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![Saurabh Sengar](/assets/img/avatar_default.png)
Common userspace interface for read/write from VMBus ringbuffer. This implementation is open for use by any userspace driver or application seeking direct control over VMBus ring buffers. A significant part of this code is borrowed from DPDK. Link: https://github.com/DPDK/dpdk/ Currently this library is not supported for ARM64. Signed-off-by: Mary Hardy <maryhardy@microsoft.com> Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com> Reviewed-by: Long Li <longli@microsoft.com> Link: https://lore.kernel.org/r/1711788723-8593-5-git-send-email-ssengar@linux.microsoft.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
159 lines
4.1 KiB
C
159 lines
4.1 KiB
C
/* SPDX-License-Identifier: BSD-3-Clause */
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#ifndef _VMBUS_BUF_H_
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#define _VMBUS_BUF_H_
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#include <stdbool.h>
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#include <stdint.h>
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#define __packed __attribute__((__packed__))
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#define unlikely(x) __builtin_expect(!!(x), 0)
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#define ICMSGHDRFLAG_TRANSACTION 1
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#define ICMSGHDRFLAG_REQUEST 2
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#define ICMSGHDRFLAG_RESPONSE 4
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#define IC_VERSION_NEGOTIATION_MAX_VER_COUNT 100
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#define ICMSG_HDR (sizeof(struct vmbuspipe_hdr) + sizeof(struct icmsg_hdr))
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#define ICMSG_NEGOTIATE_PKT_SIZE(icframe_vercnt, icmsg_vercnt) \
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(ICMSG_HDR + sizeof(struct icmsg_negotiate) + \
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(((icframe_vercnt) + (icmsg_vercnt)) * sizeof(struct ic_version)))
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/*
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* Channel packets
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*/
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/* Channel packet flags */
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#define VMBUS_CHANPKT_TYPE_INBAND 0x0006
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#define VMBUS_CHANPKT_TYPE_RXBUF 0x0007
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#define VMBUS_CHANPKT_TYPE_GPA 0x0009
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#define VMBUS_CHANPKT_TYPE_COMP 0x000b
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#define VMBUS_CHANPKT_FLAG_NONE 0
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#define VMBUS_CHANPKT_FLAG_RC 0x0001 /* report completion */
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#define VMBUS_CHANPKT_SIZE_SHIFT 3
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#define VMBUS_CHANPKT_SIZE_ALIGN BIT(VMBUS_CHANPKT_SIZE_SHIFT)
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#define VMBUS_CHANPKT_HLEN_MIN \
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(sizeof(struct vmbus_chanpkt_hdr) >> VMBUS_CHANPKT_SIZE_SHIFT)
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/*
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* Buffer ring
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*/
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struct vmbus_bufring {
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volatile uint32_t windex;
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volatile uint32_t rindex;
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/*
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* Interrupt mask {0,1}
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*
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* For TX bufring, host set this to 1, when it is processing
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* the TX bufring, so that we can safely skip the TX event
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* notification to host.
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*
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* For RX bufring, once this is set to 1 by us, host will not
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* further dispatch interrupts to us, even if there are data
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* pending on the RX bufring. This effectively disables the
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* interrupt of the channel to which this RX bufring is attached.
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*/
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volatile uint32_t imask;
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/*
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* Win8 uses some of the reserved bits to implement
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* interrupt driven flow management. On the send side
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* we can request that the receiver interrupt the sender
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* when the ring transitions from being full to being able
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* to handle a message of size "pending_send_sz".
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*
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* Add necessary state for this enhancement.
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*/
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volatile uint32_t pending_send;
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uint32_t reserved1[12];
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union {
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struct {
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uint32_t feat_pending_send_sz:1;
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};
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uint32_t value;
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} feature_bits;
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/* Pad it to rte_mem_page_size() so that data starts on page boundary */
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uint8_t reserved2[4028];
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/*
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* Ring data starts here + RingDataStartOffset
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* !!! DO NOT place any fields below this !!!
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*/
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uint8_t data[];
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} __packed;
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struct vmbus_br {
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struct vmbus_bufring *vbr;
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uint32_t dsize;
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uint32_t windex; /* next available location */
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};
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struct vmbus_chanpkt_hdr {
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uint16_t type; /* VMBUS_CHANPKT_TYPE_ */
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uint16_t hlen; /* header len, in 8 bytes */
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uint16_t tlen; /* total len, in 8 bytes */
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uint16_t flags; /* VMBUS_CHANPKT_FLAG_ */
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uint64_t xactid;
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} __packed;
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struct vmbus_chanpkt {
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struct vmbus_chanpkt_hdr hdr;
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} __packed;
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struct vmbuspipe_hdr {
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unsigned int flags;
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unsigned int msgsize;
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} __packed;
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struct ic_version {
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unsigned short major;
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unsigned short minor;
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} __packed;
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struct icmsg_negotiate {
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unsigned short icframe_vercnt;
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unsigned short icmsg_vercnt;
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unsigned int reserved;
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struct ic_version icversion_data[]; /* any size array */
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} __packed;
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struct icmsg_hdr {
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struct ic_version icverframe;
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unsigned short icmsgtype;
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struct ic_version icvermsg;
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unsigned short icmsgsize;
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unsigned int status;
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unsigned char ictransaction_id;
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unsigned char icflags;
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unsigned char reserved[2];
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} __packed;
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int rte_vmbus_chan_recv_raw(struct vmbus_br *rxbr, void *data, uint32_t *len);
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int rte_vmbus_chan_send(struct vmbus_br *txbr, uint16_t type, void *data,
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uint32_t dlen, uint32_t flags);
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void vmbus_br_setup(struct vmbus_br *br, void *buf, unsigned int blen);
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void *vmbus_uio_map(int *fd, int size);
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/* Amount of space available for write */
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static inline uint32_t vmbus_br_availwrite(const struct vmbus_br *br, uint32_t windex)
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{
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uint32_t rindex = br->vbr->rindex;
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if (windex >= rindex)
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return br->dsize - (windex - rindex);
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else
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return rindex - windex;
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}
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static inline uint32_t vmbus_br_availread(const struct vmbus_br *br)
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{
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return br->dsize - vmbus_br_availwrite(br, br->vbr->windex);
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}
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#endif /* !_VMBUS_BUF_H_ */
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