An upcoming user of DOE is CMA (Component Measurement and Authentication, PCIe r6.0 sec 6.31). It builds on SPDM (Security Protocol and Data Model): https://www.dmtf.org/dsp/DSP0274 SPDM message sizes are not always a multiple of dwords. To transport them over DOE without using bounce buffers, allow sending requests and receiving responses whose final dword is only partially populated. Tested-by: Ira Weiny <ira.weiny@xxxxxxxxx> Signed-off-by: Lukas Wunner <lukas@xxxxxxxxx> Cc: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> --- drivers/pci/doe.c | 66 ++++++++++++++++++++++++++++------------------- 1 file changed, 40 insertions(+), 26 deletions(-) diff --git a/drivers/pci/doe.c b/drivers/pci/doe.c index 0263bcfdddd8..2113ec95379f 100644 --- a/drivers/pci/doe.c +++ b/drivers/pci/doe.c @@ -76,13 +76,6 @@ struct pci_doe_protocol { * @private: Private data for the consumer * @work: Used internally by the mailbox * @doe_mb: Used internally by the mailbox - * - * The payload sizes and rv are specified in bytes with the following - * restrictions concerning the protocol. - * - * 1) The request_pl_sz must be a multiple of double words (4 bytes) - * 2) The response_pl_sz must be >= a single double word (4 bytes) - * 3) rv is returned as bytes but it will be a multiple of double words */ struct pci_doe_task { struct pci_doe_protocol prot; @@ -153,7 +146,7 @@ static int pci_doe_send_req(struct pci_doe_mb *doe_mb, { struct pci_dev *pdev = doe_mb->pdev; int offset = doe_mb->cap_offset; - size_t length; + size_t length, remainder; u32 val; int i; @@ -171,7 +164,7 @@ static int pci_doe_send_req(struct pci_doe_mb *doe_mb, return -EIO; /* Length is 2 DW of header + length of payload in DW */ - length = 2 + task->request_pl_sz / sizeof(u32); + length = 2 + DIV_ROUND_UP(task->request_pl_sz, sizeof(u32)); if (length > PCI_DOE_MAX_LENGTH) return -EIO; if (length == PCI_DOE_MAX_LENGTH) @@ -184,10 +177,20 @@ static int pci_doe_send_req(struct pci_doe_mb *doe_mb, pci_write_config_dword(pdev, offset + PCI_DOE_WRITE, FIELD_PREP(PCI_DOE_DATA_OBJECT_HEADER_2_LENGTH, length)); + + /* Write payload */ for (i = 0; i < task->request_pl_sz / sizeof(u32); i++) pci_write_config_dword(pdev, offset + PCI_DOE_WRITE, task->request_pl[i]); + /* Write last payload dword */ + remainder = task->request_pl_sz % sizeof(u32); + if (remainder) { + val = 0; + memcpy(&val, &task->request_pl[i], remainder); + pci_write_config_dword(pdev, offset + PCI_DOE_WRITE, val); + } + pci_doe_write_ctrl(doe_mb, PCI_DOE_CTRL_GO); return 0; @@ -207,11 +210,11 @@ static bool pci_doe_data_obj_ready(struct pci_doe_mb *doe_mb) static int pci_doe_recv_resp(struct pci_doe_mb *doe_mb, struct pci_doe_task *task) { + size_t length, payload_length, remainder, received; struct pci_dev *pdev = doe_mb->pdev; int offset = doe_mb->cap_offset; - size_t length, payload_length; + int i = 0; u32 val; - int i; /* Read the first dword to get the protocol */ pci_read_config_dword(pdev, offset + PCI_DOE_READ, &val); @@ -238,15 +241,34 @@ static int pci_doe_recv_resp(struct pci_doe_mb *doe_mb, struct pci_doe_task *tas /* First 2 dwords have already been read */ length -= 2; - payload_length = min(length, task->response_pl_sz / sizeof(u32)); - /* Read the rest of the response payload */ - for (i = 0; i < payload_length; i++) { - pci_read_config_dword(pdev, offset + PCI_DOE_READ, - &task->response_pl[i]); + received = task->response_pl_sz; + payload_length = DIV_ROUND_UP(task->response_pl_sz, sizeof(u32)); + remainder = task->response_pl_sz % sizeof(u32); + if (!remainder) + remainder = sizeof(u32); + + if (length < payload_length) { + received = length * sizeof(u32); + payload_length = length; + remainder = sizeof(u32); + } + + if (payload_length) { + /* Read all payload dwords except the last */ + for (; i < payload_length - 1; i++) { + pci_read_config_dword(pdev, offset + PCI_DOE_READ, + &task->response_pl[i]); + pci_write_config_dword(pdev, offset + PCI_DOE_READ, 0); + } + + /* Read last payload dword */ + pci_read_config_dword(pdev, offset + PCI_DOE_READ, &val); + memcpy(&task->response_pl[i], &val, remainder); /* Prior to the last ack, ensure Data Object Ready */ - if (i == (payload_length - 1) && !pci_doe_data_obj_ready(doe_mb)) + if (!pci_doe_data_obj_ready(doe_mb)) return -EIO; pci_write_config_dword(pdev, offset + PCI_DOE_READ, 0); + i++; } /* Flush excess length */ @@ -260,7 +282,7 @@ static int pci_doe_recv_resp(struct pci_doe_mb *doe_mb, struct pci_doe_task *tas if (FIELD_GET(PCI_DOE_STATUS_ERROR, val)) return -EIO; - return min(length, task->response_pl_sz / sizeof(u32)) * sizeof(u32); + return received; } static void signal_task_complete(struct pci_doe_task *task, int rv) @@ -560,14 +582,6 @@ static int pci_doe_submit_task(struct pci_doe_mb *doe_mb, if (!pci_doe_supports_prot(doe_mb, task->prot.vid, task->prot.type)) return -EINVAL; - /* - * DOE requests must be a whole number of DW and the response needs to - * be big enough for at least 1 DW - */ - if (task->request_pl_sz % sizeof(u32) || - task->response_pl_sz < sizeof(u32)) - return -EINVAL; - if (test_bit(PCI_DOE_FLAG_DEAD, &doe_mb->flags)) return -EIO; -- 2.39.1
