| Message ID | 20241112-ep-msi-v6-3-45f9722e3c2a@nxp.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | PCI: EP: Add RC-to-EP doorbell with platform MSI controller | expand |
Hello Frank, On Tue, Nov 12, 2024 at 12:48:16PM -0500, Frank Li wrote: > Add three registers: doorbell_bar, doorbell_addr, and doorbell_data, > along with doorbell_done. 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 doorbell_done in the doorbell callback to indicate completion. > > To avoid broken compatibility, 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, 'pcitest -B' return success. > If EP side doesn't support MSI, the same to 'F'. > > F: 'pcitest -B' return failure, other case as usual. > > Tested-by: Niklas Cassel <cassel@kernel.org> > Signed-off-by: Frank Li <Frank.Li@nxp.com> > --- > Change from v5 to v6 > - rename doorbell_addr to doorbell_offset Is there a reason why you chose to not incorporate the helper function that I suggested here: https://lore.kernel.org/linux-pci/ZzMtKUFi30_o6SwL@ryzen/ I didn't see any reply from you to that message. Personally I think that it is nice to have the alignment code in a single function, rather than duplicating the code. The helper also looks quite similar to how we do outbound address translation alignment: https://git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git/commit/?h=endpoint&id=e73ea1c2d4d8f7ba5daaf7aa51171f63cf79bcd8 so that people will recognize the pattern more easily. But I guess you didn't like my suggestion? (Which is fine, but I would have expected some motivation.) Kind regards, Niklas
On Tue, Nov 12, 2024 at 09:14:49PM +0100, Niklas Cassel wrote: > Hello Frank, > > On Tue, Nov 12, 2024 at 12:48:16PM -0500, Frank Li wrote: > > Add three registers: doorbell_bar, doorbell_addr, and doorbell_data, > > along with doorbell_done. 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 doorbell_done in the doorbell callback to indicate completion. > > > > To avoid broken compatibility, 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, 'pcitest -B' return success. > > If EP side doesn't support MSI, the same to 'F'. > > > > F: 'pcitest -B' return failure, other case as usual. > > > > Tested-by: Niklas Cassel <cassel@kernel.org> > > Signed-off-by: Frank Li <Frank.Li@nxp.com> > > --- > > Change from v5 to v6 > > - rename doorbell_addr to doorbell_offset > > Is there a reason why you chose to not incorporate the helper function > that I suggested here: > https://lore.kernel.org/linux-pci/ZzMtKUFi30_o6SwL@ryzen/ > > I didn't see any reply from you to that message. Oh, you said at https://lore.kernel.org/imx/ZzIVzfkZe-hkAb4G@ryzen/T/#mc10e69e0e1e20cc8d8da9a8808177407d22bce06 I think you give up your idea about helper function, because it is one for doorbell_offset, the other is for the atu address. bar's struct is difference with reg. even it is similar, one if use "addr & (align - 1)" to get offset, the other is "addr & ~algin" to get base address. > > Personally I think that it is nice to have the alignment code in a single > function, rather than duplicating the code. The helper also looks quite > similar to how we do outbound address translation alignment: > https://git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git/commit/?h=endpoint&id=e73ea1c2d4d8f7ba5daaf7aa51171f63cf79bcd8 > so that people will recognize the pattern more easily. Do you means add help function, which wrap epc's .align_addr()? I know you make some improvement about EP's alignment, but I have not realized that related this thread at all. > > But I guess you didn't like my suggestion? > (Which is fine, but I would have expected some motivation.) May "I now see why you did this. One function is using the db offset, and the other is using the db base." mis-lead me. If I understand correct here, I can add wrap function for epc's .align_addr(). at next version. Frank > > > Kind regards, > Niklas
On Tue, Nov 12, 2024 at 03:37:34PM -0500, Frank Li wrote: > > > > Is there a reason why you chose to not incorporate the helper function > > that I suggested here: > > https://lore.kernel.org/linux-pci/ZzMtKUFi30_o6SwL@ryzen/ > > > > I didn't see any reply from you to that message. > > Oh, you said at > https://lore.kernel.org/imx/ZzIVzfkZe-hkAb4G@ryzen/T/#mc10e69e0e1e20cc8d8da9a8808177407d22bce06 > > I think you give up your idea about helper function, because it is one > for doorbell_offset, the other is for the atu address. bar's struct is > difference with reg. even it is similar, Yes, that is why the helper returns both base addess and offset (just like .align_addr()). > Do you means add help function, which wrap epc's .align_addr()? I know you > make some improvement about EP's alignment, but I have not realized that > related this thread at all. Look at the suggested helper that I wrote in: https://lore.kernel.org/linux-pci/ZzMtKUFi30_o6SwL@ryzen/ If you think that the code is cleaner, feel free to incorporate it in your next version, no need to add my SoB. .align_addr() is not related at all. (.align_addr() is for alignment for outbound PCI address, and theoretically the alignment requirement for outbound could be different from inbound address alignment requirement (which is defined in epc->features->align). The only relation is that both my suggested helper, and .align_addr() both return a base address and an offset. > May "I now see why you did this. > One function is using the db offset, and the other is using the db base." > mis-lead me. Yes, I can see that this sentence can be misunderstood. > If I understand correct here, I can add wrap function for epc's > .align_addr(). at next version. Please do not wrap .align_addr(). Kishon has been very clear that he wants outbound and inbound translation requirements to not depend on each other. Kind regards, Niklas
diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c index ef6677f34116e..2d05ab5e4ac6a 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) @@ -74,6 +83,9 @@ struct pci_epf_test_reg { u32 irq_type; u32 irq_number; u32 flags; + u32 doorbell_bar; + u32 doorbell_offset; + u32 doorbell_data; } __packed; static struct pci_epf_header test_header = { @@ -642,6 +654,63 @@ static void pci_epf_test_raise_irq(struct pci_epf_test *epf_test, } } +static void pci_epf_enable_doorbell(struct pci_epf_test *epf_test, struct pci_epf_test_reg *reg) +{ + enum pci_barno bar = reg->doorbell_bar; + struct pci_epf *epf = epf_test->epf; + struct pci_epc *epc = epf->epc; + struct pci_epf_bar db_bar; + struct msi_msg *msg; + u64 doorbell_addr; + u32 align; + int ret; + + align = epf_test->epc_features->align; + align = align ? align : 128; + + if (epf_test->epc_features->bar[bar].type == BAR_FIXED) + align = max(epf_test->epc_features->bar[bar].fixed_size, align); + + if (bar < BAR_0 || bar == epf_test->test_reg_bar || !epf->db_msg) { + reg->status |= STATUS_DOORBELL_ENABLE_FAIL; + return; + } + + msg = &epf->db_msg[0].msg; + doorbell_addr = msg->address_hi; + doorbell_addr <<= 32; + doorbell_addr |= msg->address_lo; + + db_bar.phys_addr = round_down(doorbell_addr, align); + db_bar.barno = bar; + db_bar.size = epf->bar[bar].size; + db_bar.flags = epf->bar[bar].flags; + db_bar.addr = NULL; + + ret = pci_epc_set_bar(epc, epf->func_no, epf->vfunc_no, &db_bar); + if (!ret) + reg->status |= STATUS_DOORBELL_ENABLE_SUCCESS; +} + +static void pci_epf_disable_doorbell(struct pci_epf_test *epf_test, struct pci_epf_test_reg *reg) +{ + enum pci_barno bar = reg->doorbell_bar; + 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) { + reg->status |= STATUS_DOORBELL_DISABLE_FAIL; + return; + } + + ret = pci_epc_set_bar(epc, epf->func_no, epf->vfunc_no, &epf->bar[bar]); + if (ret) + reg->status |= STATUS_DOORBELL_DISABLE_FAIL; + else + reg->status |= STATUS_DOORBELL_DISABLE_SUCCESS; +} + static void pci_epf_test_cmd_handler(struct work_struct *work) { u32 command; @@ -688,6 +757,14 @@ 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_enable_doorbell(epf_test, reg); + pci_epf_test_raise_irq(epf_test, reg); + break; + case COMMAND_DISABLE_DOORBELL: + pci_epf_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; @@ -822,6 +899,18 @@ static int pci_epf_test_link_down(struct pci_epf *epf) return 0; } +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]; + + reg->status |= STATUS_DOORBELL_SUCCESS; + pci_epf_test_raise_irq(epf_test, reg); + + return IRQ_HANDLED; +} + static const struct pci_epc_event_ops pci_epf_test_event_ops = { .epc_init = pci_epf_test_epc_init, .epc_deinit = pci_epf_test_epc_deinit, @@ -921,12 +1010,46 @@ static int pci_epf_test_bind(struct pci_epf *epf) if (ret) return ret; + ret = pci_epf_alloc_doorbell(epf, 1); + if (!ret) { + struct pci_epf_test_reg *reg = epf_test->reg[test_reg_bar]; + struct msi_msg *msg = &epf->db_msg[0].msg; + u32 align = epc_features->align; + u64 doorbell_addr; + enum pci_barno bar; + + bar = pci_epc_get_next_free_bar(epc_features, test_reg_bar + 1); + + 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); + return 0; + } + + align = align ? align : 128; + + if (epf_test->epc_features->bar[bar].type == BAR_FIXED) + align = max(epf_test->epc_features->bar[bar].fixed_size, align); + + doorbell_addr = msg->address_hi; + doorbell_addr <<= 32; + doorbell_addr |= msg->address_lo; + + reg->doorbell_offset = doorbell_addr & (align - 1); + reg->doorbell_data = msg->data; + reg->doorbell_bar = bar; + } + return 0; } static void pci_epf_test_unbind(struct pci_epf *epf) { struct pci_epf_test *epf_test = epf_get_drvdata(epf); + struct pci_epf_test_reg *reg = epf_test->reg[epf_test->test_reg_bar]; struct pci_epc *epc = epf->epc; cancel_delayed_work_sync(&epf_test->cmd_handler); @@ -934,6 +1057,12 @@ static void pci_epf_test_unbind(struct pci_epf *epf) pci_epf_test_clean_dma_chan(epf_test); pci_epf_test_clear_bar(epf); } + + if (reg->doorbell_bar > 0) { + free_irq(epf->db_msg[0].virq, epf_test); + pci_epf_free_doorbell(epf); + } + pci_epf_test_free_space(epf); }