On Wed, 31 May 2023 13:47:43 +0200 Klaus Jensen <i...@irrelevant.dk> wrote:
> From: Klaus Jensen <k.jen...@samsung.com> > > Add an abstract MCTP over I2C endpoint model. This implements MCTP > control message handling as well as handling the actual I2C transport > (packetization). > > Devices are intended to derive from this and implement the class > methods. > > Parts of this implementation is inspired by code[1] previously posted by > Jonathan Cameron. > > Squashed a fix[2] from Matt Johnston. > > [1]: > https://lore.kernel.org/qemu-devel/20220520170128.4436-1-jonathan.came...@huawei.com/ > [2]: > https://lore.kernel.org/qemu-devel/20221121080445.ga29...@codeconstruct.com.au/ > > Signed-off-by: Klaus Jensen <k.jen...@samsung.com> Hi Klaus, A few minor comments inline. With those tidied up feel free to add Reviewed-by: Jonathan Cameron <jonathan.came...@huawei.com> > + > + if (pkt->mctp.hdr.flags & MCTP_H_FLAGS_SOM) { > + mctp->tx.is_control = false; > + > + if (mctp->state == I2C_MCTP_STATE_RX) { > + mc->reset(mctp); > + } > + > + mctp->state = I2C_MCTP_STATE_RX; > + > + mctp->tx.addr = pkt->i2c.source; > + mctp->tx.eid = pkt->mctp.hdr.eid.source; > + mctp->tx.flags = pkt->mctp.hdr.flags & 0x7; Maybe worth either defining that mask, or adding a comment that this is copying the msg tag. Or rename flags... > + mctp->tx.pktseq = (pkt->mctp.hdr.flags >> 4) & 0x3; > + > + if ((pkt->mctp.payload[0] & 0x7f) == MCTP_MESSAGE_TYPE_CONTROL) { > + mctp->tx.is_control = true; > + > + i2c_mctp_handle_control(mctp); > + > + return 0; > + } > + } else if (mctp->state == I2C_MCTP_STATE_RX_STARTED) { > + trace_i2c_mctp_drop_expected_som(); > + goto drop; > + } else if (((pkt->mctp.hdr.flags >> 4) & 0x3) != (++mctp->tx.pktseq > & 0x3)) { > + trace_i2c_mctp_drop_invalid_pktseq((pkt->mctp.hdr.flags >> 4) & > 0x3, > + mctp->tx.pktseq & 0x3); > + goto drop; > + } > + > + mc->put_buf(mctp, i2c_mctp_payload(mctp->buffer), payload_len); > + > + if (pkt->mctp.hdr.flags & MCTP_H_FLAGS_EOM) { > + mc->handle(mctp); > + mctp->state = I2C_MCTP_STATE_WAIT_TX; > + } > + > + return 0; > + > + default: > + return -1; > + } > + > +drop: > + mc->reset(mctp); > + > + mctp->state = I2C_MCTP_STATE_IDLE; > + > + return 0; > +} > diff --git a/include/hw/i2c/mctp.h b/include/hw/i2c/mctp.h > new file mode 100644 > index 000000000000..ea97792e8d43 > --- /dev/null > +++ b/include/hw/i2c/mctp.h ... > +struct MCTPI2CEndpointClass { > + I2CSlaveClass parent_class; > + > + /** > + * > + * put_buf() - receive incoming message fragment > + * > + * Must returns 0 for succes or -1 for error. > + */ > + int (*put_buf)(MCTPI2CEndpoint *mctp, uint8_t *buf, size_t len); > + > + /** > + * get_buf() - provide pointer to message fragment > + * > + * Called by the mctp subsystem to request a pointer to the next message > + * fragment. The implementation must advance its internal position such > + * that successive calls returns the next fragments. > + * > + * Must return the number of bytes available. > + */ > + size_t (*get_buf)(MCTPI2CEndpoint *mctp, const uint8_t **buf, > + size_t maxlen, uint8_t *mctp_flags); > + > + /** > + * handle() - handle an MCTP message > + * > + * Called by the mctp subsystem when a full message has been delivered > and > + * may be parsed and processed. > + */ > + void (*handle)(MCTPI2CEndpoint *mctp); > + > + /** > + * reset() - reset internal state > + * > + * Called by the mctp subsystem in the event of some transport error. > + * Implementation must reset its internal state and drop any fragments > + * previously receieved. > + */ > + void (*reset)(MCTPI2CEndpoint *mctp); > + > + /** > + * get_types() - provide supported mctp message types > + * > + * Must provide a buffer with a full MCTP supported message types payload > + * (i.e. `0x0(SUCCESS),0x1(ONE),0x4(NMI)`). ONE? Looks to be PLDM Good to reference DSP0239 Management Component Transport Protocol (MCTP) IDs and Codes which has the list. > + * > + * Returns the size of the response. > + */ > + size_t (*get_types)(MCTPI2CEndpoint *mctp, const uint8_t **data); > +}; > diff --git a/include/net/mctp.h b/include/net/mctp.h > new file mode 100644 > index 000000000000..70b49235ddb2 > --- /dev/null > +++ b/include/net/mctp.h > @@ -0,0 +1,28 @@ > +#ifndef QEMU_MCTP_H > +#define QEMU_MCTP_H > + > +#define MCTP_BASELINE_MTU 64 Ideally add a reference for this as well. 8.3.1 Baseline transmission unit in DSP0236 1.3.0 > + > +enum { > + MCTP_H_FLAGS_EOM = 1 << 6, > + MCTP_H_FLAGS_SOM = 1 << 7, Trivial: I'm not really seeing the enum here as useful vs a pair of defines. > +}; > + > +#define MCTP_MESSAGE_IC (1 << 7) > +
