Re: [PATCH net-next v11 3/7] r8169: add support for new interrupt mapping
From: Mohsin Bashir
Date: Fri Aug 14 2026 - 18:46:19 EST
On 8/13/26 6:51 PM, javen wrote:
From: Javen Xu <javen_xu@xxxxxxxxxxxxxx>
To support RSS, the number of hardware interrupt bits should match the
interrupt of software. So we add support for new interrupt mapping here.
ISR_VEC_MAP_REG is the hardware register to indicate interrupt status.
IMR_SET_VEC_MAP_REG is interrupt mask which is set to enable irq.
Signed-off-by: Javen Xu <javen_xu@xxxxxxxxxxxxxx>
---
Changes in v2:
- no changes
Changes in v3:
- init index in napi_struct and get message_id from index
- move rtl8169_disable_hw_interrupt_msix directly before the call to
napi_schedule()
- change the condition in rtl8169_request_irq when RTL_VEC_MAP_ENABLE
enabled, use rtl8169_interrupt_msix
Changes in v4:
- remove flag tp->feature, replace tp->features & RTL_VEC_MAP_ENABLE
with tp->irq_nvecs > 1, they are equivalent.
- follow reverse xmas tree, in rtl8169_interrupt_msix(),
rtl8169_poll_msix_rx(), rtl8169_poll_msix_tx(),
rtl8169_poll_msix_other()
- use napi->index in rtl8169_poll_msix_other()
- add a comment to describe RTL8127 MSI-X vector layout
- simplify r8169_init_napi()
Changes in v5:
- replace magic number in rtl8169_poll_msix_tx()
Changes in v6:
- when irq_nvecs <= 1, use register IntrMask_8125, else using vec map
- fix irq sequence in rtl8169_interrupt_msix(), disable interrupts
before clean it
- remove dead code in rtl8169_poll_msix_tx()
Changes in v7:
- remove recheck_desc_ownbit
- change return value of rtl_tx
- remove message_id which only used once
Changes in v8:
- fix rtl8169_netpoll()
- remove tx_done
Changes in v9:
- change the way of getting message_id of napi
Changes in v10:
- no changes
Changes in v11:
- add comment on rtl8169_poll_msix_tx, only use 1 tx
- remove napi for other. Separate napi only for datapath, control path
like linkchg is handled in interrupt function, which will not call
napi any more.
---
drivers/net/ethernet/realtek/r8169_main.c | 213 +++++++++++++++++++---
1 file changed, 187 insertions(+), 26 deletions(-)
diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
index 9311a0cab4eb..b30f0a31d7c7 100644
--- a/drivers/net/ethernet/realtek/r8169_main.c
+++ b/drivers/net/ethernet/realtek/r8169_main.c
@@ -84,6 +84,7 @@
#define R8169_RX_RING_BYTES ((NUM_RX_DESC + 1) * sizeof(struct RxDesc))
#define R8169_TX_STOP_THRS (MAX_SKB_FRAGS + 1)
#define R8169_TX_START_THRS (2 * R8169_TX_STOP_THRS)
+#define R8169_MAX_QUEUES 16
#define R8169_MAX_RX_QUEUES 8
#define R8169_DEFAULT_RX_QUEUES 1
#define R8169_MAX_TX_QUEUES 1
@@ -455,8 +456,12 @@ enum rtl8125_registers {
RSS_CTRL_8125 = 0x4500,
Q_NUM_CTRL_8125 = 0x4800,
EEE_TXIDLE_TIMER_8125 = 0x6048,
+ IMR_CLEAR_VEC_MAP_REG = 0x0d00,
+ ISR_VEC_MAP_REG = 0x0d04,
+ IMR_SET_VEC_MAP_REG = 0x0d0c,
};
+#define MSIX_ID_VEC_MAP_LINKCHG 29
#define LEDSEL_MASK_8125 0x23f
#define RX_VLAN_INNER_8125 BIT(22)
@@ -587,6 +592,9 @@ enum rtl_register_content {
/* magic enable v2 */
MagicPacket_v2 = (1 << 16), /* Wake up when receives a Magic Packet */
+#define ISRIMR_LINKCHG BIT(29)
+#define ISRIMR_TOK_Q0 BIT(8)
+#define ISRIMR_ROK_Q0 BIT(0)
};
enum rtl_desc_bit {
@@ -1663,26 +1671,38 @@ static u32 rtl_get_events(struct rtl8169_private *tp)
static void rtl_ack_events(struct rtl8169_private *tp, u32 bits)
{
- if (rtl_is_8125(tp))
- RTL_W32(tp, IntrStatus_8125, bits);
- else
+ if (rtl_is_8125(tp)) {
+ if (tp->irq_nvecs > 1)
+ RTL_W32(tp, ISR_VEC_MAP_REG, bits);
+ else
+ RTL_W32(tp, IntrStatus_8125, bits);
+ } else {
RTL_W16(tp, IntrStatus, bits);
+ }
}
static void rtl_irq_disable(struct rtl8169_private *tp)
{
- if (rtl_is_8125(tp))
- RTL_W32(tp, IntrMask_8125, 0);
- else
+ if (rtl_is_8125(tp)) {
+ if (tp->irq_nvecs > 1)
+ RTL_W32(tp, IMR_CLEAR_VEC_MAP_REG, 0xffffffff);
+ else
+ RTL_W32(tp, IntrMask_8125, 0);
+ } else {
RTL_W16(tp, IntrMask, 0);
+ }
}
static void rtl_irq_enable(struct rtl8169_private *tp)
{
- if (rtl_is_8125(tp))
- RTL_W32(tp, IntrMask_8125, tp->irq_mask);
- else
+ if (rtl_is_8125(tp)) {
+ if (tp->irq_nvecs > 1)
+ RTL_W32(tp, IMR_SET_VEC_MAP_REG, tp->irq_mask);
+ else
+ RTL_W32(tp, IntrMask_8125, tp->irq_mask);
+ } else {
RTL_W16(tp, IntrMask, tp->irq_mask);
+ }
}
static void rtl8169_irq_mask_and_ack(struct rtl8169_private *tp)
@@ -4382,13 +4402,17 @@ static void rtl8169_tx_clear(struct rtl8169_private *tp)
static void rtl8169_napi_disable(struct rtl8169_private *tp)
{
- for (int i = 0; i < tp->irq_nvecs; i++)
+ int napi_num = min(tp->irq_nvecs, R8169_MAX_QUEUES);
+
+ for (int i = 0; i < napi_num; i++)
napi_disable(&tp->rtl8169_napi[i]);
}
static void rtl8169_napi_enable(struct rtl8169_private *tp)
{
- for (int i = 0; i < tp->irq_nvecs; i++)
+ int napi_num = min(tp->irq_nvecs, R8169_MAX_QUEUES);
+
+ for (int i = 0; i < napi_num; i++)
napi_enable(&tp->rtl8169_napi[i]);
}
@@ -5030,13 +5054,66 @@ static irqreturn_t rtl8169_interrupt(int irq, void *dev_instance)
return IRQ_HANDLED;
}
+static void rtl8169_free_one_irq(struct rtl8169_private *tp, int i)
+{
+ if (tp->irq_nvecs > 1) {
+ if (i < R8169_MAX_QUEUES)
+ pci_free_irq(tp->pci_dev, i, &tp->rtl8169_napi[i]);
+ else if (i == MSIX_ID_VEC_MAP_LINKCHG)
+ pci_free_irq(tp->pci_dev, i, tp);
+ } else {
+ pci_free_irq(tp->pci_dev, i, &tp->rtl8169_napi[i]);
+ }
+}
+
static void rtl8169_free_irq(struct rtl8169_private *tp)
{
- for (int i = 0; i < tp->irq_nvecs; i++) {
- struct napi_struct *napi = &tp->rtl8169_napi[i];
+ for (int i = 0; i < tp->irq_nvecs; i++)
+ rtl8169_free_one_irq(tp, i);
+}
- pci_free_irq(tp->pci_dev, i, napi);
- }
+static void rtl8169_disable_hw_interrupt_msix(struct rtl8169_private *tp,
+ int message_id)
+{
+ RTL_W32(tp, IMR_CLEAR_VEC_MAP_REG, BIT(message_id));
+}
+
+static void rtl8169_clear_hw_isr(struct rtl8169_private *tp, int message_id)
+{
+ RTL_W32(tp, ISR_VEC_MAP_REG, BIT(message_id));
+}
+
+static void rtl8169_enable_hw_interrupt_msix(struct rtl8169_private *tp,
+ int message_id)
+{
+ RTL_W32(tp, IMR_SET_VEC_MAP_REG, BIT(message_id));
+}
+
+static irqreturn_t rtl8169_interrupt_msix(int irq, void *dev_instance)
+{
+ struct napi_struct *napi = dev_instance;
+ struct net_device *dev = napi->dev;
+ struct rtl8169_private *tp;
+ int message_id;
+
+ tp = netdev_priv(dev);
+ message_id = napi - tp->rtl8169_napi;
+
+ rtl8169_disable_hw_interrupt_msix(tp, message_id);
+ rtl8169_clear_hw_isr(tp, message_id);
+
+ napi_schedule(napi);
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t rtl8169_interrupt_other(int irq, void *dev_instance)
+{
+ struct rtl8169_private *tp = dev_instance;
+
+ rtl8169_clear_hw_isr(tp, MSIX_ID_VEC_MAP_LINKCHG);
+ phy_mac_interrupt(tp->phydev);
+ return IRQ_HANDLED;
}
static int rtl8169_request_irq(struct rtl8169_private *tp)
@@ -5047,8 +5124,26 @@ static int rtl8169_request_irq(struct rtl8169_private *tp)
for (i = 0; i < tp->irq_nvecs; i++) {
napi = &tp->rtl8169_napi[i];
- rc = pci_request_irq(tp->pci_dev, i, rtl8169_interrupt,
- NULL, napi, "%s-%d", dev->name, i);
+ if (tp->irq_nvecs > 1) {
+ if (i < R8169_MAX_QUEUES)
+ rc = pci_request_irq(tp->pci_dev, i,
+ rtl8169_interrupt_msix,
+ NULL, napi, "%s-%d",
+ dev->name, i);
+ else if (i == MSIX_ID_VEC_MAP_LINKCHG)
+ rc = pci_request_irq(tp->pci_dev, i,
+ rtl8169_interrupt_other,
+ NULL, tp, "%s-%d",
+ dev->name, i);
+ else
+ continue;
+ } else {
+ rc = pci_request_irq(tp->pci_dev, i,
+ rtl8169_interrupt,
+ NULL, napi, "%s-%d",
+ dev->name, i);
+ }
+
if (rc)
goto free_irq;
}
@@ -5056,7 +5151,7 @@ static int rtl8169_request_irq(struct rtl8169_private *tp)
free_irq:
while (--i >= 0)
- pci_free_irq(tp->pci_dev, i, &tp->rtl8169_napi[i]);
+ rtl8169_free_one_irq(tp, i);
return rc;
}
@@ -5255,8 +5350,12 @@ static void rtl8169_netpoll(struct net_device *dev)
struct rtl8169_private *tp = netdev_priv(dev);
for (int i = 0; i < tp->irq_nvecs; i++) {
Looking at r8169_init_napi(), later down the patch, it only calls netif_napi_add() for min(tp->irq_nvecs, R8169_MAX_QUEUES) vectors, but this loop iterates all tp->irq_nvecs. Can this be an issue? Looks like it will be because entries entries >= R8169_MAX_QUEUES are zeroed but rtl8169_interrupt_msix() would set dev to NULL.
- rtl8169_interrupt(pci_irq_vector(tp->pci_dev, i),
- &tp->rtl8169_napi[i]);
+ if (tp->irq_nvecs > 1)
+ rtl8169_interrupt_msix(pci_irq_vector(tp->pci_dev, i),
+ &tp->rtl8169_napi[i]);
+ else
+ rtl8169_interrupt(pci_irq_vector(tp->pci_dev, i),
+ &tp->rtl8169_napi[i]);
}
}
#endif
@@ -5454,7 +5553,9 @@ static void rtl_shutdown(struct pci_dev *pdev)
static void r8169_free_napi(struct rtl8169_private *tp)
{
- for (int i = 0; i < tp->irq_nvecs; i++)
+ int napi_num = min(tp->irq_nvecs, R8169_MAX_QUEUES);
+
+ for (int i = 0; i < napi_num; i++)
netif_napi_del(&tp->rtl8169_napi[i]);
kfree(tp->rtl8169_napi);
@@ -5508,10 +5609,16 @@ static const struct net_device_ops rtl_netdev_ops = {
static void rtl_set_irq_mask(struct rtl8169_private *tp)
{
- tp->irq_mask = RxOK | RxErr | TxOK | TxErr | LinkChg;
+ if (tp->irq_nvecs > 1) {
+ tp->irq_mask = ISRIMR_LINKCHG | ISRIMR_TOK_Q0;
+ for (int i = 0; i < tp->num_rx_rings; i++)
+ tp->irq_mask |= ISRIMR_ROK_Q0 << i;
+ } else {
+ tp->irq_mask = RxOK | RxErr | TxOK | TxErr | LinkChg;
- if (tp->mac_version <= RTL_GIGA_MAC_VER_06)
- tp->irq_mask |= SYSErr | RxFIFOOver;
+ if (tp->mac_version <= RTL_GIGA_MAC_VER_06)
+ tp->irq_mask |= SYSErr | RxFIFOOver;
+ }
}
static int rtl_alloc_irq(struct rtl8169_private *tp)
@@ -5796,10 +5903,64 @@ static bool rtl_aspm_is_safe(struct rtl8169_private *tp)
return false;
}
+static int rtl8169_poll_msix_rx(struct napi_struct *napi, int budget)
+{
+ struct net_device *dev = napi->dev;
+ struct rtl8169_private *tp;
+ int work_done = 0;
+ int message_id;
+
+ tp = netdev_priv(dev);
+ message_id = napi - tp->rtl8169_napi;
+
+ if (message_id < tp->num_rx_rings)
+ work_done += rtl_rx(dev, tp, &tp->rx_ring[message_id],
+ budget, napi);
+
+ if (work_done < budget && napi_complete_done(napi, work_done))
+ rtl8169_enable_hw_interrupt_msix(tp, message_id);
+
+ return work_done;
+}
+
+static int rtl8169_poll_msix_tx(struct napi_struct *napi, int budget)
+{
+ struct net_device *dev = napi->dev;
+ struct rtl8169_private *tp;
+
+ tp = netdev_priv(dev);
+
+ /* Currently r8169 only supports a single Tx ring.
+ * Therefore, we don't need a per-ring Tx processing loop here.
+ */
+ rtl_tx(dev, tp, budget);
+
+ if (napi_complete_done(napi, 0))
+ rtl8169_enable_hw_interrupt_msix(tp, (int)(napi - tp->rtl8169_napi));
+
+ return 0;
+}
+
+/* RTL8127 MSI-X vector layout:
+ * Vectors 0 .. (RxQs - 1) : Rx Queues
+ * Vectors RxQs .. (RxQs + TxQs - 1) : Tx Queues
+ * NAPI is only allocated for data path
+ */
static void r8169_init_napi(struct rtl8169_private *tp)
{
- for (int i = 0; i < tp->irq_nvecs; i++)
- netif_napi_add(tp->dev, &tp->rtl8169_napi[i], rtl8169_poll);
+ int napi_num = min(tp->irq_nvecs, R8169_MAX_QUEUES);
+
+ for (int i = 0; i < napi_num; i++) {
+ int (*poll_fn)(struct napi_struct *, int) = rtl8169_poll;
+
+ if (tp->irq_nvecs > 1) {
+ if (i < R8169_MAX_RX_QUEUES)
+ poll_fn = rtl8169_poll_msix_rx;
+ else
+ poll_fn = rtl8169_poll_msix_tx;
+ }
+ netif_napi_add(tp->dev, &tp->rtl8169_napi[i], poll_fn);
+ }
}
static int rtl_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)