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path: root/drivers/ntb/hw/epf
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2026-06-28Merge tag 'ntb-7.2' of https://github.com/jonmason/ntbLinus Torvalds
Pull NTB updates from Jon Mason: "An EPF bug fix to prevent an invalid unmap during device removal, along with documentation fixes and minor AMD driver cleanups" * tag 'ntb-7.2' of https://github.com/jonmason/ntb: ntb: amd: Use named initializer for pci_device_id::driver_data NTB: fix kernel-doc warnings in ntb.h NTB: epf: Avoid pci_iounmap() with offset when PEER_SPAD and CONFIG share BAR ntb_hw_amd: Fix incorrect debug message in link disable path
2026-06-26NTB: epf: Avoid pci_iounmap() with offset when PEER_SPAD and CONFIG share BARKoichiro Den
When BAR_PEER_SPAD and BAR_CONFIG share one PCI BAR, the module teardown path ends up calling pci_iounmap() on the same iomem with some offset, which is unnecessary and triggers a kernel warning like the following: Trying to vunmap() nonexistent vm area (0000000069a5ffe8) WARNING: mm/vmalloc.c:3470 at vunmap+0x58/0x68, CPU#5: modprobe/2937 [...] Call trace: vunmap+0x58/0x68 (P) iounmap+0x34/0x48 pci_iounmap+0x2c/0x40 ntb_epf_pci_remove+0x44/0x80 [ntb_hw_epf] pci_device_remove+0x48/0xf8 device_remove+0x50/0x88 device_release_driver_internal+0x1c8/0x228 driver_detach+0x50/0xb0 bus_remove_driver+0x74/0x100 driver_unregister+0x34/0x68 pci_unregister_driver+0x34/0xa0 ntb_epf_pci_driver_exit+0x14/0xfe0 [ntb_hw_epf] [...] Fix it by unmapping only when PEER_SPAD and CONFIG use difference bars. Cc: stable@vger.kernel.org Fixes: e75d5ae8ab88 ("NTB: epf: Allow more flexibility in the memory BAR map method") Reviewed-by: Frank Li <Frank.Li@nxp.com> Signed-off-by: Koichiro Den <den@valinux.co.jp> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2026-06-23NTB: epf: Implement .db_vector_count()/mask() for doorbellsKoichiro Den
Implement .db_vector_count() and .db_vector_mask() so NTB core/clients can map doorbell events to per-vector work. Report vectors as 0..(db_count - 2) (skipping the unused slot) and return BIT_ULL(db_vector) for the corresponding doorbell bit. Use ntb_epf_db_vector_count() for bounds checks in ntb_epf_db_vector_mask(), so the same lower-bound guard is applied before building the bitmask. 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> Link: https://patch.msgid.link/20260513024923.451765-13-den@valinux.co.jp
2026-06-23NTB: epf: Fix doorbell bitmask and IRQ vector handlingKoichiro Den
The EPF driver currently stores the incoming doorbell as a vector number (irq_no + 1) in db_val and db_clear() clears all bits unconditionally. This breaks db_read()/db_clear() semantics when multiple doorbells are used. Store doorbells as a bitmask (BIT_ULL(vector)) and make db_clear(db_bits) clear only the specified bits. Use atomic64 operations as db_val is updated from interrupt context. Once db_val is stored as a bitmask, the ISR's doorbell vector is used not only for ntb_db_event(), but also as the bit index for BIT_ULL(). The existing ISR derives that vector by subtracting pci_irq_vector(pdev, 0) from the Linux IRQ number passed to the handler, but Linux IRQ numbers are not guaranteed to be contiguous. Pass per-vector context as request_irq() dev_id instead, so the ISR gets the device vector directly. Validate the doorbell vector before updating db_val or calling ntb_db_event(), so an unexpected vector cannot create an invalid shift or be reported to NTB clients. While at it, read and validate mw_count before requesting interrupt vectors. An unsupported memory-window count does not need IRQs, and failing before ntb_epf_init_isr() keeps the probe error path simple. 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/20260513024923.451765-12-den@valinux.co.jp
2026-06-23NTB: epf: Report 0-based doorbell vector via ntb_db_event()Koichiro Den
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
2026-06-23NTB: epf: Make db_valid_mask cover only real doorbell bitsKoichiro Den
ndev->db_count includes an unused doorbell slot due to the legacy extra offset in the peer doorbell path. db_valid_mask must cover only the real doorbell bits and exclude the unused slot. Set db_valid_mask to BIT_ULL(db_count - 1) - 1. Fixes: 812ce2f8d14e ("NTB: Add support for EPF PCI Non-Transparent Bridge") 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: Frank Li <Frank.Li@nxp.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://patch.msgid.link/20260513024923.451765-10-den@valinux.co.jp
2026-06-23NTB: epf: Document legacy doorbell slot offset in ntb_epf_peer_db_set()Koichiro Den
ntb_epf_peer_db_set() uses ffs(db_bits) to select a doorbell to ring. ffs() returns a 1-based bit index (bit 0 -> 1). Entry 0 is reserved for link events, so doorbell bit 0 must map to entry 1. However, since the initial commit 812ce2f8d14e ("NTB: Add support for EPF PCI Non-Transparent Bridge"), the implementation has been adding an extra +1, ending up using entry 2 for bit 0. Fixing the extra increment would break interoperability with peers running older kernels. Keep the legacy behavior and document the offset and the resulting slot layout to avoid confusion when enabling per-db-vector handling. 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/20260513024923.451765-9-den@valinux.co.jp
2026-06-22NTB: epf: Avoid calling pci_irq_vector() from hardirq contextKoichiro Den
ntb_epf_vec_isr() calls pci_irq_vector() in hardirq context to derive the vector number. pci_irq_vector() calls msi_get_virq() that takes a mutex and can therefore trigger "scheduling while atomic" splats: BUG: scheduling while atomic: kworker/u33:0/55/0x00010001 ... Call trace: ... schedule+0x38/0x110 schedule_preempt_disabled+0x28/0x50 __mutex_lock.constprop.0+0x848/0x908 __mutex_lock_slowpath+0x18/0x30 mutex_lock+0x4c/0x60 msi_domain_get_virq+0xe8/0x138 pci_irq_vector+0x2c/0x60 ntb_epf_vec_isr+0x28/0x120 [ntb_hw_epf] __handle_irq_event_percpu+0x70/0x3a8 handle_irq_event+0x48/0x100 handle_edge_irq+0x100/0x1c8 ... Cache the Linux IRQ number for vector 0 when vectors are allocated and use it as a base in the ISR. Running the ISR in a threaded IRQ handler would also avoid the problem, but that would be unnecessary here. Fixes: 812ce2f8d14e ("NTB: Add support for EPF PCI Non-Transparent Bridge") 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> Cc: stable@vger.kernel.org # v5.12+ Link: https://patch.msgid.link/20260304083028.1391068-3-den@valinux.co.jp
2026-06-22NTB: epf: Fix request_irq() unwind in ntb_epf_init_isr()Koichiro Den
ntb_epf_init_isr() requests multiple MSI/MSI-X vectors in a loop. If request_irq() fails part-way through, it jumps straight to pci_free_irq_vectors() without freeing already requested IRQs. Fix the error path by freeing any successfully requested IRQs before releasing the vectors. Fixes: 812ce2f8d14e ("NTB: Add support for EPF PCI Non-Transparent Bridge") 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> Cc: stable@vger.kernel.org # v5.12+ Link: https://patch.msgid.link/20260304083028.1391068-2-den@valinux.co.jp
2026-02-20NTB: epf: allow built-in buildBaruch Siach
ntb_hw_epf works just as well when built into the kernel image. Don't force module build. Signed-off-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2025-09-22NTB: epf: Add Renesas rcar supportJerome Brunet
Add virtual non-transparent bridge support for Renesas rcar platform Reviewed-by: Frank Li <Frank.Li@nxp.com> Signed-off-by: Jerome Brunet <jbrunet@baylibre.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2025-09-22NTB: epf: Allow arbitrary BAR mappingJerome Brunet
The NTB epf host driver assumes the BAR number associated with a memory window is just incremented from the BAR number associated with MW1. This seems to have been enough so far but this is not really how the endpoint side work and the two could easily become mis-aligned. ntb_epf_mw_to_bar() even assumes that the BAR number is the memory window index + 2, which means the function only returns a proper result if BAR_2 is associated with MW1. Instead, fully describe and allow arbitrary NTB BAR mapping. Signed-off-by: Jerome Brunet <jbrunet@baylibre.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2024-09-20NTB: epf: don't misuse kernel-doc markerRandy Dunlap
Use "/*" instead of "/**" for common C comments to prevent warnings from scripts/kernel-doc. ntb_hw_epf.c:15: warning: expecting prototype for Host side endpoint driver to implement Non(). Prototype was for NTB_EPF_COMMAND() instead Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jon Mason <jdmason@kudzu.us> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Allen Hubbe <allenbh@gmail.com> Cc: ntb@lists.linux.dev Signed-off-by: Jon Mason <jdmason@kudzu.us>
2023-07-08ntb: epf: Remove redundant pci_clear_masterCai Huoqing
Remove pci_clear_master to simplify the code, the bus-mastering is also cleared in do_pci_disable_device, like this: ./drivers/pci/pci.c:2197 static void do_pci_disable_device(struct pci_dev *dev) { u16 pci_command; pci_read_config_word(dev, PCI_COMMAND, &pci_command); if (pci_command & PCI_COMMAND_MASTER) { pci_command &= ~PCI_COMMAND_MASTER; pci_write_config_word(dev, PCI_COMMAND, pci_command); } pcibios_disable_device(dev); }. And dev->is_busmaster is set to 0 in pci_disable_device. Signed-off-by: Cai Huoqing <cai.huoqing@linux.dev> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2022-08-09NTB: epf: Allow more flexibility in the memory BAR map methodFrank Li
Support the below BAR configuration methods for epf NTB. BAR 0: config and scratchpad BAR 2: doorbell BAR 4: memory map windows Set difference BAR number information into struct ntb_epf_data. So difference VID/PID can choose different BAR configurations. There are difference BAR map method between epf NTB and epf vNTB Endpoint function. Signed-off-by: Frank Li <Frank.Li@nxp.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2021-02-23NTB: Add support for EPF PCI Non-Transparent BridgeKishon Vijay Abraham I
Add support for EPF PCI Non-Transparent Bridge (NTB) devices. This driver is platform independent and may be used by any platform that has multiple PCI endpoint instances configured using the pci-epf-ntb driver. The driver connnects to the standard NTB subsystem interface. The EPF NTB device has a configurable number of memory windows (max 4), a configurable number of doorbells (max 32), and a configurable number of scratch-pad registers. Link: https://lore.kernel.org/r/20210201195809.7342-16-kishon@ti.com Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com>