From: Frank Li Date: Thu, 10 Jul 2025 19:13:52 +0000 (-0400) Subject: PCI: endpoint: pci-epf-test: Add doorbell test support X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=eff0c286aa916221a69126a43eee7c218d6f4011;p=thirdparty%2Fkernel%2Flinux.git PCI: endpoint: pci-epf-test: Add doorbell test support Add doorbell support by allocating a dedicated BAR using the pci_epf_alloc_doorbell() API and mapping the Endpoint MSI controller message data address to it. The data to be written in the message address is stored in the 'pci_epf_test_reg::doorbell_data' register. Finally, the RC can trigger doorbell in the Endpoint by writing the content of 'doorbell_data' register to the offset specified in 'doorbell_offset' of the 'doorbell_bar' BAR. Triggering of the doorbell is detected by pci_epf_test_doorbell_handler(), which is bound to the doorbell IRQ. On successful completion, STATUS_DOORBELL_SUCCESS status is set in the above mentioned handler. To avoid breaking compatibility between host and endpoint, add two new commands: COMMAND_ENABLE_DOORBELL and COMMAND_DISABLE_DOORBELL. The doorbell is allocated when COMMAND_ENABLE_DOORBELL command is called and destroyed when COMMAND_DISABLE_DOORBELL is called. This doorbell feature only works when both RC and EP drivers support it. If one of them doesn't support the feature, the testcase will fail. Signed-off-by: Frank Li [mani: code cleanups and reworded commit message] Signed-off-by: Manivannan Sadhasivam Signed-off-by: Bjorn Helgaas Tested-by: Niklas Cassel Link: https://patch.msgid.link/20250710-ep-msi-v21-6-57683fc7fb25@nxp.com --- diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c index 50eb4106369f4..e091193bd8a8a 100644 --- a/drivers/pci/endpoint/functions/pci-epf-test.c +++ b/drivers/pci/endpoint/functions/pci-epf-test.c @@ -11,12 +11,14 @@ #include #include #include +#include #include #include #include #include #include +#include #include #define IRQ_TYPE_INTX 0 @@ -29,6 +31,8 @@ #define COMMAND_READ BIT(3) #define COMMAND_WRITE BIT(4) #define COMMAND_COPY BIT(5) +#define COMMAND_ENABLE_DOORBELL BIT(6) +#define COMMAND_DISABLE_DOORBELL BIT(7) #define STATUS_READ_SUCCESS BIT(0) #define STATUS_READ_FAIL BIT(1) @@ -39,6 +43,11 @@ #define STATUS_IRQ_RAISED BIT(6) #define STATUS_SRC_ADDR_INVALID BIT(7) #define STATUS_DST_ADDR_INVALID BIT(8) +#define STATUS_DOORBELL_SUCCESS BIT(9) +#define STATUS_DOORBELL_ENABLE_SUCCESS BIT(10) +#define STATUS_DOORBELL_ENABLE_FAIL BIT(11) +#define STATUS_DOORBELL_DISABLE_SUCCESS BIT(12) +#define STATUS_DOORBELL_DISABLE_FAIL BIT(13) #define FLAG_USE_DMA BIT(0) @@ -66,6 +75,7 @@ struct pci_epf_test { bool dma_supported; bool dma_private; const struct pci_epc_features *epc_features; + struct pci_epf_bar db_bar; }; struct pci_epf_test_reg { @@ -80,6 +90,9 @@ struct pci_epf_test_reg { __le32 irq_number; __le32 flags; __le32 caps; + __le32 doorbell_bar; + __le32 doorbell_offset; + __le32 doorbell_data; } __packed; static struct pci_epf_header test_header = { @@ -667,6 +680,115 @@ static void pci_epf_test_raise_irq(struct pci_epf_test *epf_test, } } +static irqreturn_t pci_epf_test_doorbell_handler(int irq, void *data) +{ + struct pci_epf_test *epf_test = data; + enum pci_barno test_reg_bar = epf_test->test_reg_bar; + struct pci_epf_test_reg *reg = epf_test->reg[test_reg_bar]; + u32 status = le32_to_cpu(reg->status); + + status |= STATUS_DOORBELL_SUCCESS; + reg->status = cpu_to_le32(status); + pci_epf_test_raise_irq(epf_test, reg); + + return IRQ_HANDLED; +} + +static void pci_epf_test_doorbell_cleanup(struct pci_epf_test *epf_test) +{ + struct pci_epf_test_reg *reg = epf_test->reg[epf_test->test_reg_bar]; + struct pci_epf *epf = epf_test->epf; + + free_irq(epf->db_msg[0].virq, epf_test); + reg->doorbell_bar = cpu_to_le32(NO_BAR); + + pci_epf_free_doorbell(epf); +} + +static void pci_epf_test_enable_doorbell(struct pci_epf_test *epf_test, + struct pci_epf_test_reg *reg) +{ + u32 status = le32_to_cpu(reg->status); + struct pci_epf *epf = epf_test->epf; + struct pci_epc *epc = epf->epc; + struct msi_msg *msg; + enum pci_barno bar; + size_t offset; + int ret; + + ret = pci_epf_alloc_doorbell(epf, 1); + if (ret) + goto set_status_err; + + msg = &epf->db_msg[0].msg; + bar = pci_epc_get_next_free_bar(epf_test->epc_features, epf_test->test_reg_bar + 1); + if (bar < BAR_0) + goto err_doorbell_cleanup; + + ret = request_irq(epf->db_msg[0].virq, pci_epf_test_doorbell_handler, 0, + "pci-ep-test-doorbell", epf_test); + if (ret) { + dev_err(&epf->dev, + "Failed to request doorbell IRQ: %d\n", + epf->db_msg[0].virq); + goto err_doorbell_cleanup; + } + + reg->doorbell_data = cpu_to_le32(msg->data); + reg->doorbell_bar = cpu_to_le32(bar); + + msg = &epf->db_msg[0].msg; + ret = pci_epf_align_inbound_addr(epf, bar, ((u64)msg->address_hi << 32) | msg->address_lo, + &epf_test->db_bar.phys_addr, &offset); + + if (ret) + goto err_doorbell_cleanup; + + reg->doorbell_offset = cpu_to_le32(offset); + + epf_test->db_bar.barno = bar; + epf_test->db_bar.size = epf->bar[bar].size; + epf_test->db_bar.flags = epf->bar[bar].flags; + + ret = pci_epc_set_bar(epc, epf->func_no, epf->vfunc_no, &epf_test->db_bar); + if (ret) + goto err_doorbell_cleanup; + + status |= STATUS_DOORBELL_ENABLE_SUCCESS; + reg->status = cpu_to_le32(status); + return; + +err_doorbell_cleanup: + pci_epf_test_doorbell_cleanup(epf_test); +set_status_err: + status |= STATUS_DOORBELL_ENABLE_FAIL; + reg->status = cpu_to_le32(status); +} + +static void pci_epf_test_disable_doorbell(struct pci_epf_test *epf_test, + struct pci_epf_test_reg *reg) +{ + enum pci_barno bar = le32_to_cpu(reg->doorbell_bar); + u32 status = le32_to_cpu(reg->status); + struct pci_epf *epf = epf_test->epf; + struct pci_epc *epc = epf->epc; + + if (bar < BAR_0) + goto set_status_err; + + pci_epf_test_doorbell_cleanup(epf_test); + pci_epc_clear_bar(epc, epf->func_no, epf->vfunc_no, &epf_test->db_bar); + + status |= STATUS_DOORBELL_DISABLE_SUCCESS; + reg->status = cpu_to_le32(status); + + return; + +set_status_err: + status |= STATUS_DOORBELL_DISABLE_FAIL; + reg->status = cpu_to_le32(status); +} + static void pci_epf_test_cmd_handler(struct work_struct *work) { u32 command; @@ -714,6 +836,14 @@ static void pci_epf_test_cmd_handler(struct work_struct *work) pci_epf_test_copy(epf_test, reg); pci_epf_test_raise_irq(epf_test, reg); break; + case COMMAND_ENABLE_DOORBELL: + pci_epf_test_enable_doorbell(epf_test, reg); + pci_epf_test_raise_irq(epf_test, reg); + break; + case COMMAND_DISABLE_DOORBELL: + pci_epf_test_disable_doorbell(epf_test, reg); + pci_epf_test_raise_irq(epf_test, reg); + break; default: dev_err(dev, "Invalid command 0x%x\n", command); break;