config MCI_MMC_GPP_PARTITIONS
Note: by default, 'MMC' devices have no 'general purpose partitions',
it requires a special one-time configuration step to enable them.
+config MCI_MMC_RPMB
+ bool "Support eMMC replay protected memory block (RPMB)"
+
comment "--- MCI host drivers ---"
config MCI_DWC_MSHC
diff --git a/drivers/mci/Makefile b/drivers/mci/Makefile
index 5e951d695f..d3df4c1bb6 100644
--- a/drivers/mci/Makefile
+++ b/drivers/mci/Makefile
@@ -1,5 +1,6 @@
# SPDX-License-Identifier: GPL-2.0-only
obj-$(CONFIG_MCI) += mci-core.o
+obj-$(CONFIG_MCI_MMC_RPMB) += rpmb.o
obj-$(CONFIG_MCI_AM654) += am654-sdhci.o
obj-$(CONFIG_MCI_ARASAN) += arasan-sdhci.o
obj-$(CONFIG_MCI_ATMEL) += atmel_mci.o atmel_mci_common.o
diff --git a/drivers/mci/mci-core.c b/drivers/mci/mci-core.c
index 18c910c4c3..9c3b35c23f 100644
--- a/drivers/mci/mci-core.c
+++ b/drivers/mci/mci-core.c
@@ -2068,7 +2068,9 @@ int mci_blk_part_switch(struct mci_part *part)
struct mci *mci = part->mci;
int ret;
- if (!IS_ENABLED(CONFIG_MCI_MMC_BOOT_PARTITIONS) && !IS_ENABLED(CONFIG_MCI_MMC_GPP_PARTITIONS))
+ if (!IS_ENABLED(CONFIG_MCI_MMC_BOOT_PARTITIONS) &&
+ !IS_ENABLED(CONFIG_MCI_MMC_GPP_PARTITIONS) &&
+ !IS_ENABLED(CONFIG_MCI_MMC_RPMB))
return 0; /* no need */
if (mci->part_curr == part)
@@ -3067,3 +3069,23 @@ struct mci *mci_get_device_by_name(const char *name)
return NULL;
}
+
+struct mci *mci_get_rpmb_dev(void)
+{
+ struct mci *mci;
+
+ if (rpmb_partition)
+ return rpmb_partition->mci;
+
+ list_for_each_entry(mci, &mci_list, list) {
+ if (mci->host->caps2 & MMC_CAP2_NO_MMC)
+ continue;
+
+ mci_detect_card(mci->host);
+
+ if (rpmb_partition)
+ return rpmb_partition->mci;
+ }
+
+ return NULL;
+}
diff --git a/drivers/mci/rpmb.c b/drivers/mci/rpmb.c
new file mode 100644
index 0000000000..5c98222bad
--- /dev/null
+++ b/drivers/mci/rpmb.c
@@ -0,0 +1,206 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2014, Staubli Faverges
+ * Pierre Aubert
+ *
+ * eMMC- Replay Protected Memory Block
+ * According to JEDEC Standard No. 84-A441
+ */
+
+#include <mci.h>
+#include <malloc.h>
+#include <dma.h>
+
+int mmc_rpmb_route_frames(struct mci *mci, void *req, unsigned long reqlen,
+ void *rsp, unsigned long rsplen);
+
+/**
+ * struct rpmb_frame - rpmb frame as defined by eMMC 5.1 (JESD84-B51)
+ *
+ * @stuff : stuff bytes
+ * @key_mac : The authentication key or the message authentication
+ * code (MAC) depending on the request/response type.
+ * The MAC will be delivered in the last (or the only)
+ * block of data.
+ * @data : Data to be written or read by signed access.
+ * @nonce : Random number generated by the host for the requests
+ * and copied to the response by the RPMB engine.
+ * @write_counter: Counter value for the total amount of the successful
+ * authenticated data write requests made by the host.
+ * @addr : Address of the data to be programmed to or read
+ * from the RPMB. Address is the serial number of
+ * the accessed block (half sector 256B).
+ * @block_count : Number of blocks (half sectors, 256B) requested to be
+ * read/programmed.
+ * @result : Includes information about the status of the write counter
+ * (valid, expired) and result of the access made to the RPMB.
+ * @req_resp : Defines the type of request and response to/from the memory.
+ *
+ * The stuff bytes and big-endian properties are modeled to fit to the spec.
+ */
+struct rpmb_frame {
+ u8 stuff[196];
+ u8 key_mac[32];
+ u8 data[256];
+ u8 nonce[16];
+ __be32 write_counter;
+ __be16 addr;
+ __be16 block_count;
+ __be16 result;
+ __be16 req_resp;
+} __packed;
+
+#define RPMB_PROGRAM_KEY 0x1 /* Program RPMB Authentication Key */
+#define RPMB_GET_WRITE_COUNTER 0x2 /* Read RPMB write counter */
+#define RPMB_WRITE_DATA 0x3 /* Write data to RPMB partition */
+#define RPMB_READ_DATA 0x4 /* Read data from RPMB partition */
+#define RPMB_RESULT_READ 0x5 /* Read result request (Internal) */
+
+static int mci_read_write_blocks(struct mci *mci, u32 opcode, int write_flag, void *buf,
+ unsigned int buf_bytes)
+{
+ int blocks = buf_bytes / 512;
+ struct mci_cmd cmd = {
+ .cmdidx = opcode,
+ .resp_type = MMC_RSP_R1,
+ };
+ struct mci_data data = {
+ .blocks = blocks,
+ .blocksize = sizeof(struct rpmb_frame),
+ };
+ int ret;
+
+ if (write_flag) {
+ data.src = buf;
+ data.flags = MMC_DATA_WRITE;
+ } else {
+ data.dest = buf;
+ data.flags = MMC_DATA_READ;
+ }
+
+ ret = mci_set_blockcount(mci, blocks | (write_flag & MMC_CMD23_ARG_REL_WR));
+ if (ret)
+ return ret;
+
+ return mci_send_cmd(mci, &cmd, &data);
+}
+
+static int rpmb_route_frames(struct mci *mci, void *req,
+ unsigned int req_len, void *resp,
+ unsigned int resp_len)
+{
+ struct rpmb_frame *frm = req;
+ unsigned int cmd_count;
+ u16 req_type;
+ bool write;
+ int ret;
+
+ if (req_len < sizeof(*frm))
+ return -EINVAL;
+
+ req_type = be16_to_cpu(frm->req_resp);
+ switch (req_type) {
+ case RPMB_PROGRAM_KEY:
+ if (req_len != sizeof(struct rpmb_frame) ||
+ resp_len != sizeof(struct rpmb_frame))
+ return -EINVAL;
+ write = true;
+ break;
+ case RPMB_GET_WRITE_COUNTER:
+ if (req_len != sizeof(struct rpmb_frame) ||
+ resp_len != sizeof(struct rpmb_frame))
+ return -EINVAL;
+ write = false;
+ break;
+ case RPMB_WRITE_DATA:
+ if (req_len % sizeof(struct rpmb_frame) ||
+ resp_len != sizeof(struct rpmb_frame))
+ return -EINVAL;
+ write = true;
+ break;
+ case RPMB_READ_DATA:
+ if (req_len != sizeof(struct rpmb_frame) ||
+ resp_len % sizeof(struct rpmb_frame))
+ return -EINVAL;
+ write = false;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (write)
+ cmd_count = 3;
+ else
+ cmd_count = 2;
+
+ if (write) {
+ struct rpmb_frame *frm = resp;
+
+ /* Send write request frame(s) */
+ ret = mci_read_write_blocks(mci, MMC_CMD_WRITE_MULTIPLE_BLOCK,
+ 1 | MMC_CMD23_ARG_REL_WR, req, req_len);
+ if (ret)
+ goto out;
+
+ /* Send result request frame */
+ memset(frm, 0, sizeof(*frm));
+ frm->req_resp = cpu_to_be16(RPMB_RESULT_READ);
+ ret = mci_read_write_blocks(mci, MMC_CMD_WRITE_MULTIPLE_BLOCK, 1,
+ resp, resp_len);
+ if (ret)
+ goto out;
+
+ /* Read response frame */
+ ret = mci_read_write_blocks(mci, MMC_CMD_READ_MULTIPLE_BLOCK, 0,
+ resp, resp_len);
+ if (ret)
+ goto out;
+ } else {
+ /* Send write request frame(s) */
+ ret = mci_read_write_blocks(mci, MMC_CMD_WRITE_MULTIPLE_BLOCK, 1,
+ req, req_len);
+ if (ret)
+ goto out;
+
+ /* Read response frame */
+ ret = mci_read_write_blocks(mci, MMC_CMD_READ_MULTIPLE_BLOCK, 0,
+ resp, resp_len);
+ if (ret)
+ goto out;
+ }
+out:
+ return ret;
+}
+
+int mci_rpmb_route_frames(struct mci *mci, void *req, unsigned long reqlen,
+ void *rsp, unsigned long rsplen)
+{
+ /*
+ * Whoever crafted the data supplied to this function knows how to
+ * format the PRMB frames and which response is expected. If
+ * there's some unexpected mismatch it's more helpful to report an
+ * error immediately than trying to guess what was the intention
+ * and possibly just delay an eventual error which will be harder
+ * to track down.
+ */
+ void *rpmb_data = NULL;
+ int ret;
+
+ mci_blk_part_switch(mci->rpmb_part);
+
+ if (!IS_ALIGNED((uintptr_t)req, ARCH_DMA_MINALIGN)) {
+ /* Memory alignment is required by MMC driver */
+ rpmb_data = dma_alloc(reqlen);
+ if (!rpmb_data)
+ return -ENOMEM;
+
+ memcpy(rpmb_data, req, reqlen);
+ req = rpmb_data;
+ }
+
+ ret = rpmb_route_frames(mci, req, reqlen, rsp, rsplen);
+
+ free(rpmb_data);
+
+ return ret;
+}
diff --git a/include/mci.h b/include/mci.h
index 08a3e46f7d..ec0390eedf 100644
--- a/include/mci.h
+++ b/include/mci.h
@@ -736,6 +736,9 @@ int mmc_select_timing(struct mci *mci);
int mci_set_blockcount(struct mci *mci, unsigned int cmdarg);
int mci_blk_part_switch(struct mci_part *part);
int mci_send_cmd(struct mci *mci, struct mci_cmd *cmd, struct mci_data *data);
+struct mci *mci_get_rpmb_dev(void);
+int mci_rpmb_route_frames(struct mci *mci, void *req, unsigned long reqlen,
+ void *rsp, unsigned long rsplen);
static inline bool mmc_card_hs200(struct mci *mci)
{
--
2.39.5
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