usb: typec: tcpm: Refactor tcpm_handle_vdm_request payload handling

Refactor the tcpm_handle_vdm_request payload handling by doing the
endianness conversion only once directly inside tcpm_handle_vdm_request
itself instead of doing it multiple times inside various helper functions
called by tcpm_handle_vdm_request.

This is a preparation patch for some further refactoring to fix an AB BA
lock inversion between the tcpm code and some altmode drivers.

Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20200724174702.61754-3-hdegoede@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index b725343..d65358a 100644 (file)
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -981,16 +981,15 @@ static void tcpm_queue_vdm_unlocked(struct tcpm_port *port, const u32 header,
        mutex_unlock(&port->lock);
 }
 
-static void svdm_consume_identity(struct tcpm_port *port, const __le32 *payload,
-                                 int cnt)
+static void svdm_consume_identity(struct tcpm_port *port, const u32 *p, int cnt)
 {
-       u32 vdo = le32_to_cpu(payload[VDO_INDEX_IDH]);
-       u32 product = le32_to_cpu(payload[VDO_INDEX_PRODUCT]);
+       u32 vdo = p[VDO_INDEX_IDH];
+       u32 product = p[VDO_INDEX_PRODUCT];
 
        memset(&port->mode_data, 0, sizeof(port->mode_data));
 
        port->partner_ident.id_header = vdo;
-       port->partner_ident.cert_stat = le32_to_cpu(payload[VDO_INDEX_CSTAT]);
+       port->partner_ident.cert_stat = p[VDO_INDEX_CSTAT];
        port->partner_ident.product = product;
 
        typec_partner_set_identity(port->partner);
@@ -1000,17 +999,15 @@ static void svdm_consume_identity(struct tcpm_port *port, const __le32 *payload,
                 PD_PRODUCT_PID(product), product & 0xffff);
 }
 
-static bool svdm_consume_svids(struct tcpm_port *port, const __le32 *payload,
-                              int cnt)
+static bool svdm_consume_svids(struct tcpm_port *port, const u32 *p, int cnt)
 {
        struct pd_mode_data *pmdata = &port->mode_data;
        int i;
 
        for (i = 1; i < cnt; i++) {
-               u32 p = le32_to_cpu(payload[i]);
                u16 svid;
 
-               svid = (p >> 16) & 0xffff;
+               svid = (p[i] >> 16) & 0xffff;
                if (!svid)
                        return false;
 
@@ -1020,7 +1017,7 @@ static bool svdm_consume_svids(struct tcpm_port *port, const __le32 *payload,
                pmdata->svids[pmdata->nsvids++] = svid;
                tcpm_log(port, "SVID %d: 0x%x", pmdata->nsvids, svid);
 
-               svid = p & 0xffff;
+               svid = p[i] & 0xffff;
                if (!svid)
                        return false;
 
@@ -1036,8 +1033,7 @@ abort:
        return false;
 }
 
-static void svdm_consume_modes(struct tcpm_port *port, const __le32 *payload,
-                              int cnt)
+static void svdm_consume_modes(struct tcpm_port *port, const u32 *p, int cnt)
 {
        struct pd_mode_data *pmdata = &port->mode_data;
        struct typec_altmode_desc *paltmode;
@@ -1054,7 +1050,7 @@ static void svdm_consume_modes(struct tcpm_port *port, const __le32 *payload,
 
                paltmode->svid = pmdata->svids[pmdata->svid_index];
                paltmode->mode = i;
-               paltmode->vdo = le32_to_cpu(payload[i]);
+               paltmode->vdo = p[i];
 
                tcpm_log(port, " Alternate mode %d: SVID 0x%04x, VDO %d: 0x%08x",
                         pmdata->altmodes, paltmode->svid,
@@ -1084,21 +1080,17 @@ static void tcpm_register_partner_altmodes(struct tcpm_port *port)
 
 #define supports_modal(port)   PD_IDH_MODAL_SUPP((port)->partner_ident.id_header)
 
-static int tcpm_pd_svdm(struct tcpm_port *port, const __le32 *payload, int cnt,
+static int tcpm_pd_svdm(struct tcpm_port *port, const u32 *p, int cnt,
                        u32 *response)
 {
        struct typec_altmode *adev;
        struct typec_altmode *pdev;
        struct pd_mode_data *modep;
-       u32 p[PD_MAX_PAYLOAD];
        int rlen = 0;
        int cmd_type;
        int cmd;
        int i;
 
-       for (i = 0; i < cnt; i++)
-               p[i] = le32_to_cpu(payload[i]);
-
        cmd_type = PD_VDO_CMDT(p[0]);
        cmd = PD_VDO_CMD(p[0]);
 
@@ -1159,13 +1151,13 @@ static int tcpm_pd_svdm(struct tcpm_port *port, const __le32 *payload, int cnt,
                switch (cmd) {
                case CMD_DISCOVER_IDENT:
                        /* 6.4.4.3.1 */
-                       svdm_consume_identity(port, payload, cnt);
+                       svdm_consume_identity(port, p, cnt);
                        response[0] = VDO(USB_SID_PD, 1, CMD_DISCOVER_SVID);
                        rlen = 1;
                        break;
                case CMD_DISCOVER_SVID:
                        /* 6.4.4.3.2 */
-                       if (svdm_consume_svids(port, payload, cnt)) {
+                       if (svdm_consume_svids(port, p, cnt)) {
                                response[0] = VDO(USB_SID_PD, 1,
                                                  CMD_DISCOVER_SVID);
                                rlen = 1;
@@ -1177,7 +1169,7 @@ static int tcpm_pd_svdm(struct tcpm_port *port, const __le32 *payload, int cnt,
                        break;
                case CMD_DISCOVER_MODES:
                        /* 6.4.4.3.3 */
-                       svdm_consume_modes(port, payload, cnt);
+                       svdm_consume_modes(port, p, cnt);
                        modep->svid_index++;
                        if (modep->svid_index < modep->nsvids) {
                                u16 svid = modep->svids[modep->svid_index];
@@ -1240,15 +1232,18 @@ static int tcpm_pd_svdm(struct tcpm_port *port, const __le32 *payload, int cnt,
 static void tcpm_handle_vdm_request(struct tcpm_port *port,
                                    const __le32 *payload, int cnt)
 {
-       int rlen = 0;
+       u32 p[PD_MAX_PAYLOAD];
        u32 response[8] = { };
-       u32 p0 = le32_to_cpu(payload[0]);
+       int i, rlen = 0;
+
+       for (i = 0; i < cnt; i++)
+               p[i] = le32_to_cpu(payload[i]);
 
        if (port->vdm_state == VDM_STATE_BUSY) {
                /* If UFP responded busy retry after timeout */
-               if (PD_VDO_CMDT(p0) == CMDT_RSP_BUSY) {
+               if (PD_VDO_CMDT(p[0]) == CMDT_RSP_BUSY) {
                        port->vdm_state = VDM_STATE_WAIT_RSP_BUSY;
-                       port->vdo_retry = (p0 & ~VDO_CMDT_MASK) |
+                       port->vdo_retry = (p[0] & ~VDO_CMDT_MASK) |
                                CMDT_INIT;
                        mod_delayed_work(port->wq, &port->vdm_state_machine,
                                         msecs_to_jiffies(PD_T_VDM_BUSY));
@@ -1257,8 +1252,8 @@ static void tcpm_handle_vdm_request(struct tcpm_port *port,
                port->vdm_state = VDM_STATE_DONE;
        }
 
-       if (PD_VDO_SVDM(p0))
-               rlen = tcpm_pd_svdm(port, payload, cnt, response);
+       if (PD_VDO_SVDM(p[0]))
+               rlen = tcpm_pd_svdm(port, p, cnt, response);
 
        if (rlen > 0)
                tcpm_queue_vdm(port, response[0], &response[1], rlen - 1);