net: stmmac: Add support for U32 TC filter using Flexible RX Parser

This adds support for U32 filter by using an HW only feature called
Flexible RX Parser. This allow us to match any given packet field with a
pattern and accept/reject or even route the packet to a specific DMA
channel.

Right now we only support acception or rejection of frame and we only
support simple rules. Though, the Parser has the flexibility of jumping to
specific rules as an if condition so complex rules can be established.

This is only supported in GMAC5.10+.

The following commands can be used to test this code:

	1) Setup an ingress qdisk:
	# tc qdisc add dev eth0 handle ffff: ingress

	2) Setup a filter (e.g. filter by IP):
	# tc filter add dev eth0 parent ffff: protocol ip u32 match ip \
		src 192.168.0.3 skip_sw action drop

In every tests performed we always used the "skip_sw" flag to make sure
only the RX Parser was involved.

Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Joao Pinto <jpinto@synopsys.com>
Cc: Vitor Soares <soares@synopsys.com>
Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Cc: Jakub Kicinski <kubakici@wp.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 195 insertions, 0 deletions

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac5.c b/drivers/net/ethernet/stmicro/stmmac/dwmac5.c
index 2978550bb7f6..b2becb80a697 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac5.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac5.c
@@ -7,6 +7,7 @@
 #include "common.h"
 #include "dwmac4.h"
 #include "dwmac5.h"
+#include "stmmac.h"
 
 struct dwmac5_error_desc {
 	bool valid;
@@ -299,3 +300,197 @@ int dwmac5_safety_feat_dump(struct stmmac_safety_stats *stats,
 		*desc = dwmac5_all_errors[module].desc[offset].desc;
 	return 0;
 }
+
+static int dwmac5_rxp_disable(void __iomem *ioaddr)
+{
+	u32 val;
+	int ret;
+
+	val = readl(ioaddr + MTL_OPERATION_MODE);
+	val &= ~MTL_FRPE;
+	writel(val, ioaddr + MTL_OPERATION_MODE);
+
+	ret = readl_poll_timeout(ioaddr + MTL_RXP_CONTROL_STATUS, val,
+			val & RXPI, 1, 10000);
+	if (ret)
+		return ret;
+	return 0;
+}
+
+static void dwmac5_rxp_enable(void __iomem *ioaddr)
+{
+	u32 val;
+
+	val = readl(ioaddr + MTL_OPERATION_MODE);
+	val |= MTL_FRPE;
+	writel(val, ioaddr + MTL_OPERATION_MODE);
+}
+
+static int dwmac5_rxp_update_single_entry(void __iomem *ioaddr,
+					  struct stmmac_tc_entry *entry,
+					  int pos)
+{
+	int ret, i;
+
+	for (i = 0; i < (sizeof(entry->val) / sizeof(u32)); i++) {
+		int real_pos = pos * (sizeof(entry->val) / sizeof(u32)) + i;
+		u32 val;
+
+		/* Wait for ready */
+		ret = readl_poll_timeout(ioaddr + MTL_RXP_IACC_CTRL_STATUS,
+				val, !(val & STARTBUSY), 1, 10000);
+		if (ret)
+			return ret;
+
+		/* Write data */
+		val = *((u32 *)&entry->val + i);
+		writel(val, ioaddr + MTL_RXP_IACC_DATA);
+
+		/* Write pos */
+		val = real_pos & ADDR;
+		writel(val, ioaddr + MTL_RXP_IACC_CTRL_STATUS);
+
+		/* Write OP */
+		val |= WRRDN;
+		writel(val, ioaddr + MTL_RXP_IACC_CTRL_STATUS);
+
+		/* Start Write */
+		val |= STARTBUSY;
+		writel(val, ioaddr + MTL_RXP_IACC_CTRL_STATUS);
+
+		/* Wait for done */
+		ret = readl_poll_timeout(ioaddr + MTL_RXP_IACC_CTRL_STATUS,
+				val, !(val & STARTBUSY), 1, 10000);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static struct stmmac_tc_entry *
+dwmac5_rxp_get_next_entry(struct stmmac_tc_entry *entries, unsigned int count,
+			  u32 curr_prio)
+{
+	struct stmmac_tc_entry *entry;
+	u32 min_prio = ~0x0;
+	int i, min_prio_idx;
+	bool found = false;
+
+	for (i = count - 1; i >= 0; i--) {
+		entry = &entries[i];
+
+		/* Do not update unused entries */
+		if (!entry->in_use)
+			continue;
+		/* Do not update already updated entries (i.e. fragments) */
+		if (entry->in_hw)
+			continue;
+		/* Let last entry be updated last */
+		if (entry->is_last)
+			continue;
+		/* Do not return fragments */
+		if (entry->is_frag)
+			continue;
+		/* Check if we already checked this prio */
+		if (entry->prio < curr_prio)
+			continue;
+		/* Check if this is the minimum prio */
+		if (entry->prio < min_prio) {
+			min_prio = entry->prio;
+			min_prio_idx = i;
+			found = true;
+		}
+	}
+
+	if (found)
+		return &entries[min_prio_idx];
+	return NULL;
+}
+
+int dwmac5_rxp_config(void __iomem *ioaddr, struct stmmac_tc_entry *entries,
+		      unsigned int count)
+{
+	struct stmmac_tc_entry *entry, *frag;
+	int i, ret, nve = 0;
+	u32 curr_prio = 0;
+	u32 old_val, val;
+
+	/* Force disable RX */
+	old_val = readl(ioaddr + GMAC_CONFIG);
+	val = old_val & ~GMAC_CONFIG_RE;
+	writel(val, ioaddr + GMAC_CONFIG);
+
+	/* Disable RX Parser */
+	ret = dwmac5_rxp_disable(ioaddr);
+	if (ret)
+		goto re_enable;
+
+	/* Set all entries as NOT in HW */
+	for (i = 0; i < count; i++) {
+		entry = &entries[i];
+		entry->in_hw = false;
+	}
+
+	/* Update entries by reverse order */
+	while (1) {
+		entry = dwmac5_rxp_get_next_entry(entries, count, curr_prio);
+		if (!entry)
+			break;
+
+		curr_prio = entry->prio;
+		frag = entry->frag_ptr;
+
+		/* Set special fragment requirements */
+		if (frag) {
+			entry->val.af = 0;
+			entry->val.rf = 0;
+			entry->val.nc = 1;
+			entry->val.ok_index = nve + 2;
+		}
+
+		ret = dwmac5_rxp_update_single_entry(ioaddr, entry, nve);
+		if (ret)
+			goto re_enable;
+
+		entry->table_pos = nve++;
+		entry->in_hw = true;
+
+		if (frag && !frag->in_hw) {
+			ret = dwmac5_rxp_update_single_entry(ioaddr, frag, nve);
+			if (ret)
+				goto re_enable;
+			frag->table_pos = nve++;
+			frag->in_hw = true;
+		}
+	}
+
+	if (!nve)
+		goto re_enable;
+
+	/* Update all pass entry */
+	for (i = 0; i < count; i++) {
+		entry = &entries[i];
+		if (!entry->is_last)
+			continue;
+
+		ret = dwmac5_rxp_update_single_entry(ioaddr, entry, nve);
+		if (ret)
+			goto re_enable;
+
+		entry->table_pos = nve++;
+	}
+
+	/* Assume n. of parsable entries == n. of valid entries */
+	val = (nve << 16) & NPE;
+	val |= nve & NVE;
+	writel(val, ioaddr + MTL_RXP_CONTROL_STATUS);
+
+	/* Enable RX Parser */
+	dwmac5_rxp_enable(ioaddr);
+
+re_enable:
+	/* Re-enable RX */
+	writel(old_val, ioaddr + GMAC_CONFIG);
+	return ret;
+}