Provide db_vector_count() and db_vector_mask() implementations for both
ntb_hw_epf and pci-epf-vntb so that ntb_transport can map MSI vectors to
doorbell bits. Without them, the upper layer cannot identify which
doorbell vector fired and ends up scheduling rxc_db_work() for all queue
pairs, resulting in a thundering-herd effect when multiple queue pairs
(QPs) are enabled.

With this change, .peer_db_set() must honor the db_bits mask and raise
all requested doorbell interrupts, so update those implementations
accordingly.

Signed-off-by: Koichiro Den <[email protected]>
---
 drivers/ntb/hw/epf/ntb_hw_epf.c               | 47 ++++++++++++-------
 drivers/pci/endpoint/functions/pci-epf-vntb.c | 41 +++++++++++++---
 2 files changed, 64 insertions(+), 24 deletions(-)

diff --git a/drivers/ntb/hw/epf/ntb_hw_epf.c b/drivers/ntb/hw/epf/ntb_hw_epf.c
index dbb5bebe63a5..c37ede4063dc 100644
--- a/drivers/ntb/hw/epf/ntb_hw_epf.c
+++ b/drivers/ntb/hw/epf/ntb_hw_epf.c
@@ -381,7 +381,7 @@ static int ntb_epf_init_isr(struct ntb_epf_dev *ndev, int 
msi_min, int msi_max)
                }
        }
 
-       ndev->db_count = irq;
+       ndev->db_count = irq - 1;
 
        ret = ntb_epf_send_command(ndev, CMD_CONFIGURE_DOORBELL,
                                   argument | irq);
@@ -415,6 +415,22 @@ static u64 ntb_epf_db_valid_mask(struct ntb_dev *ntb)
        return ntb_ndev(ntb)->db_valid_mask;
 }
 
+static int ntb_epf_db_vector_count(struct ntb_dev *ntb)
+{
+       return ntb_ndev(ntb)->db_count;
+}
+
+static u64 ntb_epf_db_vector_mask(struct ntb_dev *ntb, int db_vector)
+{
+       struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+
+       db_vector--; /* vector 0 is reserved for link events */
+       if (db_vector < 0 || db_vector >= ndev->db_count)
+               return 0;
+
+       return ndev->db_valid_mask & BIT_ULL(db_vector);
+}
+
 static int ntb_epf_db_set_mask(struct ntb_dev *ntb, u64 db_bits)
 {
        return 0;
@@ -507,26 +523,21 @@ static int ntb_epf_peer_mw_get_addr(struct ntb_dev *ntb, 
int idx,
 static int ntb_epf_peer_db_set(struct ntb_dev *ntb, u64 db_bits)
 {
        struct ntb_epf_dev *ndev = ntb_ndev(ntb);
-       u32 interrupt_num = ffs(db_bits) + 1;
-       struct device *dev = ndev->dev;
+       u32 interrupt_num;
        u32 db_entry_size;
        u32 db_offset;
        u32 db_data;
-
-       if (interrupt_num >= ndev->db_count) {
-               dev_err(dev, "DB interrupt %d greater than Max Supported %d\n",
-                       interrupt_num, ndev->db_count);
-               return -EINVAL;
-       }
+       unsigned long i;
 
        db_entry_size = readl(ndev->ctrl_reg + NTB_EPF_DB_ENTRY_SIZE);
 
-       db_data = readl(ndev->ctrl_reg + NTB_EPF_DB_DATA(interrupt_num));
-       db_offset = readl(ndev->ctrl_reg + NTB_EPF_DB_OFFSET(interrupt_num));
-
-       writel(db_data, ndev->db_reg + (db_entry_size * interrupt_num) +
-              db_offset);
-
+       for_each_set_bit(i, (unsigned long *)&db_bits, ndev->db_count) {
+               interrupt_num = i + 1;
+               db_data = readl(ndev->ctrl_reg + 
NTB_EPF_DB_DATA(interrupt_num));
+               db_offset = readl(ndev->ctrl_reg + 
NTB_EPF_DB_OFFSET(interrupt_num));
+               writel(db_data, ndev->db_reg + (db_entry_size * interrupt_num) +
+                      db_offset);
+       }
        return 0;
 }
 
@@ -556,6 +567,8 @@ static const struct ntb_dev_ops ntb_epf_ops = {
        .spad_count             = ntb_epf_spad_count,
        .peer_mw_count          = ntb_epf_peer_mw_count,
        .db_valid_mask          = ntb_epf_db_valid_mask,
+       .db_vector_count        = ntb_epf_db_vector_count,
+       .db_vector_mask         = ntb_epf_db_vector_mask,
        .db_set_mask            = ntb_epf_db_set_mask,
        .mw_set_trans           = ntb_epf_mw_set_trans,
        .mw_clear_trans         = ntb_epf_mw_clear_trans,
@@ -607,8 +620,8 @@ static int ntb_epf_init_dev(struct ntb_epf_dev *ndev)
        int ret;
 
        /* One Link interrupt and rest doorbell interrupt */
-       ret = ntb_epf_init_isr(ndev, NTB_EPF_MIN_DB_COUNT + NTB_EPF_IRQ_RESERVE,
-                              NTB_EPF_MAX_DB_COUNT + NTB_EPF_IRQ_RESERVE);
+       ret = ntb_epf_init_isr(ndev, NTB_EPF_MIN_DB_COUNT + 1 + 
NTB_EPF_IRQ_RESERVE,
+                              NTB_EPF_MAX_DB_COUNT + 1 + NTB_EPF_IRQ_RESERVE);
        if (ret) {
                dev_err(dev, "Failed to init ISR\n");
                return ret;
diff --git a/drivers/pci/endpoint/functions/pci-epf-vntb.c 
b/drivers/pci/endpoint/functions/pci-epf-vntb.c
index 4927faa28255..39e784e21236 100644
--- a/drivers/pci/endpoint/functions/pci-epf-vntb.c
+++ b/drivers/pci/endpoint/functions/pci-epf-vntb.c
@@ -1384,6 +1384,22 @@ static u64 vntb_epf_db_valid_mask(struct ntb_dev *ntb)
        return BIT_ULL(ntb_ndev(ntb)->db_count) - 1;
 }
 
+static int vntb_epf_db_vector_count(struct ntb_dev *ntb)
+{
+       return ntb_ndev(ntb)->db_count;
+}
+
+static u64 vntb_epf_db_vector_mask(struct ntb_dev *ntb, int db_vector)
+{
+       struct epf_ntb *ndev = ntb_ndev(ntb);
+
+       db_vector--; /* vector 0 is reserved for link events */
+       if (db_vector < 0 || db_vector >= ndev->db_count)
+               return 0;
+
+       return BIT_ULL(db_vector);
+}
+
 static int vntb_epf_db_set_mask(struct ntb_dev *ntb, u64 db_bits)
 {
        return 0;
@@ -1487,20 +1503,29 @@ static int vntb_epf_peer_spad_write(struct ntb_dev 
*ndev, int pidx, int idx, u32
 
 static int vntb_epf_peer_db_set(struct ntb_dev *ndev, u64 db_bits)
 {
-       u32 interrupt_num = ffs(db_bits) + 1;
        struct epf_ntb *ntb = ntb_ndev(ndev);
        u8 func_no, vfunc_no;
-       int ret;
+       u64 failed = 0;
+       unsigned long i;
 
        func_no = ntb->epf->func_no;
        vfunc_no = ntb->epf->vfunc_no;
 
-       ret = pci_epc_raise_irq(ntb->epf->epc, func_no, vfunc_no,
-                               PCI_IRQ_MSI, interrupt_num + 1);
-       if (ret)
-               dev_err(&ntb->ntb->dev, "Failed to raise IRQ\n");
+       for_each_set_bit(i, (unsigned long *)&db_bits, ntb->db_count) {
+               /*
+                * DB bit i is MSI interrupt (i + 2).
+                * Vector 0 is used for link events and MSI vectors are
+                * 1-based for pci_epc_raise_irq().
+                */
+               if (pci_epc_raise_irq(ntb->epf->epc, func_no, vfunc_no,
+                                     PCI_IRQ_MSI, i + 2))
+                       failed |= BIT_ULL(i);
+       }
+       if (failed)
+               dev_err(&ntb->ntb->dev, "Failed to raise IRQ (%#llx)\n",
+                       failed);
 
-       return ret;
+       return failed ? -EIO : 0;
 }
 
 static u64 vntb_epf_db_read(struct ntb_dev *ndev)
@@ -1561,6 +1586,8 @@ static const struct ntb_dev_ops vntb_epf_ops = {
        .spad_count             = vntb_epf_spad_count,
        .peer_mw_count          = vntb_epf_peer_mw_count,
        .db_valid_mask          = vntb_epf_db_valid_mask,
+       .db_vector_count        = vntb_epf_db_vector_count,
+       .db_vector_mask         = vntb_epf_db_vector_mask,
        .db_set_mask            = vntb_epf_db_set_mask,
        .mw_set_trans           = vntb_epf_mw_set_trans,
        .mw_clear_trans         = vntb_epf_mw_clear_trans,
-- 
2.51.0


Reply via email to