scsi: mpi3mr: Resource Based Metering

Update driver to track cumulative pending large data size at the controller
level and at the throttle group level.  When one of the values meet or
exceed the controller's firmware-determined high threshold value, then the
driver will divert future selective I/O to the firmware. Once both
controller level and at the throttle group level cumulative pending large
data size reach controller's firmware determined low threshold value, then
the driver will stop diverting I/Os to the firmware.

Link: https://lore.kernel.org/r/20220708195020.8323-2-sreekanth.reddy@broadcom.com
Signed-off-by: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 62 insertions, 0 deletions

diff --git a/drivers/scsi/mpi3mr/mpi3mr_fw.c b/drivers/scsi/mpi3mr/mpi3mr_fw.c
index f1d4ea8ba989..ab79374bb6e1 100644
--- a/drivers/scsi/mpi3mr/mpi3mr_fw.c
+++ b/drivers/scsi/mpi3mr/mpi3mr_fw.c
@@ -2785,6 +2785,27 @@ static void mpi3mr_process_factsdata(struct mpi3mr_ioc *mrioc,
 	mrioc->facts.shutdown_timeout =
 	    le16_to_cpu(facts_data->shutdown_timeout);
 
+	mrioc->facts.max_dev_per_tg =
+	    facts_data->max_devices_per_throttle_group;
+	mrioc->facts.io_throttle_data_length =
+	    le16_to_cpu(facts_data->io_throttle_data_length);
+	mrioc->facts.max_io_throttle_group =
+	    le16_to_cpu(facts_data->max_io_throttle_group);
+	mrioc->facts.io_throttle_low = le16_to_cpu(facts_data->io_throttle_low);
+	mrioc->facts.io_throttle_high =
+	    le16_to_cpu(facts_data->io_throttle_high);
+
+	/* Store in 512b block count */
+	if (mrioc->facts.io_throttle_data_length)
+		mrioc->io_throttle_data_length =
+		    (mrioc->facts.io_throttle_data_length * 2 * 4);
+	else
+		/* set the length to 1MB + 1K to disable throttle */
+		mrioc->io_throttle_data_length = MPI3MR_MAX_SECTORS + 2;
+
+	mrioc->io_throttle_high = (mrioc->facts.io_throttle_high * 2 * 1024);
+	mrioc->io_throttle_low = (mrioc->facts.io_throttle_low * 2 * 1024);
+
 	ioc_info(mrioc, "ioc_num(%d), maxopQ(%d), maxopRepQ(%d), maxdh(%d),",
 	    mrioc->facts.ioc_num, mrioc->facts.max_op_req_q,
 	    mrioc->facts.max_op_reply_q, mrioc->facts.max_devhandle);
@@ -2798,6 +2819,13 @@ static void mpi3mr_process_factsdata(struct mpi3mr_ioc *mrioc,
 	ioc_info(mrioc, "DMA mask %d InitialPE status 0x%x\n",
 	    mrioc->facts.dma_mask, (facts_flags &
 	    MPI3_IOCFACTS_FLAGS_INITIAL_PORT_ENABLE_MASK));
+	ioc_info(mrioc,
+	    "max_dev_per_throttle_group(%d), max_throttle_groups(%d)\n",
+	    mrioc->facts.max_dev_per_tg, mrioc->facts.max_io_throttle_group);
+	ioc_info(mrioc,
+	   "io_throttle_data_len(%dKiB), io_throttle_high(%dMiB), io_throttle_low(%dMiB)\n",
+	   mrioc->facts.io_throttle_data_length * 4,
+	   mrioc->facts.io_throttle_high, mrioc->facts.io_throttle_low);
 }
 
 /**
@@ -3666,6 +3694,7 @@ int mpi3mr_init_ioc(struct mpi3mr_ioc *mrioc)
 	int retval = 0;
 	u8 retry = 0;
 	struct mpi3_ioc_facts_data facts_data;
+	u32 sz;
 
 retry_init:
 	retval = mpi3mr_bring_ioc_ready(mrioc);
@@ -3691,6 +3720,9 @@ retry_init:
 
 	mrioc->max_host_ios = mrioc->facts.max_reqs - MPI3MR_INTERNAL_CMDS_RESVD;
 
+	mrioc->num_io_throttle_group = mrioc->facts.max_io_throttle_group;
+	atomic_set(&mrioc->pend_large_data_sz, 0);
+
 	if (reset_devices)
 		mrioc->max_host_ios = min_t(int, mrioc->max_host_ios,
 		    MPI3MR_HOST_IOS_KDUMP);
@@ -3760,6 +3792,15 @@ retry_init:
 		}
 	}
 
+	if (!mrioc->throttle_groups && mrioc->num_io_throttle_group) {
+		dprint_init(mrioc, "allocating memory for throttle groups\n");
+		sz = sizeof(struct mpi3mr_throttle_group_info);
+		mrioc->throttle_groups = (struct mpi3mr_throttle_group_info *)
+		    kcalloc(mrioc->num_io_throttle_group, sz, GFP_KERNEL);
+		if (!mrioc->throttle_groups)
+			goto out_failed_noretry;
+	}
+
 	retval = mpi3mr_enable_events(mrioc);
 	if (retval) {
 		ioc_err(mrioc, "failed to enable events %d\n",
@@ -3981,6 +4022,7 @@ static void mpi3mr_memset_op_req_q_buffers(struct mpi3mr_ioc *mrioc, u16 qidx)
 void mpi3mr_memset_buffers(struct mpi3mr_ioc *mrioc)
 {
 	u16 i;
+	struct mpi3mr_throttle_group_info *tg;
 
 	mrioc->change_count = 0;
 	mrioc->active_poll_qcount = 0;
@@ -4029,6 +4071,18 @@ void mpi3mr_memset_buffers(struct mpi3mr_ioc *mrioc)
 		spin_lock_init(&mrioc->req_qinfo[i].q_lock);
 		mpi3mr_memset_op_req_q_buffers(mrioc, i);
 	}
+
+	atomic_set(&mrioc->pend_large_data_sz, 0);
+	if (mrioc->throttle_groups) {
+		tg = mrioc->throttle_groups;
+		for (i = 0; i < mrioc->num_io_throttle_group; i++, tg++) {
+			tg->id = 0;
+			tg->io_divert = 0;
+			tg->high = 0;
+			tg->low = 0;
+			atomic_set(&tg->pend_large_data_sz, 0);
+		}
+	}
 }
 
 /**
@@ -4663,6 +4717,14 @@ int mpi3mr_soft_reset_handler(struct mpi3mr_ioc *mrioc,
 		ioc_err(mrioc, "Failed to issue soft reset to the ioc\n");
 		goto out;
 	}
+	if (mrioc->num_io_throttle_group !=
+	    mrioc->facts.max_io_throttle_group) {
+		ioc_err(mrioc,
+		    "max io throttle group doesn't match old(%d), new(%d)\n",
+		    mrioc->num_io_throttle_group,
+		    mrioc->facts.max_io_throttle_group);
+		return -EPERM;
+	}
 
 	mpi3mr_flush_delayed_cmd_lists(mrioc);
 	mpi3mr_flush_drv_cmds(mrioc);