scsi: qla2xxx: Add boundary checks for exchanges to be offloaded

Max boundary for exchange off load is 32k exchanges. If a system
is unable to allocate large memory buffer to support this feature,
then driver will reduce the number of exchanges down to a value
system can support.

Signed-off-by: Quinn Tran <quinn.tran@cavium.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/qla2xxx/qla_def.h b/drivers/scsi/qla2xxx/qla_def.h
index 969a7dee9f72f7c758d20614ccbfe5a23da8e4b2..043dd51a27600e9167ec61892efb83334326e900 100644 (file)
--- a/drivers/scsi/qla2xxx/qla_def.h
+++ b/drivers/scsi/qla2xxx/qla_def.h
@@ -288,6 +288,8 @@ struct name_list_extended {
 #define ATIO_ENTRY_CNT_24XX            4096    /* Number of ATIO entries. */
 #define RESPONSE_ENTRY_CNT_FX00                256     /* Number of response entries.*/
 #define FW_DEF_EXCHANGES_CNT 2048
+#define FW_MAX_EXCHANGES_CNT (32 * 1024)
+#define REDUCE_EXCHANGES_CNT  (8 * 1024)
 
 struct req_que;
 struct qla_tgt_sess;
@@ -3506,6 +3508,7 @@ struct qla_hw_data {
                uint32_t        using_lr_setting:1;
        } flags;
 
+       uint16_t max_exchg;
        uint16_t long_range_distance;   /* 32G & above */
 #define LR_DISTANCE_5K  1
 #define LR_DISTANCE_10K 0

diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index 987bade1c606305eef60801ec06aab40b2aebd74..029b95b2bd8ad056d071127ce1ca4a0350ecdc2a 100644 (file)
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -2789,6 +2789,7 @@ qla2x00_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
        ha->init_cb_size = sizeof(init_cb_t);
        ha->link_data_rate = PORT_SPEED_UNKNOWN;
        ha->optrom_size = OPTROM_SIZE_2300;
+       ha->max_exchg = FW_MAX_EXCHANGES_CNT;
 
        /* Assign ISP specific operations. */
        if (IS_QLA2100(ha)) {
@@ -4230,6 +4231,9 @@ qla2x00_number_of_exch(scsi_qla_host_t *vha, u32 *ret_cnt, u16 max_cnt)
        u32 temp;
        *ret_cnt = FW_DEF_EXCHANGES_CNT;
 
+       if (max_cnt > vha->hw->max_exchg)
+               max_cnt = vha->hw->max_exchg;
+
        if (qla_ini_mode_enabled(vha)) {
                if (ql2xiniexchg > max_cnt)
                        ql2xiniexchg = max_cnt;
@@ -4259,8 +4263,8 @@ int
 qla2x00_set_exchoffld_buffer(scsi_qla_host_t *vha)
 {
        int rval;
-       u16 size, max_cnt;
-       u32 temp;
+       u16     size, max_cnt;
+       u32 actual_cnt, totsz;
        struct qla_hw_data *ha = vha->hw;
 
        if (!ha->flags.exchoffld_enabled)
@@ -4277,16 +4281,19 @@ qla2x00_set_exchoffld_buffer(scsi_qla_host_t *vha)
                return rval;
        }
 
-       qla2x00_number_of_exch(vha, &temp, max_cnt);
-       temp *= size;
+       qla2x00_number_of_exch(vha, &actual_cnt, max_cnt);
+       ql_log(ql_log_info, vha, 0xd014,
+           "Actual exchange offload count: %d.\n", actual_cnt);
+
+       totsz = actual_cnt * size;
 
-       if (temp != ha->exchoffld_size) {
+       if (totsz != ha->exchoffld_size) {
                qla2x00_free_exchoffld_buffer(ha);
-               ha->exchoffld_size = temp;
+               ha->exchoffld_size = totsz;
 
                ql_log(ql_log_info, vha, 0xd016,
-                   "Exchange offload: max_count=%d, buffers=0x%x, total=%d.\n",
-                   max_cnt, size, temp);
+                   "Exchange offload: max_count=%d, actual count=%d entry sz=0x%x, total sz=0x%x\n",
+                   max_cnt, actual_cnt, size, totsz);
 
                ql_log(ql_log_info, vha, 0xd017,
                    "Exchange Buffers requested size = 0x%x\n",
@@ -4297,7 +4304,21 @@ qla2x00_set_exchoffld_buffer(scsi_qla_host_t *vha)
                        ha->exchoffld_size, &ha->exchoffld_buf_dma, GFP_KERNEL);
                if (!ha->exchoffld_buf) {
                        ql_log_pci(ql_log_fatal, ha->pdev, 0xd013,
-                       "Failed to allocate memory for exchoffld_buf_dma.\n");
+                       "Failed to allocate memory for Exchange Offload.\n");
+
+                       if (ha->max_exchg >
+                           (FW_DEF_EXCHANGES_CNT + REDUCE_EXCHANGES_CNT)) {
+                               ha->max_exchg -= REDUCE_EXCHANGES_CNT;
+                       } else if (ha->max_exchg >
+                           (FW_DEF_EXCHANGES_CNT + 512)) {
+                               ha->max_exchg -= 512;
+                       } else {
+                               ha->flags.exchoffld_enabled = 0;
+                               ql_log_pci(ql_log_fatal, ha->pdev, 0xd013,
+                                   "Disabling Exchange offload due to lack of memory\n");
+                       }
+                       ha->exchoffld_size = 0;
+
                        return -ENOMEM;
                }
        }