From: Volodymyr Babchuk <volodymyr_babchuk@epam.com>
To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        tee-dev@lists.linaro.org, Jens Wiklander <jens.wiklander@linaro.org>
Cc: Volodymyr Babchuk <vlad.babchuk@gmail.com>
Subject: [PATCH v1 05/14] tee: optee: Update protocol definitions
Date: Thu, 28 Sep 2017 21:04:02 +0300
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From: Volodymyr Babchuk <vlad.babchuk@gmail.com>

There were changes in REE<->OP-TEE ABI recently.
Now ABI allows us to pass non-contiguous memory buffers as list of
pages to OP-TEE. This can be achieved by using new parameter attribute
OPTEE_MSG_ATTR_NONCONTIG.

OP-TEE also is able to use all non-secure RAM for shared buffers. This
new capability is enabled with OPTEE_SMC_SEC_CAP_DYNAMIC_SHM flag.

This patch adds necessary definitions to the protocol definition files at
Linux side.

Signed-off-by: Volodymyr Babchuk <vlad.babchuk@gmail.com>
---
 drivers/tee/optee/optee_msg.h | 38 ++++++++++++++++++++++++++++++++------
 drivers/tee/optee/optee_smc.h |  7 +++++++
 2 files changed, 39 insertions(+), 6 deletions(-)

diff --git a/drivers/tee/optee/optee_msg.h b/drivers/tee/optee/optee_msg.h
index dd7a06e..3050490 100644
--- a/drivers/tee/optee/optee_msg.h
+++ b/drivers/tee/optee/optee_msg.h
@@ -67,11 +67,32 @@
 #define OPTEE_MSG_ATTR_META			BIT(8)
 
 /*
- * The temporary shared memory object is not physically contigous and this
- * temp memref is followed by another fragment until the last temp memref
- * that doesn't have this bit set.
+ * Pointer to a list of pages used to register user-defined SHM buffer.
+ * Used with OPTEE_MSG_ATTR_TYPE_TMEM_*.
+ * buf_ptr should point to the beginning of the buffer. Buffer will contain
+ * list of page addresses. OP-TEE core can reconstruct contiguous buffer from
+ * that page addresses list. Page addresses are stored as 64 bit values.
+ * Last entry on a page should point to the next page of buffer.
+ * Every entry in buffer should point to a 4k page beginning (12 least
+ * significant bits must be equal to zero).
+ *
+ * 12 least significant bints of optee_msg_param.u.tmem.buf_ptr should hold page
+ * offset of the user buffer.
+ *
+ * So, entries should be placed like members of this structure:
+ *
+ * struct page_data {
+ *   uint64_t pages_array[OPTEE_MSG_NONCONTIG_PAGE_SIZE/sizeof(uint64_t) - 1];
+ *   uint64_t next_page_data;
+ * };
+ *
+ * Structure is designed to exactly fit into the page size
+ * OPTEE_MSG_NONCONTIG_PAGE_SIZE which is a standard 4KB page.
+ *
+ * The size of 4KB is chosen because this is the smallest page size for ARM
+ * architectures. If REE uses larger pages, it should divide them to 4KB ones.
  */
-#define OPTEE_MSG_ATTR_FRAGMENT			BIT(9)
+#define OPTEE_MSG_ATTR_NONCONTIG		BIT(9)
 
 /*
  * Memory attributes for caching passed with temp memrefs. The actual value
@@ -94,6 +115,11 @@
 #define OPTEE_MSG_LOGIN_APPLICATION_USER	0x00000005
 #define OPTEE_MSG_LOGIN_APPLICATION_GROUP	0x00000006
 
+/*
+ * Page size used in non-contiguous buffer entries
+ */
+#define OPTEE_MSG_NONCONTIG_PAGE_SIZE		4096
+
 /**
  * struct optee_msg_param_tmem - temporary memory reference parameter
  * @buf_ptr:	Address of the buffer
@@ -145,8 +171,8 @@ struct optee_msg_param_value {
  *
  * @attr & OPTEE_MSG_ATTR_TYPE_MASK indicates if tmem, rmem or value is used in
  * the union. OPTEE_MSG_ATTR_TYPE_VALUE_* indicates value,
- * OPTEE_MSG_ATTR_TYPE_TMEM_* indicates tmem and
- * OPTEE_MSG_ATTR_TYPE_RMEM_* indicates rmem.
+ * OPTEE_MSG_ATTR_TYPE_TMEM_* indicates @tmem and
+ * OPTEE_MSG_ATTR_TYPE_RMEM_* indicates @rmem,
  * OPTEE_MSG_ATTR_TYPE_NONE indicates that none of the members are used.
  */
 struct optee_msg_param {
diff --git a/drivers/tee/optee/optee_smc.h b/drivers/tee/optee/optee_smc.h
index 069c8e1..7cd3272 100644
--- a/drivers/tee/optee/optee_smc.h
+++ b/drivers/tee/optee/optee_smc.h
@@ -222,6 +222,13 @@ struct optee_smc_get_shm_config_result {
 #define OPTEE_SMC_SEC_CAP_HAVE_RESERVED_SHM	BIT(0)
 /* Secure world can communicate via previously unregistered shared memory */
 #define OPTEE_SMC_SEC_CAP_UNREGISTERED_SHM	BIT(1)
+
+/*
+ * Secure world supports commands "register/unregister shared memory",
+ * secure world accepts command buffers located in any parts of non-secure RAM
+ */
+#define OPTEE_SMC_SEC_CAP_DYNAMIC_SHM		BIT(2)
+
 #define OPTEE_SMC_FUNCID_EXCHANGE_CAPABILITIES	9
 #define OPTEE_SMC_EXCHANGE_CAPABILITIES \
 	OPTEE_SMC_FAST_CALL_VAL(OPTEE_SMC_FUNCID_EXCHANGE_CAPABILITIES)
-- 
2.7.4