Add three registers: doorbell_bar, doorbell_addr, and doorbell_data. Use pci_epf_alloc_doorbell() to allocate a doorbell address space.
Enable the Root Complex (RC) side driver to trigger pci-epc-test's doorbell callback handler by writing doorbell_data to the mapped doorbell_bar's address space.
Set STATUS_DOORBELL_SUCCESS in the doorbell callback to indicate completion.
Avoid breaking compatibility between host and endpoint, add new command COMMAND_ENABLE_DOORBELL and COMMAND_DISABLE_DOORBELL. Host side need send COMMAND_ENABLE_DOORBELL to map one bar's inbound address to MSI space. the command COMMAND_DISABLE_DOORBELL to recovery original inbound address mapping.
Host side new driver Host side old driver
EP: new driver S F EP: old driver F F
S: If EP side support MSI, 'pci_endpoint_test -f pcie_ep_doorbell' return success. If EP side doesn't support MSI, the same to 'F'.
F: 'pci_endpoint_test -f pcie_ep_doorbell' return failure, other case as usual.
Tested-by: Niklas Cassel cassel@kernel.org Signed-off-by: Frank Li Frank.Li@nxp.com --- change from v15 to v16 - use le32 for doorbell_* register and use cpu_to_le32() and le32_to_cpu() when use it.
change from v14 to v15 - none
Change from v9 to v14 - update commit message by use pci_endpoint_test -f pcie_ep_doorbell
Change from v8 to v9 - move pci_epf_alloc_doorbell() into pci_epf_{enable/disable}_doorbell(). - remove doorbell_done in commit message. - rename pci_epf_{enable/disable}_doorbell() to pci_epf_test_{enable/disable}_doorbell() to align corrent code style.
Change from v7 to v8 - rename to pci_epf_align_inbound_addr_lo_hi()
Change from v6 to v7 - use help function pci_epf_align_addr_lo_hi()
Change from v5 to v6 - rename doorbell_addr to doorbell_offset
Chagne from v4 to v5 - Add doorbell free at unbind function. - Move msi irq handler to here to more complex user case, such as differece doorbell can use difference handler function. - Add Niklas's code to handle fixed bar's case. If need add your signed-off tag or co-developer tag, please let me know.
change from v3 to v4 - remove revid requirement - Add command COMMAND_ENABLE_DOORBELL and COMMAND_DISABLE_DOORBELL. - call pci_epc_set_bar() to map inbound address to MSI space only at COMMAND_ENABLE_DOORBELL. --- drivers/pci/endpoint/functions/pci-epf-test.c | 142 ++++++++++++++++++++++++++ 1 file changed, 142 insertions(+)
diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c index 50eb4106369f4..b9cb1ab218f2b 100644 --- a/drivers/pci/endpoint/functions/pci-epf-test.c +++ b/drivers/pci/endpoint/functions/pci-epf-test.c @@ -11,12 +11,14 @@ #include <linux/dmaengine.h> #include <linux/io.h> #include <linux/module.h> +#include <linux/msi.h> #include <linux/slab.h> #include <linux/pci_ids.h> #include <linux/random.h>
#include <linux/pci-epc.h> #include <linux/pci-epf.h> +#include <linux/pci-ep-msi.h> #include <linux/pci_regs.h>
#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 +680,126 @@ 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; + + if (le32_to_cpu(reg->doorbell_bar) > 0) { + free_irq(epf->db_msg[0].virq, epf_test); + reg->doorbell_bar = cpu_to_le32(NO_BAR); + } + + if (epf->db_msg) + 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) { + status |= STATUS_DOORBELL_ENABLE_FAIL; + goto set_status; + } + + 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 || bar == epf_test->test_reg_bar || !epf->db_msg) { + status |= STATUS_DOORBELL_ENABLE_FAIL; + goto set_status; + } + + ret = request_irq(epf->db_msg[0].virq, pci_epf_test_doorbell_handler, 0, + "pci-test-doorbell", epf_test); + if (ret) { + dev_err(&epf->dev, + "Failed to request irq %d, doorbell feature is not supported\n", + epf->db_msg[0].virq); + status |= STATUS_DOORBELL_ENABLE_FAIL; + pci_epf_test_doorbell_cleanup(epf_test); + goto set_status; + } + + 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) { + status |= STATUS_DOORBELL_ENABLE_FAIL; + pci_epf_test_doorbell_cleanup(epf_test); + goto set_status; + } + + 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) { + status |= STATUS_DOORBELL_ENABLE_FAIL; + pci_epf_test_doorbell_cleanup(epf_test); + } else { + status |= STATUS_DOORBELL_ENABLE_SUCCESS; + } + +set_status: + 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; + int ret; + + if (bar < BAR_0 || bar == epf_test->test_reg_bar || !epf->db_msg) { + status |= STATUS_DOORBELL_DISABLE_FAIL; + goto set_status; + } + + ret = pci_epc_set_bar(epc, epf->func_no, epf->vfunc_no, &epf->bar[bar]); + if (ret) + status |= STATUS_DOORBELL_DISABLE_FAIL; + else + status |= STATUS_DOORBELL_DISABLE_SUCCESS; + + pci_epf_test_doorbell_cleanup(epf_test); + +set_status: + reg->status = cpu_to_le32(status); +} + static void pci_epf_test_cmd_handler(struct work_struct *work) { u32 command; @@ -714,6 +847,14 @@ 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; @@ -987,6 +1128,7 @@ static void pci_epf_test_unbind(struct pci_epf *epf) pci_epf_test_clean_dma_chan(epf_test); pci_epf_test_clear_bar(epf); } + pci_epf_test_doorbell_cleanup(epf_test); pci_epf_test_free_space(epf); }