nfp: reset local locks on init

NFP locks record the owner when held, for PCIe devices the owner
ID will be the PCIe link number.  When driver loads it should scan
known locks and if they indicate that they are held by local
endpoint but the driver doesn't hold them - release them.

Locks can be left taken for instance when kernel gets kexec-ed or
after a crash.  Management FW tries to clean up stale locks too,
but it currently depends on PCIe link going down which doesn't
always happen.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 59 insertions, 0 deletions

diff --git a/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_resource.c b/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_resource.c
index 7e14725055c7..2dd89dba9311 100644
--- a/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_resource.c
+++ b/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_resource.c
@@ -338,3 +338,62 @@ u64 nfp_resource_size(struct nfp_resource *res)
 {
 	return res->size;
 }
+
+/**
+ * nfp_resource_table_init() - Run initial checks on the resource table
+ * @cpp:	NFP CPP handle
+ *
+ * Start-of-day init procedure for resource table.  Must be called before
+ * any local resource table users may exist.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+int nfp_resource_table_init(struct nfp_cpp *cpp)
+{
+	struct nfp_cpp_mutex *dev_mutex;
+	int i, err;
+
+	err = nfp_cpp_mutex_reclaim(cpp, NFP_RESOURCE_TBL_TARGET,
+				    NFP_RESOURCE_TBL_BASE);
+	if (err < 0) {
+		nfp_err(cpp, "Error: failed to reclaim resource table mutex\n");
+		return err;
+	}
+	if (err)
+		nfp_warn(cpp, "Warning: busted main resource table mutex\n");
+
+	dev_mutex = nfp_cpp_mutex_alloc(cpp, NFP_RESOURCE_TBL_TARGET,
+					NFP_RESOURCE_TBL_BASE,
+					NFP_RESOURCE_TBL_KEY);
+	if (!dev_mutex)
+		return -ENOMEM;
+
+	if (nfp_cpp_mutex_lock(dev_mutex)) {
+		nfp_err(cpp, "Error: failed to claim resource table mutex\n");
+		nfp_cpp_mutex_free(dev_mutex);
+		return -EINVAL;
+	}
+
+	/* Resource 0 is the dev_mutex, start from 1 */
+	for (i = 1; i < NFP_RESOURCE_TBL_ENTRIES; i++) {
+		u64 addr = NFP_RESOURCE_TBL_BASE +
+			sizeof(struct nfp_resource_entry) * i;
+
+		err = nfp_cpp_mutex_reclaim(cpp, NFP_RESOURCE_TBL_TARGET, addr);
+		if (err < 0) {
+			nfp_err(cpp,
+				"Error: failed to reclaim resource %d mutex\n",
+				i);
+			goto err_unlock;
+		}
+		if (err)
+			nfp_warn(cpp, "Warning: busted resource %d mutex\n", i);
+	}
+
+	err = 0;
+err_unlock:
+	nfp_cpp_mutex_unlock(dev_mutex);
+	nfp_cpp_mutex_free(dev_mutex);
+
+	return err;
+}