On Thu, Feb 02, 2023 at 11:43:48AM +0100, Daniel Machon wrote:
> Add support for Service Dual Leacky Buckets (SDLB), used to implement
> PSFP flow-meters. Buckets are linked together in a leak chain of a leak
> group. Leak groups a preconfigured to serve buckets within a certain
> rate interval.
>
> Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
...
> diff --git a/drivers/net/ethernet/microchip/sparx5/sparx5_sdlb.c b/drivers/net/ethernet/microchip/sparx5/sparx5_sdlb.c
> new file mode 100644
> index 000000000000..f5267218caeb
> --- /dev/null
> +++ b/drivers/net/ethernet/microchip/sparx5/sparx5_sdlb.c
...
> +static u32 sparx5_sdlb_group_get_next(struct sparx5 *sparx5, u32 group,
> + u32 lb)
> +{
> + u32 val;
> +
> + val = spx5_rd(sparx5, ANA_AC_SDLB_XLB_NEXT(lb));
> +
> + return ANA_AC_SDLB_XLB_NEXT_LBSET_NEXT_GET(val);
> +}
...
> +static u32 sparx5_sdlb_group_get_last(struct sparx5 *sparx5, u32 group)
> +{
> + u32 itr, next;
> +
> + itr = sparx5_sdlb_group_get_first(sparx5, group);
> +
> + for (;;) {
Unbounded loops like this give me some apprehension.
Will they always terminate?
> + next = sparx5_sdlb_group_get_next(sparx5, group, itr);
> + if (itr == next)
> + return itr;
> +
> + itr = next;
> + }
> +}
...
> +static int sparx5_sdlb_group_get_adjacent(struct sparx5 *sparx5, u32 group,
> + u32 idx, u32 *prev, u32 *next,
> + u32 *first)
> +{
> + u32 itr;
> +
> + *first = sparx5_sdlb_group_get_first(sparx5, group);
> + *prev = *first;
> + *next = *first;
> + itr = *first;
> +
> + for (;;) {
> + *next = sparx5_sdlb_group_get_next(sparx5, group, itr);
> +
> + if (itr == idx)
> + return 0; /* Found it */
> +
> + if (itr == *next)
> + return -EINVAL; /* Was not found */
> +
> + *prev = itr;
> + itr = *next;
> + }
> +}
> +
> +static int sparx5_sdlb_group_get_count(struct sparx5 *sparx5, u32 group)
> +{
> + u32 itr, next;
> + int count = 0;
> +
> + itr = sparx5_sdlb_group_get_first(sparx5, group);
> +
> + for (;;) {
> + next = sparx5_sdlb_group_get_next(sparx5, group, itr);
> + if (itr == next)
> + return count;
> +
> + itr = next;
> + count++;
> + }
> +}
...
> +int sparx5_sdlb_group_get_by_index(struct sparx5 *sparx5, u32 idx, u32 *group)
> +{
> + u32 itr, next;
> + int i;
> +
> + for (i = 0; i < SPX5_SDLB_GROUP_CNT; i++) {
> + if (sparx5_sdlb_group_is_empty(sparx5, i))
> + continue;
> +
> + itr = sparx5_sdlb_group_get_first(sparx5, i);
> +
> + for (;;) {
> + next = sparx5_sdlb_group_get_next(sparx5, i, itr);
> +
> + if (itr == idx) {
> + *group = i;
> + return 0; /* Found it */
> + }
> + if (itr == next)
> + break; /* Was not found */
> +
> + itr = next;
> + }
> + }
> +
> + return -EINVAL;
> +}
...
Hi Simon,
Thanks for reviewing my patches, appreciate it!
> > +static u32 sparx5_sdlb_group_get_last(struct sparx5 *sparx5, u32 group)
> > +{
> > + u32 itr, next;
> > +
> > + itr = sparx5_sdlb_group_get_first(sparx5, group);
> > +
> > + for (;;) {
>
> Unbounded loops like this give me some apprehension.
> Will they always terminate?
Yes, it will always terminate - unless the add() del() functions are
buggy to begin with.
The end of the leak chain is marked by an index pointing to itself, and
this is the exit condition I am looking for in the unbounded loop.
>
> > + next = sparx5_sdlb_group_get_next(sparx5, group, itr);
> > + if (itr == next)
> > + return itr;
> > +
> > + itr = next;
> > + }
> > +}
>
> ...
>
> > +static int sparx5_sdlb_group_get_adjacent(struct sparx5 *sparx5, u32 group,
> > + u32 idx, u32 *prev, u32 *next,
> > + u32 *first)
> > +{
> > + u32 itr;
> > +
> > + *first = sparx5_sdlb_group_get_first(sparx5, group);
> > + *prev = *first;
> > + *next = *first;
> > + itr = *first;
> > +
> > + for (;;) {
> > + *next = sparx5_sdlb_group_get_next(sparx5, group, itr);
> > +
> > + if (itr == idx)
> > + return 0; /* Found it */
> > +
> > + if (itr == *next)
> > + return -EINVAL; /* Was not found */
> > +
> > + *prev = itr;
> > + itr = *next;
> > + }
> > +}
> > +
> > +static int sparx5_sdlb_group_get_count(struct sparx5 *sparx5, u32 group)
> > +{
> > + u32 itr, next;
> > + int count = 0;
> > +
> > + itr = sparx5_sdlb_group_get_first(sparx5, group);
> > +
> > + for (;;) {
> > + next = sparx5_sdlb_group_get_next(sparx5, group, itr);
> > + if (itr == next)
> > + return count;
> > +
> > + itr = next;
> > + count++;
> > + }
> > +}
>
> ...
>
> > +int sparx5_sdlb_group_get_by_index(struct sparx5 *sparx5, u32 idx, u32 *group)
> > +{
> > + u32 itr, next;
> > + int i;
> > +
> > + for (i = 0; i < SPX5_SDLB_GROUP_CNT; i++) {
> > + if (sparx5_sdlb_group_is_empty(sparx5, i))
> > + continue;
> > +
> > + itr = sparx5_sdlb_group_get_first(sparx5, i);
> > +
> > + for (;;) {
> > + next = sparx5_sdlb_group_get_next(sparx5, i, itr);
> > +
> > + if (itr == idx) {
> > + *group = i;
> > + return 0; /* Found it */
> > + }
> > + if (itr == next)
> > + break; /* Was not found */
> > +
> > + itr = next;
> > + }
> > + }
> > +
> > + return -EINVAL;
> > +}
>
> ...
@@ -10,7 +10,7 @@ sparx5-switch-y := sparx5_main.o sparx5_packet.o \
sparx5_switchdev.o sparx5_calendar.o sparx5_ethtool.o sparx5_fdma.o \
sparx5_ptp.o sparx5_pgid.o sparx5_tc.o sparx5_qos.o \
sparx5_vcap_impl.o sparx5_vcap_ag_api.o sparx5_tc_flower.o \
- sparx5_tc_matchall.o sparx5_pool.o
+ sparx5_tc_matchall.o sparx5_pool.o sparx5_sdlb.o
sparx5-switch-$(CONFIG_SPARX5_DCB) += sparx5_dcb.o
sparx5-switch-$(CONFIG_DEBUG_FS) += sparx5_vcap_debugfs.o
@@ -425,6 +425,37 @@ int sparx5_pool_get(struct sparx5_pool_entry *pool, int size, u32 *id);
int sparx5_pool_get_with_idx(struct sparx5_pool_entry *pool, int size, u32 idx,
u32 *id);
+/* sparx5_sdlb.c */
+#define SPX5_SDLB_PUP_TOKEN_DISABLE 0x1FFF
+#define SPX5_SDLB_PUP_TOKEN_MAX (SPX5_SDLB_PUP_TOKEN_DISABLE - 1)
+#define SPX5_SDLB_GROUP_RATE_MAX 25000000000ULL
+#define SPX5_SDLB_2CYCLES_TYPE2_THRES_OFFSET 13
+#define SPX5_SDLB_CNT 4096
+#define SPX5_SDLB_GROUP_CNT 10
+#define SPX5_CLK_PER_100PS_DEFAULT 16
+
+struct sparx5_sdlb_group {
+ u64 max_rate;
+ u32 min_burst;
+ u32 frame_size;
+ u32 pup_interval;
+ u32 nsets;
+};
+
+extern struct sparx5_sdlb_group sdlb_groups[SPX5_SDLB_GROUP_CNT];
+int sparx5_sdlb_pup_token_get(struct sparx5 *sparx5, u32 pup_interval,
+ u64 rate);
+
+int sparx5_sdlb_clk_hz_get(struct sparx5 *sparx5);
+int sparx5_sdlb_group_get_by_rate(struct sparx5 *sparx5, u32 rate, u32 burst);
+int sparx5_sdlb_group_get_by_index(struct sparx5 *sparx5, u32 idx, u32 *group);
+
+int sparx5_sdlb_group_add(struct sparx5 *sparx5, u32 group, u32 idx);
+int sparx5_sdlb_group_del(struct sparx5 *sparx5, u32 group, u32 idx);
+
+void sparx5_sdlb_group_init(struct sparx5 *sparx5, u64 max_rate, u32 min_burst,
+ u32 frame_size, u32 idx);
+
/* Clock period in picoseconds */
static inline u32 sparx5_clk_period(enum sparx5_core_clockfreq cclock)
{
new file mode 100644
@@ -0,0 +1,335 @@
+// SPDX-License-Identifier: GPL-2.0+
+/* Microchip Sparx5 Switch driver
+ *
+ * Copyright (c) 2023 Microchip Technology Inc. and its subsidiaries.
+ */
+
+#include "sparx5_main_regs.h"
+#include "sparx5_main.h"
+
+struct sparx5_sdlb_group sdlb_groups[SPX5_SDLB_GROUP_CNT] = {
+ { SPX5_SDLB_GROUP_RATE_MAX, 8192 / 1, 64 }, /* 25 G */
+ { 15000000000ULL, 8192 / 1, 64 }, /* 15 G */
+ { 10000000000ULL, 8192 / 1, 64 }, /* 10 G */
+ { 5000000000ULL, 8192 / 1, 64 }, /* 5 G */
+ { 2500000000ULL, 8192 / 1, 64 }, /* 2.5 G */
+ { 1000000000ULL, 8192 / 2, 64 }, /* 1 G */
+ { 500000000ULL, 8192 / 2, 64 }, /* 500 M */
+ { 100000000ULL, 8192 / 4, 64 }, /* 100 M */
+ { 50000000ULL, 8192 / 4, 64 }, /* 50 M */
+ { 5000000ULL, 8192 / 8, 64 } /* 5 M */
+};
+
+int sparx5_sdlb_clk_hz_get(struct sparx5 *sparx5)
+{
+ u32 clk_per_100ps;
+ u64 clk_hz;
+
+ clk_per_100ps = HSCH_SYS_CLK_PER_100PS_GET(spx5_rd(sparx5,
+ HSCH_SYS_CLK_PER));
+ if (!clk_per_100ps)
+ clk_per_100ps = SPX5_CLK_PER_100PS_DEFAULT;
+
+ clk_hz = (10 * 1000 * 1000) / clk_per_100ps;
+ return clk_hz *= 1000;
+}
+
+static int sparx5_sdlb_pup_interval_get(struct sparx5 *sparx5, u32 max_token,
+ u64 max_rate)
+{
+ u64 clk_hz;
+
+ clk_hz = sparx5_sdlb_clk_hz_get(sparx5);
+
+ return div64_u64((8 * clk_hz * max_token), max_rate);
+}
+
+int sparx5_sdlb_pup_token_get(struct sparx5 *sparx5, u32 pup_interval, u64 rate)
+{
+ u64 clk_hz;
+
+ if (!rate)
+ return SPX5_SDLB_PUP_TOKEN_DISABLE;
+
+ clk_hz = sparx5_sdlb_clk_hz_get(sparx5);
+
+ return DIV64_U64_ROUND_UP((rate * pup_interval), (clk_hz * 8));
+}
+
+static void sparx5_sdlb_group_disable(struct sparx5 *sparx5, u32 group)
+{
+ spx5_rmw(ANA_AC_SDLB_PUP_CTRL_PUP_ENA_SET(0),
+ ANA_AC_SDLB_PUP_CTRL_PUP_ENA, sparx5,
+ ANA_AC_SDLB_PUP_CTRL(group));
+}
+
+static void sparx5_sdlb_group_enable(struct sparx5 *sparx5, u32 group)
+{
+ spx5_rmw(ANA_AC_SDLB_PUP_CTRL_PUP_ENA_SET(1),
+ ANA_AC_SDLB_PUP_CTRL_PUP_ENA, sparx5,
+ ANA_AC_SDLB_PUP_CTRL(group));
+}
+
+static u32 sparx5_sdlb_group_get_first(struct sparx5 *sparx5, u32 group)
+{
+ u32 val;
+
+ val = spx5_rd(sparx5, ANA_AC_SDLB_XLB_START(group));
+
+ return ANA_AC_SDLB_XLB_START_LBSET_START_GET(val);
+}
+
+static u32 sparx5_sdlb_group_get_next(struct sparx5 *sparx5, u32 group,
+ u32 lb)
+{
+ u32 val;
+
+ val = spx5_rd(sparx5, ANA_AC_SDLB_XLB_NEXT(lb));
+
+ return ANA_AC_SDLB_XLB_NEXT_LBSET_NEXT_GET(val);
+}
+
+static bool sparx5_sdlb_group_is_first(struct sparx5 *sparx5, u32 group,
+ u32 lb)
+{
+ return lb == sparx5_sdlb_group_get_first(sparx5, group);
+}
+
+static bool sparx5_sdlb_group_is_last(struct sparx5 *sparx5, u32 group,
+ u32 lb)
+{
+ return lb == sparx5_sdlb_group_get_next(sparx5, group, lb);
+}
+
+static bool sparx5_sdlb_group_is_empty(struct sparx5 *sparx5, u32 group)
+{
+ u32 val;
+
+ val = spx5_rd(sparx5, ANA_AC_SDLB_PUP_CTRL(group));
+
+ return ANA_AC_SDLB_PUP_CTRL_PUP_ENA_GET(val) == 0;
+}
+
+static u32 sparx5_sdlb_group_get_last(struct sparx5 *sparx5, u32 group)
+{
+ u32 itr, next;
+
+ itr = sparx5_sdlb_group_get_first(sparx5, group);
+
+ for (;;) {
+ next = sparx5_sdlb_group_get_next(sparx5, group, itr);
+ if (itr == next)
+ return itr;
+
+ itr = next;
+ }
+}
+
+static bool sparx5_sdlb_group_is_singular(struct sparx5 *sparx5, u32 group)
+{
+ if (sparx5_sdlb_group_is_empty(sparx5, group))
+ return false;
+
+ return sparx5_sdlb_group_get_first(sparx5, group) ==
+ sparx5_sdlb_group_get_last(sparx5, group);
+}
+
+static int sparx5_sdlb_group_get_adjacent(struct sparx5 *sparx5, u32 group,
+ u32 idx, u32 *prev, u32 *next,
+ u32 *first)
+{
+ u32 itr;
+
+ *first = sparx5_sdlb_group_get_first(sparx5, group);
+ *prev = *first;
+ *next = *first;
+ itr = *first;
+
+ for (;;) {
+ *next = sparx5_sdlb_group_get_next(sparx5, group, itr);
+
+ if (itr == idx)
+ return 0; /* Found it */
+
+ if (itr == *next)
+ return -EINVAL; /* Was not found */
+
+ *prev = itr;
+ itr = *next;
+ }
+}
+
+static int sparx5_sdlb_group_get_count(struct sparx5 *sparx5, u32 group)
+{
+ u32 itr, next;
+ int count = 0;
+
+ itr = sparx5_sdlb_group_get_first(sparx5, group);
+
+ for (;;) {
+ next = sparx5_sdlb_group_get_next(sparx5, group, itr);
+ if (itr == next)
+ return count;
+
+ itr = next;
+ count++;
+ }
+}
+
+int sparx5_sdlb_group_get_by_rate(struct sparx5 *sparx5, u32 rate, u32 burst)
+{
+ const struct sparx5_sdlb_group *group;
+ u64 rate_bps;
+ int i, count;
+
+ rate_bps = rate * 1000;
+
+ for (i = SPX5_SDLB_GROUP_CNT - 1; i >= 0; i--) {
+ group = &sdlb_groups[i];
+
+ count = sparx5_sdlb_group_get_count(sparx5, i);
+
+ /* Check that this group is not full.
+ * According to LB group configuration rules: the number of XLBs
+ * in a group must not exceed PUP_INTERVAL/4 - 1.
+ */
+ if (count > ((group->pup_interval / 4) - 1))
+ continue;
+
+ if (rate_bps < group->max_rate)
+ return i;
+ }
+
+ return -ENOSPC;
+}
+
+int sparx5_sdlb_group_get_by_index(struct sparx5 *sparx5, u32 idx, u32 *group)
+{
+ u32 itr, next;
+ int i;
+
+ for (i = 0; i < SPX5_SDLB_GROUP_CNT; i++) {
+ if (sparx5_sdlb_group_is_empty(sparx5, i))
+ continue;
+
+ itr = sparx5_sdlb_group_get_first(sparx5, i);
+
+ for (;;) {
+ next = sparx5_sdlb_group_get_next(sparx5, i, itr);
+
+ if (itr == idx) {
+ *group = i;
+ return 0; /* Found it */
+ }
+ if (itr == next)
+ break; /* Was not found */
+
+ itr = next;
+ }
+ }
+
+ return -EINVAL;
+}
+
+static int sparx5_sdlb_group_link(struct sparx5 *sparx5, u32 group, u32 idx,
+ u32 first, u32 next, bool empty)
+{
+ /* Stop leaking */
+ sparx5_sdlb_group_disable(sparx5, group);
+
+ if (empty)
+ return 0;
+
+ /* Link insertion lb to next lb */
+ spx5_wr(ANA_AC_SDLB_XLB_NEXT_LBSET_NEXT_SET(next) |
+ ANA_AC_SDLB_XLB_NEXT_LBGRP_SET(group),
+ sparx5, ANA_AC_SDLB_XLB_NEXT(idx));
+
+ /* Set the first lb */
+ spx5_wr(ANA_AC_SDLB_XLB_START_LBSET_START_SET(first), sparx5,
+ ANA_AC_SDLB_XLB_START(group));
+
+ /* Start leaking */
+ sparx5_sdlb_group_enable(sparx5, group);
+
+ return 0;
+};
+
+int sparx5_sdlb_group_add(struct sparx5 *sparx5, u32 group, u32 idx)
+{
+ u32 first, next;
+
+ /* We always add to head of the list */
+ first = idx;
+
+ if (sparx5_sdlb_group_is_empty(sparx5, group))
+ next = idx;
+ else
+ next = sparx5_sdlb_group_get_first(sparx5, group);
+
+ return sparx5_sdlb_group_link(sparx5, group, idx, first, next, false);
+}
+
+int sparx5_sdlb_group_del(struct sparx5 *sparx5, u32 group, u32 idx)
+{
+ u32 first, next, prev;
+ bool empty = false;
+
+ if (sparx5_sdlb_group_get_adjacent(sparx5, group, idx, &prev, &next,
+ &first) < 0) {
+ pr_err("%s:%d Could not find idx: %d in group: %d", __func__,
+ __LINE__, idx, group);
+ return -EINVAL;
+ }
+
+ if (sparx5_sdlb_group_is_singular(sparx5, group)) {
+ empty = true;
+ } else if (sparx5_sdlb_group_is_last(sparx5, group, idx)) {
+ /* idx is removed, prev is now last */
+ idx = prev;
+ next = prev;
+ } else if (sparx5_sdlb_group_is_first(sparx5, group, idx)) {
+ /* idx is removed and points to itself, first is next */
+ first = next;
+ next = idx;
+ } else {
+ /* Next is not touched */
+ idx = prev;
+ }
+
+ return sparx5_sdlb_group_link(sparx5, group, idx, first, next, empty);
+}
+
+void sparx5_sdlb_group_init(struct sparx5 *sparx5, u64 max_rate, u32 min_burst,
+ u32 frame_size, u32 idx)
+{
+ u32 thres_shift, mask = 0x01, power = 0;
+ struct sparx5_sdlb_group *group;
+ u64 max_token;
+
+ group = &sdlb_groups[idx];
+
+ /* Number of positions to right-shift LB's threshold value. */
+ while ((min_burst & mask) == 0) {
+ power++;
+ mask <<= 1;
+ }
+ thres_shift = SPX5_SDLB_2CYCLES_TYPE2_THRES_OFFSET - power;
+
+ max_token = (min_burst > SPX5_SDLB_PUP_TOKEN_MAX) ?
+ SPX5_SDLB_PUP_TOKEN_MAX :
+ min_burst;
+ group->pup_interval =
+ sparx5_sdlb_pup_interval_get(sparx5, max_token, max_rate);
+
+ group->frame_size = frame_size;
+
+ spx5_wr(ANA_AC_SDLB_PUP_INTERVAL_PUP_INTERVAL_SET(group->pup_interval),
+ sparx5, ANA_AC_SDLB_PUP_INTERVAL(idx));
+
+ spx5_wr(ANA_AC_SDLB_FRM_RATE_TOKENS_FRM_RATE_TOKENS_SET(frame_size),
+ sparx5, ANA_AC_SDLB_FRM_RATE_TOKENS(idx));
+
+ spx5_wr(ANA_AC_SDLB_LBGRP_MISC_THRES_SHIFT_SET(thres_shift), sparx5,
+ ANA_AC_SDLB_LBGRP_MISC(idx));
+}