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| author | Koichiro Den <den@valinux.co.jp> | 2026-05-13 11:49:21 +0900 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2026-06-23 11:37:44 -0500 |
| commit | 3147f0964cecca15e349cbfbdd6a28eb6d50379d (patch) | |
| tree | bdac6f56ec33278606ef8a69775410e0ced3a380 | |
| parent | 6eb7e28f1f24a28234add38755687a7ed8bc2654 (diff) | |
| download | linux-stable-3147f0964cecca15e349cbfbdd6a28eb6d50379d.tar.gz linux-stable-3147f0964cecca15e349cbfbdd6a28eb6d50379d.zip | |
NTB: epf: Report 0-based doorbell vector via ntb_db_event()
ntb_db_event() expects the vector number to be relative to the first
doorbell vector starting at 0.
Vector 0 is reserved for link events in the EPF driver, so doorbells
start at vector 1. However, both supported peers (ntb_hw_epf with
pci-epf-ntb, and pci-epf-vntb) have historically skipped vector 1 and
started doorbells at vector 2.
Pass (irq_no - 2) to ntb_db_event() so doorbells are reported as 0..N-1.
If irq_no == 1 is ever observed, warn and ignore it, since the slot is
reserved in the legacy layout and reporting it as DB#0 would collide with
the real DB#0 slot.
Fixes: 812ce2f8d14e ("NTB: Add support for EPF PCI Non-Transparent Bridge")
Suggested-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Koichiro Den <den@valinux.co.jp>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260513024923.451765-11-den@valinux.co.jp
| -rw-r--r-- | drivers/ntb/hw/epf/ntb_hw_epf.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/drivers/ntb/hw/epf/ntb_hw_epf.c b/drivers/ntb/hw/epf/ntb_hw_epf.c index c0bab3292075..7b0fc7ef00c6 100644 --- a/drivers/ntb/hw/epf/ntb_hw_epf.c +++ b/drivers/ntb/hw/epf/ntb_hw_epf.c @@ -81,6 +81,12 @@ enum epf_ntb_bar { NTB_BAR_NUM, }; +enum epf_irq_slot { + EPF_IRQ_LINK = 0, + EPF_IRQ_RESERVED_DB, /* Historically skipped slot */ + EPF_IRQ_DB_START, +}; + #define NTB_EPF_MAX_MW_COUNT (NTB_BAR_NUM - BAR_MW1) struct ntb_epf_dev { @@ -334,10 +340,14 @@ static irqreturn_t ntb_epf_vec_isr(int irq, void *dev) irq_no = irq - ndev->irq_base; ndev->db_val = irq_no + 1; - if (irq_no == 0) + if (irq_no == EPF_IRQ_LINK) { ntb_link_event(&ndev->ntb); - else - ntb_db_event(&ndev->ntb, irq_no); + } else if (irq_no == EPF_IRQ_RESERVED_DB) { + dev_warn_ratelimited(ndev->dev, + "Unexpected reserved doorbell slot IRQ received\n"); + } else { + ntb_db_event(&ndev->ntb, irq_no - EPF_IRQ_DB_START); + } return IRQ_HANDLED; } |