qed*: Add support for VFs over legacy PFs

Modern VFs can't run on old non-compatible as the fastpath HSI is
slightly changed - but as the HSI is actually very close [basically,
a single bit whose meaning flipped] this can be supported with small
modifications.

The major differences would be in:
  - Recognizing that VF is running on top of a legacy PF.
  - Returning some slowpath configurations that are no longer needed
    on top of modern PFs, but would be required when working over
    the legacy ones.

Signed-off-by: Yuval Mintz <Yuval.Mintz@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

6 files changed, 109 insertions, 20 deletions

diff --git a/drivers/net/ethernet/qlogic/qed/qed_l2.c b/drivers/net/ethernet/qlogic/qed/qed_l2.c
index bf433016551a..4409ea3f7d40 100644
--- a/drivers/net/ethernet/qlogic/qed/qed_l2.c
+++ b/drivers/net/ethernet/qlogic/qed/qed_l2.c
@@ -1685,6 +1685,8 @@ static int qed_fill_eth_dev_info(struct qed_dev *cdev,
                 qed_vf_get_num_vlan_filters(&cdev->hwfns[0],
                                             &info->num_vlan_filters);
                 qed_vf_get_port_mac(&cdev->hwfns[0], info->port_mac);
+
+                info->is_legacy = !!cdev->hwfns[0].vf_iov_info->b_pre_fp_hsi;
         }
 
         qed_fill_dev_info(cdev, &info->common);
diff --git a/drivers/net/ethernet/qlogic/qed/qed_vf.c b/drivers/net/ethernet/qlogic/qed/qed_vf.c
index 9b780b31b15c..f9f68da8b277 100644
--- a/drivers/net/ethernet/qlogic/qed/qed_vf.c
+++ b/drivers/net/ethernet/qlogic/qed/qed_vf.c
@@ -191,6 +191,9 @@ static int qed_vf_pf_acquire(struct qed_hwfn *p_hwfn)
                 DP_VERBOSE(p_hwfn,
                            QED_MSG_IOV, "attempting to acquire resources\n");
 
+                /* Clear response buffer, as this might be a re-send */
+                memset(p_iov->pf2vf_reply, 0, sizeof(union pfvf_tlvs));
+
                 /* send acquire request */
                 rc = qed_send_msg2pf(p_hwfn, &resp->hdr.status, sizeof(*resp));
                 if (rc)
@@ -205,9 +208,12 @@ static int qed_vf_pf_acquire(struct qed_hwfn *p_hwfn)
                         /* PF agrees to allocate our resources */
                         if (!(resp->pfdev_info.capabilities &
                               PFVF_ACQUIRE_CAP_POST_FW_OVERRIDE)) {
-                                DP_INFO(p_hwfn,
-                                        "PF is using old incompatible driver; Either downgrade driver or request provider to update hypervisor version\n");
-                                return -EINVAL;
+                                /* It's possible legacy PF mistakenly accepted;
+                                 * but we don't care - simply mark it as
+                                 * legacy and continue.
+                                 */
+                                req->vfdev_info.capabilities |=
+                                    VFPF_ACQUIRE_CAP_PRE_FP_HSI;
                         }
                         DP_VERBOSE(p_hwfn, QED_MSG_IOV, "resources acquired\n");
                         resources_acquired = true;
@@ -215,27 +221,55 @@ static int qed_vf_pf_acquire(struct qed_hwfn *p_hwfn)
                            attempts < VF_ACQUIRE_THRESH) {
                         qed_vf_pf_acquire_reduce_resc(p_hwfn, p_resc,
                                                       &resp->resc);
+                } else if (resp->hdr.status == PFVF_STATUS_NOT_SUPPORTED) {
+                        if (pfdev_info->major_fp_hsi &&
+                            (pfdev_info->major_fp_hsi != ETH_HSI_VER_MAJOR)) {
+                                DP_NOTICE(p_hwfn,
+                                          "PF uses an incompatible fastpath HSI %02x.%02x [VF requires %02x.%02x]. Please change to a VF driver using %02x.xx.\n",
+                                          pfdev_info->major_fp_hsi,
+                                          pfdev_info->minor_fp_hsi,
+                                          ETH_HSI_VER_MAJOR,
+                                          ETH_HSI_VER_MINOR,
+                                          pfdev_info->major_fp_hsi);
+                                rc = -EINVAL;
+                                goto exit;
+                        }
 
-                        /* Clear response buffer */
-                        memset(p_iov->pf2vf_reply, 0, sizeof(union pfvf_tlvs));
-                } else if ((resp->hdr.status == PFVF_STATUS_NOT_SUPPORTED) &&
-                           pfdev_info->major_fp_hsi &&
-                           (pfdev_info->major_fp_hsi != ETH_HSI_VER_MAJOR)) {
-                        DP_NOTICE(p_hwfn,
-                                  "PF uses an incompatible fastpath HSI %02x.%02x [VF requires %02x.%02x]. Please change to a VF driver using %02x.xx.\n",
-                                  pfdev_info->major_fp_hsi,
-                                  pfdev_info->minor_fp_hsi,
-                                  ETH_HSI_VER_MAJOR,
-                                  ETH_HSI_VER_MINOR, pfdev_info->major_fp_hsi);
-                        return -EINVAL;
+                        if (!pfdev_info->major_fp_hsi) {
+                                if (req->vfdev_info.capabilities &
+                                    VFPF_ACQUIRE_CAP_PRE_FP_HSI) {
+                                        DP_NOTICE(p_hwfn,
+                                                  "PF uses very old drivers. Please change to a VF driver using no later than 8.8.x.x.\n");
+                                        rc = -EINVAL;
+                                        goto exit;
+                                } else {
+                                        DP_INFO(p_hwfn,
+                                                "PF is old - try re-acquire to see if it supports FW-version override\n");
+                                        req->vfdev_info.capabilities |=
+                                            VFPF_ACQUIRE_CAP_PRE_FP_HSI;
+                                        continue;
+                                }
+                        }
+
+                        /* If PF/VF are using same Major, PF must have had
+                         * it's reasons. Simply fail.
+                         */
+                        DP_NOTICE(p_hwfn, "PF rejected acquisition by VF\n");
+                        rc = -EINVAL;
+                        goto exit;
                 } else {
                         DP_ERR(p_hwfn,
                                "PF returned error %d to VF acquisition request\n",
                                resp->hdr.status);
-                        return -EAGAIN;
+                        rc = -EAGAIN;
+                        goto exit;
                 }
         }
 
+        /* Mark the PF as legacy, if needed */
+        if (req->vfdev_info.capabilities & VFPF_ACQUIRE_CAP_PRE_FP_HSI)
+                p_iov->b_pre_fp_hsi = true;
+
         /* Update bulletin board size with response from PF */
         p_iov->bulletin.size = resp->bulletin_size;
 
@@ -253,14 +287,16 @@ static int qed_vf_pf_acquire(struct qed_hwfn *p_hwfn)
                 }
         }
 
-        if (ETH_HSI_VER_MINOR &&
+        if (!p_iov->b_pre_fp_hsi &&
+            ETH_HSI_VER_MINOR &&
             (resp->pfdev_info.minor_fp_hsi < ETH_HSI_VER_MINOR)) {
                 DP_INFO(p_hwfn,
                         "PF is using older fastpath HSI; %02x.%02x is configured\n",
                         ETH_HSI_VER_MAJOR, resp->pfdev_info.minor_fp_hsi);
         }
 
-        return 0;
+exit:
+        return rc;
 }
 
 int qed_vf_hw_prepare(struct qed_hwfn *p_hwfn)
@@ -347,6 +383,9 @@ free_p_iov:
 
         return -ENOMEM;
 }
+#define TSTORM_QZONE_START   PXP_VF_BAR0_START_SDM_ZONE_A
+#define MSTORM_QZONE_START(dev)   (TSTORM_QZONE_START + \
+                                   (TSTORM_QZONE_SIZE * NUM_OF_L2_QUEUES(dev)))
 
 int qed_vf_pf_rxq_start(struct qed_hwfn *p_hwfn,
                         u8 rx_qid,
@@ -374,6 +413,21 @@ int qed_vf_pf_rxq_start(struct qed_hwfn *p_hwfn,
         req->bd_max_bytes = bd_max_bytes;
         req->stat_id = -1;
 
+        /* If PF is legacy, we'll need to calculate producers ourselves
+         * as well as clean them.
+         */
+        if (pp_prod && p_iov->b_pre_fp_hsi) {
+                u8 hw_qid = p_iov->acquire_resp.resc.hw_qid[rx_qid];
+                u32 init_prod_val = 0;
+
+                *pp_prod = (u8 __iomem *)p_hwfn->regview +
+                                         MSTORM_QZONE_START(p_hwfn->cdev) +
+                                         hw_qid * MSTORM_QZONE_SIZE;
+
+                /* Init the rcq, rx bd and rx sge (if valid) producers to 0 */
+                __internal_ram_wr(p_hwfn, *pp_prod, sizeof(u32),
+                                  (u32 *)(&init_prod_val));
+        }
         /* add list termination tlv */
         qed_add_tlv(p_hwfn, &p_iov->offset,
                     CHANNEL_TLV_LIST_END, sizeof(struct channel_list_end_tlv));
@@ -387,7 +441,7 @@ int qed_vf_pf_rxq_start(struct qed_hwfn *p_hwfn,
                 return -EINVAL;
 
         /* Learn the address of the producer from the response */
-        if (pp_prod) {
+        if (pp_prod && !p_iov->b_pre_fp_hsi) {
                 u32 init_prod_val = 0;
 
                 *pp_prod = (u8 __iomem *)p_hwfn->regview + resp->offset;
@@ -470,7 +524,20 @@ int qed_vf_pf_txq_start(struct qed_hwfn *p_hwfn,
         }
 
         if (pp_doorbell) {
-                *pp_doorbell = (u8 __iomem *)p_hwfn->doorbells + resp->offset;
+                /* Modern PFs provide the actual offsets, while legacy
+                 * provided only the queue id.
+                 */
+                if (!p_iov->b_pre_fp_hsi) {
+                        *pp_doorbell = (u8 __iomem *)p_hwfn->doorbells +
+                                                     resp->offset;
+                } else {
+                        u8 cid = p_iov->acquire_resp.resc.cid[tx_queue_id];
+                        u32 db_addr;
+
+                        db_addr = qed_db_addr(cid, DQ_DEMS_LEGACY);
+                        *pp_doorbell = (u8 __iomem *)p_hwfn->doorbells +
+                                                     db_addr;
+                }
 
                 DP_VERBOSE(p_hwfn, QED_MSG_IOV,
                            "Txq[0x%02x]: doorbell at %p [offset 0x%08x]\n",
diff --git a/drivers/net/ethernet/qlogic/qed/qed_vf.h b/drivers/net/ethernet/qlogic/qed/qed_vf.h
index 60a599b579bd..35db7a28aa13 100644
--- a/drivers/net/ethernet/qlogic/qed/qed_vf.h
+++ b/drivers/net/ethernet/qlogic/qed/qed_vf.h
@@ -551,6 +551,11 @@ struct qed_vf_iov {
 
         /* we set aside a copy of the acquire response */
         struct pfvf_acquire_resp_tlv acquire_resp;
+
+        /* In case PF originates prior to the fp-hsi version comparison,
+         * this has to be propagated as it affects the fastpath.
+         */
+        bool b_pre_fp_hsi;
 };
 
 #ifdef CONFIG_QED_SRIOV
diff --git a/drivers/net/ethernet/qlogic/qede/qede.h b/drivers/net/ethernet/qlogic/qede/qede.h
index 32325ca5951f..700b509f7143 100644
--- a/drivers/net/ethernet/qlogic/qede/qede.h
+++ b/drivers/net/ethernet/qlogic/qede/qede.h
@@ -268,6 +268,8 @@ struct qede_tx_queue {
         u16                     num_tx_buffers;
         u64                     xmit_pkts;
         u64                     stopped_cnt;
+
+        bool                    is_legacy;
 };
 
 #define BD_UNMAP_ADDR(bd)               HILO_U64(le32_to_cpu((bd)->addr.hi), \
diff --git a/drivers/net/ethernet/qlogic/qede/qede_main.c b/drivers/net/ethernet/qlogic/qede/qede_main.c
index a05459f96962..ac126e6067ae 100644
--- a/drivers/net/ethernet/qlogic/qede/qede_main.c
+++ b/drivers/net/ethernet/qlogic/qede/qede_main.c
@@ -598,6 +598,14 @@ static netdev_tx_t qede_start_xmit(struct sk_buff *skb,
                             1 << ETH_TX_DATA_1ST_BD_TUNN_FLAG_SHIFT;
                 }
 
+                /* Legacy FW had flipped behavior in regard to this bit -
+                 * I.e., needed to set to prevent FW from touching encapsulated
+                 * packets when it didn't need to.
+                 */
+                if (unlikely(txq->is_legacy))
+                        first_bd->data.bitfields ^=
+                            1 << ETH_TX_DATA_1ST_BD_TUNN_FLAG_SHIFT;
+
                 /* If the packet is IPv6 with extension header, indicate that
                  * to FW and pass few params, since the device cracker doesn't
                  * support parsing IPv6 with extension header/s.
@@ -2991,6 +2999,8 @@ static void qede_init_fp(struct qede_dev *edev)
                 for (tc = 0; tc < edev->num_tc; tc++) {
                         txq_index = tc * QEDE_RSS_CNT(edev) + rss_id;
                         fp->txqs[tc].index = txq_index;
+                        if (edev->dev_info.is_legacy)
+                                fp->txqs[tc].is_legacy = true;
                 }
 
                 snprintf(fp->name, sizeof(fp->name), "%s-fp-%d",
diff --git a/include/linux/qed/qed_eth_if.h b/include/linux/qed/qed_eth_if.h
index 4475a9d8ae15..33c24ebc9b7f 100644
--- a/include/linux/qed/qed_eth_if.h
+++ b/include/linux/qed/qed_eth_if.h
@@ -23,6 +23,9 @@ struct qed_dev_eth_info {
 
         u8      port_mac[ETH_ALEN];
         u8      num_vlan_filters;
+
+        /* Legacy VF - this affects the datapath, so qede has to know */
+        bool is_legacy;
 };
 
 struct qed_update_vport_rss_params {