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 04/10] PCI: endpoint: pci-epf-vntb: Exclude reserved slots from db_valid_mask
Date: Mon, 23 Mar 2026 12:15:38 +0900 [thread overview]
Message-ID: <20260323031544.2598111-5-den@valinux.co.jp> (raw)
In-Reply-To: <20260323031544.2598111-1-den@valinux.co.jp>
In pci-epf-vntb, db_count represents the total number of doorbell slots
exposed to the peer, including:
- slot #0 reserved for link events, and
- slot #1 historically unused (kept for compatibility).
Only the remaining slots correspond to actual doorbell bits. The current
db_valid_mask() exposes all slots as valid doorbells.
Limit db_valid_mask() to the real doorbell bits by returning
BIT_ULL(db_count - 2) - 1, and guard against db_count < 2.
Fixes: e35f56bb0330 ("PCI: endpoint: Support NTB transfer between RC and EP")
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Koichiro Den <den@valinux.co.jp>
---
drivers/pci/endpoint/functions/pci-epf-vntb.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/pci/endpoint/functions/pci-epf-vntb.c b/drivers/pci/endpoint/functions/pci-epf-vntb.c
index e86dc530c08e..d91033ab8e03 100644
--- a/drivers/pci/endpoint/functions/pci-epf-vntb.c
+++ b/drivers/pci/endpoint/functions/pci-epf-vntb.c
@@ -1268,7 +1268,10 @@ static int vntb_epf_peer_mw_count(struct ntb_dev *ntb)
static u64 vntb_epf_db_valid_mask(struct ntb_dev *ntb)
{
- return BIT_ULL(ntb_ndev(ntb)->db_count) - 1;
+ if (ntb_ndev(ntb)->db_count < EPF_IRQ_DB_START)
+ return 0;
+
+ return BIT_ULL(ntb_ndev(ntb)->db_count - EPF_IRQ_DB_START) - 1;
}
static int vntb_epf_db_set_mask(struct ntb_dev *ntb, u64 db_bits)
--
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 ` Koichiro Den [this message]
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 ` [PATCH v3 08/10] NTB: epf: Report 0-based doorbell vector via ntb_db_event() Koichiro Den
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
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