thunderbolt: Call tb_eeprom_get_drom_offset() from tb_eeprom_read_n()

We are going to re-use tb_drom_read() for USB4 DROM reading as well.
USB4 has separate router operations for this which does not need the
drom_offset. Therefore we move call to tb_eeprom_get_drom_offset() into
tb_eeprom_read_n() where it is needed.

While there change return -ENOSYS to -ENODEV because the former is only
supposed to be used with system calls (invalid syscall nr).

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Link: https://lore.kernel.org/r/20191217123345.31850-3-mika.westerberg@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/thunderbolt/eeprom.c b/drivers/thunderbolt/eeprom.c
index 8dd7de0..540e010 100644 (file)
--- a/drivers/thunderbolt/eeprom.c
+++ b/drivers/thunderbolt/eeprom.c
@@ -131,12 +131,51 @@ static int tb_eeprom_in(struct tb_switch *sw, u8 *val)
 }
 
 /**
+ * tb_eeprom_get_drom_offset - get drom offset within eeprom
+ */
+static int tb_eeprom_get_drom_offset(struct tb_switch *sw, u16 *offset)
+{
+       struct tb_cap_plug_events cap;
+       int res;
+
+       if (!sw->cap_plug_events) {
+               tb_sw_warn(sw, "no TB_CAP_PLUG_EVENTS, cannot read eeprom\n");
+               return -ENODEV;
+       }
+       res = tb_sw_read(sw, &cap, TB_CFG_SWITCH, sw->cap_plug_events,
+                            sizeof(cap) / 4);
+       if (res)
+               return res;
+
+       if (!cap.eeprom_ctl.present || cap.eeprom_ctl.not_present) {
+               tb_sw_warn(sw, "no NVM\n");
+               return -ENODEV;
+       }
+
+       if (cap.drom_offset > 0xffff) {
+               tb_sw_warn(sw, "drom offset is larger than 0xffff: %#x\n",
+                               cap.drom_offset);
+               return -ENXIO;
+       }
+       *offset = cap.drom_offset;
+       return 0;
+}
+
+/**
  * tb_eeprom_read_n - read count bytes from offset into val
  */
 static int tb_eeprom_read_n(struct tb_switch *sw, u16 offset, u8 *val,
                size_t count)
 {
+       u16 drom_offset;
        int i, res;
+
+       res = tb_eeprom_get_drom_offset(sw, &drom_offset);
+       if (res)
+               return res;
+
+       offset += drom_offset;
+
        res = tb_eeprom_active(sw, true);
        if (res)
                return res;
@@ -239,36 +278,6 @@ struct tb_drom_entry_port {
 
 
 /**
- * tb_eeprom_get_drom_offset - get drom offset within eeprom
- */
-static int tb_eeprom_get_drom_offset(struct tb_switch *sw, u16 *offset)
-{
-       struct tb_cap_plug_events cap;
-       int res;
-       if (!sw->cap_plug_events) {
-               tb_sw_warn(sw, "no TB_CAP_PLUG_EVENTS, cannot read eeprom\n");
-               return -ENOSYS;
-       }
-       res = tb_sw_read(sw, &cap, TB_CFG_SWITCH, sw->cap_plug_events,
-                            sizeof(cap) / 4);
-       if (res)
-               return res;
-
-       if (!cap.eeprom_ctl.present || cap.eeprom_ctl.not_present) {
-               tb_sw_warn(sw, "no NVM\n");
-               return -ENOSYS;
-       }
-
-       if (cap.drom_offset > 0xffff) {
-               tb_sw_warn(sw, "drom offset is larger than 0xffff: %#x\n",
-                               cap.drom_offset);
-               return -ENXIO;
-       }
-       *offset = cap.drom_offset;
-       return 0;
-}
-
-/**
  * tb_drom_read_uid_only - read uid directly from drom
  *
  * Does not use the cached copy in sw->drom. Used during resume to check switch
@@ -277,17 +286,11 @@ static int tb_eeprom_get_drom_offset(struct tb_switch *sw, u16 *offset)
 int tb_drom_read_uid_only(struct tb_switch *sw, u64 *uid)
 {
        u8 data[9];
-       u16 drom_offset;
        u8 crc;
-       int res = tb_eeprom_get_drom_offset(sw, &drom_offset);
-       if (res)
-               return res;
-
-       if (drom_offset == 0)
-               return -ENODEV;
+       int res;
 
        /* read uid */
-       res = tb_eeprom_read_n(sw, drom_offset, data, 9);
+       res = tb_eeprom_read_n(sw, 0, data, 9);
        if (res)
                return res;
 
@@ -489,7 +492,6 @@ err_free:
  */
 int tb_drom_read(struct tb_switch *sw)
 {
-       u16 drom_offset;
        u16 size;
        u32 crc;
        struct tb_drom_header *header;
@@ -517,11 +519,7 @@ int tb_drom_read(struct tb_switch *sw)
                return 0;
        }
 
-       res = tb_eeprom_get_drom_offset(sw, &drom_offset);
-       if (res)
-               return res;
-
-       res = tb_eeprom_read_n(sw, drom_offset + 14, (u8 *) &size, 2);
+       res = tb_eeprom_read_n(sw, 14, (u8 *) &size, 2);
        if (res)
                return res;
        size &= 0x3ff;
@@ -535,7 +533,7 @@ int tb_drom_read(struct tb_switch *sw)
        sw->drom = kzalloc(size, GFP_KERNEL);
        if (!sw->drom)
                return -ENOMEM;
-       res = tb_eeprom_read_n(sw, drom_offset, sw->drom, size);
+       res = tb_eeprom_read_n(sw, 0, sw->drom, size);
        if (res)
                goto err;