soc: qcom: cmd-db: Make endian-agnostic

This driver deals with memory that is stored in little-endian format.
Update the structures with the proper little-endian types and then
do the proper conversions when reading the fields. Note that we compare
the ids with a memcmp() because we already pad out the string 'id' field
to exactly 8 bytes with the strncpy() onto the stack.

Cc: Mahesh Sivasubramanian <msivasub@codeaurora.org>
Cc: Lina Iyer <ilina@codeaurora.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Evan Green <evgreen@chromium.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>

diff --git a/drivers/soc/qcom/cmd-db.c b/drivers/soc/qcom/cmd-db.c
index b517204..a6f6462 100644 (file)
--- a/drivers/soc/qcom/cmd-db.c
+++ b/drivers/soc/qcom/cmd-db.c
@@ -13,18 +13,9 @@
 
 #define NUM_PRIORITY           2
 #define MAX_SLV_ID             8
-#define CMD_DB_MAGIC           0x0C0330DBUL
 #define SLAVE_ID_MASK          0x7
 #define SLAVE_ID_SHIFT         16
 
-#define ENTRY_HEADER(hdr)      ((void *)cmd_db_header +        \
-                               sizeof(*cmd_db_header) +        \
-                               hdr->header_offset)
-
-#define RSC_OFFSET(hdr, ent)   ((void *)cmd_db_header +        \
-                               sizeof(*cmd_db_header) +        \
-                               hdr.data_offset + ent.offset)
-
 /**
  * struct entry_header: header for each entry in cmddb
  *
@@ -35,11 +26,11 @@
  * @offset: offset from :@data_offset, start of the data
  */
 struct entry_header {
-       u64 id;
-       u32 priority[NUM_PRIORITY];
-       u32 addr;
-       u16 len;
-       u16 offset;
+       u8 id[8];
+       __le32 priority[NUM_PRIORITY];
+       __le32 addr;
+       __le16 len;
+       __le16 offset;
 };
 
 /**
@@ -53,30 +44,30 @@ struct entry_header {
  * @reserved: reserved for future use.
  */
 struct rsc_hdr {
-       u16 slv_id;
-       u16 header_offset;
-       u16 data_offset;
-       u16 cnt;
-       u16 version;
-       u16 reserved[3];
+       __le16 slv_id;
+       __le16 header_offset;
+       __le16 data_offset;
+       __le16 cnt;
+       __le16 version;
+       __le16 reserved[3];
 };
 
 /**
  * struct cmd_db_header: The DB header information
  *
  * @version: The cmd db version
- * @magic_number: constant expected in the database
+ * @magic: constant expected in the database
  * @header: array of resources
  * @checksum: checksum for the header. Unused.
  * @reserved: reserved memory
  * @data: driver specific data
  */
 struct cmd_db_header {
-       u32 version;
-       u32 magic_num;
+       __le32 version;
+       u8 magic[4];
        struct rsc_hdr header[MAX_SLV_ID];
-       u32 checksum;
-       u32 reserved;
+       __le32 checksum;
+       __le32 reserved;
        u8 data[];
 };
 
@@ -99,8 +90,34 @@ struct cmd_db_header {
  * h/w accelerator and request a resource state.
  */
 
+static const u8 CMD_DB_MAGIC[] = { 0xdb, 0x30, 0x03, 0x0c };
+
+static bool cmd_db_magic_matches(const struct cmd_db_header *header)
+{
+       const u8 *magic = header->magic;
+
+       return memcmp(magic, CMD_DB_MAGIC, ARRAY_SIZE(CMD_DB_MAGIC)) == 0;
+}
+
 static struct cmd_db_header *cmd_db_header;
 
+
+static inline void *rsc_to_entry_header(struct rsc_hdr *hdr)
+{
+       u16 offset = le16_to_cpu(hdr->header_offset);
+
+       return cmd_db_header->data + offset;
+}
+
+static inline void *
+rsc_offset(struct rsc_hdr *hdr, struct entry_header *ent)
+{
+       u16 offset = le16_to_cpu(hdr->data_offset);
+       u16 loffset = le16_to_cpu(ent->offset);
+
+       return cmd_db_header->data + offset + loffset;
+}
+
 /**
  * cmd_db_ready - Indicates if command DB is available
  *
@@ -110,29 +127,20 @@ int cmd_db_ready(void)
 {
        if (cmd_db_header == NULL)
                return -EPROBE_DEFER;
-       else if (cmd_db_header->magic_num != CMD_DB_MAGIC)
+       else if (!cmd_db_magic_matches(cmd_db_header))
                return -EINVAL;
 
        return 0;
 }
 EXPORT_SYMBOL(cmd_db_ready);
 
-static u64 cmd_db_get_u64_id(const char *id)
-{
-       u64 rsc_id = 0;
-       u8 *ch = (u8 *)&rsc_id;
-
-       strncpy(ch, id, min(strlen(id), sizeof(rsc_id)));
-
-       return rsc_id;
-}
-
-static int cmd_db_get_header(u64 query, struct entry_header *eh,
+static int cmd_db_get_header(const char *id, struct entry_header *eh,
                             struct rsc_hdr *rh)
 {
        struct rsc_hdr *rsc_hdr;
        struct entry_header *ent;
        int ret, i, j;
+       u8 query[8];
 
        ret = cmd_db_ready();
        if (ret)
@@ -141,18 +149,21 @@ static int cmd_db_get_header(u64 query, struct entry_header *eh,
        if (!eh || !rh)
                return -EINVAL;
 
+       /* Pad out query string to same length as in DB */
+       strncpy(query, id, sizeof(query));
+
        for (i = 0; i < MAX_SLV_ID; i++) {
                rsc_hdr = &cmd_db_header->header[i];
                if (!rsc_hdr->slv_id)
                        break;
 
-               ent = ENTRY_HEADER(rsc_hdr);
-               for (j = 0; j < rsc_hdr->cnt; j++, ent++) {
-                       if (ent->id == query)
+               ent = rsc_to_entry_header(rsc_hdr);
+               for (j = 0; j < le16_to_cpu(rsc_hdr->cnt); j++, ent++) {
+                       if (memcmp(ent->id, query, sizeof(ent->id)) == 0)
                                break;
                }
 
-               if (j < rsc_hdr->cnt) {
+               if (j < le16_to_cpu(rsc_hdr->cnt)) {
                        memcpy(eh, ent, sizeof(*ent));
                        memcpy(rh, rsc_hdr, sizeof(*rh));
                        return 0;
@@ -162,15 +173,6 @@ static int cmd_db_get_header(u64 query, struct entry_header *eh,
        return -ENODEV;
 }
 
-static int cmd_db_get_header_by_rsc_id(const char *id,
-                                      struct entry_header *ent_hdr,
-                                      struct rsc_hdr *rsc_hdr)
-{
-       u64 rsc_id = cmd_db_get_u64_id(id);
-
-       return cmd_db_get_header(rsc_id, ent_hdr, rsc_hdr);
-}
-
 /**
  * cmd_db_read_addr() - Query command db for resource id address.
  *
@@ -187,9 +189,9 @@ u32 cmd_db_read_addr(const char *id)
        struct entry_header ent;
        struct rsc_hdr rsc_hdr;
 
-       ret = cmd_db_get_header_by_rsc_id(id, &ent, &rsc_hdr);
+       ret = cmd_db_get_header(id, &ent, &rsc_hdr);
 
-       return ret < 0 ? 0 : ent.addr;
+       return ret < 0 ? 0 : le32_to_cpu(ent.addr);
 }
 EXPORT_SYMBOL(cmd_db_read_addr);
 
@@ -207,19 +209,21 @@ int cmd_db_read_aux_data(const char *id, u8 *data, size_t len)
        int ret;
        struct entry_header ent;
        struct rsc_hdr rsc_hdr;
+       u16 ent_len;
 
        if (!data)
                return -EINVAL;
 
-       ret = cmd_db_get_header_by_rsc_id(id, &ent, &rsc_hdr);
+       ret = cmd_db_get_header(id, &ent, &rsc_hdr);
        if (ret)
                return ret;
 
-       if (len < ent.len)
+       ent_len = le16_to_cpu(ent.len);
+       if (len < ent_len)
                return -EINVAL;
 
-       len = min_t(u16, ent.len, len);
-       memcpy(data, RSC_OFFSET(rsc_hdr, ent), len);
+       len = min_t(u16, ent_len, len);
+       memcpy(data, rsc_offset(&rsc_hdr, &ent), len);
 
        return len;
 }
@@ -238,9 +242,9 @@ size_t cmd_db_read_aux_data_len(const char *id)
        struct entry_header ent;
        struct rsc_hdr rsc_hdr;
 
-       ret = cmd_db_get_header_by_rsc_id(id, &ent, &rsc_hdr);
+       ret = cmd_db_get_header(id, &ent, &rsc_hdr);
 
-       return ret < 0 ? 0 : ent.len;
+       return ret < 0 ? 0 : le16_to_cpu(ent.len);
 }
 EXPORT_SYMBOL(cmd_db_read_aux_data_len);
 
@@ -256,11 +260,14 @@ enum cmd_db_hw_type cmd_db_read_slave_id(const char *id)
        int ret;
        struct entry_header ent;
        struct rsc_hdr rsc_hdr;
+       u32 addr;
 
-       ret = cmd_db_get_header_by_rsc_id(id, &ent, &rsc_hdr);
+       ret = cmd_db_get_header(id, &ent, &rsc_hdr);
+       if (ret < 0)
+               return CMD_DB_HW_INVALID;
 
-       return ret < 0 ? CMD_DB_HW_INVALID :
-                      (ent.addr >> SLAVE_ID_SHIFT) & SLAVE_ID_MASK;
+       addr = le32_to_cpu(ent.addr);
+       return (addr >> SLAVE_ID_SHIFT) & SLAVE_ID_MASK;
 }
 EXPORT_SYMBOL(cmd_db_read_slave_id);
 
@@ -282,7 +289,7 @@ static int cmd_db_dev_probe(struct platform_device *pdev)
                return ret;
        }
 
-       if (cmd_db_header->magic_num != CMD_DB_MAGIC) {
+       if (!cmd_db_magic_matches(cmd_db_header)) {
                dev_err(&pdev->dev, "Invalid Command DB Magic\n");
                return -EINVAL;
        }