net: microchip: sparx5: Add raw VCAP debugFS support for the VCAP API

This adds support for decoding VCAP rules with a minimum number of
attributes: address, rule size and keyset.

This allows for a quick inspection of a VCAP instance to determine if the
rule are present and in the correct order.

Signed-off-by: Steen Hegelund <steen.hegelund@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 267 insertions, 7 deletions

diff --git a/drivers/net/ethernet/microchip/vcap/vcap_api_debugfs.c b/drivers/net/ethernet/microchip/vcap/vcap_api_debugfs.c
index 0c7557b1ed81..4a1ca26be901 100644
--- a/drivers/net/ethernet/microchip/vcap/vcap_api_debugfs.c
+++ b/drivers/net/ethernet/microchip/vcap/vcap_api_debugfs.c
@@ -5,11 +5,7 @@
  *
  */
 
-#include <linux/types.h>
-#include <linux/debugfs.h>
-#include <linux/seq_file.h>
-#include <linux/netdevice.h>
-
+#include "vcap_api_private.h"
 #include "vcap_api_debugfs.h"
 
 struct vcap_admin_debugfs_info {
@@ -22,6 +18,265 @@ struct vcap_port_debugfs_info {
 	struct net_device *ndev;
 };
 
+static bool vcap_bitarray_zero(int width, u8 *value)
+{
+	int bytes = DIV_ROUND_UP(width, BITS_PER_BYTE);
+	u8 total = 0, bmask = 0xff;
+	int rwidth = width;
+	int idx;
+
+	for (idx = 0; idx < bytes; ++idx, rwidth -= BITS_PER_BYTE) {
+		if (rwidth && rwidth < BITS_PER_BYTE)
+			bmask = (1 << rwidth) - 1;
+		total += value[idx] & bmask;
+	}
+	return total == 0;
+}
+
+static bool vcap_get_bit(u32 *stream, struct vcap_stream_iter *itr)
+{
+	u32 mask = BIT(itr->reg_bitpos);
+	u32 *p = &stream[itr->reg_idx];
+
+	return !!(*p & mask);
+}
+
+static void vcap_decode_field(u32 *stream, struct vcap_stream_iter *itr,
+			      int width, u8 *value)
+{
+	int idx;
+
+	/* Loop over the field value bits and get the field bits and
+	 * set them in the output value byte array
+	 */
+	for (idx = 0; idx < width; idx++) {
+		u8 bidx = idx & 0x7;
+
+		/* Decode one field value bit */
+		if (vcap_get_bit(stream, itr))
+			*value |= 1 << bidx;
+		vcap_iter_next(itr);
+		if (bidx == 7)
+			value++;
+	}
+}
+
+/* Verify that the typegroup bits have the correct values */
+static int vcap_verify_typegroups(u32 *stream, int sw_width,
+				  const struct vcap_typegroup *tgt, bool mask,
+				  int sw_max)
+{
+	struct vcap_stream_iter iter;
+	int sw_cnt, idx;
+
+	vcap_iter_set(&iter, sw_width, tgt, 0);
+	sw_cnt = 0;
+	while (iter.tg->width) {
+		u32 value = 0;
+		u32 tg_value = iter.tg->value;
+
+		if (mask)
+			tg_value = (1 << iter.tg->width) - 1;
+		/* Set position to current typegroup bit */
+		iter.offset = iter.tg->offset;
+		vcap_iter_update(&iter);
+		for (idx = 0; idx < iter.tg->width; idx++) {
+			/* Decode one typegroup bit */
+			if (vcap_get_bit(stream, &iter))
+				value |= 1 << idx;
+			iter.offset++;
+			vcap_iter_update(&iter);
+		}
+		if (value != tg_value)
+			return -EINVAL;
+		iter.tg++; /* next typegroup */
+		sw_cnt++;
+		/* Stop checking more typegroups */
+		if (sw_max && sw_cnt >= sw_max)
+			break;
+	}
+	return 0;
+}
+
+/* Find the subword width of the key typegroup that matches the stream data */
+static int vcap_find_keystream_typegroup_sw(struct vcap_control *vctrl,
+					    enum vcap_type vt, u32 *stream,
+					    bool mask, int sw_max)
+{
+	const struct vcap_typegroup **tgt;
+	int sw_idx, res;
+
+	tgt = vctrl->vcaps[vt].keyfield_set_typegroups;
+	/* Try the longest subword match first */
+	for (sw_idx = vctrl->vcaps[vt].sw_count; sw_idx >= 0; sw_idx--) {
+		if (!tgt[sw_idx])
+			continue;
+
+		res = vcap_verify_typegroups(stream, vctrl->vcaps[vt].sw_width,
+					     tgt[sw_idx], mask, sw_max);
+		if (res == 0)
+			return sw_idx;
+	}
+	return -EINVAL;
+}
+
+/* Verify that the type id in the stream matches the type id of the keyset */
+static bool vcap_verify_keystream_keyset(struct vcap_control *vctrl,
+					 enum vcap_type vt,
+					 u32 *keystream,
+					 u32 *mskstream,
+					 enum vcap_keyfield_set keyset)
+{
+	const struct vcap_info *vcap = &vctrl->vcaps[vt];
+	const struct vcap_field *typefld;
+	const struct vcap_typegroup *tgt;
+	const struct vcap_field *fields;
+	struct vcap_stream_iter iter;
+	const struct vcap_set *info;
+	u32 value = 0;
+	u32 mask = 0;
+
+	if (vcap_keyfield_count(vctrl, vt, keyset) == 0)
+		return false;
+
+	info = vcap_keyfieldset(vctrl, vt, keyset);
+	/* Check that the keyset is valid */
+	if (!info)
+		return false;
+
+	/* a type_id of value -1 means that there is no type field */
+	if (info->type_id == (u8)-1)
+		return true;
+
+	/* Get a valid typegroup for the specific keyset */
+	tgt = vcap_keyfield_typegroup(vctrl, vt, keyset);
+	if (!tgt)
+		return false;
+
+	fields = vcap_keyfields(vctrl, vt, keyset);
+	if (!fields)
+		return false;
+
+	typefld = &fields[VCAP_KF_TYPE];
+	vcap_iter_init(&iter, vcap->sw_width, tgt, typefld->offset);
+	vcap_decode_field(mskstream, &iter, typefld->width, (u8 *)&mask);
+	/* no type info if there are no mask bits */
+	if (vcap_bitarray_zero(typefld->width, (u8 *)&mask))
+		return false;
+
+	/* Get the value of the type field in the stream and compare to the
+	 * one define in the vcap keyset
+	 */
+	vcap_iter_init(&iter, vcap->sw_width, tgt, typefld->offset);
+	vcap_decode_field(keystream, &iter, typefld->width, (u8 *)&value);
+
+	return (value == info->type_id);
+}
+
+/* Verify that the typegroup information, subword count, keyset and type id
+ * are in sync and correct, return the keyset
+ */
+static enum
+vcap_keyfield_set vcap_find_keystream_keyset(struct vcap_control *vctrl,
+					     enum vcap_type vt,
+					     u32 *keystream,
+					     u32 *mskstream,
+					     bool mask, int sw_max)
+{
+	const struct vcap_set *keyfield_set;
+	int sw_count, idx;
+	bool res;
+
+	sw_count = vcap_find_keystream_typegroup_sw(vctrl, vt, keystream, mask,
+						    sw_max);
+	if (sw_count < 0)
+		return sw_count;
+
+	keyfield_set = vctrl->vcaps[vt].keyfield_set;
+	for (idx = 0; idx < vctrl->vcaps[vt].keyfield_set_size; ++idx) {
+		if (keyfield_set[idx].sw_per_item != sw_count)
+			continue;
+
+		res = vcap_verify_keystream_keyset(vctrl, vt, keystream,
+						   mskstream, idx);
+		if (res)
+			return idx;
+	}
+	return -EINVAL;
+}
+
+/* Read key data from a VCAP address and discover if there is a rule keyset
+ * here
+ */
+static int vcap_addr_keyset(struct vcap_control *vctrl,
+			    struct net_device *ndev,
+			    struct vcap_admin *admin,
+			    int addr)
+{
+	enum vcap_type vt = admin->vtype;
+	int keyset_sw_regs, idx;
+	u32 key = 0, mask = 0;
+
+	/* Read the cache at the specified address */
+	keyset_sw_regs = DIV_ROUND_UP(vctrl->vcaps[vt].sw_width, 32);
+	vctrl->ops->update(ndev, admin, VCAP_CMD_READ, VCAP_SEL_ALL, addr);
+	vctrl->ops->cache_read(ndev, admin, VCAP_SEL_ENTRY, 0,
+			       keyset_sw_regs);
+	/* Skip uninitialized key/mask entries */
+	for (idx = 0; idx < keyset_sw_regs; ++idx) {
+		key |= ~admin->cache.keystream[idx];
+		mask |= admin->cache.maskstream[idx];
+	}
+	if (key == 0 && mask == 0)
+		return -EINVAL;
+	/* Decode and locate the keyset */
+	return vcap_find_keystream_keyset(vctrl, vt, admin->cache.keystream,
+					  admin->cache.maskstream, false, 0);
+}
+
+static int vcap_show_admin_raw(struct vcap_control *vctrl,
+			       struct vcap_admin *admin,
+			       struct vcap_output_print *out)
+{
+	enum vcap_type vt = admin->vtype;
+	struct vcap_rule_internal *ri;
+	const struct vcap_set *info;
+	int keyset;
+	int addr;
+	int ret;
+
+	if (list_empty(&admin->rules))
+		return 0;
+
+	ret = vcap_api_check(vctrl);
+	if (ret)
+		return ret;
+
+	ri = list_first_entry(&admin->rules, struct vcap_rule_internal, list);
+
+	/* Go from higher to lower addresses searching for a keyset */
+	for (addr = admin->last_valid_addr; addr >= admin->first_valid_addr;
+	     --addr) {
+		keyset = vcap_addr_keyset(vctrl, ri->ndev, admin,  addr);
+		if (keyset < 0)
+			continue;
+		info = vcap_keyfieldset(vctrl, vt, keyset);
+		if (!info)
+			continue;
+		if (addr % info->sw_per_item)
+			pr_info("addr: %d X%d error rule, keyset: %s\n",
+				addr,
+				info->sw_per_item,
+				vcap_keyset_name(vctrl, keyset));
+		else
+			out->prf(out->dst, "  addr: %d, X%d rule, keyset: %s\n",
+			   addr,
+			   info->sw_per_item,
+			   vcap_keyset_name(vctrl, keyset));
+	}
+	return 0;
+}
+
 /* Show the port configuration and status */
 static int vcap_port_debugfs_show(struct seq_file *m, void *unused)
 {
@@ -61,8 +316,13 @@ EXPORT_SYMBOL_GPL(vcap_port_debugfs);
 /* Show the raw VCAP instance data (rules with address info) */
 static int vcap_raw_debugfs_show(struct seq_file *m, void *unused)
 {
-	/* The output will be added later */
-	return 0;
+	struct vcap_admin_debugfs_info *info = m->private;
+	struct vcap_output_print out = {
+		.prf = (void *)seq_printf,
+		.dst = m,
+	};
+
+	return vcap_show_admin_raw(info->vctrl, info->admin, &out);
 }
 DEFINE_SHOW_ATTRIBUTE(vcap_raw_debugfs);