diff options
Diffstat (limited to 'arch/sparc64/kernel/ldc.c')
| -rw-r--r-- | arch/sparc64/kernel/ldc.c | 2338 |
1 files changed, 2338 insertions, 0 deletions
diff --git a/arch/sparc64/kernel/ldc.c b/arch/sparc64/kernel/ldc.c new file mode 100644 index 00000000000..0fa04d6f978 --- /dev/null +++ b/arch/sparc64/kernel/ldc.c @@ -0,0 +1,2338 @@ +/* ldc.c: Logical Domain Channel link-layer protocol driver. + * + * Copyright (C) 2007 David S. Miller <davem@davemloft.net> + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/delay.h> +#include <linux/errno.h> +#include <linux/string.h> +#include <linux/scatterlist.h> +#include <linux/interrupt.h> +#include <linux/list.h> +#include <linux/init.h> + +#include <asm/hypervisor.h> +#include <asm/iommu.h> +#include <asm/page.h> +#include <asm/ldc.h> +#include <asm/mdesc.h> + +#define DRV_MODULE_NAME "ldc" +#define PFX DRV_MODULE_NAME ": " +#define DRV_MODULE_VERSION "1.0" +#define DRV_MODULE_RELDATE "June 25, 2007" + +static char version[] __devinitdata = + DRV_MODULE_NAME ".c:v" DRV_MODULE_VERSION " (" DRV_MODULE_RELDATE ")\n"; +#define LDC_PACKET_SIZE 64 + +/* Packet header layout for unreliable and reliable mode frames. + * When in RAW mode, packets are simply straight 64-byte payloads + * with no headers. + */ +struct ldc_packet { + u8 type; +#define LDC_CTRL 0x01 +#define LDC_DATA 0x02 +#define LDC_ERR 0x10 + + u8 stype; +#define LDC_INFO 0x01 +#define LDC_ACK 0x02 +#define LDC_NACK 0x04 + + u8 ctrl; +#define LDC_VERS 0x01 /* Link Version */ +#define LDC_RTS 0x02 /* Request To Send */ +#define LDC_RTR 0x03 /* Ready To Receive */ +#define LDC_RDX 0x04 /* Ready for Data eXchange */ +#define LDC_CTRL_MSK 0x0f + + u8 env; +#define LDC_LEN 0x3f +#define LDC_FRAG_MASK 0xc0 +#define LDC_START 0x40 +#define LDC_STOP 0x80 + + u32 seqid; + + union { + u8 u_data[LDC_PACKET_SIZE - 8]; + struct { + u32 pad; + u32 ackid; + u8 r_data[LDC_PACKET_SIZE - 8 - 8]; + } r; + } u; +}; + +struct ldc_version { + u16 major; + u16 minor; +}; + +/* Ordered from largest major to lowest. */ +static struct ldc_version ver_arr[] = { + { .major = 1, .minor = 0 }, +}; + +#define LDC_DEFAULT_MTU (4 * LDC_PACKET_SIZE) +#define LDC_DEFAULT_NUM_ENTRIES (PAGE_SIZE / LDC_PACKET_SIZE) + +struct ldc_channel; + +struct ldc_mode_ops { + int (*write)(struct ldc_channel *, const void *, unsigned int); + int (*read)(struct ldc_channel *, void *, unsigned int); +}; + +static const struct ldc_mode_ops raw_ops; +static const struct ldc_mode_ops nonraw_ops; +static const struct ldc_mode_ops stream_ops; + +int ldom_domaining_enabled; + +struct ldc_iommu { + /* Protects arena alloc/free. */ + spinlock_t lock; + struct iommu_arena arena; + struct ldc_mtable_entry *page_table; +}; + +struct ldc_channel { + /* Protects all operations that depend upon channel state. */ + spinlock_t lock; + + unsigned long id; + + u8 *mssbuf; + u32 mssbuf_len; + u32 mssbuf_off; + + struct ldc_packet *tx_base; + unsigned long tx_head; + unsigned long tx_tail; + unsigned long tx_num_entries; + unsigned long tx_ra; + + unsigned long tx_acked; + + struct ldc_packet *rx_base; + unsigned long rx_head; + unsigned long rx_tail; + unsigned long rx_num_entries; + unsigned long rx_ra; + + u32 rcv_nxt; + u32 snd_nxt; + + unsigned long chan_state; + + struct ldc_channel_config cfg; + void *event_arg; + + const struct ldc_mode_ops *mops; + + struct ldc_iommu iommu; + + struct ldc_version ver; + + u8 hs_state; +#define LDC_HS_CLOSED 0x00 +#define LDC_HS_OPEN 0x01 +#define LDC_HS_GOTVERS 0x02 +#define LDC_HS_SENTRTR 0x03 +#define LDC_HS_GOTRTR 0x04 +#define LDC_HS_COMPLETE 0x10 + + u8 flags; +#define LDC_FLAG_ALLOCED_QUEUES 0x01 +#define LDC_FLAG_REGISTERED_QUEUES 0x02 +#define LDC_FLAG_REGISTERED_IRQS 0x04 +#define LDC_FLAG_RESET 0x10 + + u8 mss; + u8 state; + + struct hlist_head mh_list; + + struct hlist_node list; +}; + +#define ldcdbg(TYPE, f, a...) \ +do { if (lp->cfg.debug & LDC_DEBUG_##TYPE) \ + printk(KERN_INFO PFX "ID[%lu] " f, lp->id, ## a); \ +} while (0) + +static const char *state_to_str(u8 state) +{ + switch (state) { + case LDC_STATE_INVALID: + return "INVALID"; + case LDC_STATE_INIT: + return "INIT"; + case LDC_STATE_BOUND: + return "BOUND"; + case LDC_STATE_READY: + return "READY"; + case LDC_STATE_CONNECTED: + return "CONNECTED"; + default: + return "<UNKNOWN>"; + } +} + +static void ldc_set_state(struct ldc_channel *lp, u8 state) +{ + ldcdbg(STATE, "STATE (%s) --> (%s)\n", + state_to_str(lp->state), + state_to_str(state)); + + lp->state = state; +} + +static unsigned long __advance(unsigned long off, unsigned long num_entries) +{ + off += LDC_PACKET_SIZE; + if (off == (num_entries * LDC_PACKET_SIZE)) + off = 0; + + return off; +} + +static unsigned long rx_advance(struct ldc_channel *lp, unsigned long off) +{ + return __advance(off, lp->rx_num_entries); +} + +static unsigned long tx_advance(struct ldc_channel *lp, unsigned long off) +{ + return __advance(off, lp->tx_num_entries); +} + +static struct ldc_packet *handshake_get_tx_packet(struct ldc_channel *lp, + unsigned long *new_tail) +{ + struct ldc_packet *p; + unsigned long t; + + t = tx_advance(lp, lp->tx_tail); + if (t == lp->tx_head) + return NULL; + + *new_tail = t; + + p = lp->tx_base; + return p + (lp->tx_tail / LDC_PACKET_SIZE); +} + +/* When we are in reliable or stream mode, have to track the next packet + * we haven't gotten an ACK for in the TX queue using tx_acked. We have + * to be careful not to stomp over the queue past that point. During + * the handshake, we don't have TX data packets pending in the queue + * and that's why handshake_get_tx_packet() need not be mindful of + * lp->tx_acked. + */ +static unsigned long head_for_data(struct ldc_channel *lp) +{ + if (lp->cfg.mode == LDC_MODE_RELIABLE || + lp->cfg.mode == LDC_MODE_STREAM) + return lp->tx_acked; + return lp->tx_head; +} + +static int tx_has_space_for(struct ldc_channel *lp, unsigned int size) +{ + unsigned long limit, tail, new_tail, diff; + unsigned int mss; + + limit = head_for_data(lp); + tail = lp->tx_tail; + new_tail = tx_advance(lp, tail); + if (new_tail == limit) + return 0; + + if (limit > new_tail) + diff = limit - new_tail; + else + diff = (limit + + ((lp->tx_num_entries * LDC_PACKET_SIZE) - new_tail)); + diff /= LDC_PACKET_SIZE; + mss = lp->mss; + + if (diff * mss < size) + return 0; + + return 1; +} + +static struct ldc_packet *data_get_tx_packet(struct ldc_channel *lp, + unsigned long *new_tail) +{ + struct ldc_packet *p; + unsigned long h, t; + + h = head_for_data(lp); + t = tx_advance(lp, lp->tx_tail); + if (t == h) + return NULL; + + *new_tail = t; + + p = lp->tx_base; + return p + (lp->tx_tail / LDC_PACKET_SIZE); +} + +static int set_tx_tail(struct ldc_channel *lp, unsigned long tail) +{ + unsigned long orig_tail = lp->tx_tail; + int limit = 1000; + + lp->tx_tail = tail; + while (limit-- > 0) { + unsigned long err; + + err = sun4v_ldc_tx_set_qtail(lp->id, tail); + if (!err) + return 0; + + if (err != HV_EWOULDBLOCK) { + lp->tx_tail = orig_tail; + return -EINVAL; + } + udelay(1); + } + + lp->tx_tail = orig_tail; + return -EBUSY; +} + +/* This just updates the head value in the hypervisor using + * a polling loop with a timeout. The caller takes care of + * upating software state representing the head change, if any. + */ +static int __set_rx_head(struct ldc_channel *lp, unsigned long head) +{ + int limit = 1000; + + while (limit-- > 0) { + unsigned long err; + + err = sun4v_ldc_rx_set_qhead(lp->id, head); + if (!err) + return 0; + + if (err != HV_EWOULDBLOCK) + return -EINVAL; + + udelay(1); + } + + return -EBUSY; +} + +static int send_tx_packet(struct ldc_channel *lp, + struct ldc_packet *p, + unsigned long new_tail) +{ + BUG_ON(p != (lp->tx_base + (lp->tx_tail / LDC_PACKET_SIZE))); + + return set_tx_tail(lp, new_tail); +} + +static struct ldc_packet *handshake_compose_ctrl(struct ldc_channel *lp, + u8 stype, u8 ctrl, + void *data, int dlen, + unsigned long *new_tail) +{ + struct ldc_packet *p = handshake_get_tx_packet(lp, new_tail); + + if (p) { + memset(p, 0, sizeof(*p)); + p->type = LDC_CTRL; + p->stype = stype; + p->ctrl = ctrl; + if (data) + memcpy(p->u.u_data, data, dlen); + } + return p; +} + +static int start_handshake(struct ldc_channel *lp) +{ + struct ldc_packet *p; + struct ldc_version *ver; + unsigned long new_tail; + + ver = &ver_arr[0]; + + ldcdbg(HS, "SEND VER INFO maj[%u] min[%u]\n", + ver->major, ver->minor); + + p = handshake_compose_ctrl(lp, LDC_INFO, LDC_VERS, + ver, sizeof(*ver), &new_tail); + if (p) { + int err = send_tx_packet(lp, p, new_tail); + if (!err) + lp->flags &= ~LDC_FLAG_RESET; + return err; + } + return -EBUSY; +} + +static int send_version_nack(struct ldc_channel *lp, + u16 major, u16 minor) +{ + struct ldc_packet *p; + struct ldc_version ver; + unsigned long new_tail; + + ver.major = major; + ver.minor = minor; + + p = handshake_compose_ctrl(lp, LDC_NACK, LDC_VERS, + &ver, sizeof(ver), &new_tail); + if (p) { + ldcdbg(HS, "SEND VER NACK maj[%u] min[%u]\n", + ver.major, ver.minor); + + return send_tx_packet(lp, p, new_tail); + } + return -EBUSY; +} + +static int send_version_ack(struct ldc_channel *lp, + struct ldc_version *vp) +{ + struct ldc_packet *p; + unsigned long new_tail; + + p = handshake_compose_ctrl(lp, LDC_ACK, LDC_VERS, + vp, sizeof(*vp), &new_tail); + if (p) { + ldcdbg(HS, "SEND VER ACK maj[%u] min[%u]\n", + vp->major, vp->minor); + + return send_tx_packet(lp, p, new_tail); + } + return -EBUSY; +} + +static int send_rts(struct ldc_channel *lp) +{ + struct ldc_packet *p; + unsigned long new_tail; + + p = handshake_compose_ctrl(lp, LDC_INFO, LDC_RTS, NULL, 0, + &new_tail); + if (p) { + p->env = lp->cfg.mode; + p->seqid = 0; + lp->rcv_nxt = 0; + + ldcdbg(HS, "SEND RTS env[0x%x] seqid[0x%x]\n", + p->env, p->seqid); + + return send_tx_packet(lp, p, new_tail); + } + return -EBUSY; +} + +static int send_rtr(struct ldc_channel *lp) +{ + struct ldc_packet *p; + unsigned long new_tail; + + p = handshake_compose_ctrl(lp, LDC_INFO, LDC_RTR, NULL, 0, + &new_tail); + if (p) { + p->env = lp->cfg.mode; + p->seqid = 0; + + ldcdbg(HS, "SEND RTR env[0x%x] seqid[0x%x]\n", + p->env, p->seqid); + + return send_tx_packet(lp, p, new_tail); + } + return -EBUSY; +} + +static int send_rdx(struct ldc_channel *lp) +{ + struct ldc_packet *p; + unsigned long new_tail; + + p = handshake_compose_ctrl(lp, LDC_INFO, LDC_RDX, NULL, 0, + &new_tail); + if (p) { + p->env = 0; + p->seqid = ++lp->snd_nxt; + p->u.r.ackid = lp->rcv_nxt; + + ldcdbg(HS, "SEND RDX env[0x%x] seqid[0x%x] ackid[0x%x]\n", + p->env, p->seqid, p->u.r.ackid); + + return send_tx_packet(lp, p, new_tail); + } + return -EBUSY; +} + +static int send_data_nack(struct ldc_channel *lp, struct ldc_packet *data_pkt) +{ + struct ldc_packet *p; + unsigned long new_tail; + int err; + + p = data_get_tx_packet(lp, &new_tail); + if (!p) + return -EBUSY; + memset(p, 0, sizeof(*p)); + p->type = data_pkt->type; + p->stype = LDC_NACK; + p->ctrl = data_pkt->ctrl & LDC_CTRL_MSK; + p->seqid = lp->snd_nxt; + p->u.r.ackid = lp->rcv_nxt; + + ldcdbg(HS, "SEND DATA NACK type[0x%x] ctl[0x%x] seq[0x%x] ack[0x%x]\n", + p->type, p->ctrl, p->seqid, p->u.r.ackid); + + err = send_tx_packet(lp, p, new_tail); + if (!err) + lp->snd_nxt++; + + return err; +} + +static int ldc_abort(struct ldc_channel *lp) +{ + unsigned long hv_err; + + ldcdbg(STATE, "ABORT\n"); + + /* We report but do not act upon the hypervisor errors because + * there really isn't much we can do if they fail at this point. + */ + hv_err = sun4v_ldc_tx_qconf(lp->id, lp->tx_ra, lp->tx_num_entries); + if (hv_err) + printk(KERN_ERR PFX "ldc_abort: " + "sun4v_ldc_tx_qconf(%lx,%lx,%lx) failed, err=%lu\n", + lp->id, lp->tx_ra, lp->tx_num_entries, hv_err); + + hv_err = sun4v_ldc_tx_get_state(lp->id, + &lp->tx_head, + &lp->tx_tail, + &lp->chan_state); + if (hv_err) + printk(KERN_ERR PFX "ldc_abort: " + "sun4v_ldc_tx_get_state(%lx,...) failed, err=%lu\n", + lp->id, hv_err); + + hv_err = sun4v_ldc_rx_qconf(lp->id, lp->rx_ra, lp->rx_num_entries); + if (hv_err) + printk(KERN_ERR PFX "ldc_abort: " + "sun4v_ldc_rx_qconf(%lx,%lx,%lx) failed, err=%lu\n", + lp->id, lp->rx_ra, lp->rx_num_entries, hv_err); + + /* Refetch the RX queue state as well, because we could be invoked + * here in the queue processing context. + */ + hv_err = sun4v_ldc_rx_get_state(lp->id, + &lp->rx_head, + &lp->rx_tail, + &lp->chan_state); + if (hv_err) + printk(KERN_ERR PFX "ldc_abort: " + "sun4v_ldc_rx_get_state(%lx,...) failed, err=%lu\n", + lp->id, hv_err); + + return -ECONNRESET; +} + +static struct ldc_version *find_by_major(u16 major) +{ + struct ldc_version *ret = NULL; + int i; + + for (i = 0; i < ARRAY_SIZE(ver_arr); i++) { + struct ldc_version *v = &ver_arr[i]; + if (v->major <= major) { + ret = v; + break; + } + } + return ret; +} + +static int process_ver_info(struct ldc_channel *lp, struct ldc_version *vp) +{ + struct ldc_version *vap; + int err; + + ldcdbg(HS, "GOT VERSION INFO major[%x] minor[%x]\n", + vp->major, vp->minor); + + if (lp->hs_state == LDC_HS_GOTVERS) { + lp->hs_state = LDC_HS_OPEN; + memset(&lp->ver, 0, sizeof(lp->ver)); + } + + vap = find_by_major(vp->major); + if (!vap) { + err = send_version_nack(lp, 0, 0); + } else if (vap->major != vp->major) { + err = send_version_nack(lp, vap->major, vap->minor); + } else { + struct ldc_version ver = *vp; + if (ver.minor > vap->minor) + ver.minor = vap->minor; + err = send_version_ack(lp, &ver); + if (!err) { + lp->ver = ver; + lp->hs_state = LDC_HS_GOTVERS; + } + } + if (err) + return ldc_abort(lp); + + return 0; +} + +static int process_ver_ack(struct ldc_channel *lp, struct ldc_version *vp) +{ + ldcdbg(HS, "GOT VERSION ACK major[%x] minor[%x]\n", + vp->major, vp->minor); + + if (lp->hs_state == LDC_HS_GOTVERS) { + if (lp->ver.major != vp->major || + lp->ver.minor != vp->minor) + return ldc_abort(lp); + } else { + lp->ver = *vp; + lp->hs_state = LDC_HS_GOTVERS; + } + if (send_rts(lp)) + return ldc_abort(lp); + return 0; +} + +static int process_ver_nack(struct ldc_channel *lp, struct ldc_version *vp) +{ + struct ldc_version *vap; + + if ((vp->major == 0 && vp->minor == 0) || + !(vap = find_by_major(vp->major))) { + return ldc_abort(lp); + } else { + struct ldc_packet *p; + unsigned long new_tail; + + p = handshake_compose_ctrl(lp, LDC_INFO, LDC_VERS, + vap, sizeof(*vap), + &new_tail); + if (p) + return send_tx_packet(lp, p, new_tail); + else + return ldc_abort(lp); + } +} + +static int process_version(struct ldc_channel *lp, + struct ldc_packet *p) +{ + struct ldc_version *vp; + + vp = (struct ldc_version *) p->u.u_data; + + switch (p->stype) { + case LDC_INFO: + return process_ver_info(lp, vp); + + case LDC_ACK: + return process_ver_ack(lp, vp); + + case LDC_NACK: + return process_ver_nack(lp, vp); + + default: + return ldc_abort(lp); + } +} + +static int process_rts(struct ldc_channel *lp, + struct ldc_packet *p) +{ + ldcdbg(HS, "GOT RTS stype[%x] seqid[%x] env[%x]\n", + p->stype, p->seqid, p->env); + + if (p->stype != LDC_INFO || + lp->hs_state != LDC_HS_GOTVERS || + p->env != lp->cfg.mode) + return ldc_abort(lp); + + lp->snd_nxt = p->seqid; + lp->rcv_nxt = p->seqid; + lp->hs_state = LDC_HS_SENTRTR; + if (send_rtr(lp)) + return ldc_abort(lp); + + return 0; +} + +static int process_rtr(struct ldc_channel *lp, + struct ldc_packet *p) +{ + ldcdbg(HS, "GOT RTR stype[%x] seqid[%x] env[%x]\n", + p->stype, p->seqid, p->env); + + if (p->stype != LDC_INFO || + p->env != lp->cfg.mode) + return ldc_abort(lp); + + lp->snd_nxt = p->seqid; + lp->hs_state = LDC_HS_COMPLETE; + ldc_set_state(lp, LDC_STATE_CONNECTED); + send_rdx(lp); + + return LDC_EVENT_UP; +} + +static int rx_seq_ok(struct ldc_channel *lp, u32 seqid) +{ + return lp->rcv_nxt + 1 == seqid; +} + +static int process_rdx(struct ldc_channel *lp, + struct ldc_packet *p) +{ + ldcdbg(HS, "GOT RDX stype[%x] seqid[%x] env[%x] ackid[%x]\n", + p->stype, p->seqid, p->env, p->u.r.ackid); + + if (p->stype != LDC_INFO || + !(rx_seq_ok(lp, p->seqid))) + return ldc_abort(lp); + + lp->rcv_nxt = p->seqid; + + lp->hs_state = LDC_HS_COMPLETE; + ldc_set_state(lp, LDC_STATE_CONNECTED); + + return LDC_EVENT_UP; +} + +static int process_control_frame(struct ldc_channel *lp, + struct ldc_packet *p) +{ + switch (p->ctrl) { + case LDC_VERS: + return process_version(lp, p); + + case LDC_RTS: + return process_rts(lp, p); + + case LDC_RTR: + return process_rtr(lp, p); + + case LDC_RDX: + return process_rdx(lp, p); + + default: + return ldc_abort(lp); + } +} + +static int process_error_frame(struct ldc_channel *lp, + struct ldc_packet *p) +{ + return ldc_abort(lp); +} + +static int process_data_ack(struct ldc_channel *lp, + struct ldc_packet *ack) +{ + unsigned long head = lp->tx_acked; + u32 ackid = ack->u.r.ackid; + + while (1) { + struct ldc_packet *p = lp->tx_base + (head / LDC_PACKET_SIZE); + + head = tx_advance(lp, head); + + if (p->seqid == ackid) { + lp->tx_acked = head; + return 0; + } + if (head == lp->tx_head) + return ldc_abort(lp); + } + + return 0; +} + +static void send_events(struct ldc_channel *lp, unsigned int event_mask) +{ + if (event_mask & LDC_EVENT_RESET) + lp->cfg.event(lp->event_arg, LDC_EVENT_RESET); + if (event_mask & LDC_EVENT_UP) + lp->cfg.event(lp->event_arg, LDC_EVENT_UP); + if (event_mask & LDC_EVENT_DATA_READY) + lp->cfg.event(lp->event_arg, LDC_EVENT_DATA_READY); +} + +static irqreturn_t ldc_rx(int irq, void *dev_id) +{ + struct ldc_channel *lp = dev_id; + unsigned long orig_state, hv_err, flags; + unsigned int event_mask; + + spin_lock_irqsave(&lp->lock, flags); + + orig_state = lp->chan_state; + hv_err = sun4v_ldc_rx_get_state(lp->id, + &lp->rx_head, + &lp->rx_tail, + &lp->chan_state); + + ldcdbg(RX, "RX state[0x%02lx:0x%02lx] head[0x%04lx] tail[0x%04lx]\n", + orig_state, lp->chan_state, lp->rx_head, lp->rx_tail); + + event_mask = 0; + + if (lp->cfg.mode == LDC_MODE_RAW && + lp->chan_state == LDC_CHANNEL_UP) { + lp->hs_state = LDC_HS_COMPLETE; + ldc_set_state(lp, LDC_STATE_CONNECTED); + + event_mask |= LDC_EVENT_UP; + + orig_state = lp->chan_state; + } + + /* If we are in reset state, flush the RX queue and ignore + * everything. + */ + if (lp->flags & LDC_FLAG_RESET) { + (void) __set_rx_head(lp, lp->rx_tail); + goto out; + } + + /* Once we finish the handshake, we let the ldc_read() + * paths do all of the control frame and state management. + * Just trigger the callback. + */ + if (lp->hs_state == LDC_HS_COMPLETE) { +handshake_complete: + if (lp->chan_state != orig_state) { + unsigned int event = LDC_EVENT_RESET; + + if (lp->chan_state == LDC_CHANNEL_UP) + event = LDC_EVENT_UP; + + event_mask |= event; + } + if (lp->rx_head != lp->rx_tail) + event_mask |= LDC_EVENT_DATA_READY; + + goto out; + } + + if (lp->chan_state != orig_state) + goto out; + + while (lp->rx_head != lp->rx_tail) { + struct ldc_packet *p; + unsigned long new; + int err; + + p = lp->rx_base + (lp->rx_head / LDC_PACKET_SIZE); + + switch (p->type) { + case LDC_CTRL: + err = process_control_frame(lp, p); + if (err > 0) + event_mask |= err; + break; + + case LDC_DATA: + event_mask |= LDC_EVENT_DATA_READY; + err = 0; + break; + + case LDC_ERR: + err = process_error_frame(lp, p); + break; + + default: + err = ldc_abort(lp); + break; + } + + if (err < 0) + break; + + new = lp->rx_head; + new += LDC_PACKET_SIZE; + if (new == (lp->rx_num_entries * LDC_PACKET_SIZE)) + new = 0; + lp->rx_head = new; + + err = __set_rx_head(lp, new); + if (err < 0) { + (void) ldc_abort(lp); + break; + } + if (lp->hs_state == LDC_HS_COMPLETE) + goto handshake_complete; + } + +out: + spin_unlock_irqrestore(&lp->lock, flags); + + send_events(lp, event_mask); + + return IRQ_HANDLED; +} + +static irqreturn_t ldc_tx(int irq, void *dev_id) +{ + struct ldc_channel *lp = dev_id; + unsigned long flags, hv_err, orig_state; + unsigned int event_mask = 0; + + spin_lock_irqsave(&lp->lock, flags); + + orig_state = lp->chan_state; + hv_err = sun4v_ldc_tx_get_state(lp->id, + &lp->tx_head, + &lp->tx_tail, + &lp->chan_state); + + ldcdbg(TX, " TX state[0x%02lx:0x%02lx] head[0x%04lx] tail[0x%04lx]\n", + orig_state, lp->chan_state, lp->tx_head, lp->tx_tail); + + if (lp->cfg.mode == LDC_MODE_RAW && + lp->chan_state == LDC_CHANNEL_UP) { + lp->hs_state = LDC_HS_COMPLETE; + ldc_set_state(lp, LDC_STATE_CONNECTED); + + event_mask |= LDC_EVENT_UP; + } + + spin_unlock_irqrestore(&lp->lock, flags); + + send_events(lp, event_mask); + + return IRQ_HANDLED; +} + +/* XXX ldc_alloc() and ldc_free() needs to run under a mutex so + * XXX that addition and removal from the ldc_channel_list has + * XXX atomicity, otherwise the __ldc_channel_exists() check is + * XXX totally pointless as another thread can slip into ldc_alloc() + * XXX and add a channel with the same ID. There also needs to be + * XXX a spinlock for ldc_channel_list. + */ +static HLIST_HEAD(ldc_channel_list); + +static int __ldc_channel_exists(unsigned long id) +{ + struct ldc_channel *lp; + struct hlist_node *n; + + hlist_for_each_entry(lp, n, &ldc_channel_list, list) { + if (lp->id == id) + return 1; + } + return 0; +} + +static int alloc_queue(const char *name, unsigned long num_entries, + struct ldc_packet **base, unsigned long *ra) +{ + unsigned long size, order; + void *q; + + size = num_entries * LDC_PACKET_SIZE; + order = get_order(size); + + q = (void *) __get_free_pages(GFP_KERNEL, order); + if (!q) { + printk(KERN_ERR PFX "Alloc of %s queue failed with " + "size=%lu order=%lu\n", name, size, order); + return -ENOMEM; + } + + memset(q, 0, PAGE_SIZE << order); + + *base = q; + *ra = __pa(q); + + return 0; +} + +static void free_queue(unsigned long num_entries, struct ldc_packet *q) +{ + unsigned long size, order; + + if (!q) + return; + + size = num_entries * LDC_PACKET_SIZE; + order = get_order(size); + + free_pages((unsigned long)q, order); +} + +/* XXX Make this configurable... XXX */ +#define LDC_IOTABLE_SIZE (8 * 1024) + +static int ldc_iommu_init(struct ldc_channel *lp) +{ + unsigned long sz, num_tsb_entries, tsbsize, order; + struct ldc_iommu *iommu = &lp->iommu; + struct ldc_mtable_entry *table; + unsigned long hv_err; + int err; + + num_tsb_entries = LDC_IOTABLE_SIZE; + tsbsize = num_tsb_entries * sizeof(struct ldc_mtable_entry); + + spin_lock_init(&iommu->lock); + + sz = num_tsb_entries / 8; + sz = (sz + 7UL) & ~7UL; + iommu->arena.map = kzalloc(sz, GFP_KERNEL); + if (!iommu->arena.map) { + printk(KERN_ERR PFX "Alloc of arena map failed, sz=%lu\n", sz); + return -ENOMEM; + } + + iommu->arena.limit = num_tsb_entries; + + order = get_order(tsbsize); + + table = (struct ldc_mtable_entry *) + __get_free_pages(GFP_KERNEL, order); + err = -ENOMEM; + if (!table) { + printk(KERN_ERR PFX "Alloc of MTE table failed, " + "size=%lu order=%lu\n", tsbsize, order); + goto out_free_map; + } + + memset(table, 0, PAGE_SIZE << order); + + iommu->page_table = table; + + hv_err = sun4v_ldc_set_map_table(lp->id, __pa(table), + num_tsb_entries); + err = -EINVAL; + if (hv_err) + goto out_free_table; + + return 0; + +out_free_table: + free_pages((unsigned long) table, order); + iommu->page_table = NULL; + +out_free_map: + kfree(iommu->arena.map); + iommu->arena.map = NULL; + + return err; +} + +static void ldc_iommu_release(struct ldc_channel *lp) +{ + struct ldc_iommu *iommu = &lp->iommu; + unsigned long num_tsb_entries, tsbsize, order; + + (void) sun4v_ldc_set_map_table(lp->id, 0, 0); + + num_tsb_entries = iommu->arena.limit; + tsbsize = num_tsb_entries * sizeof(struct ldc_mtable_entry); + order = get_order(tsbsize); + + free_pages((unsigned long) iommu->page_table, order); + iommu->page_table = NULL; + + kfree(iommu->arena.map); + iommu->arena.map = NULL; +} + +struct ldc_channel *ldc_alloc(unsigned long id, + const struct ldc_channel_config *cfgp, + void *event_arg) +{ + struct ldc_channel *lp; + const struct ldc_mode_ops *mops; + unsigned long dummy1, dummy2, hv_err; + u8 mss, *mssbuf; + int err; + + err = -ENODEV; + if (!ldom_domaining_enabled) + goto out_err; + + err = -EINVAL; + if (!cfgp) + goto out_err; + + switch (cfgp->mode) { + case LDC_MODE_RAW: + mops = &raw_ops; + mss = LDC_PACKET_SIZE; + break; + + case LDC_MODE_UNRELIABLE: + mops = &nonraw_ops; + mss = LDC_PACKET_SIZE - 8; + break; + + case LDC_MODE_RELIABLE: + mops = &nonraw_ops; + mss = LDC_PACKET_SIZE - 8 - 8; + break; + + case LDC_MODE_STREAM: + mops = &stream_ops; + mss = LDC_PACKET_SIZE - 8 - 8; + break; + + default: + goto out_err; + } + + if (!cfgp->event || !event_arg || !cfgp->rx_irq || !cfgp->tx_irq) + goto out_err; + + hv_err = sun4v_ldc_tx_qinfo(id, &dummy1, &dummy2); + err = -ENODEV; + if (hv_err == HV_ECHANNEL) + goto out_err; + + err = -EEXIST; + if (__ldc_channel_exists(id)) + goto out_err; + + mssbuf = NULL; + + lp = kzalloc(sizeof(*lp), GFP_KERNEL); + err = -ENOMEM; + if (!lp) + goto out_err; + + spin_lock_init(&lp->lock); + + lp->id = id; + + err = ldc_iommu_init(lp); + if (err) + goto out_free_ldc; + + lp->mops = mops; + lp->mss = mss; + + lp->cfg = *cfgp; + if (!lp->cfg.mtu) + lp->cfg.mtu = LDC_DEFAULT_MTU; + + if (lp->cfg.mode == LDC_MODE_STREAM) { + mssbuf = kzalloc(lp->cfg.mtu, GFP_KERNEL); + if (!mssbuf) { + err = -ENOMEM; + goto out_free_iommu; + } + lp->mssbuf = mssbuf; + } + + lp->event_arg = event_arg; + + /* XXX allow setting via ldc_channel_config to override defaults + * XXX or use some formula based upon mtu + */ + lp->tx_num_entries = LDC_DEFAULT_NUM_ENTRIES; + lp->rx_num_entries = LDC_DEFAULT_NUM_ENTRIES; + + err = alloc_queue("TX", lp->tx_num_entries, + &lp->tx_base, &lp->tx_ra); + if (err) + goto out_free_mssbuf; + + err = alloc_queue("RX", lp->rx_num_entries, + &lp->rx_base, &lp->rx_ra); + if (err) + goto out_free_txq; + + lp->flags |= LDC_FLAG_ALLOCED_QUEUES; + + lp->hs_state = LDC_HS_CLOSED; + ldc_set_state(lp, LDC_STATE_INIT); + + INIT_HLIST_NODE(&lp->list); + hlist_add_head(&lp->list, &ldc_channel_list); + + INIT_HLIST_HEAD(&lp->mh_list); + + return lp; + +out_free_txq: + free_queue(lp->tx_num_entries, lp->tx_base); + +out_free_mssbuf: + if (mssbuf) + kfree(mssbuf); + +out_free_iommu: + ldc_iommu_release(lp); + +out_free_ldc: + kfree(lp); + +out_err: + return ERR_PTR(err); +} +EXPORT_SYMBOL(ldc_alloc); + +void ldc_free(struct ldc_channel *lp) +{ + if (lp->flags & LDC_FLAG_REGISTERED_IRQS) { + free_irq(lp->cfg.rx_irq, lp); + free_irq(lp->cfg.tx_irq, lp); + } + + if (lp->flags & LDC_FLAG_REGISTERED_QUEUES) { + sun4v_ldc_tx_qconf(lp->id, 0, 0); + sun4v_ldc_rx_qconf(lp->id, 0, 0); + lp->flags &= ~LDC_FLAG_REGISTERED_QUEUES; + } + if (lp->flags & LDC_FLAG_ALLOCED_QUEUES) { + free_queue(lp->tx_num_entries, lp->tx_base); + free_queue(lp->rx_num_entries, lp->rx_base); + lp->flags &= ~LDC_FLAG_ALLOCED_QUEUES; + } + + hlist_del(&lp->list); + + if (lp->mssbuf) + kfree(lp->mssbuf); + + ldc_iommu_release(lp); + + kfree(lp); +} +EXPORT_SYMBOL(ldc_free); + +/* Bind the channel. This registers the LDC queues with + * the hypervisor and puts the channel into a pseudo-listening + * state. This does not initiate a handshake, ldc_connect() does + * that. + */ +int ldc_bind(struct ldc_channel *lp) +{ + unsigned long hv_err, flags; + int err = -EINVAL; + + spin_lock_irqsave(&lp->lock, flags); + + if (lp->state != LDC_STATE_INIT) + goto out_err; + + err = request_irq(lp->cfg.rx_irq, ldc_rx, + IRQF_SAMPLE_RANDOM | IRQF_SHARED, + "LDC RX", lp); + if (err) + goto out_err; + + err = request_irq(lp->cfg.tx_irq, ldc_tx, + IRQF_SAMPLE_RANDOM | IRQF_SHARED, + "LDC TX", lp); + if (err) + goto out_free_rx_irq; + + + lp->flags |= LDC_FLAG_REGISTERED_IRQS; + + err = -ENODEV; + hv_err = sun4v_ldc_tx_qconf(lp->id, 0, 0); + if (hv_err) + goto out_free_tx_irq; + + hv_err = sun4v_ldc_tx_qconf(lp->id, lp->tx_ra, lp->tx_num_entries); + if (hv_err) + goto out_free_tx_irq; + + hv_err = sun4v_ldc_rx_qconf(lp->id, 0, 0); + if (hv_err) + goto out_unmap_tx; + + hv_err = sun4v_ldc_rx_qconf(lp->id, lp->rx_ra, lp->rx_num_entries); + if (hv_err) + goto out_unmap_tx; + + lp->flags |= LDC_FLAG_REGISTERED_QUEUES; + + hv_err = sun4v_ldc_tx_get_state(lp->id, + &lp->tx_head, + &lp->tx_tail, + &lp->chan_state); + err = -EBUSY; + if (hv_err) + goto out_unmap_rx; + + lp->tx_acked = lp->tx_head; + + lp->hs_state = LDC_HS_OPEN; + ldc_set_state(lp, LDC_STATE_BOUND); + + spin_unlock_irqrestore(&lp->lock, flags); + + return 0; + +out_unmap_rx: + lp->flags &= ~LDC_FLAG_REGISTERED_QUEUES; + sun4v_ldc_rx_qconf(lp->id, 0, 0); + +out_unmap_tx: + sun4v_ldc_tx_qconf(lp->id, 0, 0); + +out_free_tx_irq: + lp->flags &= ~LDC_FLAG_REGISTERED_IRQS; + free_irq(lp->cfg.tx_irq, lp); + +out_free_rx_irq: + free_irq(lp->cfg.rx_irq, lp); + +out_err: + spin_unlock_irqrestore(&lp->lock, flags); + + return err; +} +EXPORT_SYMBOL(ldc_bind); + +int ldc_connect(struct ldc_channel *lp) +{ + unsigned long flags; + int err; + + if (lp->cfg.mode == LDC_MODE_RAW) + return -EINVAL; + + spin_lock_irqsave(&lp->lock, flags); + + if (!(lp->flags & LDC_FLAG_ALLOCED_QUEUES) || + !(lp->flags & LDC_FLAG_REGISTERED_QUEUES) || + lp->hs_state != LDC_HS_OPEN) + err = -EINVAL; + else + err = start_handshake(lp); + + spin_unlock_irqrestore(&lp->lock, flags); + + return err; +} +EXPORT_SYMBOL(ldc_connect); + +int ldc_disconnect(struct ldc_channel *lp) +{ + unsigned long hv_err, flags; + int err; + + if (lp->cfg.mode == LDC_MODE_RAW) + return -EINVAL; + + if (!(lp->flags & LDC_FLAG_ALLOCED_QUEUES) || + !(lp->flags & LDC_FLAG_REGISTERED_QUEUES)) + return -EINVAL; + + spin_lock_irqsave(&lp->lock, flags); + + err = -ENODEV; + hv_err = sun4v_ldc_tx_qconf(lp->id, 0, 0); + if (hv_err) + goto out_err; + + hv_err = sun4v_ldc_tx_qconf(lp->id, lp->tx_ra, lp->tx_num_entries); + if (hv_err) + goto out_err; + + hv_err = sun4v_ldc_rx_qconf(lp->id, 0, 0); + if (hv_err) + goto out_err; + + hv_err = sun4v_ldc_rx_qconf(lp->id, lp->rx_ra, lp->rx_num_entries); + if (hv_err) + goto out_err; + + ldc_set_state(lp, LDC_STATE_BOUND); + lp->hs_state = LDC_HS_OPEN; + lp->flags |= LDC_FLAG_RESET; + + spin_unlock_irqrestore(&lp->lock, flags); + + return 0; + +out_err: + sun4v_ldc_tx_qconf(lp->id, 0, 0); + sun4v_ldc_rx_qconf(lp->id, 0, 0); + free_irq(lp->cfg.tx_irq, lp); + free_irq(lp->cfg.rx_irq, lp); + lp->flags &= ~(LDC_FLAG_REGISTERED_IRQS | + LDC_FLAG_REGISTERED_QUEUES); + ldc_set_state(lp, LDC_STATE_INIT); + + spin_unlock_irqrestore(&lp->lock, flags); + + return err; +} +EXPORT_SYMBOL(ldc_disconnect); + +int ldc_state(struct ldc_channel *lp) +{ + return lp->state; +} +EXPORT_SYMBOL(ldc_state); + +static int write_raw(struct ldc_channel *lp, const void *buf, unsigned int size) +{ + struct ldc_packet *p; + unsigned long new_tail; + int err; + + if (size > LDC_PACKET_SIZE) + return -EMSGSIZE; + + p = data_get_tx_packet(lp, &new_tail); + if (!p) + return -EAGAIN; + + memcpy(p, buf, size); + + err = send_tx_packet(lp, p, new_tail); + if (!err) + err = size; + + return err; +} + +static int read_raw(struct ldc_channel *lp, void *buf, unsigned int size) +{ + struct ldc_packet *p; + unsigned long hv_err, new; + int err; + + if (size < LDC_PACKET_SIZE) + return -EINVAL; + + hv_err = sun4v_ldc_rx_get_state(lp->id, + &lp->rx_head, + &lp->rx_tail, + &lp->chan_state); + if (hv_err) + return ldc_abort(lp); + + if (lp->chan_state == LDC_CHANNEL_DOWN || + lp->chan_state == LDC_CHANNEL_RESETTING) + return -ECONNRESET; + + if (lp->rx_head == lp->rx_tail) + return 0; + + p = lp->rx_base + (lp->rx_head / LDC_PACKET_SIZE); + memcpy(buf, p, LDC_PACKET_SIZE); + + new = rx_advance(lp, lp->rx_head); + lp->rx_head = new; + + err = __set_rx_head(lp, new); + if (err < 0) + err = -ECONNRESET; + else + err = LDC_PACKET_SIZE; + + return err; +} + +static const struct ldc_mode_ops raw_ops = { + .write = write_raw, + .read = read_raw, +}; + +static int write_nonraw(struct ldc_channel *lp, const void *buf, + unsigned int size) +{ + unsigned long hv_err, tail; + unsigned int copied; + u32 seq; + int err; + + hv_err = sun4v_ldc_tx_get_state(lp->id, &lp->tx_head, &lp->tx_tail, + &lp->chan_state); + if (unlikely(hv_err)) + return -EBUSY; + + if (unlikely(lp->chan_state != LDC_CHANNEL_UP)) + return ldc_abort(lp); + + if (!tx_has_space_for(lp, size)) + return -EAGAIN; + + seq = lp->snd_nxt; + copied = 0; + tail = lp->tx_tail; + while (copied < size) { + struct ldc_packet *p = lp->tx_base + (tail / LDC_PACKET_SIZE); + u8 *data = ((lp->cfg.mode == LDC_MODE_UNRELIABLE) ? + p->u.u_data : + p->u.r.r_data); + int data_len; + + p->type = LDC_DATA; + p->stype = LDC_INFO; + p->ctrl = 0; + + data_len = size - copied; + if (data_len > lp->mss) + data_len = lp->mss; + + BUG_ON(data_len > LDC_LEN); + + p->env = (data_len | + (copied == 0 ? LDC_START : 0) | + (data_len == size - copied ? LDC_STOP : 0)); + + p->seqid = ++seq; + + ldcdbg(DATA, "SENT DATA [%02x:%02x:%02x:%02x:%08x]\n", + p->type, + p->stype, + p->ctrl, + p->env, + p->seqid); + + memcpy(data, buf, data_len); + buf += data_len; + copied += data_len; + + tail = tx_advance(lp, tail); + } + + err = set_tx_tail(lp, tail); + if (!err) { + lp->snd_nxt = seq; + err = size; + } + + return err; +} + +static int rx_bad_seq(struct ldc_channel *lp, struct ldc_packet *p, + struct ldc_packet *first_frag) +{ + int err; + + if (first_frag) + lp->rcv_nxt = first_frag->seqid - 1; + + err = send_data_nack(lp, p); + if (err) + return err; + + err = __set_rx_head(lp, lp->rx_tail); + if (err < 0) + return ldc_abort(lp); + + return 0; +} + +static int data_ack_nack(struct ldc_channel *lp, struct ldc_packet *p) +{ + if (p->stype & LDC_ACK) { + int err = process_data_ack(lp, p); + if (err) + return err; + } + if (p->stype & LDC_NACK) + return ldc_abort(lp); + + return 0; +} + +static int rx_data_wait(struct ldc_channel *lp, unsigned long cur_head) +{ + unsigned long dummy; + int limit = 1000; + + ldcdbg(DATA, "DATA WAIT cur_head[%lx] rx_head[%lx] rx_tail[%lx]\n", + cur_head, lp->rx_head, lp->rx_tail); + while (limit-- > 0) { + unsigned long hv_err; + + hv_err = sun4v_ldc_rx_get_state(lp->id, + &dummy, + &lp->rx_tail, + &lp->chan_state); + if (hv_err) + return ldc_abort(lp); + + ldcdbg(DATA, "REREAD head[%lx] tail[%lx] chan_state[%lx]\n", + dummy, lp->rx_tail, lp->chan_state); + + if (lp->chan_state == LDC_CHANNEL_DOWN || + lp->chan_state == LDC_CHANNEL_RESETTING) + return -ECONNRESET; + + if (cur_head != lp->rx_tail) { + ldcdbg(DATA, "DATA WAIT DONE\n"); + return 0; + } + + udelay(1); + } + return -EAGAIN; +} + +static int rx_set_head(struct ldc_channel *lp, unsigned long head) +{ + int err = __set_rx_head(lp, head); + + if (err < 0) + return ldc_abort(lp); + + lp->rx_head = head; + return 0; +} + +static int read_nonraw(struct ldc_channel *lp, void *buf, unsigned int size) +{ + struct ldc_packet *first_frag; + unsigned long hv_err, new; + int err, copied; + + hv_err = sun4v_ldc_rx_get_state(lp->id, + &lp->rx_head, + &lp->rx_tail, + &lp->chan_state); + if (hv_err) + return ldc_abort(lp); + + if (lp->chan_state == LDC_CHANNEL_DOWN || + lp->chan_state == LDC_CHANNEL_RESETTING) + return -ECONNRESET; + + if (lp->rx_head == lp->rx_tail) + return 0; + + first_frag = NULL; + copied = err = 0; + new = lp->rx_head; + while (1) { + struct ldc_packet *p; + int pkt_len; + + BUG_ON(new == lp->rx_tail); + p = lp->rx_base + (new / LDC_PACKET_SIZE); + + ldcdbg(RX, "RX read pkt[%02x:%02x:%02x:%02x:%08x] " + "rcv_nxt[%08x]\n", + p->type, + p->stype, + p->ctrl, + p->env, + p->seqid, + lp->rcv_nxt); + + if (unlikely(!rx_seq_ok(lp, p->seqid))) { + err = rx_bad_seq(lp, p, first_frag); + copied = 0; + break; + } + + if (p->type & LDC_CTRL) { + err = process_control_frame(lp, p); + if (err < 0) + break; + err = 0; + } + + lp->rcv_nxt = p->seqid; + + if (!(p->type & LDC_DATA)) { + new = rx_advance(lp, new); + goto no_data; + } + if (p->stype & (LDC_ACK | LDC_NACK)) { + err = data_ack_nack(lp, p); + if (err) + break; + } + if (!(p->stype & LDC_INFO)) { + new = rx_advance(lp, new); + goto no_data; + } + + pkt_len = p->env & LDC_LEN; + + /* Every initial packet starts with the START bit set. + * + * Singleton packets will have both START+STOP set. + * + * Fragments will have START set in the first frame, STOP + * set in the last frame, and neither bit set in middle + * frames of the packet. + * + * Therefore if we are at the beginning of a packet and + * we don't see START, or we are in the middle of a fragmented + * packet and do see START, we are unsynchronized and should + * flush the RX queue. + */ + if ((first_frag == NULL && !(p->env & LDC_START)) || + (first_frag != NULL && (p->env & LDC_START))) { + if (!first_frag) + new = rx_advance(lp, new); + + err = rx_set_head(lp, new); + if (err) + break; + + if (!first_frag) + goto no_data; + } + if (!first_frag) + first_frag = p; + + if (pkt_len > size - copied) { + /* User didn't give us a big enough buffer, + * what to do? This is a pretty serious error. + * + * Since we haven't updated the RX ring head to + * consume any of the packets, signal the error + * to the user and just leave the RX ring alone. + * + * This seems the best behavior because this allows + * a user of the LDC layer to start with a small + * RX buffer for ldc_read() calls and use -EMSGSIZE + * as a cue to enlarge it's read buffer. + */ + err = -EMSGSIZE; + break; + } + + /* Ok, we are gonna eat this one. */ + new = rx_advance(lp, new); + + memcpy(buf, + (lp->cfg.mode == LDC_MODE_UNRELIABLE ? + p->u.u_data : p->u.r.r_data), pkt_len); + buf += pkt_len; + copied += pkt_len; + + if (p->env & LDC_STOP) + break; + +no_data: + if (new == lp->rx_tail) { + err = rx_data_wait(lp, new); + if (err) + break; + } + } + + if (!err) + err = rx_set_head(lp, new); + + if (err && first_frag) + lp->rcv_nxt = first_frag->seqid - 1; + + if (!err) + err = copied; + + return err; +} + +static const struct ldc_mode_ops nonraw_ops = { + .write = write_nonraw, + .read = read_nonraw, +}; + +static int write_stream(struct ldc_channel *lp, const void *buf, + unsigned int size) +{ + if (size > lp->cfg.mtu) + size = lp->cfg.mtu; + return write_nonraw(lp, buf, size); +} + +static int read_stream(struct ldc_channel *lp, void *buf, unsigned int size) +{ + if (!lp->mssbuf_len) { + int err = read_nonraw(lp, lp->mssbuf, + (size > lp->cfg.mtu ? + lp->cfg.mtu : size)); + if (err < 0) + return err; + + lp->mssbuf_len = err; + lp->mssbuf_off = 0; + } + + if (size > lp->mssbuf_len) + size = lp->mssbuf_len; + memcpy(buf, lp->mssbuf + lp->mssbuf_off, size); + + lp->mssbuf_off += size; + lp->mssbuf_len -= size; + + return size; +} + +static const struct ldc_mode_ops stream_ops = { + .write = write_stream, + .read = read_stream, +}; + +int ldc_write(struct ldc_channel *lp, const void *buf, unsigned int size) +{ + unsigned long flags; + int err; + + if (!buf) + return -EINVAL; + + if (!size) + return 0; + + spin_lock_irqsave(&lp->lock, flags); + + if (lp->hs_state != LDC_HS_COMPLETE) + err = -ENOTCONN; + else + err = lp->mops->write(lp, buf, size); + + spin_unlock_irqrestore(&lp->lock, flags); + + return err; +} +EXPORT_SYMBOL(ldc_write); + +int ldc_read(struct ldc_channel *lp, void *buf, unsigned int size) +{ + unsigned long flags; + int err; + + if (!buf) + return -EINVAL; + + if (!size) + return 0; + + spin_lock_irqsave(&lp->lock, flags); + + if (lp->hs_state != LDC_HS_COMPLETE) + err = -ENOTCONN; + else + err = lp->mops->read(lp, buf, size); + + spin_unlock_irqrestore(&lp->lock, flags); + + return err; +} +EXPORT_SYMBOL(ldc_read); + +static long arena_alloc(struct ldc_iommu *iommu, unsigned long npages) +{ + struct iommu_arena *arena = &iommu->arena; + unsigned long n, i, start, end, limit; + int pass; + + limit = arena->limit; + start = arena->hint; + pass = 0; + +again: + n = find_next_zero_bit(arena->map, limit, start); + end = n + npages; + if (unlikely(end >= limit)) { + if (likely(pass < 1)) { + limit = start; + start = 0; + pass++; + goto again; + } else { + /* Scanned the whole thing, give up. */ + return -1; + } + } + + for (i = n; i < end; i++) { + if (test_bit(i, arena->map)) { + start = i + 1; + goto again; + } + } + + for (i = n; i < end; i++) + __set_bit(i, arena->map); + + arena->hint = end; + + return n; +} + +#define COOKIE_PGSZ_CODE 0xf000000000000000ULL +#define COOKIE_PGSZ_CODE_SHIFT 60ULL + +static u64 pagesize_code(void) +{ + switch (PAGE_SIZE) { + default: + case (8ULL * 1024ULL): + return 0; + case (64ULL * 1024ULL): + return 1; + case (512ULL * 1024ULL): + return 2; + case (4ULL * 1024ULL * 1024ULL): + return 3; + case (32ULL * 1024ULL * 1024ULL): + return 4; + case (256ULL * 1024ULL * 1024ULL): + return 5; + } +} + +static u64 make_cookie(u64 index, u64 pgsz_code, u64 page_offset) +{ + return ((pgsz_code << COOKIE_PGSZ_CODE_SHIFT) | + (index << PAGE_SHIFT) | + page_offset); +} + +static u64 cookie_to_index(u64 cookie, unsigned long *shift) +{ + u64 szcode = cookie >> COOKIE_PGSZ_CODE_SHIFT; + + cookie &= ~COOKIE_PGSZ_CODE; + + *shift = szcode * 3; + + return (cookie >> (13ULL + (szcode * 3ULL))); +} + +static struct ldc_mtable_entry *alloc_npages(struct ldc_iommu *iommu, + unsigned long npages) +{ + long entry; + + entry = arena_alloc(iommu, npages); + if (unlikely(entry < 0)) + return NULL; + + return iommu->page_table + entry; +} + +static u64 perm_to_mte(unsigned int map_perm) +{ + u64 mte_base; + + mte_base = pagesize_code(); + + if (map_perm & LDC_MAP_SHADOW) { + if (map_perm & LDC_MAP_R) + mte_base |= LDC_MTE_COPY_R; + if (map_perm & LDC_MAP_W) + mte_base |= LDC_MTE_COPY_W; + } + if (map_perm & LDC_MAP_DIRECT) { + if (map_perm & LDC_MAP_R) + mte_base |= LDC_MTE_READ; + if (map_perm & LDC_MAP_W) + mte_base |= LDC_MTE_WRITE; + if (map_perm & LDC_MAP_X) + mte_base |= LDC_MTE_EXEC; + } + if (map_perm & LDC_MAP_IO) { + if (map_perm & LDC_MAP_R) + mte_base |= LDC_MTE_IOMMU_R; + if (map_perm & LDC_MAP_W) + mte_base |= LDC_MTE_IOMMU_W; + } + + return mte_base; +} + +static int pages_in_region(unsigned long base, long len) +{ + int count = 0; + + do { + unsigned long new = (base + PAGE_SIZE) & PAGE_MASK; + + len -= (new - base); + base = new; + count++; + } while (len > 0); + + return count; +} + +struct cookie_state { + struct ldc_mtable_entry *page_table; + struct ldc_trans_cookie *cookies; + u64 mte_base; + u64 prev_cookie; + u32 pte_idx; + u32 nc; +}; + +static void fill_cookies(struct cookie_state *sp, unsigned long pa, + unsigned long off, unsigned long len) +{ + do { + unsigned long tlen, new = pa + PAGE_SIZE; + u64 this_cookie; + + sp->page_table[sp->pte_idx].mte = sp->mte_base | pa; + + tlen = PAGE_SIZE; + if (off) + tlen = PAGE_SIZE - off; + if (tlen > len) + tlen = len; + + this_cookie = make_cookie(sp->pte_idx, + pagesize_code(), off); + + off = 0; + + if (this_cookie == sp->prev_cookie) { + sp->cookies[sp->nc - 1].cookie_size += tlen; + } else { + sp->cookies[sp->nc].cookie_addr = this_cookie; + sp->cookies[sp->nc].cookie_size = tlen; + sp->nc++; + } + sp->prev_cookie = this_cookie + tlen; + + sp->pte_idx++; + + len -= tlen; + pa = new; + } while (len > 0); +} + +static int sg_count_one(struct scatterlist *sg) +{ + unsigned long base = page_to_pfn(sg->page) << PAGE_SHIFT; + long len = sg->length; + + if ((sg->offset | len) & (8UL - 1)) + return -EFAULT; + + return pages_in_region(base + sg->offset, len); +} + +static int sg_count_pages(struct scatterlist *sg, int num_sg) +{ + int count; + int i; + + count = 0; + for (i = 0; i < num_sg; i++) { + int err = sg_count_one(sg + i); + if (err < 0) + return err; + count += err; + } + + return count; +} + +int ldc_map_sg(struct ldc_channel *lp, + struct scatterlist *sg, int num_sg, + struct ldc_trans_cookie *cookies, int ncookies, + unsigned int map_perm) +{ + unsigned long i, npages, flags; + struct ldc_mtable_entry *base; + struct cookie_state state; + struct ldc_iommu *iommu; + int err; + + if (map_perm & ~LDC_MAP_ALL) + return -EINVAL; + + err = sg_count_pages(sg, num_sg); + if (err < 0) + return err; + + npages = err; + if (err > ncookies) + return -EMSGSIZE; + + iommu = &lp->iommu; + + spin_lock_irqsave(&iommu->lock, flags); + base = alloc_npages(iommu, npages); + spin_unlock_irqrestore(&iommu->lock, flags); + + if (!base) + return -ENOMEM; + + state.page_table = iommu->page_table; + state.cookies = cookies; + state.mte_base = perm_to_mte(map_perm); + state.prev_cookie = ~(u64)0; + state.pte_idx = (base - iommu->page_table); + state.nc = 0; + + for (i = 0; i < num_sg; i++) + fill_cookies(&state, page_to_pfn(sg[i].page) << PAGE_SHIFT, + sg[i].offset, sg[i].length); + + return state.nc; +} +EXPORT_SYMBOL(ldc_map_sg); + +int ldc_map_single(struct ldc_channel *lp, + void *buf, unsigned int len, + struct ldc_trans_cookie *cookies, int ncookies, + unsigned int map_perm) +{ + unsigned long npages, pa, flags; + struct ldc_mtable_entry *base; + struct cookie_state state; + struct ldc_iommu *iommu; + + if ((map_perm & ~LDC_MAP_ALL) || (ncookies < 1)) + return -EINVAL; + + pa = __pa(buf); + if ((pa | len) & (8UL - 1)) + return -EFAULT; + + npages = pages_in_region(pa, len); + + iommu = &lp->iommu; + + spin_lock_irqsave(&iommu->lock, flags); + base = alloc_npages(iommu, npages); + spin_unlock_irqrestore(&iommu->lock, flags); + + if (!base) + return -ENOMEM; + + state.page_table = iommu->page_table; + state.cookies = cookies; + state.mte_base = perm_to_mte(map_perm); + state.prev_cookie = ~(u64)0; + state.pte_idx = (base - iommu->page_table); + state.nc = 0; + fill_cookies(&state, (pa & PAGE_MASK), (pa & ~PAGE_MASK), len); + BUG_ON(state.nc != 1); + + return state.nc; +} +EXPORT_SYMBOL(ldc_map_single); + +static void free_npages(unsigned long id, struct ldc_iommu *iommu, + u64 cookie, u64 size) +{ + struct iommu_arena *arena = &iommu->arena; + unsigned long i, shift, index, npages; + struct ldc_mtable_entry *base; + + npages = PAGE_ALIGN(((cookie & ~PAGE_MASK) + size)) >> PAGE_SHIFT; + index = cookie_to_index(cookie, &shift); + base = iommu->page_table + index; + + BUG_ON(index > arena->limit || + (index + npages) > arena->limit); + + for (i = 0; i < npages; i++) { + if (base->cookie) + sun4v_ldc_revoke(id, cookie + (i << shift), + base->cookie); + base->mte = 0; + __clear_bit(index + i, arena->map); + } +} + +void ldc_unmap(struct ldc_channel *lp, struct ldc_trans_cookie *cookies, + int ncookies) +{ + struct ldc_iommu *iommu = &lp->iommu; + unsigned long flags; + int i; + + spin_lock_irqsave(&iommu->lock, flags); + for (i = 0; i < ncookies; i++) { + u64 addr = cookies[i].cookie_addr; + u64 size = cookies[i].cookie_size; + + free_npages(lp->id, iommu, addr, size); + } + spin_unlock_irqrestore(&iommu->lock, flags); +} +EXPORT_SYMBOL(ldc_unmap); + +int ldc_copy(struct ldc_channel *lp, int copy_dir, + void *buf, unsigned int len, unsigned long offset, + struct ldc_trans_cookie *cookies, int ncookies) +{ + unsigned int orig_len; + unsigned long ra; + int i; + + if (copy_dir != LDC_COPY_IN && copy_dir != LDC_COPY_OUT) { + printk(KERN_ERR PFX "ldc_copy: ID[%lu] Bad copy_dir[%d]\n", + lp->id, copy_dir); + return -EINVAL; + } + + ra = __pa(buf); + if ((ra | len | offset) & (8UL - 1)) { + printk(KERN_ERR PFX "ldc_copy: ID[%lu] Unaligned buffer " + "ra[%lx] len[%x] offset[%lx]\n", + lp->id, ra, len, offset); + return -EFAULT; + } + + if (lp->hs_state != LDC_HS_COMPLETE || + (lp->flags & LDC_FLAG_RESET)) { + printk(KERN_ERR PFX "ldc_copy: ID[%lu] Link down hs_state[%x] " + "flags[%x]\n", lp->id, lp->hs_state, lp->flags); + return -ECONNRESET; + } + + orig_len = len; + for (i = 0; i < ncookies; i++) { + unsigned long cookie_raddr = cookies[i].cookie_addr; + unsigned long this_len = cookies[i].cookie_size; + unsigned long actual_len; + + if (unlikely(offset)) { + unsigned long this_off = offset; + + if (this_off > this_len) + this_off = this_len; + + offset -= this_off; + this_len -= this_off; + if (!this_len) + continue; + cookie_raddr += this_off; + } + + if (this_len > len) + this_len = len; + + while (1) { + unsigned long hv_err; + + hv_err = sun4v_ldc_copy(lp->id, copy_dir, + cookie_raddr, ra, + this_len, &actual_len); + if (unlikely(hv_err)) { + printk(KERN_ERR PFX "ldc_copy: ID[%lu] " + "HV error %lu\n", + lp->id, hv_err); + if (lp->hs_state != LDC_HS_COMPLETE || + (lp->flags & LDC_FLAG_RESET)) + return -ECONNRESET; + else + return -EFAULT; + } + + cookie_raddr += actual_len; + ra += actual_len; + len -= actual_len; + if (actual_len == this_len) + break; + + this_len -= actual_len; + } + + if (!len) + break; + } + + /* It is caller policy what to do about short copies. + * For example, a networking driver can declare the + * packet a runt and drop it. + */ + + return orig_len - len; +} +EXPORT_SYMBOL(ldc_copy); + +void *ldc_alloc_exp_dring(struct ldc_channel *lp, unsigned int len, + struct ldc_trans_cookie *cookies, int *ncookies, + unsigned int map_perm) +{ + void *buf; + int err; + + if (len & (8UL - 1)) + return ERR_PTR(-EINVAL); + + buf = kzalloc(len, GFP_KERNEL); + if (!buf) + return ERR_PTR(-ENOMEM); + + err = ldc_map_single(lp, buf, len, cookies, *ncookies, map_perm); + if (err < 0) { + kfree(buf); + return ERR_PTR(err); + } + *ncookies = err; + + return buf; +} +EXPORT_SYMBOL(ldc_alloc_exp_dring); + +void ldc_free_exp_dring(struct ldc_channel *lp, void *buf, unsigned int len, + struct ldc_trans_cookie *cookies, int ncookies) +{ + ldc_unmap(lp, cookies, ncookies); + kfree(buf); +} +EXPORT_SYMBOL(ldc_free_exp_dring); + +static int __init ldc_init(void) +{ + struct mdesc_node *mp; + unsigned long major, minor; + const u64 *v; + + mp = md_find_node_by_name(NULL, "platform"); + if (!mp) + return -ENODEV; + + v = md_get_property(mp, "domaining-enabled", NULL); + if (!v) + return -ENODEV; + + major = 1; + minor = 0; + if (sun4v_hvapi_register(HV_GRP_LDOM, major, &minor)) { + printk(KERN_INFO PFX "Could not register LDOM hvapi.\n"); + return -ENODEV; + } + + printk(KERN_INFO "%s", version); + + if (!*v) { + printk(KERN_INFO PFX "Domaining disabled.\n"); + return -ENODEV; + } + ldom_domaining_enabled = 1; + + return 0; +} + +core_initcall(ldc_init); |