@@ -6,7 +6,8 @@ mscc_ocelot_switch_lib-y := \
ocelot_police.o \
ocelot_vcap.o \
ocelot_flower.o \
- ocelot_ptp.o
+ ocelot_ptp.o \
+ ocelot_devlink.o
obj-$(CONFIG_MSCC_OCELOT_SWITCH) += mscc_ocelot.o
mscc_ocelot-y := \
ocelot_vsc7514.o \
@@ -1624,6 +1624,7 @@ int ocelot_init(struct ocelot *ocelot)
INIT_DELAYED_WORK(&ocelot->stats_work, ocelot_check_stats_work);
queue_delayed_work(ocelot->stats_queue, &ocelot->stats_work,
OCELOT_STATS_CHECK_DELAY);
+ ocelot_watermark_init(ocelot);
return 0;
}
@@ -126,6 +126,7 @@ void ocelot_devlink_teardown(struct ocelot *ocelot);
int ocelot_port_devlink_init(struct ocelot *ocelot, int port,
enum devlink_port_flavour flavour);
void ocelot_port_devlink_teardown(struct ocelot *ocelot, int port);
+void ocelot_watermark_init(struct ocelot *ocelot);
extern struct notifier_block ocelot_netdevice_nb;
extern struct notifier_block ocelot_switchdev_nb;
new file mode 100644
@@ -0,0 +1,442 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+/* Copyright 2020-2021 NXP Semiconductors
+ */
+#include <net/devlink.h>
+#include "ocelot.h"
+
+/* The queue system tracks four resource consumptions:
+ * Resource 0: Memory tracked per source port
+ * Resource 1: Frame references tracked per source port
+ * Resource 2: Memory tracked per destination port
+ * Resource 3: Frame references tracked per destination port
+ */
+#define OCELOT_RESOURCE_SZ 256
+#define OCELOT_NUM_RESOURCES 4
+
+#define BUF_xxxx_I (0 * OCELOT_RESOURCE_SZ)
+#define REF_xxxx_I (1 * OCELOT_RESOURCE_SZ)
+#define BUF_xxxx_E (2 * OCELOT_RESOURCE_SZ)
+#define REF_xxxx_E (3 * OCELOT_RESOURCE_SZ)
+
+/* For each resource type there are 4 types of watermarks:
+ * Q_RSRV: reservation per QoS class per port
+ * PRIO_SHR: sharing watermark per QoS class across all ports
+ * P_RSRV: reservation per port
+ * COL_SHR: sharing watermark per color (drop precedence) across all ports
+ */
+#define xxx_Q_RSRV_x 0
+#define xxx_PRIO_SHR_x 216
+#define xxx_P_RSRV_x 224
+#define xxx_COL_SHR_x 254
+
+/* Reservation Watermarks
+ * ----------------------
+ *
+ * For setting up the reserved areas, egress watermarks exist per port and per
+ * QoS class for both ingress and egress.
+ */
+
+/* Amount of packet buffer
+ * | per QoS class
+ * | | reserved
+ * | | | per egress port
+ * | | | |
+ * V V v v
+ * BUF_Q_RSRV_E
+ */
+#define BUF_Q_RSRV_E(port, prio) \
+ (BUF_xxxx_E + xxx_Q_RSRV_x + OCELOT_NUM_TC * (port) + (prio))
+
+/* Amount of packet buffer
+ * | for all port's traffic classes
+ * | | reserved
+ * | | | per egress port
+ * | | | |
+ * V V v v
+ * BUF_P_RSRV_E
+ */
+#define BUF_P_RSRV_E(port) \
+ (BUF_xxxx_E + xxx_P_RSRV_x + (port))
+
+/* Amount of packet buffer
+ * | per QoS class
+ * | | reserved
+ * | | | per ingress port
+ * | | | |
+ * V V v v
+ * BUF_Q_RSRV_I
+ */
+#define BUF_Q_RSRV_I(port, prio) \
+ (BUF_xxxx_I + xxx_Q_RSRV_x + OCELOT_NUM_TC * (port) + (prio))
+
+/* Amount of packet buffer
+ * | for all port's traffic classes
+ * | | reserved
+ * | | | per ingress port
+ * | | | |
+ * V V v v
+ * BUF_P_RSRV_I
+ */
+#define BUF_P_RSRV_I(port) \
+ (BUF_xxxx_I + xxx_P_RSRV_x + (port))
+
+/* Amount of frame references
+ * | per QoS class
+ * | | reserved
+ * | | | per egress port
+ * | | | |
+ * V V v v
+ * REF_Q_RSRV_E
+ */
+#define REF_Q_RSRV_E(port, prio) \
+ (REF_xxxx_E + xxx_Q_RSRV_x + OCELOT_NUM_TC * (port) + (prio))
+
+/* Amount of frame references
+ * | for all port's traffic classes
+ * | | reserved
+ * | | | per egress port
+ * | | | |
+ * V V v v
+ * REF_P_RSRV_E
+ */
+#define REF_P_RSRV_E(port) \
+ (REF_xxxx_E + xxx_P_RSRV_x + (port))
+
+/* Amount of frame references
+ * | per QoS class
+ * | | reserved
+ * | | | per ingress port
+ * | | | |
+ * V V v v
+ * REF_Q_RSRV_I
+ */
+#define REF_Q_RSRV_I(port, prio) \
+ (REF_xxxx_I + xxx_Q_RSRV_x + OCELOT_NUM_TC * (port) + (prio))
+
+/* Amount of frame references
+ * | for all port's traffic classes
+ * | | reserved
+ * | | | per ingress port
+ * | | | |
+ * V V v v
+ * REF_P_RSRV_I
+ */
+#define REF_P_RSRV_I(port) \
+ (REF_xxxx_I + xxx_P_RSRV_x + (port))
+
+/* Sharing Watermarks
+ * ------------------
+ *
+ * The shared memory area is shared between all ports.
+ */
+
+/* Amount of buffer
+ * | per QoS class
+ * | | from the shared memory area
+ * | | | for egress traffic
+ * | | | |
+ * V V v v
+ * BUF_PRIO_SHR_E
+ */
+#define BUF_PRIO_SHR_E(prio) \
+ (BUF_xxxx_E + xxx_PRIO_SHR_x + (prio))
+
+/* Amount of buffer
+ * | per color (drop precedence level)
+ * | | from the shared memory area
+ * | | | for egress traffic
+ * | | | |
+ * V V v v
+ * BUF_COL_SHR_E
+ */
+#define BUF_COL_SHR_E(dp) \
+ (BUF_xxxx_E + xxx_COL_SHR_x + (1 - (dp)))
+
+/* Amount of buffer
+ * | per QoS class
+ * | | from the shared memory area
+ * | | | for ingress traffic
+ * | | | |
+ * V V v v
+ * BUF_PRIO_SHR_I
+ */
+#define BUF_PRIO_SHR_I(prio) \
+ (BUF_xxxx_I + xxx_PRIO_SHR_x + (prio))
+
+/* Amount of buffer
+ * | per color (drop precedence level)
+ * | | from the shared memory area
+ * | | | for ingress traffic
+ * | | | |
+ * V V v v
+ * BUF_COL_SHR_I
+ */
+#define BUF_COL_SHR_I(dp) \
+ (BUF_xxxx_I + xxx_COL_SHR_x + (1 - (dp)))
+
+/* Amount of frame references
+ * | per QoS class
+ * | | from the shared area
+ * | | | for egress traffic
+ * | | | |
+ * V V v v
+ * REF_PRIO_SHR_E
+ */
+#define REF_PRIO_SHR_E(prio) \
+ (REF_xxxx_E + xxx_PRIO_SHR_x + (prio))
+
+/* Amount of frame references
+ * | per color (drop precedence level)
+ * | | from the shared area
+ * | | | for egress traffic
+ * | | | |
+ * V V v v
+ * REF_COL_SHR_E
+ */
+#define REF_COL_SHR_E(dp) \
+ (REF_xxxx_E + xxx_COL_SHR_x + (1 - (dp)))
+
+/* Amount of frame references
+ * | per QoS class
+ * | | from the shared area
+ * | | | for ingress traffic
+ * | | | |
+ * V V v v
+ * REF_PRIO_SHR_I
+ */
+#define REF_PRIO_SHR_I(prio) \
+ (REF_xxxx_I + xxx_PRIO_SHR_x + (prio))
+
+/* Amount of frame references
+ * | per color (drop precedence level)
+ * | | from the shared area
+ * | | | for ingress traffic
+ * | | | |
+ * V V v v
+ * REF_COL_SHR_I
+ */
+#define REF_COL_SHR_I(dp) \
+ (REF_xxxx_I + xxx_COL_SHR_x + (1 - (dp)))
+
+static u32 ocelot_wm_read(struct ocelot *ocelot, int index)
+{
+ int wm = ocelot_read_gix(ocelot, QSYS_RES_CFG, index);
+
+ return ocelot->ops->wm_dec(wm);
+}
+
+static void ocelot_wm_write(struct ocelot *ocelot, int index, u32 val)
+{
+ u32 wm = ocelot->ops->wm_enc(val);
+
+ ocelot_write_gix(ocelot, wm, QSYS_RES_CFG, index);
+}
+
+/* The hardware comes out of reset with strange defaults: the sum of all
+ * reservations for frame memory is larger than the total buffer size.
+ * One has to wonder how can the reservation watermarks still guarantee
+ * anything under congestion.
+ * Bring some sense into the hardware by changing the defaults to disable all
+ * reservations and rely only on the sharing watermark for frames with drop
+ * precedence 0. The user can still explicitly request reservations per port
+ * and per port-tc through devlink-sb.
+ */
+static void ocelot_disable_reservation_watermarks(struct ocelot *ocelot,
+ int port)
+{
+ int prio;
+
+ for (prio = 0; prio < OCELOT_NUM_TC; prio++) {
+ ocelot_wm_write(ocelot, BUF_Q_RSRV_I(port, prio), 0);
+ ocelot_wm_write(ocelot, BUF_Q_RSRV_E(port, prio), 0);
+ ocelot_wm_write(ocelot, REF_Q_RSRV_I(port, prio), 0);
+ ocelot_wm_write(ocelot, REF_Q_RSRV_E(port, prio), 0);
+ }
+
+ ocelot_wm_write(ocelot, BUF_P_RSRV_I(port), 0);
+ ocelot_wm_write(ocelot, BUF_P_RSRV_E(port), 0);
+ ocelot_wm_write(ocelot, REF_P_RSRV_I(port), 0);
+ ocelot_wm_write(ocelot, REF_P_RSRV_E(port), 0);
+}
+
+/* We want the sharing watermarks to consume all nonreserved resources, for
+ * efficient resource utilization (a single traffic flow should be able to use
+ * up the entire buffer space and frame resources as long as there's no
+ * interference).
+ * The switch has 10 sharing watermarks per lookup: 8 per traffic class and 2
+ * per color (drop precedence).
+ * The trouble with configuring these sharing watermarks is that:
+ * (1) There's a risk that we overcommit the resources if we configure
+ * (a) all 8 per-TC sharing watermarks to the max
+ * (b) all 2 per-color sharing watermarks to the max
+ * (2) There's a risk that we undercommit the resources if we configure
+ * (a) all 8 per-TC sharing watermarks to "max / 8"
+ * (b) all 2 per-color sharing watermarks to "max / 2"
+ * So for Linux, let's just disable the sharing watermarks per traffic class
+ * (setting them to 0 will make them always exceeded), and rely only on the
+ * sharing watermark for drop priority 0. So frames with drop priority set to 1
+ * by QoS classification or policing will still be allowed, but only as long as
+ * the port and port-TC reservations are not exceeded.
+ */
+static void ocelot_disable_tc_sharing_watermarks(struct ocelot *ocelot)
+{
+ int prio;
+
+ for (prio = 0; prio < OCELOT_NUM_TC; prio++) {
+ ocelot_wm_write(ocelot, BUF_PRIO_SHR_I(prio), 0);
+ ocelot_wm_write(ocelot, BUF_PRIO_SHR_E(prio), 0);
+ ocelot_wm_write(ocelot, REF_PRIO_SHR_I(prio), 0);
+ ocelot_wm_write(ocelot, REF_PRIO_SHR_E(prio), 0);
+ }
+}
+
+static void ocelot_get_buf_rsrv(struct ocelot *ocelot, u32 *buf_rsrv_i,
+ u32 *buf_rsrv_e)
+{
+ int port, prio;
+
+ *buf_rsrv_i = 0;
+ *buf_rsrv_e = 0;
+
+ for (port = 0; port <= ocelot->num_phys_ports; port++) {
+ for (prio = 0; prio < OCELOT_NUM_TC; prio++) {
+ *buf_rsrv_i += ocelot_wm_read(ocelot,
+ BUF_Q_RSRV_I(port, prio));
+ *buf_rsrv_e += ocelot_wm_read(ocelot,
+ BUF_Q_RSRV_E(port, prio));
+ }
+
+ *buf_rsrv_i += ocelot_wm_read(ocelot, BUF_P_RSRV_I(port));
+ *buf_rsrv_e += ocelot_wm_read(ocelot, BUF_P_RSRV_E(port));
+ }
+
+ *buf_rsrv_i *= OCELOT_BUFFER_CELL_SZ;
+ *buf_rsrv_e *= OCELOT_BUFFER_CELL_SZ;
+}
+
+static void ocelot_get_ref_rsrv(struct ocelot *ocelot, u32 *ref_rsrv_i,
+ u32 *ref_rsrv_e)
+{
+ int port, prio;
+
+ *ref_rsrv_i = 0;
+ *ref_rsrv_e = 0;
+
+ for (port = 0; port <= ocelot->num_phys_ports; port++) {
+ for (prio = 0; prio < OCELOT_NUM_TC; prio++) {
+ *ref_rsrv_i += ocelot_wm_read(ocelot,
+ REF_Q_RSRV_I(port, prio));
+ *ref_rsrv_e += ocelot_wm_read(ocelot,
+ REF_Q_RSRV_E(port, prio));
+ }
+
+ *ref_rsrv_i += ocelot_wm_read(ocelot, REF_P_RSRV_I(port));
+ *ref_rsrv_e += ocelot_wm_read(ocelot, REF_P_RSRV_E(port));
+ }
+}
+
+/* Calculate all reservations, then set up the sharing watermark for DP=0 to
+ * consume the remaining resources up to the pool's configured size.
+ */
+static void ocelot_setup_sharing_watermarks(struct ocelot *ocelot)
+{
+ u32 buf_rsrv_i, buf_rsrv_e;
+ u32 ref_rsrv_i, ref_rsrv_e;
+ u32 buf_shr_i, buf_shr_e;
+ u32 ref_shr_i, ref_shr_e;
+
+ ocelot_get_buf_rsrv(ocelot, &buf_rsrv_i, &buf_rsrv_e);
+ ocelot_get_ref_rsrv(ocelot, &ref_rsrv_i, &ref_rsrv_e);
+
+ buf_shr_i = ocelot->packet_buffer_size - buf_rsrv_i;
+ buf_shr_e = ocelot->packet_buffer_size - buf_rsrv_e;
+ ref_shr_i = ocelot->num_frame_refs - ref_rsrv_i;
+ ref_shr_e = ocelot->num_frame_refs - ref_rsrv_e;
+
+ buf_shr_i /= OCELOT_BUFFER_CELL_SZ;
+ buf_shr_e /= OCELOT_BUFFER_CELL_SZ;
+
+ ocelot_wm_write(ocelot, BUF_COL_SHR_I(0), buf_shr_i);
+ ocelot_wm_write(ocelot, BUF_COL_SHR_E(0), buf_shr_e);
+ ocelot_wm_write(ocelot, REF_COL_SHR_E(0), ref_shr_e);
+ ocelot_wm_write(ocelot, REF_COL_SHR_I(0), ref_shr_i);
+ ocelot_wm_write(ocelot, BUF_COL_SHR_I(1), 0);
+ ocelot_wm_write(ocelot, BUF_COL_SHR_E(1), 0);
+ ocelot_wm_write(ocelot, REF_COL_SHR_E(1), 0);
+ ocelot_wm_write(ocelot, REF_COL_SHR_I(1), 0);
+}
+
+/* The hardware works like this:
+ *
+ * Frame forwarding decision taken
+ * |
+ * v
+ * +--------------------+--------------------+--------------------+
+ * | | | |
+ * v v v v
+ * Ingress memory Egress memory Ingress frame Egress frame
+ * check check reference check reference check
+ * | | | |
+ * v v v v
+ * BUF_Q_RSRV_I ok BUF_Q_RSRV_E ok REF_Q_RSRV_I ok REF_Q_RSRV_E ok
+ *(src port, prio) -+ (dst port, prio) -+ (src port, prio) -+ (dst port, prio) -+
+ * | | | | | | | |
+ * |exceeded | |exceeded | |exceeded | |exceeded |
+ * v | v | v | v |
+ * BUF_P_RSRV_I ok| BUF_P_RSRV_E ok| REF_P_RSRV_I ok| REF_P_RSRV_E ok|
+ * (src port) ----+ (dst port) ----+ (src port) ----+ (dst port) -----+
+ * | | | | | | | |
+ * |exceeded | |exceeded | |exceeded | |exceeded |
+ * v | v | v | v |
+ * BUF_PRIO_SHR_I ok| BUF_PRIO_SHR_E ok| REF_PRIO_SHR_I ok| REF_PRIO_SHR_E ok|
+ * (prio) ------+ (prio) ------+ (prio) ------+ (prio) -------+
+ * | | | | | | | |
+ * |exceeded | |exceeded | |exceeded | |exceeded |
+ * v | v | v | v |
+ * BUF_COL_SHR_I ok| BUF_COL_SHR_E ok| REF_COL_SHR_I ok| REF_COL_SHR_E ok|
+ * (dp) -------+ (dp) -------+ (dp) -------+ (dp) --------+
+ * | | | | | | | |
+ * |exceeded | |exceeded | |exceeded | |exceeded |
+ * v v v v v v v v
+ * fail success fail success fail success fail success
+ * | | | | | | | |
+ * v v v v v v v v
+ * +-----+----+ +-----+----+ +-----+----+ +-----+-----+
+ * | | | |
+ * +-------> OR <-------+ +-------> OR <-------+
+ * | |
+ * v v
+ * +----------------> AND <-----------------+
+ * |
+ * v
+ * FIFO drop / accept
+ *
+ * We are modeling each of the 4 parallel lookups as a devlink-sb pool.
+ * At least one (ingress or egress) memory pool and one (ingress or egress)
+ * frame reference pool need to have resources for frame acceptance to succeed.
+ *
+ * The following watermarks are controlled explicitly through devlink-sb:
+ * BUF_Q_RSRV_I, BUF_Q_RSRV_E, REF_Q_RSRV_I, REF_Q_RSRV_E
+ * BUF_P_RSRV_I, BUF_P_RSRV_E, REF_P_RSRV_I, REF_P_RSRV_E
+ * The following watermarks are controlled implicitly through devlink-sb:
+ * BUF_COL_SHR_I, BUF_COL_SHR_E, REF_COL_SHR_I, REF_COL_SHR_E
+ * The following watermarks are unused and disabled:
+ * BUF_PRIO_SHR_I, BUF_PRIO_SHR_E, REF_PRIO_SHR_I, REF_PRIO_SHR_E
+ *
+ * This function overrides the hardware defaults with more sane ones (no
+ * reservations by default, let sharing use all resources) and disables the
+ * unused watermarks.
+ */
+void ocelot_watermark_init(struct ocelot *ocelot)
+{
+ int all_tcs = GENMASK(OCELOT_NUM_TC - 1, 0);
+ int port;
+
+ ocelot_write(ocelot, all_tcs, QSYS_RES_QOS_MODE);
+
+ for (port = 0; port <= ocelot->num_phys_ports; port++)
+ ocelot_disable_reservation_watermarks(ocelot, port);
+
+ ocelot_disable_tc_sharing_watermarks(ocelot);
+ ocelot_setup_sharing_watermarks(ocelot);
+}