[PATCH 5/5] firmware: arm_ffa: Fix big-endian support in __ffa_partition_info_regs_get()

[Sudeep Holla <sudeep.holla@arm.com>]

Currently the FF-A driver doesn't support big-endian correctly. It is
hard to regularly test the setup due to lack of test infrastructure and
tools.

In order to support full stack, we need to take small steps in getting
the support for big-endian kernel added slowly. This change fixes the
support in __ffa_partition_info_regs_get() so that the response from the
firmware are converted correctly as required. With this change, we can
enumerate all the FF-A devices correctly in the big-endian kernel if the
FFA_PARTITION_INFO_REGS_GET is supported.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
---
 drivers/firmware/arm_ffa/driver.c | 31 +++++++++++++++++++++++++++++--
 1 file changed, 29 insertions(+), 2 deletions(-)

diff --git a/drivers/firmware/arm_ffa/driver.c b/drivers/firmware/arm_ffa/driver.c
index bc6ffd25ad2e2fea0fe3610cf896718dbed8f0ad..87e106c728b89f3ce7c11219cf7cad9cc166dda2 100644
--- a/drivers/firmware/arm_ffa/driver.c
+++ b/drivers/firmware/arm_ffa/driver.c
@@ -307,14 +307,24 @@ __ffa_partition_info_get(u32 uuid0, u32 uuid1, u32 uuid2, u32 uuid3,
 #define CURRENT_INDEX(x)	((u16)(FIELD_GET(CURRENT_INDEX_MASK, (x))))
 #define UUID_INFO_TAG(x)	((u16)(FIELD_GET(UUID_INFO_TAG_MASK, (x))))
 #define PARTITION_INFO_SZ(x)	((u16)(FIELD_GET(PARTITION_INFO_SZ_MASK, (x))))
+#define PART_INFO_ID_MASK	GENMASK(15, 0)
+#define PART_INFO_EXEC_CXT_MASK	GENMASK(31, 16)
+#define PART_INFO_PROPS_MASK	GENMASK(63, 32)
+#define PART_INFO_ID(x)		((u16)(FIELD_GET(PART_INFO_ID_MASK, (x))))
+#define PART_INFO_EXEC_CXT(x)	((u16)(FIELD_GET(PART_INFO_EXEC_CXT_MASK, (x))))
+#define PART_INFO_PROPERTIES(x)	((u32)(FIELD_GET(PART_INFO_PROPS_MASK, (x))))
 static int
 __ffa_partition_info_get_regs(u32 uuid0, u32 uuid1, u32 uuid2, u32 uuid3,
 			      struct ffa_partition_info *buffer, int num_parts)
 {
 	u16 buf_sz, start_idx, cur_idx, count = 0, prev_idx = 0, tag = 0;
+	struct ffa_partition_info *buf = buffer;
 	ffa_value_t partition_info;
 
 	do {
+		__le64 *regs;
+		int idx;
+
 		start_idx = prev_idx ? prev_idx + 1 : 0;
 
 		invoke_ffa_fn((ffa_value_t){
@@ -338,8 +348,25 @@ __ffa_partition_info_get_regs(u32 uuid0, u32 uuid1, u32 uuid2, u32 uuid3,
 		if (buf_sz > sizeof(*buffer))
 			buf_sz = sizeof(*buffer);
 
-		memcpy(buffer + prev_idx * buf_sz, &partition_info.a3,
-		       (cur_idx - start_idx + 1) * buf_sz);
+		regs = (void *)&partition_info.a3;
+		for (idx = 0; idx < cur_idx - start_idx + 1; idx++, buf++) {
+			union {
+				uuid_t uuid;
+				u64 regs[2];
+			} uuid_regs = {
+				.regs = {
+					le64_to_cpu(*(regs + 1)),
+					le64_to_cpu(*(regs + 2)),
+					}
+			};
+			u64 val = *(u64 *)regs;
+
+			buf->id = PART_INFO_ID(val);
+			buf->exec_ctxt = PART_INFO_EXEC_CXT(val);
+			buf->properties = PART_INFO_PROPERTIES(val);
+			uuid_copy(&buf->uuid, &uuid_regs.uuid);
+			regs += 3;
+		}
 		prev_idx = cur_idx;
 
 	} while (cur_idx < (count - 1));

-- 
2.34.1