From: Koichiro Den Date: Wed, 13 May 2026 02:49:22 +0000 (+0900) Subject: NTB: epf: Fix doorbell bitmask and IRQ vector handling X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4fdea8dbb62d746429498e07385a3ba0b0f6d1ab;p=thirdparty%2Flinux.git NTB: epf: Fix doorbell bitmask and IRQ vector handling 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 Signed-off-by: Koichiro Den Signed-off-by: Manivannan Sadhasivam Signed-off-by: Bjorn Helgaas Reviewed-by: Dave Jiang Reviewed-by: Frank Li Link: https://patch.msgid.link/20260513024923.451765-12-den@valinux.co.jp --- diff --git a/drivers/ntb/hw/epf/ntb_hw_epf.c b/drivers/ntb/hw/epf/ntb_hw_epf.c index 7b0fc7ef00c6..10618e462229 100644 --- a/drivers/ntb/hw/epf/ntb_hw_epf.c +++ b/drivers/ntb/hw/epf/ntb_hw_epf.c @@ -6,6 +6,7 @@ * Author: Kishon Vijay Abraham I */ +#include #include #include #include @@ -89,6 +90,13 @@ enum epf_irq_slot { #define NTB_EPF_MAX_MW_COUNT (NTB_BAR_NUM - BAR_MW1) +struct ntb_epf_dev; + +struct ntb_epf_irq_ctx { + struct ntb_epf_dev *ndev; + unsigned int irq_no; +}; + struct ntb_epf_dev { struct ntb_dev ntb; struct device *dev; @@ -108,9 +116,9 @@ struct ntb_epf_dev { unsigned int self_spad; unsigned int peer_spad; - int db_val; + atomic64_t db_val; u64 db_valid_mask; - int irq_base; + struct ntb_epf_irq_ctx irq_ctx[NTB_EPF_MAX_DB_COUNT + 1]; }; #define ntb_ndev(__ntb) container_of(__ntb, struct ntb_epf_dev, ntb) @@ -334,11 +342,10 @@ static int ntb_epf_link_disable(struct ntb_dev *ntb) static irqreturn_t ntb_epf_vec_isr(int irq, void *dev) { - struct ntb_epf_dev *ndev = dev; - int irq_no; - - irq_no = irq - ndev->irq_base; - ndev->db_val = irq_no + 1; + struct ntb_epf_irq_ctx *ctx = dev; + struct ntb_epf_dev *ndev = ctx->ndev; + unsigned int db_vector; + unsigned int irq_no = ctx->irq_no; if (irq_no == EPF_IRQ_LINK) { ntb_link_event(&ndev->ntb); @@ -346,7 +353,17 @@ static irqreturn_t ntb_epf_vec_isr(int irq, void *dev) dev_warn_ratelimited(ndev->dev, "Unexpected reserved doorbell slot IRQ received\n"); } else { - ntb_db_event(&ndev->ntb, irq_no - EPF_IRQ_DB_START); + db_vector = irq_no - EPF_IRQ_DB_START; + if (ndev->db_count < NTB_EPF_MIN_DB_COUNT || + db_vector >= ndev->db_count - 1) { + dev_warn_ratelimited(ndev->dev, + "Unexpected doorbell vector %u (db_count %u)\n", + db_vector, ndev->db_count); + return IRQ_HANDLED; + } + + atomic64_or(BIT_ULL(db_vector), &ndev->db_val); + ntb_db_event(&ndev->ntb, db_vector); } return IRQ_HANDLED; @@ -373,18 +390,18 @@ static int ntb_epf_init_isr(struct ntb_epf_dev *ndev, int msi_min, int msi_max) argument &= ~MSIX_ENABLE; } - ndev->irq_base = pci_irq_vector(pdev, 0); + ndev->db_count = irq - 1; for (i = 0; i < irq; i++) { + ndev->irq_ctx[i].ndev = ndev; + ndev->irq_ctx[i].irq_no = i; ret = request_irq(pci_irq_vector(pdev, i), ntb_epf_vec_isr, - 0, "ntb_epf", ndev); + 0, "ntb_epf", &ndev->irq_ctx[i]); if (ret) { dev_err(dev, "Failed to request irq\n"); goto err_free_irq; } } - ndev->db_count = irq - 1; - ret = ntb_epf_send_command(ndev, CMD_CONFIGURE_DOORBELL, argument | irq); if (ret) { @@ -396,7 +413,7 @@ static int ntb_epf_init_isr(struct ntb_epf_dev *ndev, int msi_min, int msi_max) err_free_irq: while (i--) - free_irq(pci_irq_vector(pdev, i), ndev); + free_irq(pci_irq_vector(pdev, i), &ndev->irq_ctx[i]); pci_free_irq_vectors(pdev); return ret; @@ -529,7 +546,7 @@ static u64 ntb_epf_db_read(struct ntb_dev *ntb) { struct ntb_epf_dev *ndev = ntb_ndev(ntb); - return ndev->db_val; + return atomic64_read(&ndev->db_val); } static int ntb_epf_db_clear_mask(struct ntb_dev *ntb, u64 db_bits) @@ -541,7 +558,7 @@ static int ntb_epf_db_clear(struct ntb_dev *ntb, u64 db_bits) { struct ntb_epf_dev *ndev = ntb_ndev(ntb); - ndev->db_val = 0; + atomic64_and(~db_bits, &ndev->db_val); return 0; } @@ -582,6 +599,12 @@ static int ntb_epf_init_dev(struct ntb_epf_dev *ndev) struct device *dev = ndev->dev; int ret; + ndev->mw_count = readl(ndev->ctrl_reg + NTB_EPF_MW_COUNT); + if (ndev->mw_count > NTB_EPF_MAX_MW_COUNT) { + dev_err(dev, "Unsupported MW count: %u\n", ndev->mw_count); + return -EINVAL; + } + /* One Link interrupt and rest doorbell interrupt */ ret = ntb_epf_init_isr(ndev, NTB_EPF_MIN_DB_COUNT + 1, NTB_EPF_MAX_DB_COUNT + 1); @@ -595,14 +618,8 @@ static int ntb_epf_init_dev(struct ntb_epf_dev *ndev) * doorbell layout, hence -1. */ ndev->db_valid_mask = BIT_ULL(ndev->db_count - 1) - 1; - ndev->mw_count = readl(ndev->ctrl_reg + NTB_EPF_MW_COUNT); ndev->spad_count = readl(ndev->ctrl_reg + NTB_EPF_SPAD_COUNT); - if (ndev->mw_count > NTB_EPF_MAX_MW_COUNT) { - dev_err(dev, "Unsupported MW count: %u\n", ndev->mw_count); - return -EINVAL; - } - return 0; } @@ -696,7 +713,7 @@ static void ntb_epf_cleanup_isr(struct ntb_epf_dev *ndev) ntb_epf_send_command(ndev, CMD_TEARDOWN_DOORBELL, ndev->db_count + 1); for (i = 0; i < ndev->db_count + 1; i++) - free_irq(pci_irq_vector(pdev, i), ndev); + free_irq(pci_irq_vector(pdev, i), &ndev->irq_ctx[i]); pci_free_irq_vectors(pdev); }