From: Koichiro Den <den@valinux.co.jp>
To: "Jon Mason" <jdmason@kudzu.us>,
"Dave Jiang" <dave.jiang@intel.com>,
"Allen Hubbe" <allenbh@gmail.com>,
"Manivannan Sadhasivam" <mani@kernel.org>,
"Krzysztof Wilczyński" <kwilczynski@kernel.org>,
"Kishon Vijay Abraham I" <kishon@kernel.org>,
"Bjorn Helgaas" <bhelgaas@google.com>,
"Frank Li" <Frank.Li@nxp.com>,
"Jerome Brunet" <jbrunet@baylibre.com>,
"Lorenzo Pieralisi" <lpieralisi@kernel.org>,
"Niklas Cassel" <cassel@kernel.org>
Cc: linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org,
ntb@lists.linux.dev
Subject: [PATCH v3 08/10] NTB: epf: Report 0-based doorbell vector via ntb_db_event()
Date: Mon, 23 Mar 2026 12:15:42 +0900 [thread overview]
Message-ID: <20260323031544.2598111-9-den@valinux.co.jp> (raw)
In-Reply-To: <20260323031544.2598111-1-den@valinux.co.jp>
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, treat it as DB#0 and emit a warning, as
this would indicate an unexpected change in the slot layout.
Fixes: 812ce2f8d14e ("NTB: Add support for EPF PCI Non-Transparent Bridge")
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Suggested-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Koichiro Den <den@valinux.co.jp>
---
drivers/ntb/hw/epf/ntb_hw_epf.c | 17 ++++++++++++++---
1 file changed, 14 insertions(+), 3 deletions(-)
diff --git a/drivers/ntb/hw/epf/ntb_hw_epf.c b/drivers/ntb/hw/epf/ntb_hw_epf.c
index 07dc97d3270b..67cdc5d729d5 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 {
@@ -333,10 +339,15 @@ static irqreturn_t ntb_epf_vec_isr(int irq, void *dev)
irq_no = irq - pci_irq_vector(ndev->ntb.pdev, 0);
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 irq_no 1 received. Treat it as DB#0.\n");
+ ntb_db_event(&ndev->ntb, 0);
+ } else {
+ ntb_db_event(&ndev->ntb, irq_no - EPF_IRQ_DB_START);
+ }
return IRQ_HANDLED;
}
--
2.51.0
next prev parent reply other threads:[~2026-03-23 3:16 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-23 3:15 [PATCH v3 00/10] PCI: endpoint: pci-epf-vntb / NTB: epf: Enable per-doorbell bit handling Koichiro Den
2026-03-23 3:15 ` [PATCH v3 01/10] PCI: endpoint: pci-epf-vntb: Document legacy MSI doorbell offset Koichiro Den
2026-03-23 3:15 ` [PATCH v3 02/10] PCI: endpoint: pci-epf-vntb: Defer pci_epc_raise_irq() out of atomic context Koichiro Den
2026-03-23 18:27 ` Frank Li
2026-05-01 16:26 ` Manivannan Sadhasivam
2026-05-11 7:54 ` Koichiro Den
2026-03-23 3:15 ` [PATCH v3 03/10] PCI: endpoint: pci-epf-vntb: Report 0-based doorbell vector via ntb_db_event() Koichiro Den
2026-03-23 3:15 ` [PATCH v3 04/10] PCI: endpoint: pci-epf-vntb: Exclude reserved slots from db_valid_mask Koichiro Den
2026-03-23 3:15 ` [PATCH v3 05/10] PCI: endpoint: pci-epf-vntb: Implement db_vector_count/mask for doorbells Koichiro Den
2026-03-23 3:15 ` [PATCH v3 06/10] NTB: epf: Document legacy doorbell slot offset in ntb_epf_peer_db_set() Koichiro Den
2026-03-23 3:15 ` [PATCH v3 07/10] NTB: epf: Make db_valid_mask cover only real doorbell bits Koichiro Den
2026-03-23 3:15 ` Koichiro Den [this message]
2026-03-23 3:15 ` [PATCH v3 09/10] NTB: epf: Fix doorbell bitmask handling in db_read/db_clear Koichiro Den
2026-05-01 16:29 ` Manivannan Sadhasivam
2026-05-11 9:15 ` Koichiro Den
2026-03-23 3:15 ` [PATCH v3 10/10] NTB: epf: Implement db_vector_count/mask for doorbells Koichiro Den
2026-03-23 15:43 ` [PATCH v3 00/10] PCI: endpoint: pci-epf-vntb / NTB: epf: Enable per-doorbell bit handling Koichiro Den
2026-03-25 6:23 ` Niklas Cassel
2026-03-25 8:44 ` Koichiro Den
2026-04-07 15:21 ` Koichiro Den
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20260323031544.2598111-9-den@valinux.co.jp \
--to=den@valinux.co.jp \
--cc=Frank.Li@nxp.com \
--cc=allenbh@gmail.com \
--cc=bhelgaas@google.com \
--cc=cassel@kernel.org \
--cc=dave.jiang@intel.com \
--cc=jbrunet@baylibre.com \
--cc=jdmason@kudzu.us \
--cc=kishon@kernel.org \
--cc=kwilczynski@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pci@vger.kernel.org \
--cc=lpieralisi@kernel.org \
--cc=mani@kernel.org \
--cc=ntb@lists.linux.dev \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).