Cr50: NvMem: Connected function stubs in /board/tpm2/NVMem.c

Used #define CONFIG_FLASH_NVMEM to have functions in
/board/tpm2/NVMem.c utlitize on chip Nvmem functions.
On chip NV Memory availability is tied to an internal nvmem
error state which itself only depends on finding at least one
valid partition.

Added nvmem_is_different and nvmem_move functions which were
needed to complete the tpm2 platform interface. In addition,
added unit tests to support these two new functions.

BUG=chrome-os-partner:44745
BRANCH=none
TEST=manual
make runtests TEST_LIST_HOST=nvmem and verify that all tests pass.
Tested with tcg_test utility to test reads/writes using the
command "build/test-tpm2/install/bin/compliance --ntpm
localhost:9883 --select CPCTPM_TC2_3_33_07_01".

Change-Id: I475fdd1331e28ede00f9b674c7bee1536fa9ea48
Signed-off-by: Scott <scollyer@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/346236
Commit-Ready: Scott Collyer <scollyer@chromium.org>
Tested-by: Scott Collyer <scollyer@chromium.org>
Reviewed-by: Bill Richardson <wfrichar@chromium.org>

1 files changed, 77 insertions, 2 deletions

diff --git a/common/nvmem.c b/common/nvmem.c
index 7fbf5ebada..63ea1581f5 100644
--- a/common/nvmem.c
+++ b/common/nvmem.c
@@ -33,6 +33,9 @@ static int nvmem_act_partition;
 /* NvMem Cache Memory pointer */
 static uint8_t *cache_base_ptr;
 
+/* NvMem error state */
+static int nvmem_error_state;
+
 static int nvmem_verify_partition_sha(int index)
 {
 	uint8_t sha_comp[NVMEM_SHA_SIZE];
@@ -319,10 +322,14 @@ int nvmem_init(void)
 		CPRINTF("%s:%d\n", __func__, __LINE__);
 		return ret;
 	}
+	/* Initialize error state, assume everything is good */
+	nvmem_error_state = EC_SUCCESS;
 	/* Default state for cache_base_ptr */
 	cache_base_ptr = NULL;
 	ret = nvmem_find_partition();
 	if (ret != EC_SUCCESS) {
+		/* Change error state to non-zero */
+		nvmem_error_state = EC_ERROR_UNKNOWN;
 		CPRINTF("%s:%d\n", __func__, __LINE__);
 		return ret;
 	}
@@ -330,7 +337,40 @@ int nvmem_init(void)
 	return EC_SUCCESS;
 }
 
-int nvmem_read(unsigned int offset, unsigned int size,
+int nvmem_get_error_state(void)
+{
+	return nvmem_error_state;
+}
+
+int nvmem_is_different(uint32_t offset, uint32_t size, void *data,
+		       enum nvmem_users user)
+{
+	int ret;
+	uint8_t *p_src;
+	uintptr_t src_addr;
+	uint32_t src_offset;
+
+	/* Point to either NvMem flash or ram if that's active */
+	if (cache_base_ptr == NULL)
+		src_addr = CONFIG_FLASH_NVMEM_BASE + nvmem_act_partition *
+			NVMEM_PARTITION_SIZE;
+
+	else
+		src_addr = (uintptr_t)cache_base_ptr;
+
+	/* Get partition offset for this read operation */
+	ret = nvmem_get_partition_off(user, offset, size, &src_offset);
+	if (ret != EC_SUCCESS)
+		return ret;
+
+	/* Advance to the correct byte within the data buffer */
+	src_addr += src_offset;
+	p_src = (uint8_t *)src_addr;
+	/* Compare NvMem with data */
+	return memcmp(p_src, data, size);
+}
+
+int nvmem_read(uint32_t offset, uint32_t size,
 		    void *data, enum nvmem_users user)
 {
 	int ret;
@@ -359,7 +399,7 @@ int nvmem_read(unsigned int offset, unsigned int size,
 	return EC_SUCCESS;
 }
 
-int nvmem_write(unsigned int offset, unsigned int size,
+int nvmem_write(uint32_t offset, uint32_t size,
 		 void *data, enum nvmem_users user)
 {
 	int ret;
@@ -388,6 +428,41 @@ int nvmem_write(unsigned int offset, unsigned int size,
 	return EC_SUCCESS;
 }
 
+int nvmem_move(uint32_t src_offset, uint32_t dest_offset, uint32_t size,
+		enum nvmem_users user)
+{
+	int ret;
+	uint8_t *p_src, *p_dest;
+	uintptr_t base_addr;
+	uint32_t s_buff_offset, d_buff_offset;
+
+	/* Make sure that the cache buffer is active */
+	ret = nvmem_update_cache_ptr();
+	if (ret)
+		/* TODO: What to do when can't access cache buffer? */
+		return ret;
+
+	/* Compute partition offset for source */
+	ret = nvmem_get_partition_off(user, src_offset, size, &s_buff_offset);
+	if (ret != EC_SUCCESS)
+		return ret;
+
+	/* Compute partition offset for destination */
+	ret = nvmem_get_partition_off(user, dest_offset, size, &d_buff_offset);
+	if (ret != EC_SUCCESS)
+		return ret;
+
+	base_addr = (uintptr_t)cache_base_ptr;
+	/* Create pointer to src location within partition */
+	p_src = (uint8_t *)(base_addr + s_buff_offset);
+	/* Create pointer to dest location within partition */
+	p_dest = (uint8_t *)(base_addr + d_buff_offset);
+	/* Move the data block in NvMem */
+	memmove(p_dest, p_src, size);
+
+	return EC_SUCCESS;
+}
+
 int nvmem_commit(void)
 {
 	int nvmem_offset;