[PATCH v2 30/49] IB/hfi1: add pio handling

Mike Marciniszyn
2015-06-15T13:28:40Z

drivers/infiniband/hw/hfi1/pio.c | 1764 +++++++++++++++++++++++++++++++++
drivers/infiniband/hw/hfi1/pio.h | 224 ++++
drivers/infiniband/hw/hfi1/pio_copy.c | 867 ++++++++++++++++
3 files changed, 2855 insertions(+)
create mode 100644 drivers/infiniband/hw/hfi1/pio.c
create mode 100644 drivers/infiniband/hw/hfi1/pio.h
create mode 100644 drivers/infiniband/hw/hfi1/pio_copy.c

diff --git a/drivers/infiniband/hw/hfi1/pio.c b/drivers/infiniband/hw/hfi1/pio.c
new file mode 100644
index 0000000..6d89808
--- /dev/null
+++ b/drivers/infiniband/hw/hfi1/pio.c
@@ -0,0 +1,1764 @@
+/*
+ *
+ * This file is provided under a dual BSD/GPLv2 license. When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * GPL LICENSE SUMMARY
+ *
+ * Copyright(c) 2015 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * BSD LICENSE
+ *
+ * Copyright(c) 2015 Intel Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ * - Neither the name of Intel Corporation nor the names of its
+ * contributors may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <linux/delay.h>
+#include "hfi.h"
+#include "qp.h"
+#include "trace.h"
+
+#define SC_CTXT_PACKET_EGRESS_TIMEOUT 350 /* in chip cycles */
+
+#define SC(name) SEND_CTXT_##name
+/*
+ * Send Context functions
+ */
+static void sc_wait_for_packet_egress(struct send_context *sc, int pause);
+
+/*
+ * Set the CM reset bit and wait for it to clear. Use the provided
+ * sendctrl register. This routine has no locking.
+ */
+void __cm_reset(struct hfi1_devdata *dd, u64 sendctrl)
+{
+ write_csr(dd, SEND_CTRL, sendctrl | SEND_CTRL_CM_RESET_SMASK);
+ while (1) {
+ udelay(1);
+ sendctrl = read_csr(dd, SEND_CTRL);
+ if ((sendctrl & SEND_CTRL_CM_RESET_SMASK) == 0)
+ break;
+ }
+}
+
+/* defined in header release 48 and higher */
+#ifndef SEND_CTRL_UNSUPPORTED_VL_SHIFT
+#define SEND_CTRL_UNSUPPORTED_VL_SHIFT 3
+#define SEND_CTRL_UNSUPPORTED_VL_MASK 0xffull
+#define SEND_CTRL_UNSUPPORTED_VL_SMASK (SEND_CTRL_UNSUPPORTED_VL_MASK \
+ << SEND_CTRL_UNSUPPORTED_VL_SHIFT)
+#endif
+
+/* global control of PIO send */
+void pio_send_control(struct hfi1_devdata *dd, int op)
+{
+ u64 reg;
+ unsigned long flags;
+ int write = 1; /* write sendctrl back */
+ int flush = 0; /* re-read sendctrl to make sure it is flushed */
+
+ spin_lock_irqsave(&dd->sendctrl_lock, flags);
+
+ reg = read_csr(dd, SEND_CTRL);
+ switch (op) {
+ case PSC_GLOBAL_ENABLE:
+ reg |= SEND_CTRL_SEND_ENABLE_SMASK;
+ break;
+ case PSC_GLOBAL_DISABLE:
+ reg &= ~SEND_CTRL_SEND_ENABLE_SMASK;
+ break;
+ case PSC_GLOBAL_VLARB_ENABLE:
+ reg |= SEND_CTRL_VL_ARBITER_ENABLE_SMASK;
+ break;
+ case PSC_GLOBAL_VLARB_DISABLE:
+ reg &= ~SEND_CTRL_VL_ARBITER_ENABLE_SMASK;
+ break;
+ case PSC_CM_RESET:
+ __cm_reset(dd, reg);
+ write = 0; /* CSR already written (and flushed) */
+ break;
+ case PSC_DATA_VL_ENABLE:
+ reg &= ~SEND_CTRL_UNSUPPORTED_VL_SMASK;
+ break;
+ case PSC_DATA_VL_DISABLE:
+ reg |= SEND_CTRL_UNSUPPORTED_VL_SMASK;
+ flush = 1;
+ break;
+ default:
+ dd_dev_err(dd, "%s: invalid control %d\n", __func__, op);
+ break;
+ }
+
+ if (write) {
+ write_csr(dd, SEND_CTRL, reg);
+ if (flush)
+ (void) read_csr(dd, SEND_CTRL); /* flush write */
+ }
+
+ spin_unlock_irqrestore(&dd->sendctrl_lock, flags);
+}
+
+/* number of send context memory pools */
+#define NUM_SC_POOLS 2
+
+/* Send Context Size (SCS) wildcards */
+#define SCS_POOL_0 -1
+#define SCS_POOL_1 -2
+/* Send Context Count (SCC) wildcards */
+#define SCC_PER_VL -1
+#define SCC_PER_CPU -2
+
+#define SCC_PER_KRCVQ -3
+#define SCC_ACK_CREDITS 32
+
+#define PIO_WAIT_BATCH_SIZE 5
+
+/* default send context sizes */
+static struct sc_config_sizes sc_config_sizes[SC_MAX] = {
+ [SC_KERNEL] = { .size = SCS_POOL_0, /* even divide, pool 0 */
+ .count = SCC_PER_VL },/* one per NUMA */
+ [SC_ACK] = { .size = SCC_ACK_CREDITS,
+ .count = SCC_PER_KRCVQ },
+ [SC_USER] = { .size = SCS_POOL_0, /* even divide, pool 0 */
+ .count = SCC_PER_CPU }, /* one per CPU */
+
+};
+
+/* send context memory pool configuration */
+struct mem_pool_config {
+ int centipercent; /* % of memory, in 100ths of 1% */
+ int absolute_blocks; /* absolute block count */
+};
+
+/* default memory pool configuration: 100% in pool 0 */
+static struct mem_pool_config sc_mem_pool_config[NUM_SC_POOLS] = {
+ /* centi%, abs blocks */
+ { 10000, -1 }, /* pool 0 */
+ { 0, -1 }, /* pool 1 */
+};
+
+/* memory pool information, used when calculating final sizes */
+struct mem_pool_info {
+ int centipercent; /* 100th of 1% of memory to use, -1 if blocks
+ already set */
+ int count; /* count of contexts in the pool */
+ int blocks; /* block size of the pool */
+ int size; /* context size, in blocks */
+};
+
+/*
+ * Convert a pool wildcard to a valid pool index. The wildcards
+ * start at -1 and increase negatively. Map them as:
+ * -1 => 0
+ * -2 => 1
+ * etc.
+ *
+ * Return -1 on non-wildcard input, otherwise convert to a pool number.
+ */
+static int wildcard_to_pool(int wc)
+{
+ if (wc >= 0)
+ return -1; /* non-wildcard */
+ return -wc - 1;
+}
+
+static const char *sc_type_names[SC_MAX] = {
+ "kernel",
+ "ack",
+ "user"
+};
+
+static const char *sc_type_name(int index)
+{
+ if (index < 0 || index >= SC_MAX)
+ return "unknown";
+ return sc_type_names[index];
+}
+
+/*
+ * Read the send context memory pool configuration and send context
+ * size configuration. Replace any wildcards and come up with final
+ * counts and sizes for the send context types.
+ */
+int init_sc_pools_and_sizes(struct hfi1_devdata *dd)
+{
+ struct mem_pool_info mem_pool_info[NUM_SC_POOLS] = { { 0 } };
+ int total_blocks = (dd->chip_pio_mem_size / PIO_BLOCK_SIZE) - 1;
+ int total_contexts = 0;
+ int fixed_blocks;
+ int pool_blocks;
+ int used_blocks;
+ int cp_total; /* centipercent total */
+ int ab_total; /* absolute block total */
+ int extra;
+ int i;
+
+ /*
+ * Step 0:
+ * - copy the centipercents/absolute sizes from the pool config
+ * - sanity check these values
+ * - add up centipercents, then later check for full value
+ * - add up absolute blocks, then later check for over-commit
+ */
+ cp_total = 0;
+ ab_total = 0;
+ for (i = 0; i < NUM_SC_POOLS; i++) {
+ int cp = sc_mem_pool_config[i].centipercent;
+ int ab = sc_mem_pool_config[i].absolute_blocks;
+
+ /*
+ * A negative value is "unused" or "invalid". Both *can*
+ * be valid, but centipercent wins, so check that first
+ */
+ if (cp >= 0) { /* centipercent valid */
+ cp_total += cp;
+ } else if (ab >= 0) { /* absolute blocks valid */
+ ab_total += ab;
+ } else { /* neither valid */
+ dd_dev_err(
+ dd,
+ "Send context memory pool %d: both the block count and centipercent are invalid\n",
+ i);
+ return -EINVAL;
+ }
+
+ mem_pool_info[i].centipercent = cp;
+ mem_pool_info[i].blocks = ab;
+ }
+
+ /* do not use both % and absolute blocks for different pools */
+ if (cp_total != 0 && ab_total != 0) {
+ dd_dev_err(
+ dd,
+ "All send context memory pools must be described as either centipercent or blocks, no mixing between pools\n");
+ return -EINVAL;
+ }
+
+ /* if any percentages are present, they must add up to 100% x 100 */
+ if (cp_total != 0 && cp_total != 10000) {
+ dd_dev_err(
+ dd,
+ "Send context memory pool centipercent is %d, expecting 10000\n",
+ cp_total);
+ return -EINVAL;
+ }
+
+ /* the absolute pool total cannot be more than the mem total */
+ if (ab_total > total_blocks) {
+ dd_dev_err(
+ dd,
+ "Send context memory pool absolute block count %d is larger than the memory size %d\n",
+ ab_total, total_blocks);
+ return -EINVAL;
+ }
+
+ /*
+ * Step 2:
+ * - copy from the context size config
+ * - replace context type wildcard counts with real values
+ * - add up non-memory pool block sizes
+ * - add up memory pool user counts
+ */
+ fixed_blocks = 0;
+ for (i = 0; i < SC_MAX; i++) {
+ int count = sc_config_sizes[i].count;
+ int size = sc_config_sizes[i].size;
+ int pool;
+
+ /*
+ * Sanity check count: Either a positive value or
+ * one of the expected wildcards is valid. The positive
+ * value is checked later when we compare against total
+ * memory available.
+ */
+ if (i == SC_ACK) {
+ count = dd->n_krcv_queues;
+ } else if (i == SC_KERNEL) {
+ count = num_vls + 1 /* VL15 */;
+ } else if (count == SCC_PER_CPU) {
+ count = num_online_cpus();
+ } else if (count < 0) {
+ dd_dev_err(
+ dd,
+ "%s send context invalid count wildcard %d\n",
+ sc_type_name(i), count);
+ return -EINVAL;
+ }
+ if (total_contexts + count > dd->chip_send_contexts)
+ count = dd->chip_send_contexts - total_contexts;
+
+ total_contexts += count;
+
+ /*
+ * Sanity check pool: The conversion will return a pool
+ * number or -1 if a fixed (non-negative) value. The fixed
+ * value is checked later when we compare against
+ * total memory available.
+ */
+ pool = wildcard_to_pool(size);
+ if (pool == -1) { /* non-wildcard */
+ fixed_blocks += size * count;
+ } else if (pool < NUM_SC_POOLS) { /* valid wildcard */
+ mem_pool_info[pool].count += count;
+ } else { /* invalid wildcard */
+ dd_dev_err(
+ dd,
+ "%s send context invalid pool wildcard %d\n",
+ sc_type_name(i), size);
+ return -EINVAL;
+ }
+
+ dd->sc_sizes[i].count = count;
+ dd->sc_sizes[i].size = size;
+ }
+ if (fixed_blocks > total_blocks) {
+ dd_dev_err(
+ dd,
+ "Send context fixed block count, %u, larger than total block count %u\n",
+ fixed_blocks, total_blocks);
+ return -EINVAL;
+ }
+
+ /* step 3: calculate the blocks in the pools, and pool context sizes */
+ pool_blocks = total_blocks - fixed_blocks;
+ if (ab_total > pool_blocks) {
+ dd_dev_err(
+ dd,
+ "Send context fixed pool sizes, %u, larger than pool block count %u\n",
+ ab_total, pool_blocks);
+ return -EINVAL;
+ }
+ /* subtract off the fixed pool blocks */
+ pool_blocks -= ab_total;
+
+ for (i = 0; i < NUM_SC_POOLS; i++) {
+ struct mem_pool_info *pi = &mem_pool_info[i];
+
+ /* % beats absolute blocks */
+ if (pi->centipercent >= 0)
+ pi->blocks = (pool_blocks * pi->centipercent) / 10000;
+
+ if (pi->blocks == 0 && pi->count != 0) {
+ dd_dev_err(
+ dd,
+ "Send context memory pool %d has %u contexts, but no blocks\n",
+ i, pi->count);
+ return -EINVAL;
+ }
+ if (pi->count == 0) {
+ /* warn about wasted blocks */
+ if (pi->blocks != 0)
+ dd_dev_err(
+ dd,
+ "Send context memory pool %d has %u blocks, but zero contexts\n",
+ i, pi->blocks);
+ pi->size = 0;
+ } else {
+ pi->size = pi->blocks / pi->count;
+ }
+ }
+
+ /* step 4: fill in the context type sizes from the pool sizes */
+ used_blocks = 0;
+ for (i = 0; i < SC_MAX; i++) {
+ if (dd->sc_sizes[i].size < 0) {
+ unsigned pool = wildcard_to_pool(dd->sc_sizes[i].size);
+
+ BUG_ON(pool >= NUM_SC_POOLS);
+ dd->sc_sizes[i].size = mem_pool_info[pool].size;
+ }
+ /* make sure we are not larger than what is allowed by the HW */
+#define PIO_MAX_BLOCKS 1024
+ if (dd->sc_sizes[i].size > PIO_MAX_BLOCKS)
+ dd->sc_sizes[i].size = PIO_MAX_BLOCKS;
+
+ /* calculate our total usage */
+ used_blocks += dd->sc_sizes[i].size * dd->sc_sizes[i].count;
+ }
+ extra = total_blocks - used_blocks;
+ if (extra != 0)
+ dd_dev_info(dd, "unused send context blocks: %d\n", extra);
+
+ return total_contexts;
+}
+
+int init_send_contexts(struct hfi1_devdata *dd)
+{
+ u16 base;
+ int ret, i, j, context;
+
+ ret = init_credit_return(dd);
+ if (ret)
+ return ret;
+
+ dd->hw_to_sw = kmalloc_array(TXE_NUM_CONTEXTS, sizeof(u8),
+ GFP_KERNEL);
+ dd->send_contexts = kcalloc(dd->num_send_contexts,
+ sizeof(struct send_context_info),
+ GFP_KERNEL);
+ if (!dd->send_contexts || !dd->hw_to_sw) {
+ dd_dev_err(dd, "Unable to allocate send context arrays\n");
+ kfree(dd->hw_to_sw);
+ kfree(dd->send_contexts);
+ free_credit_return(dd);
+ return -ENOMEM;
+ }
+
+ /* hardware context map starts with invalid send context indices */
+ for (i = 0; i < TXE_NUM_CONTEXTS; i++)
+ dd->hw_to_sw[i] = INVALID_SCI;
+
+ /*
+ * All send contexts have their credit sizes. Allocate credits
+ * for each context one after another from the global space.
+ */
+ context = 0;
+ base = 1;
+ for (i = 0; i < SC_MAX; i++) {
+ struct sc_config_sizes *scs = &dd->sc_sizes[i];
+
+ for (j = 0; j < scs->count; j++) {
+ struct send_context_info *sci =
+ &dd->send_contexts[context];
+ sci->type = i;
+ sci->base = base;
+ sci->credits = scs->size;
+
+ context++;
+ base += scs->size;
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * Allocate a software index and hardware context of the given type.
+ *
+ * Must be called with dd->sc_lock held.
+ */
+static int sc_hw_alloc(struct hfi1_devdata *dd, int type, u32 *sw_index,
+ u32 *hw_context)
+{
+ struct send_context_info *sci;
+ u32 index;
+ u32 context;
+
+ for (index = 0, sci = &dd->send_contexts[0];
+ index < dd->num_send_contexts; index++, sci++) {
+ if (sci->type == type && sci->allocated == 0) {
+ sci->allocated = 1;
+ /* use a 1:1 mapping, but make them non-equal */
+ context = dd->chip_send_contexts - index - 1;
+ dd->hw_to_sw[context] = index;
+ *sw_index = index;
+ *hw_context = context;
+ return 0; /* success */
+ }
+ }
+ dd_dev_err(dd, "Unable to locate a free type %d send context\n", type);
+ return -ENOSPC;
+}
+
+/*
+ * Free the send context given by its software index.
+ *
+ * Must be called with dd->sc_lock held.
+ */
+static void sc_hw_free(struct hfi1_devdata *dd, u32 sw_index, u32 hw_context)
+{
+ struct send_context_info *sci;
+
+ sci = &dd->send_contexts[sw_index];
+ if (!sci->allocated) {
+ dd_dev_err(dd, "%s: sw_index %u not allocated? hw_context %u\n",
+ __func__, sw_index, hw_context);
+ }
+ sci->allocated = 0;
+ dd->hw_to_sw[hw_context] = INVALID_SCI;
+}
+
+/* return the base context of a context in a group */
+static inline u32 group_context(u32 context, u32 group)
+{
+ return (context >> group) << group;
+}
+
+/* return the size of a group */
+static inline u32 group_size(u32 group)
+{
+ return 1 << group;
+}
+
+/*
+ * Obtain the credit return addresses, kernel virtual and physical, for the
+ * given sc.
+ *
+ * To understand this routine:
+ * o va and pa are arrays of struct credit_return. One for each physical
+ * send context, per NUMA.
+ * o Each send context always looks in its relative location in a struct
+ * credit_return for its credit return.
+ * o Each send context in a group must have its return address CSR programmed
+ * with the same value. Use the address of the first send context in the
+ * group.
+ */
+static void cr_group_addresses(struct send_context *sc, dma_addr_t *pa)
+{
+ u32 gc = group_context(sc->hw_context, sc->group);
+ u32 index = sc->hw_context & 0x7;
+
+ sc->hw_free = &sc->dd->cr_base[sc->node].va[gc].cr[index];
+ *pa = (unsigned long)
+ &((struct credit_return *)sc->dd->cr_base[sc->node].pa)[gc];
+}
+
+/*
+ * Work queue function triggered in error interrupt routine for
+ * kernel contexts.
+ */
+static void sc_halted(struct work_struct *work)
+{
+ struct send_context *sc;
+
+ sc = container_of(work, struct send_context, halt_work);
+ sc_restart(sc);
+}
+
+/*
+ * Calculate PIO block threshold for this send context using the given MTU.
+ * Trigger a return when one MTU plus optional header of credits remain.
+ *
+ * Parameter mtu is in bytes.
+ * Parameter hdrqentsize is in DWORDs.
+ *
+ * Return value is what to write into the CSR: trigger return when
+ * unreturned credits pass this count.
+ */
+u32 sc_mtu_to_threshold(struct send_context *sc, u32 mtu, u32 hdrqentsize)
+{
+ u32 release_credits;
+ u32 threshold;
+
+ /* add in the header size, then divide by the PIO block size */
+ mtu += hdrqentsize << 2;
+ release_credits = DIV_ROUND_UP(mtu, PIO_BLOCK_SIZE);
+
+ /* check against this context's credits */
+ if (sc->credits <= release_credits)
+ threshold = 1;
+ else
+ threshold = sc->credits - release_credits;
+
+ return threshold;
+}
+
+/*
+ * Calculate credit threshold in terms of percent of the allocated credits.
+ * Trigger when unreturned credits equal or exceed the percentage of the whole.
+ *
+ * Return value is what to write into the CSR: trigger return when
+ * unreturned credits pass this count.
+ */
+static u32 sc_percent_to_threshold(struct send_context *sc, u32 percent)
+{
+ return (sc->credits * percent) / 100;
+}
+
+/*
+ * Set the credit return threshold.
+ */
+void sc_set_cr_threshold(struct send_context *sc, u32 new_threshold)
+{
+ unsigned long flags;
+ u32 old_threshold;
+ int force_return = 0;
+
+ spin_lock_irqsave(&sc->credit_ctrl_lock, flags);
+
+ old_threshold = (sc->credit_ctrl >>
+ SC(CREDIT_CTRL_THRESHOLD_SHIFT))
+ & SC(CREDIT_CTRL_THRESHOLD_MASK);
+
+ if (new_threshold != old_threshold) {
+ sc->credit_ctrl =
+ (sc->credit_ctrl
+ & ~SC(CREDIT_CTRL_THRESHOLD_SMASK))
+ | ((new_threshold
+ & SC(CREDIT_CTRL_THRESHOLD_MASK))
+ << SC(CREDIT_CTRL_THRESHOLD_SHIFT));
+ write_kctxt_csr(sc->dd, sc->hw_context,
+ SC(CREDIT_CTRL), sc->credit_ctrl);
+
+ /* force a credit return on change to avoid a possible stall */
+ force_return = 1;
+ }
+
+ spin_unlock_irqrestore(&sc->credit_ctrl_lock, flags);
+
+ if (force_return)
+ sc_return_credits(sc);
+}
+
+/*
+ * set_pio_integrity
+ *
+ * Set the CHECK_ENABLE register for the send context 'sc'.
+ */
+void set_pio_integrity(struct send_context *sc)
+{
+ struct hfi1_devdata *dd = sc->dd;
+ u64 reg = 0;
+ u32 hw_context = sc->hw_context;
+ int type = sc->type;
+
+ /*
+ * No integrity checks if HFI1_CAP_NO_INTEGRITY is set, or if
+ * we're snooping.
+ */
+ if (likely(!HFI1_CAP_IS_KSET(NO_INTEGRITY)) &&
+ dd->hfi1_snoop.mode_flag != HFI1_PORT_SNOOP_MODE)
+ reg = hfi1_pkt_default_send_ctxt_mask(dd, type);
+
+ write_kctxt_csr(dd, hw_context, SC(CHECK_ENABLE), reg);
+}
+
+/*
+ * Allocate a NUMA relative send context structure of the given type along
+ * with a HW context.
+ */
+struct send_context *sc_alloc(struct hfi1_devdata *dd, int type,
+ uint hdrqentsize, int numa)
+{
+ struct send_context_info *sci;
+ struct send_context *sc;
+ dma_addr_t pa;
+ unsigned long flags;
+ u64 reg;
+ u32 thresh;
+ u32 sw_index;
+ u32 hw_context;
+ int ret;
+ u8 opval, opmask;
+
+ /* do not allocate while frozen */
+ if (dd->flags & HFI1_FROZEN)
+ return NULL;
+
+ sc = kzalloc_node(sizeof(struct send_context), GFP_KERNEL, numa);
+ if (!sc) {
+ dd_dev_err(dd, "Cannot allocate send context structure\n");
+ return NULL;
+ }
+
+ spin_lock_irqsave(&dd->sc_lock, flags);
+ ret = sc_hw_alloc(dd, type, &sw_index, &hw_context);
+ if (ret) {
+ spin_unlock_irqrestore(&dd->sc_lock, flags);
+ kfree(sc);
+ return NULL;
+ }
+
+ sci = &dd->send_contexts[sw_index];
+ sci->sc = sc;
+
+ sc->dd = dd;
+ sc->node = numa;
+ sc->type = type;
+ spin_lock_init(&sc->alloc_lock);
+ spin_lock_init(&sc->release_lock);
+ spin_lock_init(&sc->credit_ctrl_lock);
+ INIT_LIST_HEAD(&sc->piowait);
+ INIT_WORK(&sc->halt_work, sc_halted);
+ atomic_set(&sc->buffers_allocated, 0);
+ init_waitqueue_head(&sc->halt_wait);
+
+ /* grouping is always single context for now */
+ sc->group = 0;
+
+ sc->sw_index = sw_index;
+ sc->hw_context = hw_context;
+ cr_group_addresses(sc, &pa);
+ sc->credits = sci->credits;
+
+/* PIO Send Memory Address details */
+#define PIO_ADDR_CONTEXT_MASK 0xfful
+#define PIO_ADDR_CONTEXT_SHIFT 16
+ sc->base_addr = dd->piobase + ((hw_context & PIO_ADDR_CONTEXT_MASK)
+ << PIO_ADDR_CONTEXT_SHIFT);
+
+ /* set base and credits */
+ reg = ((sci->credits & SC(CTRL_CTXT_DEPTH_MASK))
+ << SC(CTRL_CTXT_DEPTH_SHIFT))
+ | ((sci->base & SC(CTRL_CTXT_BASE_MASK))
+ << SC(CTRL_CTXT_BASE_SHIFT));
+ write_kctxt_csr(dd, hw_context, SC(CTRL), reg);
+
+ set_pio_integrity(sc);
+
+ /* unmask all errors */
+ write_kctxt_csr(dd, hw_context, SC(ERR_MASK), (u64)-1);
+
+ /* set the default partition key */
+ write_kctxt_csr(dd, hw_context, SC(CHECK_PARTITION_KEY),
+ (DEFAULT_PKEY &
+ SC(CHECK_PARTITION_KEY_VALUE_MASK))
+ << SC(CHECK_PARTITION_KEY_VALUE_SHIFT));
+
+ /* per context type checks */
+ if (type == SC_USER) {
+ opval = USER_OPCODE_CHECK_VAL;
+ opmask = USER_OPCODE_CHECK_MASK;
+ } else {
+ opval = OPCODE_CHECK_VAL_DISABLED;
+ opmask = OPCODE_CHECK_MASK_DISABLED;
+ }
+
+ /* set the send context check opcode mask and value */
+ write_kctxt_csr(dd, hw_context, SC(CHECK_OPCODE),
+ ((u64)opmask << SC(CHECK_OPCODE_MASK_SHIFT)) |
+ ((u64)opval << SC(CHECK_OPCODE_VALUE_SHIFT)));
+
+ /* set up credit return */
+ reg = pa & SC(CREDIT_RETURN_ADDR_ADDRESS_SMASK);
+ write_kctxt_csr(dd, hw_context, SC(CREDIT_RETURN_ADDR), reg);
+
+ /*
+ * Calculate the initial credit return threshold.
+ *
+ * For Ack contexts, set a threshold for half the credits.
+ * For User contexts use the given percentage. This has been
+ * sanitized on driver start-up.
+ * For Kernel contexts, use the default MTU plus a header.
+ */
+ if (type == SC_ACK) {
+ thresh = sc_percent_to_threshold(sc, 50);
+ } else if (type == SC_USER) {
+ thresh = sc_percent_to_threshold(sc,
+ user_credit_return_threshold);
+ } else { /* kernel */
+ thresh = sc_mtu_to_threshold(sc, hfi1_max_mtu, hdrqentsize);
+ }
+ reg = thresh << SC(CREDIT_CTRL_THRESHOLD_SHIFT);
+ /* add in early return */
+ if (type == SC_USER && HFI1_CAP_IS_USET(EARLY_CREDIT_RETURN))
+ reg |= SC(CREDIT_CTRL_EARLY_RETURN_SMASK);
+ else if (HFI1_CAP_IS_KSET(EARLY_CREDIT_RETURN)) /* kernel, ack */
+ reg |= SC(CREDIT_CTRL_EARLY_RETURN_SMASK);
+
+ /* set up write-through credit_ctrl */
+ sc->credit_ctrl = reg;
+ write_kctxt_csr(dd, hw_context, SC(CREDIT_CTRL), reg);
+
+ spin_unlock_irqrestore(&dd->sc_lock, flags);
+
+ /*
+ * Allocate shadow ring to track outstanding PIO buffers _after_
+ * unlocking. We don't know the size until the lock is held and
+ * we can't allocate while the lock is held. No one is using
+ * the context yet, so allocate it now.
+ *
+ * User contexts do not get a shadow ring.
+ */
+ if (type != SC_USER) {
+ /*
+ * Size the shadow ring 1 larger than the number of credits
+ * so head == tail can mean empty.
+ */
+ sc->sr_size = sci->credits + 1;
+ sc->sr = kzalloc_node(sizeof(union pio_shadow_ring) *
+ sc->sr_size, GFP_KERNEL, numa);
+ if (!sc->sr) {
+ dd_dev_err(dd,
+ "Cannot allocate send context shadow ring structure\n");
+ sc_free(sc);
+ return NULL;
+ }
+ }
+
+ dd_dev_info(dd,
+ "Send context %u(%u) %s group %u credits %u credit_ctrl 0x%llx threshold %u\n",
+ sw_index,
+ hw_context,
+ sc_type_name(type),
+ sc->group,
+ sc->credits,
+ sc->credit_ctrl,
+ thresh);
+
+ return sc;
+}
+
+/* free a per-NUMA send context structure */
+void sc_free(struct send_context *sc)
+{
+ struct hfi1_devdata *dd;
+ unsigned long flags;
+ u32 sw_index;
+ u32 hw_context;
+
+ if (!sc)
+ return;
+
+ sc->flags |= SCF_IN_FREE; /* ensure no restarts */
+ dd = sc->dd;
+ if (!list_empty(&sc->piowait))
+ dd_dev_err(dd, "piowait list not empty!\n");
+ sw_index = sc->sw_index;
+ hw_context = sc->hw_context;
+ sc_disable(sc); /* make sure the HW is disabled */
+ flush_work(&sc->halt_work);
+
+ spin_lock_irqsave(&dd->sc_lock, flags);
+ dd->send_contexts[sw_index].sc = NULL;
+
+ /* clear/disable all registers set in sc_alloc */
+ write_kctxt_csr(dd, hw_context, SC(CTRL), 0);
+ write_kctxt_csr(dd, hw_context, SC(CHECK_ENABLE), 0);
+ write_kctxt_csr(dd, hw_context, SC(ERR_MASK), 0);
+ write_kctxt_csr(dd, hw_context, SC(CHECK_PARTITION_KEY), 0);
+ write_kctxt_csr(dd, hw_context, SC(CHECK_OPCODE), 0);
+ write_kctxt_csr(dd, hw_context, SC(CREDIT_RETURN_ADDR), 0);
+ write_kctxt_csr(dd, hw_context, SC(CREDIT_CTRL), 0);
+
+ /* release the index and context for re-use */
+ sc_hw_free(dd, sw_index, hw_context);
+ spin_unlock_irqrestore(&dd->sc_lock, flags);
+
+ kfree(sc->sr);
+ kfree(sc);
+}
+
+/* disable the context */
+void sc_disable(struct send_context *sc)
+{
+ u64 reg;
+ unsigned long flags;
+ struct pio_buf *pbuf;
+
+ if (!sc)
+ return;
+
+ /* do all steps, even if already disabled */
+ spin_lock_irqsave(&sc->alloc_lock, flags);
+ reg = read_kctxt_csr(sc->dd, sc->hw_context, SC(CTRL));
+ reg &= ~SC(CTRL_CTXT_ENABLE_SMASK);
+ sc->flags &= ~SCF_ENABLED;
+ sc_wait_for_packet_egress(sc, 1);
+ write_kctxt_csr(sc->dd, sc->hw_context, SC(CTRL), reg);
+ spin_unlock_irqrestore(&sc->alloc_lock, flags);
+
+ /*
+ * Flush any waiters. Once the context is disabled,
+ * credit return interrupts are stopped (although there
+ * could be one in-process when the context is disabled).
+ * Wait one microsecond for any lingering interrupts, then
+ * proceed with the flush.
+ */
+ udelay(1);
+ spin_lock_irqsave(&sc->release_lock, flags);
+ if (sc->sr) { /* this context has a shadow ring */
+ while (sc->sr_tail != sc->sr_head) {
+ pbuf = &sc->sr[sc->sr_tail].pbuf;
+ if (pbuf->cb)
+ (*pbuf->cb)(pbuf->arg, PRC_SC_DISABLE);
+ sc->sr_tail++;
+ if (sc->sr_tail >= sc->sr_size)
+ sc->sr_tail = 0;
+ }
+ }
+ spin_unlock_irqrestore(&sc->release_lock, flags);
+}
+
+/* return SendEgressCtxtStatus.PacketOccupancy */
+#define packet_occupancy(r) \
+ (((r) & SEND_EGRESS_CTXT_STATUS_CTXT_EGRESS_PACKET_OCCUPANCY_SMASK)\
+ >> SEND_EGRESS_CTXT_STATUS_CTXT_EGRESS_PACKET_OCCUPANCY_SHIFT)
+
+/* is egress halted on the context? */
+#define egress_halted(r) \
+ ((r) & SEND_EGRESS_CTXT_STATUS_CTXT_EGRESS_HALT_STATUS_SMASK)
+
+/* wait for packet egress, optionally pause for credit return */
+static void sc_wait_for_packet_egress(struct send_context *sc, int pause)
+{
+ struct hfi1_devdata *dd = sc->dd;
+ u64 reg;
+ u32 loop = 0;
+
+ while (1) {
+ reg = read_csr(dd, sc->hw_context * 8 +
+ SEND_EGRESS_CTXT_STATUS);
+ /* done if egress is stopped */
+ if (egress_halted(reg))
+ break;
+ reg = packet_occupancy(reg);
+ if (reg == 0)
+ break;
+ if (loop > 100) {
+ dd_dev_err(dd,
+ "%s: context %u(%u) timeout waiting for packets to egress, remaining count %u\n",
+ __func__, sc->sw_index,
+ sc->hw_context, (u32)reg);
+ break;
+ }
+ loop++;
+ udelay(1);
+ }
+
+ if (pause)
+ /* Add additional delay to ensure chip returns all credits */
+ pause_for_credit_return(dd);
+}
+
+void sc_wait(struct hfi1_devdata *dd)
+{
+ int i;
+
+ for (i = 0; i < dd->num_send_contexts; i++) {
+ struct send_context *sc = dd->send_contexts[i].sc;
+
+ if (!sc)
+ continue;
+ sc_wait_for_packet_egress(sc, 0);
+ }
+}
+
+/*
+ * Restart a context after it has been halted due to error.
+ *
+ * If the first step fails - wait for the halt to be asserted, return early.
+ * Otherwise complain about timeouts but keep going.
+ *
+ * It is expected that allocations (enabled flag bit) have been shut off
+ * already (only applies to kernel contexts).
+ */
+int sc_restart(struct send_context *sc)
+{
+ struct hfi1_devdata *dd = sc->dd;
+ u64 reg;
+ u32 loop;
+ int count;
+
+ /* bounce off if not halted, or being free'd */
+ if (!(sc->flags & SCF_HALTED) || (sc->flags & SCF_IN_FREE))
+ return -EINVAL;
+
+ dd_dev_info(dd, "restarting send context %u(%u)\n", sc->sw_index,
+ sc->hw_context);
+
+ /*
+ * Step 1: Wait for the context to actually halt.
+ *
+ * The error interrupt is asynchronous to actually setting halt
+ * on the context.
+ */
+ loop = 0;
+ while (1) {
+ reg = read_kctxt_csr(dd, sc->hw_context, SC(STATUS));
+ if (reg & SC(STATUS_CTXT_HALTED_SMASK))
+ break;
+ if (loop > 100) {
+ dd_dev_err(dd, "%s: context %u(%u) not halting, skipping\n",
+ __func__, sc->sw_index, sc->hw_context);
+ return -ETIME;
+ }
+ loop++;
+ udelay(1);
+ }
+
+ /*
+ * Step 2: Ensure no users are still trying to write to PIO.
+ *
+ * For kernel contexts, we have already turned off buffer allocation.
+ * Now wait for the buffer count to go to zero.
+ *
+ * For user contexts, the user handling code has cut off write access
+ * to the context's PIO pages before calling this routine and will
+ * restore write access after this routine returns.
+ */
+ if (sc->type != SC_USER) {
+ /* kernel context */
+ loop = 0;
+ while (1) {
+ count = atomic_read(&sc->buffers_allocated);
+ if (count == 0)
+ break;
+ if (loop > 100) {
+ dd_dev_err(dd,
+ "%s: context %u(%u) timeout waiting for PIO buffers to zero, remaining %d\n",
+ __func__, sc->sw_index,
+ sc->hw_context, count);
+ }
+ loop++;
+ udelay(1);
+ }
+ }
+
+ /*
+ * Step 3: Wait for all packets to egress.
+ * This is done while disabling the send context
+ *
+ * Step 4: Disable the context
+ *
+ * This is a superset of the halt. After the disable, the
+ * errors can be cleared.
+ */
+ sc_disable(sc);
+
+ /*
+ * Step 5: Enable the context
+ *
+ * This enable will clear the halted flag and per-send context
+ * error flags.
+ */
+ return sc_enable(sc);
+}
+
+/*
+ * PIO freeze processing. To be called after the TXE block is fully frozen.
+ * Go through all frozen send contexts and disable them. The contexts are
+ * already stopped by the freeze.
+ */
+void pio_freeze(struct hfi1_devdata *dd)
+{
+ struct send_context *sc;
+ int i;
+
+ for (i = 0; i < dd->num_send_contexts; i++) {
+ sc = dd->send_contexts[i].sc;
+ /*
+ * Don't disable unallocated, unfrozen, or user send contexts.
+ * User send contexts will be disabled when the process
+ * calls into the driver to reset its context.
+ */
+ if (!sc || !(sc->flags & SCF_FROZEN) || sc->type == SC_USER)
+ continue;
+
+ /* only need to disable, the context is already stopped */
+ sc_disable(sc);
+ }
+}
+
+/*
+ * Unfreeze PIO for kernel send contexts. The precondition for calling this
+ * is that all PIO send contexts have been disabled and the SPC freeze has
+ * been cleared. Now perform the last step and re-enable each kernel context.
+ * User (PSM) processing will occur when PSM calls into the kernel to
+ * acknowledge the freeze.
+ */
+void pio_kernel_unfreeze(struct hfi1_devdata *dd)
+{
+ struct send_context *sc;
+ int i;
+
+ for (i = 0; i < dd->num_send_contexts; i++) {
+ sc = dd->send_contexts[i].sc;
+ if (!sc || !(sc->flags & SCF_FROZEN) || sc->type == SC_USER)
+ continue;
+
+ sc_enable(sc); /* will clear the sc frozen flag */
+ }
+}
+
+/*
+ * Wait for the SendPioInitCtxt.PioInitInProgress bit to clear.
+ * Returns:
+ * -ETIMEDOUT - if we wait too long
+ * -EIO - if there was an error
+ */
+static int pio_init_wait_progress(struct hfi1_devdata *dd)
+{
+ u64 reg;
+ int count = 0;
+
+ while (1) {
+ reg = read_csr(dd, SEND_PIO_INIT_CTXT);
+ if (!(reg & SEND_PIO_INIT_CTXT_PIO_INIT_IN_PROGRESS_SMASK))
+ break;
+ mdelay(20);
+ if (count++ > 10)
+ return -ETIMEDOUT;
+ }
+
+ return reg & SEND_PIO_INIT_CTXT_PIO_INIT_ERR_SMASK ? -EIO : 0;
+}
+
+/*
+ * Reset all of the send contexts to their power-on state. Used
+ * only during manual init - no lock against sc_enable needed.
+ */
+void pio_reset_all(struct hfi1_devdata *dd)
+{
+ int ret;
+
+ /* make sure the init engine is not busy */
+ ret = pio_init_wait_progress(dd);
+ if (ret == -ETIMEDOUT) {
+ dd_dev_err(dd,
+ "PIO send context init is stuck, not initializing PIO blocks\n");
+ return;
+ }
+
+ if (ret == -EIO) {
+ /* clear the error */
+ write_csr(dd, SEND_PIO_ERR_CLEAR,
+ SEND_PIO_ERR_CLEAR_PIO_INIT_SM_IN_ERR_SMASK);
+ }
+
+ /* reset init all */
+ write_csr(dd, SEND_PIO_INIT_CTXT,
+ SEND_PIO_INIT_CTXT_PIO_ALL_CTXT_INIT_SMASK);
+ udelay(2);
+ ret = pio_init_wait_progress(dd);
+ if (ret < 0) {
+ dd_dev_err(dd,
+ "PIO send context init %s while initializing all PIO blocks\n",
+ ret == -ETIMEDOUT ? "is stuck" : "had an error");
+ }
+}
+
+/* enable the context */
+int sc_enable(struct send_context *sc)
+{
+ u64 sc_ctrl, reg, pio;
+ struct hfi1_devdata *dd;
+ unsigned long flags;
+ int ret = 0;
+
+ if (!sc)
+ return -EINVAL;
+ dd = sc->dd;
+
+ /*
+ * Obtain the allocator lock to guard against any allocation
+ * attempts (which should not happen prior to context being
+ * enabled). On the release/disable side we don't need to
+ * worry about locking since the releaser will not do anything
+ * if the context accounting values have not changed.
+ */
+ spin_lock_irqsave(&sc->alloc_lock, flags);
+ sc_ctrl = read_kctxt_csr(dd, sc->hw_context, SC(CTRL));
+ if ((sc_ctrl & SC(CTRL_CTXT_ENABLE_SMASK)))
+ goto unlock; /* already enabled */
+
+ /* IMPORTANT: only clear free and fill if transitioning 0 -> 1 */
+
+ *sc->hw_free = 0;
+ sc->free = 0;
+ sc->alloc_free = 0;
+ sc->fill = 0;
+ sc->sr_head = 0;
+ sc->sr_tail = 0;
+ sc->flags = 0;
+ atomic_set(&sc->buffers_allocated, 0);
+
+ /*
+ * Clear all per-context errors. Some of these will be set when
+ * we are re-enabling after a context halt. Now that the context
+ * is disabled, the halt will not clear until after the PIO init
+ * engine runs below.
+ */
+ reg = read_kctxt_csr(dd, sc->hw_context, SC(ERR_STATUS));
+ if (reg)
+ write_kctxt_csr(dd, sc->hw_context, SC(ERR_CLEAR),
+ reg);
+
+ /*
+ * The HW PIO initialization engine can handle only one init
+ * request at a time. Serialize access to each device's engine.
+ */
+ spin_lock(&dd->sc_init_lock);
+ /*
+ * Since access to this code block is serialized and
+ * each access waits for the initialization to complete
+ * before releasing the lock, the PIO initialization engine
+ * should not be in use, so we don't have to wait for the
+ * InProgress bit to go down.
+ */
+ pio = ((sc->hw_context & SEND_PIO_INIT_CTXT_PIO_CTXT_NUM_MASK) <<
+ SEND_PIO_INIT_CTXT_PIO_CTXT_NUM_SHIFT) |
+ SEND_PIO_INIT_CTXT_PIO_SINGLE_CTXT_INIT_SMASK;
+ write_csr(dd, SEND_PIO_INIT_CTXT, pio);
+ /*
+ * Wait until the engine is done. Give the chip the required time
+ * so, hopefully, we read the register just once.
+ */
+ udelay(2);
+ ret = pio_init_wait_progress(dd);
+ spin_unlock(&dd->sc_init_lock);
+ if (ret) {
+ dd_dev_err(dd,
+ "sctxt%u(%u): Context not enabled due to init failure %d\n",
+ sc->sw_index, sc->hw_context, ret);
+ goto unlock;
+ }
+
+ /*
+ * All is well. Enable the context.
+ */
+ sc_ctrl |= SC(CTRL_CTXT_ENABLE_SMASK);
+ write_kctxt_csr(dd, sc->hw_context, SC(CTRL), sc_ctrl);
+ /*
+ * Read SendCtxtCtrl to force the write out and prevent a timing
+ * hazard where a PIO write may reach the context before the enable.
+ */
+ read_kctxt_csr(dd, sc->hw_context, SC(CTRL));
+ sc->flags |= SCF_ENABLED;
+
+unlock:
+ spin_unlock_irqrestore(&sc->alloc_lock, flags);
+
+ return ret;
+}
+
+/* force a credit return on the context */
+void sc_return_credits(struct send_context *sc)
+{
+ if (!sc)
+ return;
+
+ /* a 0->1 transition schedules a credit return */
+ write_kctxt_csr(sc->dd, sc->hw_context, SC(CREDIT_FORCE),
+ SC(CREDIT_FORCE_FORCE_RETURN_SMASK));
+ /*
+ * Ensure that the write is flushed and the credit return is
+ * scheduled. We care more about the 0 -> 1 transition.
+ */
+ read_kctxt_csr(sc->dd, sc->hw_context, SC(CREDIT_FORCE));
+ /* set back to 0 for next time */
+ write_kctxt_csr(sc->dd, sc->hw_context, SC(CREDIT_FORCE), 0);
+}
+
+/* allow all in-flight packets to drain on the context */
+void sc_flush(struct send_context *sc)
+{
+ if (!sc)
+ return;
+
+ sc_wait_for_packet_egress(sc, 1);
+}
+
+/* drop all packets on the context, no waiting until they are sent */
+void sc_drop(struct send_context *sc)
+{
+ if (!sc)
+ return;
+
+ dd_dev_info(sc->dd, "%s: context %u(%u) - not implemented\n",
+ __func__, sc->sw_index, sc->hw_context);
+}
+
+/*
+ * Start the software reaction to a context halt or SPC freeze:
+ * - mark the context as halted or frozen
+ * - stop buffer allocations
+ *
+ * Called from the error interrupt. Other work is deferred until
+ * out of the interrupt.
+ */
+void sc_stop(struct send_context *sc, int flag)
+{
+ unsigned long flags;
+
+ /* mark the context */
+ sc->flags |= flag;
+
+ /* stop buffer allocations */
+ spin_lock_irqsave(&sc->alloc_lock, flags);
+ sc->flags &= ~SCF_ENABLED;
+ spin_unlock_irqrestore(&sc->alloc_lock, flags);
+ wake_up(&sc->halt_wait);
+}
+
+#define BLOCK_DWORDS (PIO_BLOCK_SIZE/sizeof(u32))
+#define dwords_to_blocks(x) DIV_ROUND_UP(x, BLOCK_DWORDS)
+
+/*
+ * The send context buffer "allocator".
+ *
+ * @sc: the PIO send context we are allocating from
+ * @len: length of whole packet - including PBC - in dwords
+ * @cb: optional callback to call when the buffer is finished sending
+ * @arg: argument for cb
+ *
+ * Return a pointer to a PIO buffer if successful, NULL if not enough room.
+ */
+struct pio_buf *sc_buffer_alloc(struct send_context *sc, u32 dw_len,
+ pio_release_cb cb, void *arg)
+{
+ struct pio_buf *pbuf = NULL;
+ unsigned long flags;
+ unsigned long avail;
+ unsigned long blocks = dwords_to_blocks(dw_len);
+ unsigned long start_fill;
+ int trycount = 0;
+ u32 head, next;
+
+ spin_lock_irqsave(&sc->alloc_lock, flags);
+ if (!(sc->flags & SCF_ENABLED)) {
+ spin_unlock_irqrestore(&sc->alloc_lock, flags);
+ goto done;
+ }
+
+retry:
+ avail = (unsigned long)sc->credits - (sc->fill - sc->alloc_free);
+ if (blocks > avail) {
+ /* not enough room */
+ if (unlikely(trycount)) { /* already tried to get more room */
+ spin_unlock_irqrestore(&sc->alloc_lock, flags);
+ goto done;
+ }
+ /* copy from receiver cache line and recalculate */
+ sc->alloc_free = ACCESS_ONCE(sc->free);
+ avail =
+ (unsigned long)sc->credits -
+ (sc->fill - sc->alloc_free);
+ if (blocks > avail) {
+ /* still no room, actively update */
+ spin_unlock_irqrestore(&sc->alloc_lock, flags);
+ sc_release_update(sc);
+ spin_lock_irqsave(&sc->alloc_lock, flags);
+ sc->alloc_free = ACCESS_ONCE(sc->free);
+ trycount++;
+ goto retry;
+ }
+ }
+
+ /* there is enough room */
+
+ atomic_inc(&sc->buffers_allocated);
+
+ /* read this once */
+ head = sc->sr_head;
+
+ /* "allocate" the buffer */
+ start_fill = sc->fill;
+ sc->fill += blocks;
+
+ /*
+ * Fill the parts that the releaser looks at before moving the head.
+ * The only necessary piece is the sent_at field. The credits
+ * we have just allocated cannot have been returned yet, so the
+ * cb and arg will not be looked at for a "while". Put them
+ * on this side of the memory barrier anyway.
+ */
+ pbuf = &sc->sr[head].pbuf;
+ pbuf->sent_at = sc->fill;
+ pbuf->cb = cb;
+ pbuf->arg = arg;
+ pbuf->sc = sc; /* could be filled in at sc->sr init time */
+ /* make sure this is in memory before updating the head */
+
+ /* calculate next head index, do not store */
+ next = head + 1;
+ if (next >= sc->sr_size)
+ next = 0;
+ /* update the head - must be last! - the releaser can look at fields
+ in pbuf once we move the head */
+ smp_wmb();
+ sc->sr_head = next;
+ spin_unlock_irqrestore(&sc->alloc_lock, flags);
+
+ /* finish filling in the buffer outside the lock */
+ pbuf->start = sc->base_addr + ((start_fill % sc->credits)
+ * PIO_BLOCK_SIZE);
+ pbuf->size = sc->credits * PIO_BLOCK_SIZE;
+ pbuf->end = sc->base_addr + pbuf->size;
+ pbuf->block_count = blocks;
+ pbuf->qw_written = 0;
+ pbuf->carry_bytes = 0;
+ pbuf->carry.val64 = 0;
+done:
+ return pbuf;
+}
+
+/*
+ * There are at least two entities that can turn on credit return
+ * interrupts and they can overlap. Avoid problems by implementing
+ * a count scheme that is enforced by a lock. The lock is needed because
+ * the count and CSR write must be paired.
+ */
+
+/*
+ * Start credit return interrupts. This is managed by a count. If already
+ * on, just increment the count.
+ */
+void sc_add_credit_return_intr(struct send_context *sc)
+{
+ unsigned long flags;
+
+ /* lock must surround both the count change and the CSR update */
+ spin_lock_irqsave(&sc->credit_ctrl_lock, flags);
+ if (sc->credit_intr_count == 0) {
+ sc->credit_ctrl |= SC(CREDIT_CTRL_CREDIT_INTR_SMASK);
+ write_kctxt_csr(sc->dd, sc->hw_context,
+ SC(CREDIT_CTRL), sc->credit_ctrl);
+ }
+ sc->credit_intr_count++;
+ spin_unlock_irqrestore(&sc->credit_ctrl_lock, flags);
+}
+
+/*
+ * Stop credit return interrupts. This is managed by a count. Decrement the
+ * count, if the last user, then turn the credit interrupts off.
+ */
+void sc_del_credit_return_intr(struct send_context *sc)
+{
+ unsigned long flags;
+
+ BUG_ON(sc->credit_intr_count == 0);
+
+ /* lock must surround both the count change and the CSR update */
+ spin_lock_irqsave(&sc->credit_ctrl_lock, flags);
+ sc->credit_intr_count--;
+ if (sc->credit_intr_count == 0) {
+ sc->credit_ctrl &= ~SC(CREDIT_CTRL_CREDIT_INTR_SMASK);
+ write_kctxt_csr(sc->dd, sc->hw_context,
+ SC(CREDIT_CTRL), sc->credit_ctrl);
+ }
+ spin_unlock_irqrestore(&sc->credit_ctrl_lock, flags);
+}
+
+/*
+ * The caller must be careful when calling this. All needint calls
+ * must be paired with !needint.
+ */
+void hfi1_sc_wantpiobuf_intr(struct send_context *sc, u32 needint)
+{
+ if (needint)
+ sc_add_credit_return_intr(sc);
+ else
+ sc_del_credit_return_intr(sc);
+ trace_hfi1_wantpiointr(sc, needint, sc->credit_ctrl);
+ if (needint) {
+ mmiowb();
+ sc_return_credits(sc);
+ }
+}
+
+/**
+ * sc_piobufavail - callback when a PIO buffer is available
+ * @sc: the send context
+ *
+ * This is called from the interrupt handler when a PIO buffer is
+ * available after hfi1_verbs_send() returned an error that no buffers were
+ * available. Disable the interrupt if there are no more QPs waiting.
+ */
+static void sc_piobufavail(struct send_context *sc)
+{
+ struct hfi1_devdata *dd = sc->dd;
+ struct hfi1_ibdev *dev = &dd->verbs_dev;
+ struct list_head *list;
+ struct hfi1_qp *qps[PIO_WAIT_BATCH_SIZE];
+ struct hfi1_qp *qp;
+ unsigned long flags;
+ unsigned i, n = 0;
+
+ if (dd->send_contexts[sc->sw_index].type != SC_KERNEL)
+ return;
+ list = &sc->piowait;
+ /*
+ * Note: checking that the piowait list is empty and clearing
+ * the buffer available interrupt needs to be atomic or we
+ * could end up with QPs on the wait list with the interrupt
+ * disabled.
+ */
+ spin_lock_irqsave(&dev->pending_lock, flags);
+ while (!list_empty(list)) {
+ struct iowait *wait;
+
+ if (n == ARRAY_SIZE(qps))
+ goto full;
+ wait = list_first_entry(list, struct iowait, list);
+ qp = container_of(wait, struct hfi1_qp, s_iowait);
+ list_del_init(&qp->s_iowait.list);
+ /* refcount held until actual wake up */
+ qps[n++] = qp;
+ }
+ /*
+ * Counting: only call wantpiobuf_intr() if there were waiters and they
+ * are now all gone.
+ */
+ if (n)
+ hfi1_sc_wantpiobuf_intr(sc, 0);
+full:
+ spin_unlock_irqrestore(&dev->pending_lock, flags);
+
+ for (i = 0; i < n; i++)
+ hfi1_qp_wakeup(qps[i], HFI1_S_WAIT_PIO);
+}
+
+/* translate a send credit update to a bit code of reasons */
+static inline int fill_code(u64 hw_free)
+{
+ int code = 0;
+
+ if (hw_free & CR_STATUS_SMASK)
+ code |= PRC_STATUS_ERR;
+ if (hw_free & CR_CREDIT_RETURN_DUE_TO_PBC_SMASK)
+ code |= PRC_PBC;
+ if (hw_free & CR_CREDIT_RETURN_DUE_TO_THRESHOLD_SMASK)
+ code |= PRC_THRESHOLD;
+ if (hw_free & CR_CREDIT_RETURN_DUE_TO_ERR_SMASK)
+ code |= PRC_FILL_ERR;
+ if (hw_free & CR_CREDIT_RETURN_DUE_TO_FORCE_SMASK)
+ code |= PRC_SC_DISABLE;
+ return code;
+}
+
+/* use the jiffies compare to get the wrap right */
+#define sent_before(a, b) time_before(a, b) /* a < b */
+
+/*
+ * The send context buffer "releaser".
+ */
+void sc_release_update(struct send_context *sc)
+{
+ struct pio_buf *pbuf;
+ u64 hw_free;
+ u32 head, tail;
+ unsigned long old_free;
+ unsigned long extra;
+ unsigned long flags;
+ int code;
+
+ if (!sc)
+ return;
+
+ spin_lock_irqsave(&sc->release_lock, flags);
+ /* update free */
+ hw_free = le64_to_cpu(*sc->hw_free); /* volatile read */
+ old_free = sc->free;
+ extra = (((hw_free & CR_COUNTER_SMASK) >> CR_COUNTER_SHIFT)
+ - (old_free & CR_COUNTER_MASK))
+ & CR_COUNTER_MASK;
+ sc->free = old_free + extra;
+ trace_hfi1_piofree(sc, extra);
+
+ /* call sent buffer callbacks */
+ code = -1; /* code not yet set */
+ head = ACCESS_ONCE(sc->sr_head); /* snapshot the head */
+ tail = sc->sr_tail;
+ while (head != tail) {
+ pbuf = &sc->sr[tail].pbuf;
+
+ if (sent_before(sc->free, pbuf->sent_at)) {
+ /* not sent yet */
+ break;
+ }
+ if (pbuf->cb) {
+ if (code < 0) /* fill in code on first user */
+ code = fill_code(hw_free);
+ (*pbuf->cb)(pbuf->arg, code);
+ }
+
+ tail++;
+ if (tail >= sc->sr_size)
+ tail = 0;
+ }
+ /* update tail, in case we moved it */
+ sc->sr_tail = tail;
+ spin_unlock_irqrestore(&sc->release_lock, flags);
+ sc_piobufavail(sc);
+}
+
+/*
+ * Send context group releaser. Argument is the send context that caused
+ * the interrupt. Called from the send context interrupt handler.
+ *
+ * Call release on all contexts in the group.
+ *
+ * This routine takes the sc_lock without an irqsave because it is only
+ * called from an interrupt handler. Adjust if that changes.
+ */
+void sc_group_release_update(struct hfi1_devdata *dd, u32 hw_context)
+{
+ struct send_context *sc;
+ u32 sw_index;
+ u32 gc, gc_end;
+
+ spin_lock(&dd->sc_lock);
+ sw_index = dd->hw_to_sw[hw_context];
+ if (unlikely(sw_index >= dd->num_send_contexts)) {
+ dd_dev_err(dd, "%s: invalid hw (%u) to sw (%u) mapping\n",
+ __func__, hw_context, sw_index);
+ goto done;
+ }
+ sc = dd->send_contexts[sw_index].sc;
+ if (unlikely(!sc))
+ goto done;
+
+ gc = group_context(hw_context, sc->group);
+ gc_end = gc + group_size(sc->group);
+ for (; gc < gc_end; gc++) {
+ sw_index = dd->hw_to_sw[gc];
+ if (unlikely(sw_index >= dd->num_send_contexts)) {
+ dd_dev_err(dd,
+ "%s: invalid hw (%u) to sw (%u) mapping\n",
+ __func__, hw_context, sw_index);
+ continue;
+ }
+ sc_release_update(dd->send_contexts[sw_index].sc);
+ }
+done:
+ spin_unlock(&dd->sc_lock);
+}
+
+int init_pervl_scs(struct hfi1_devdata *dd)
+{
+ int i;
+ u64 mask, all_vl_mask = (u64) 0x80ff; /* VLs 0-7, 15 */
+ u32 ctxt;
+
+ dd->vld[15].sc = sc_alloc(dd, SC_KERNEL,
+ dd->rcd[0]->rcvhdrqentsize, dd->node);
+ if (!dd->vld[15].sc)
+ goto nomem;
+ hfi1_init_ctxt(dd->vld[15].sc);
+ dd->vld[15].mtu = enum_to_mtu(OPA_MTU_2048);
+ for (i = 0; i < num_vls; i++) {
+ /*
+ * Since this function does not deal with a specific
+ * receive context but we need the RcvHdrQ entry size,
+ * use the size from rcd[0]. It is guaranteed to be
+ * valid at this point and will remain the same for all
+ * receive contexts.
+ */
+ dd->vld[i].sc = sc_alloc(dd, SC_KERNEL,
+ dd->rcd[0]->rcvhdrqentsize, dd->node);
+ if (!dd->vld[i].sc)
+ goto nomem;
+
+ hfi1_init_ctxt(dd->vld[i].sc);
+
+ /* non VL15 start with the max MTU */
+ dd->vld[i].mtu = hfi1_max_mtu;
+ }
+ sc_enable(dd->vld[15].sc);
+ ctxt = dd->vld[15].sc->hw_context;
+ mask = all_vl_mask & ~(1LL << 15);
+ write_kctxt_csr(dd, ctxt, SC(CHECK_VL), mask);
+ dd_dev_info(dd,
+ "Using send context %u(%u) for VL15\n",
+ dd->vld[15].sc->sw_index, ctxt);
+ for (i = 0; i < num_vls; i++) {
+ sc_enable(dd->vld[i].sc);
+ ctxt = dd->vld[i].sc->hw_context;
+ mask = all_vl_mask & ~(1LL << i);
+ write_kctxt_csr(dd, ctxt, SC(CHECK_VL), mask);
+ }
+ return 0;
+nomem:
+ sc_free(dd->vld[15].sc);
+ for (i = 0; i < num_vls; i++)
+ sc_free(dd->vld[i].sc);
+ return -ENOMEM;
+}
+
+int init_credit_return(struct hfi1_devdata *dd)
+{
+ int ret;
+ int num_numa;
+ int i;
+
+ num_numa = num_online_nodes();
+ /* enforce the expectation that the numas are compact */
+ for (i = 0; i < num_numa; i++) {
+ if (!node_online(i)) {
+ dd_dev_err(dd, "NUMA nodes are not compact\n");
+ ret = -EINVAL;
+ goto done;
+ }
+ }
+
+ dd->cr_base = kcalloc(
+ num_numa,
+ sizeof(struct credit_return_base),
+ GFP_KERNEL);
+ if (!dd->cr_base) {
+ dd_dev_err(dd, "Unable to allocate credit return base\n");
+ ret = -ENOMEM;
+ goto done;
+ }
+ for (i = 0; i < num_numa; i++) {
+ int bytes = TXE_NUM_CONTEXTS * sizeof(struct credit_return);
+
+ set_dev_node(&dd->pcidev->dev, i);
+ dd->cr_base[i].va = dma_zalloc_coherent(
+ &dd->pcidev->dev,
+ bytes,
+ &dd->cr_base[i].pa,
+ GFP_KERNEL);
+ if (dd->cr_base[i].va == NULL) {
+ set_dev_node(&dd->pcidev->dev, dd->node);
+ dd_dev_err(dd,
+ "Unable to allocate credit return DMA range for NUMA %d\n",
+ i);
+ ret = -ENOMEM;
+ goto done;
+ }
+ }
+ set_dev_node(&dd->pcidev->dev, dd->node);
+
+ ret = 0;
+done:
+ return ret;
+}
+
+void free_credit_return(struct hfi1_devdata *dd)
+{
+ int num_numa;
+ int i;
+
+ if (!dd->cr_base)
+ return;
+
+ num_numa = num_online_nodes();
+ for (i = 0; i < num_numa; i++) {
+ if (dd->cr_base[i].va) {
+ dma_free_coherent(&dd->pcidev->dev,
+ TXE_NUM_CONTEXTS
+ * sizeof(struct credit_return),
+ dd->cr_base[i].va,
+ dd->cr_base[i].pa);
+ }
+ }
+ kfree(dd->cr_base);
+ dd->cr_base = NULL;
+}
diff --git a/drivers/infiniband/hw/hfi1/pio.h b/drivers/infiniband/hw/hfi1/pio.h
new file mode 100644
index 0000000..0bb885c
--- /dev/null
+++ b/drivers/infiniband/hw/hfi1/pio.h
@@ -0,0 +1,224 @@
+#ifndef _PIO_H
+#define _PIO_H
+/*
+ *
+ * This file is provided under a dual BSD/GPLv2 license. When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * GPL LICENSE SUMMARY
+ *
+ * Copyright(c) 2015 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * BSD LICENSE
+ *
+ * Copyright(c) 2015 Intel Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ * - Neither the name of Intel Corporation nor the names of its
+ * contributors may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+
+/* send context types */
+#define SC_KERNEL 0
+#define SC_ACK 1
+#define SC_USER 2
+#define SC_MAX 3
+
+/* invalid send context index */
+#define INVALID_SCI 0xff
+
+/* PIO buffer release callback function */
+typedef void (*pio_release_cb)(void *arg, int code);
+
+/* PIO release codes - in bits, as there could more than one that apply */
+#define PRC_OK 0 /* no known error */
+#define PRC_STATUS_ERR 0x01 /* credit return due to status error */
+#define PRC_PBC 0x02 /* credit return due to PBC */
+#define PRC_THRESHOLD 0x04 /* credit return due to threshold */
+#define PRC_FILL_ERR 0x08 /* credit return due fill error */
+#define PRC_FORCE 0x10 /* credit return due credit force */
+#define PRC_SC_DISABLE 0x20 /* clean-up after a context disable */
+
+/* byte helper */
+union mix {
+ u64 val64;
+ u32 val32[2];
+ u8 val8[8];
+};
+
+/* an allocated PIO buffer */
+struct pio_buf {
+ struct send_context *sc;/* back pointer to owning send context */
+ pio_release_cb cb; /* called when the buffer is released */
+ void *arg; /* argument for cb */
+ void __iomem *start; /* buffer start address */
+ void __iomem *end; /* context end address */
+ unsigned long size; /* context size, in bytes */
+ unsigned long sent_at; /* buffer is sent when <= free */
+ u32 block_count; /* size of buffer, in blocks */
+ u32 qw_written; /* QW written so far */
+ u32 carry_bytes; /* number of valid bytes in carry */
+ union mix carry; /* pending unwritten bytes */
+};
+
+/* cache line aligned pio buffer array */
+union pio_shadow_ring {
+ struct pio_buf pbuf;
+ u64 unused[16]; /* cache line spacer */
+} ____cacheline_aligned;
+
+/* per-NUMA send context */
+struct send_context {
+ /* read-only after init */
+ struct hfi1_devdata *dd; /* device */
+ void __iomem *base_addr; /* start of PIO memory */
+ union pio_shadow_ring *sr; /* shadow ring */
+ volatile __le64 *hw_free; /* HW free counter */
+ struct work_struct halt_work; /* halted context work queue entry */
+ unsigned long flags; /* flags */
+ int node; /* context home node */
+ int type; /* context type */
+ u32 sw_index; /* software index number */
+ u32 hw_context; /* hardware context number */
+ u32 credits; /* number of blocks in context */
+ u32 sr_size; /* size of the shadow ring */
+ u32 group; /* credit return group */
+ /* allocator fields */
+ spinlock_t alloc_lock ____cacheline_aligned_in_smp;
+ unsigned long fill; /* official alloc count */
+ unsigned long alloc_free; /* copy of free (less cache thrash) */
+ u32 sr_head; /* shadow ring head */
+ /* releaser fields */
+ spinlock_t release_lock ____cacheline_aligned_in_smp;
+ unsigned long free; /* official free count */
+ u32 sr_tail; /* shadow ring tail */
+ /* list for PIO waiters */
+ struct list_head piowait ____cacheline_aligned_in_smp;
+ spinlock_t credit_ctrl_lock ____cacheline_aligned_in_smp;
+ u64 credit_ctrl; /* cache for credit control */
+ u32 credit_intr_count; /* count of credit intr users */
+ atomic_t buffers_allocated; /* count of buffers allocated */
+ wait_queue_head_t halt_wait; /* wait until kernel sees interrupt */
+};
+
+/* send context flags */
+#define SCF_ENABLED 0x01
+#define SCF_IN_FREE 0x02
+#define SCF_HALTED 0x04
+#define SCF_FROZEN 0x08
+
+struct send_context_info {
+ struct send_context *sc; /* allocated working context */
+ u16 allocated; /* has this been allocated? */
+ u16 type; /* context type */
+ u16 base; /* base in PIO array */
+ u16 credits; /* size in PIO array */
+};
+
+/* DMA credit return, index is always (context & 0x7) */
+struct credit_return {
+ volatile __le64 cr[8];
+};
+
+/* NUMA indexed credit return array */
+struct credit_return_base {
+ struct credit_return *va;
+ dma_addr_t pa;
+};
+
+/* send context configuration sizes (one per type) */
+struct sc_config_sizes {
+ short int size;
+ short int count;
+};
+
+/* send context functions */
+int init_credit_return(struct hfi1_devdata *dd);
+void free_credit_return(struct hfi1_devdata *dd);
+int init_sc_pools_and_sizes(struct hfi1_devdata *dd);
+int init_send_contexts(struct hfi1_devdata *dd);
+int init_credit_return(struct hfi1_devdata *dd);
+int init_pervl_scs(struct hfi1_devdata *dd);
+struct send_context *sc_alloc(struct hfi1_devdata *dd, int type,
+ uint hdrqentsize, int numa);
+void sc_free(struct send_context *sc);
+int sc_enable(struct send_context *sc);
+void sc_disable(struct send_context *sc);
+int sc_restart(struct send_context *sc);
+void sc_return_credits(struct send_context *sc);
+void sc_flush(struct send_context *sc);
+void sc_drop(struct send_context *sc);
+void sc_stop(struct send_context *sc, int bit);
+struct pio_buf *sc_buffer_alloc(struct send_context *sc, u32 dw_len,
+ pio_release_cb cb, void *arg);
+void sc_release_update(struct send_context *sc);
+void sc_return_credits(struct send_context *sc);
+void sc_group_release_update(struct hfi1_devdata *dd, u32 hw_context);
+void sc_add_credit_return_intr(struct send_context *sc);
+void sc_del_credit_return_intr(struct send_context *sc);
+void sc_set_cr_threshold(struct send_context *sc, u32 new_threshold);
+u32 sc_mtu_to_threshold(struct send_context *sc, u32 mtu, u32 hdrqentsize);
+void hfi1_sc_wantpiobuf_intr(struct send_context *sc, u32 needint);
+void sc_wait(struct hfi1_devdata *dd);
+void set_pio_integrity(struct send_context *sc);
+
+/* support functions */
+void pio_reset_all(struct hfi1_devdata *dd);
+void pio_freeze(struct hfi1_devdata *dd);
+void pio_kernel_unfreeze(struct hfi1_devdata *dd);
+
+/* global PIO send control operations */
+#define PSC_GLOBAL_ENABLE 0
+#define PSC_GLOBAL_DISABLE 1
+#define PSC_GLOBAL_VLARB_ENABLE 2
+#define PSC_GLOBAL_VLARB_DISABLE 3
+#define PSC_CM_RESET 4
+#define PSC_DATA_VL_ENABLE 5
+#define PSC_DATA_VL_DISABLE 6
+
+void __cm_reset(struct hfi1_devdata *dd, u64 sendctrl);
+void pio_send_control(struct hfi1_devdata *dd, int op);
+
+
+/* PIO copy routines */
+void pio_copy(struct hfi1_devdata *dd, struct pio_buf *pbuf, u64 pbc,
+ const void *from, size_t count);
+void seg_pio_copy_start(struct pio_buf *pbuf, u64 pbc,
+ const void *from, size_t nbytes);
+void seg_pio_copy_mid(struct pio_buf *pbuf, const void *from, size_t nbytes);
+void seg_pio_copy_end(struct pio_buf *pbuf);
+
+#endif /* _PIO_H */
diff --git a/drivers/infiniband/hw/hfi1/pio_copy.c b/drivers/infiniband/hw/hfi1/pio_copy.c
new file mode 100644
index 0000000..baa09d3
--- /dev/null
+++ b/drivers/infiniband/hw/hfi1/pio_copy.c
@@ -0,0 +1,867 @@
+/*
+ *
+ * This file is provided under a dual BSD/GPLv2 license. When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * GPL LICENSE SUMMARY
+ *
+ * Copyright(c) 2015 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * BSD LICENSE
+ *
+ * Copyright(c) 2015 Intel Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ * - Neither the name of Intel Corporation nor the names of its
+ * contributors may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "hfi.h"
+
+/* additive distance between non-SOP and SOP space */
+#define SOP_DISTANCE (TXE_PIO_SIZE / 2)
+#define PIO_BLOCK_MASK (PIO_BLOCK_SIZE-1)
+/* number of QUADWORDs in a block */
+#define PIO_BLOCK_QWS (PIO_BLOCK_SIZE/sizeof(u64))
+
+/**
+ * pio_copy - copy data block to MMIO space
+ * @pbuf: a number of blocks allocated within a PIO send context
+ * @pbc: PBC to send
+ * @from: source, must be 8 byte aligned
+ * @count: number of DWORD (32-bit) quantities to copy from source
+ *
+ * Copy data from source to PIO Send Buffer memory, 8 bytes at a time.
+ * Must always write full BLOCK_SIZE bytes blocks. The first block must
+ * be written to the corresponding SOP=1 address.
+ *
+ * Known:
+ * o pbuf->start always starts on a block boundary
+ * o pbuf can wrap only at a block boundary
+ */
+void pio_copy(struct hfi1_devdata *dd, struct pio_buf *pbuf, u64 pbc,
+ const void *from, size_t count)
+{
+ void __iomem *dest = pbuf->start + SOP_DISTANCE;
+ void __iomem *send = dest + PIO_BLOCK_SIZE;
+ void __iomem *dend; /* 8-byte data end */
+
+ /* write the PBC */
+ writeq(pbc, dest);
+ dest += sizeof(u64);
+
+ /* calculate where the QWORD data ends - in SOP=1 space */
+ dend = dest + ((count>>1) * sizeof(u64));
+
+ if (dend < send) {
+ /* all QWORD data is within the SOP block, does *not*
+ reach the end of the SOP block */
+
+ while (dest < dend) {
+ writeq(*(u64 *)from, dest);
+ from += sizeof(u64);
+ dest += sizeof(u64);
+ }
+ /*
+ * No boundary checks are needed here:
+ * 0. We're not on the SOP block boundary
+ * 1. The possible DWORD dangle will still be within
+ * the SOP block
+ * 2. We cannot wrap except on a block boundary.
+ */
+ } else {
+ /* QWORD data extends _to_ or beyond the SOP block */
+
+ /* write 8-byte SOP chunk data */
+ while (dest < send) {
+ writeq(*(u64 *)from, dest);
+ from += sizeof(u64);
+ dest += sizeof(u64);
+ }
+ /* drop out of the SOP range */
+ dest -= SOP_DISTANCE;
+ dend -= SOP_DISTANCE;
+
+ /*
+ * If the wrap comes before or matches the data end,
+ * copy until until the wrap, then wrap.
+ *
+ * If the data ends at the end of the SOP above and
+ * the buffer wraps, then pbuf->end == dend == dest
+ * and nothing will get written, but we will wrap in
+ * case there is a dangling DWORD.
+ */
+ if (pbuf->end <= dend) {
+ while (dest < pbuf->end) {
+ writeq(*(u64 *)from, dest);
+ from += sizeof(u64);
+ dest += sizeof(u64);
+ }
+
+ dest -= pbuf->size;
+ dend -= pbuf->size;
+ }
+
+ /* write 8-byte non-SOP, non-wrap chunk data */
+ while (dest < dend) {
+ writeq(*(u64 *)from, dest);
+ from += sizeof(u64);
+ dest += sizeof(u64);
+ }
+ }
+ /* at this point we have wrapped if we are going to wrap */
+
+ /* write dangling u32, if any */
+ if (count & 1) {
+ union mix val;
+
+ val.val64 = 0;
+ val.val32[0] = *(u32 *)from;
+ writeq(val.val64, dest);
+ dest += sizeof(u64);
+ }
+ /* fill in rest of block, no need to check pbuf->end
+ as we only wrap on a block boundary */
+ while (((unsigned long)dest & PIO_BLOCK_MASK) != 0) {
+ writeq(0, dest);
+ dest += sizeof(u64);
+ }
+
+ /* finished with this buffer */
+ atomic_dec(&pbuf->sc->buffers_allocated);
+}
+
+/* USE_SHIFTS is faster in user-space tests on a Xeon X5570 @ 2.93GHz */
+#define USE_SHIFTS 1
+#ifdef USE_SHIFTS
+/*
+ * Handle carry bytes using shifts and masks.
+ *
+ * NOTE: the value the unused portion of carry is expected to always be zero.
+ */
+
+/*
+ * "zero" shift - bit shift used to zero out upper bytes. Input is
+ * the count of LSB bytes to preserve.
+ */
+#define zshift(x) (8 * (8-(x)))
+
+/*
+ * "merge" shift - bit shift used to merge with carry bytes. Input is
+ * the LSB byte count to move beyond.
+ */
+#define mshift(x) (8 * (x))
+
+/*
+ * Read nbytes bytes from "from" and return them in the LSB bytes
+ * of pbuf->carry. Other bytes are zeroed. Any previous value
+ * pbuf->carry is lost.
+ *
+ * NOTES:
+ * o do not read from from if nbytes is zero
+ * o from may _not_ be u64 aligned
+ * o nbytes must not span a QW boundary
+ */
+static inline void read_low_bytes(struct pio_buf *pbuf, const void *from,
+ unsigned int nbytes)
+{
+ unsigned long off;
+
+ if (nbytes == 0) {
+ pbuf->carry.val64 = 0;
+ } else {
+ /* align our pointer */
+ off = (unsigned long)from & 0x7;
+ BUG_ON(nbytes+off > 8);
+ from = (void *)((unsigned long)from & ~0x7l);
+ pbuf->carry.val64 = ((*(u64 *)from)
+ << zshift(nbytes + off))/* zero upper bytes */
+ >> zshift(nbytes); /* place at bottom */
+ }
+ pbuf->carry_bytes = nbytes;
+}
+
+/*
+ * Read nbytes bytes from "from" and put them at the next significant bytes
+ * of pbuf->carry. Unused bytes are zeroed. It is expected that the extra
+ * read does not overfill carry.
+ *
+ * NOTES:
+ * o from may _not_ be u64 aligned
+ * o nbytes may span a QW boundary
+ */
+static inline void read_extra_bytes(struct pio_buf *pbuf,
+ const void *from, unsigned int nbytes)
+{
+ unsigned long off = (unsigned long)from & 0x7;
+ unsigned int room, xbytes;
+
+ BUG_ON(pbuf->carry_bytes + nbytes > 8);
+
+ /* align our pointer */
+ from = (void *)((unsigned long)from & ~0x7l);
+
+ /* check count first - don't read anything if count is zero */
+ while (nbytes) {
+ /* find the number of bytes in this u64 */
+ room = 8 - off; /* this u64 has room for this many bytes */
+ xbytes = nbytes > room ? room : nbytes;
+
+ /*
+ * shift down to zero lower bytes, shift up to zero upper
+ * bytes, shift back down to move into place
+ */
+ pbuf->carry.val64 |= (((*(u64 *)from)
+ >> mshift(off))
+ << zshift(xbytes))
+ >> zshift(xbytes+pbuf->carry_bytes);
+ off = 0;
+ pbuf->carry_bytes += xbytes;
+ nbytes -= xbytes;
+ from += sizeof(u64);
+ }
+}
+
+/*
+ * Zero extra bytes from the end of pbuf->carry.
+ *
+ * NOTES:
+ * o zbytes <= old_bytes
+ */
+static inline void zero_extra_bytes(struct pio_buf *pbuf, unsigned int zbytes)
+{
+ unsigned int remaining;
+
+ BUG_ON(pbuf->carry_bytes < zbytes);
+
+ if (zbytes == 0) /* nothing to do */
+ return;
+
+ remaining = pbuf->carry_bytes - zbytes; /* remaining bytes */
+
+ /* NOTE: zshift only guaranteed to work if remaining != 0 */
+ if (remaining)
+ pbuf->carry.val64 = (pbuf->carry.val64 << zshift(remaining))
+ >> zshift(remaining);
+ else
+ pbuf->carry.val64 = 0;
+ pbuf->carry_bytes = remaining;
+}
+
+/*
+ * Write a quad word using parts of pbuf->carry and the next 8 bytes of src.
+ * Put the unused part of the next 8 bytes of src into the LSB bytes of
+ * pbuf->carry with the upper bytes zeroed..
+ *
+ * NOTES:
+ * o result must keep unused bytes zeroed
+ * o src must be u64 aligned
+ */
+static inline void merge_write8(
+ struct pio_buf *pbuf,
+ void __iomem *dest,
+ const void *src)
+{
+ u64 new, temp;
+
+ new = *(u64 *)src;
+ temp = pbuf->carry.val64 | (new << mshift(pbuf->carry_bytes));
+ writeq(temp, dest);
+ pbuf->carry.val64 = new >> zshift(pbuf->carry_bytes);
+}
+
+/*
+ * Write a quad word using all bytes of carry.
+ */
+static inline void carry8_write8(union mix carry, void __iomem *dest)
+{
+ writeq(carry.val64, dest);
+}
+
+/*
+ * Write a quad word using all the valid bytes of carry. If carry
+ * has zero valid bytes, nothing is written.
+ * Returns 0 on nothing written, non-zero on quad word written.
+ */
+static inline int carry_write8(struct pio_buf *pbuf, void __iomem *dest)
+{
+ if (pbuf->carry_bytes) {
+ /* unused bytes are always kept zeroed, so just write */
+ writeq(pbuf->carry.val64, dest);
+ return 1;
+ }
+
+ return 0;
+}
+
+#else /* USE_SHIFTS */
+/*
+ * Handle carry bytes using byte copies.
+ *
+ * NOTE: the value the unused portion of carry is left uninitialized.
+ */
+
+/*
+ * Jump copy - no-loop copy for < 8 bytes.
+ */
+static inline void jcopy(u8 *dest, const u8 *src, u32 n)
+{
+ switch (n) {
+ case 7:
+ *dest++ = *src++;
+ case 6:
+ *dest++ = *src++;
+ case 5:
+ *dest++ = *src++;
+ case 4:
+ *dest++ = *src++;
+ case 3:
+ *dest++ = *src++;
+ case 2:
+ *dest++ = *src++;
+ case 1:
+ *dest++ = *src++;
+ }
+}
+
+/*
+ * Read nbytes from "from" and and place them in the low bytes
+ * of pbuf->carry. Other bytes are left as-is. Any previous
+ * value in pbuf->carry is lost.
+ *
+ * NOTES:
+ * o do not read from from if nbytes is zero
+ * o from may _not_ be u64 aligned.
+ */
+static inline void read_low_bytes(struct pio_buf *pbuf, const void *from,
+ unsigned int nbytes)
+{
+ BUG_ON(nbytes >= 8);
+
+ jcopy(&pbuf->carry.val8[0], from, nbytes);
+ pbuf->carry_bytes = nbytes;
+}
+
+/*
+ * Read nbytes bytes from "from" and put them at the end of pbuf->carry.
+ * It is expected that the extra read does not overfill carry.
+ *
+ * NOTES:
+ * o from may _not_ be u64 aligned
+ * o nbytes may span a QW boundary
+ */
+static inline void read_extra_bytes(struct pio_buf *pbuf,
+ const void *from, unsigned int nbytes)
+{
+ BUG_ON(pbuf->carry_bytes + nbytes > 8);
+ jcopy(&pbuf->carry.val8[pbuf->carry_bytes], from, nbytes);
+ pbuf->carry_bytes += nbytes;
+}
+
+/*
+ * Zero extra bytes from the end of pbuf->carry.
+ *
+ * We do not care about the value of unused bytes in carry, so just
+ * reduce the byte count.
+ *
+ * NOTES:
+ * o zbytes <= old_bytes
+ */
+static inline void zero_extra_bytes(struct pio_buf *pbuf, unsigned int zbytes)
+{
+ BUG_ON(pbuf->carry_bytes < zbytes);
+ pbuf->carry_bytes -= zbytes;
+}
+
+/*
+ * Write a quad word using parts of pbuf->carry and the next 8 bytes of src.
+ * Put the unused part of the next 8 bytes of src into the low bytes of
+ * pbuf->carry.
+ */
+static inline void merge_write8(
+ struct pio_buf *pbuf,
+ void *dest,
+ const void *src)
+{
+ u32 remainder = 8 - pbuf->carry_bytes;
+
+ jcopy(&pbuf->carry.val8[pbuf->carry_bytes], src, remainder);
+ writeq(pbuf->carry.val64, dest);
+ jcopy(&pbuf->carry.val8[0], src+remainder, pbuf->carry_bytes);
+}
+
+/*
+ * Write a quad word using all bytes of carry.
+ */
+static inline void carry8_write8(union mix carry, void *dest)
+{
+ writeq(carry.val64, dest);
+}
+
+/*
+ * Write a quad word using all the valid bytes of carry. If carry
+ * has zero valid bytes, nothing is written.
+ * Returns 0 on nothing written, non-zero on quad word written.
+ */
+static inline int carry_write8(struct pio_buf *pbuf, void *dest)
+{
+ if (pbuf->carry_bytes) {
+ u64 zero = 0;
+
+ jcopy(&pbuf->carry.val8[pbuf->carry_bytes], (u8 *)&zero,
+ 8 - pbuf->carry_bytes);
+ writeq(pbuf->carry.val64, dest);
+ return 1;
+ }
+
+ return 0;
+}
+#endif /* USE_SHIFTS */
+
+/*
+ * Segmented PIO Copy - start
+ *
+ * Start a PIO copy.
+ *
+ * @pbuf: destination buffer
+ * @pbc: the PBC for the PIO buffer
+ * @from: data source, QWORD aligned
+ * @nbytes: bytes to copy
+ */
+void seg_pio_copy_start(struct pio_buf *pbuf, u64 pbc,
+ const void *from, size_t nbytes)
+{
+ void __iomem *dest = pbuf->start + SOP_DISTANCE;
+ void __iomem *send = dest + PIO_BLOCK_SIZE;
+ void __iomem *dend; /* 8-byte data end */
+
+ writeq(pbc, dest);
+ dest += sizeof(u64);
+
+ /* calculate where the QWORD data ends - in SOP=1 space */
+ dend = dest + ((nbytes>>3) * sizeof(u64));
+
+ if (dend < send) {
+ /* all QWORD data is within the SOP block, does *not*
+ reach the end of the SOP block */
+
+ while (dest < dend) {
+ writeq(*(u64 *)from, dest);
+ from += sizeof(u64);
+ dest += sizeof(u64);
+ }
+ /*
+ * No boundary checks are needed here:
+ * 0. We're not on the SOP block boundary
+ * 1. The possible DWORD dangle will still be within
+ * the SOP block
+ * 2. We cannot wrap except on a block boundary.
+ */
+ } else {
+ /* QWORD data extends _to_ or beyond the SOP block */
+
+ /* write 8-byte SOP chunk data */
+ while (dest < send) {
+ writeq(*(u64 *)from, dest);
+ from += sizeof(u64);
+ dest += sizeof(u64);
+ }
+ /* drop out of the SOP range */
+ dest -= SOP_DISTANCE;
+ dend -= SOP_DISTANCE;
+
+ /*
+ * If the wrap comes before or matches the data end,
+ * copy until until the wrap, then wrap.
+ *
+ * If the data ends at the end of the SOP above and
+ * the buffer wraps, then pbuf->end == dend == dest
+ * and nothing will get written, but we will wrap in
+ * case there is a dangling DWORD.
+ */
+ if (pbuf->end <= dend) {
+ while (dest < pbuf->end) {
+ writeq(*(u64 *)from, dest);
+ from += sizeof(u64);
+ dest += sizeof(u64);
+ }
+
+ dest -= pbuf->size;
+ dend -= pbuf->size;
+ }
+
+ /* write 8-byte non-SOP, non-wrap chunk data */
+ while (dest < dend) {
+ writeq(*(u64 *)from, dest);
+ from += sizeof(u64);
+ dest += sizeof(u64);
+ }
+ }
+ /* at this point we have wrapped if we are going to wrap */
+
+ /* ...but it doesn't matter as we're done writing */
+
+ /* save dangling bytes, if any */
+ read_low_bytes(pbuf, from, nbytes & 0x7);
+
+ pbuf->qw_written = 1 /*PBC*/ + (nbytes >> 3);
+}
+
+/*
+ * Mid copy helper, "mixed case" - source is 64-bit aligned but carry
+ * bytes are non-zero.
+ *
+ * Whole u64s must be written to the chip, so bytes must be manually merged.
+ *
+ * @pbuf: destination buffer
+ * @from: data source, is QWORD aligned.
+ * @nbytes: bytes to copy
+ *
+ * Must handle nbytes < 8.
+ */
+static void mid_copy_mix(struct pio_buf *pbuf, const void *from, size_t nbytes)
+{
+ void __iomem *dest = pbuf->start + (pbuf->qw_written * sizeof(u64));
+ void __iomem *dend; /* 8-byte data end */
+ unsigned long qw_to_write = (pbuf->carry_bytes + nbytes) >> 3;
+ unsigned long bytes_left = (pbuf->carry_bytes + nbytes) & 0x7;
+
+ /* calculate 8-byte data end */
+ dend = dest + (qw_to_write * sizeof(u64));
+
+ if (pbuf->qw_written < PIO_BLOCK_QWS) {
+ /*
+ * Still within SOP block. We don't need to check for
+ * wrap because we are still in the first block and
+ * can only wrap on block boundaries.
+ */
+ void __iomem *send; /* SOP end */
+ void __iomem *xend;
+
+ /* calculate the end of data or end of block, whichever
+ comes first */
+ send = pbuf->start + PIO_BLOCK_SIZE;
+ xend = send < dend ? send : dend;
+
+ /* shift up to SOP=1 space */
+ dest += SOP_DISTANCE;
+ xend += SOP_DISTANCE;
+
+ /* write 8-byte chunk data */
+ while (dest < xend) {
+ merge_write8(pbuf, dest, from);
+ from += sizeof(u64);
+ dest += sizeof(u64);
+ }
+
+ /* shift down to SOP=0 space */
+ dest -= SOP_DISTANCE;
+ }
+ /*
+ * At this point dest could be (either, both, or neither):
+ * - at dend
+ * - at the wrap
+ */
+
+ /*
+ * If the wrap comes before or matches the data end,
+ * copy until until the wrap, then wrap.
+ *
+ * If dest is at the wrap, we will fall into the if,
+ * not do the loop, when wrap.
+ *
+ * If the data ends at the end of the SOP above and
+ * the buffer wraps, then pbuf->end == dend == dest
+ * and nothing will get written.
+ */
+ if (pbuf->end <= dend) {
+ while (dest < pbuf->end) {
+ merge_write8(pbuf, dest, from);
+ from += sizeof(u64);
+ dest += sizeof(u64);
+ }
+
+ dest -= pbuf->size;
+ dend -= pbuf->size;
+ }
+
+ /* write 8-byte non-SOP, non-wrap chunk data */
+ while (dest < dend) {
+ merge_write8(pbuf, dest, from);
+ from += sizeof(u64);
+ dest += sizeof(u64);
+ }
+
+ /* adjust carry */
+ if (pbuf->carry_bytes < bytes_left) {
+ /* need to read more */
+ read_extra_bytes(pbuf, from, bytes_left - pbuf->carry_bytes);
+ } else {
+ /* remove invalid bytes */
+ zero_extra_bytes(pbuf, pbuf->carry_bytes - bytes_left);
+ }
+
+ pbuf->qw_written += qw_to_write;
+}
+
+/*
+ * Mid copy helper, "straight case" - source pointer is 64-bit aligned
+ * with no carry bytes.
+ *
+ * @pbuf: destination buffer
+ * @from: data source, is QWORD aligned
+ * @nbytes: bytes to copy
+ *
+ * Must handle nbytes < 8.
+ */
+static void mid_copy_straight(struct pio_buf *pbuf,
+ const void *from, size_t nbytes)
+{
+ void __iomem *dest = pbuf->start + (pbuf->qw_written * sizeof(u64));
+ void __iomem *dend; /* 8-byte data end */
+
+ /* calculate 8-byte data end */
+ dend = dest + ((nbytes>>3) * sizeof(u64));
+
+ if (pbuf->qw_written < PIO_BLOCK_QWS) {
+ /*
+ * Still within SOP block. We don't need to check for
+ * wrap because we are still in the first block and
+ * can only wrap on block boundaries.
+ */
+ void __iomem *send; /* SOP end */
+ void __iomem *xend;
+
+ /* calculate the end of data or end of block, whichever
+ comes first */
+ send = pbuf->start + PIO_BLOCK_SIZE;
+ xend = send < dend ? send : dend;
+
+ /* shift up to SOP=1 space */
+ dest += SOP_DISTANCE;
+ xend += SOP_DISTANCE;
+
+ /* write 8-byte chunk data */
+ while (dest < xend) {
+ writeq(*(u64 *)from, dest);
+ from += sizeof(u64);
+ dest += sizeof(u64);
+ }
+
+ /* shift down to SOP=0 space */
+ dest -= SOP_DISTANCE;
+ }
+ /*
+ * At this point dest could be (either, both, or neither):
+ * - at dend
+ * - at the wrap
+ */
+
+ /*
+ * If the wrap comes before or matches the data end,
+ * copy until until the wrap, then wrap.
+ *
+ * If dest is at the wrap, we will fall into the if,
+ * not do the loop, when wrap.
+ *
+ * If the data ends at the end of the SOP above and
+ * the buffer wraps, then pbuf->end == dend == dest
+ * and nothing will get written.
+ */
+ if (pbuf->end <= dend) {
+ while (dest < pbuf->end) {
+ writeq(*(u64 *)from, dest);
+ from += sizeof(u64);
+ dest += sizeof(u64);
+ }
+
+ dest -= pbuf->size;
+ dend -= pbuf->size;
+ }
+
+ /* write 8-byte non-SOP, non-wrap chunk data */
+ while (dest < dend) {
+ writeq(*(u64 *)from, dest);
+ from += sizeof(u64);
+ dest += sizeof(u64);
+ }
+
+ /* we know carry_bytes was zero on entry to this routine */
+ read_low_bytes(pbuf, from, nbytes & 0x7);
+
+ pbuf->qw_written += nbytes>>3;
+}
+
+/*
+ * Segmented PIO Copy - middle
+ *
+ * Must handle any aligned tail and any aligned source with any byte count.
+ *
+ * @pbuf: a number of blocks allocated within a PIO send context
+ * @from: data source
+ * @nbytes: number of bytes to copy
+ */
+void seg_pio_copy_mid(struct pio_buf *pbuf, const void *from, size_t nbytes)
+{
+ unsigned long from_align = (unsigned long)from & 0x7;
+
+ if (pbuf->carry_bytes + nbytes < 8) {
+ /* not enough bytes to fill a QW */
+ read_extra_bytes(pbuf, from, nbytes);
+ return;
+ }
+
+ if (from_align) {
+ /* misaligned source pointer - align it */
+ unsigned long to_align;
+
+ /* bytes to read to align "from" */
+ to_align = 8 - from_align;
+
+ /*
+ * In the advance-to-alignment logic below, we do not need
+ * to check if we are using more than nbytes. This is because
+ * if we are here, we already know that carry+nbytes will
+ * fill at least one QW.
+ */
+ if (pbuf->carry_bytes + to_align < 8) {
+ /* not enough align bytes to fill a QW */
+ read_extra_bytes(pbuf, from, to_align);
+ from += to_align;
+ nbytes -= to_align;
+ } else {
+ /* bytes to fill carry */
+ unsigned long to_fill = 8 - pbuf->carry_bytes;
+ /* bytes left over to be read */
+ unsigned long extra = to_align - to_fill;
+ void __iomem *dest;
+
+ /* fill carry... */
+ read_extra_bytes(pbuf, from, to_fill);
+ from += to_fill;
+ nbytes -= to_fill;
+
+ /* ...now write carry */
+ dest = pbuf->start + (pbuf->qw_written * sizeof(u64));
+
+ /*
+ * The two checks immediately below cannot both be
+ * true, hence the else. If we have wrapped, we
+ * cannot still be within the first block.
+ * Conversely, if we are still in the first block, we
+ * cannot have wrapped. We do the wrap check first
+ * as that is more likely.
+ */
+ /* adjust if we've wrapped */
+ if (dest >= pbuf->end)
+ dest -= pbuf->size;
+ /* jump to SOP range if within the first block */
+ else if (pbuf->qw_written < PIO_BLOCK_QWS)
+ dest += SOP_DISTANCE;
+
+ carry8_write8(pbuf->carry, dest);
+ pbuf->qw_written++;
+
+ /* read any extra bytes to do final alignment */
+ /* this will overwrite anything in pbuf->carry */
+ read_low_bytes(pbuf, from, extra);
+ from += extra;
+ nbytes -= extra;
+ }
+
+ /* at this point, from is QW aligned */
+ }
+
+ if (pbuf->carry_bytes)
+ mid_copy_mix(pbuf, from, nbytes);
+ else
+ mid_copy_straight(pbuf, from, nbytes);
+}
+
+/*
+ * Segmented PIO Copy - end
+ *
+ * Write any remainder (in pbuf->carry) and finish writing the whole block.
+ *
+ * @pbuf: a number of blocks allocated within a PIO send context
+ */
+void seg_pio_copy_end(struct pio_buf *pbuf)
+{
+ void __iomem *dest = pbuf->start + (pbuf->qw_written * sizeof(u64));
+
+ /*
+ * The two checks immediately below cannot both be true, hence the
+ * else. If we have wrapped, we cannot still be within the first
+ * block. Conversely, if we are still in the first block, we
+ * cannot have wrapped. We do the wrap check first as that is
+ * more likely.
+ */
+ /* adjust if we have wrapped */
+ if (dest >= pbuf->end)
+ dest -= pbuf->size;
+ /* jump to the SOP range if within the first block */
+ else if (pbuf->qw_written < PIO_BLOCK_QWS)
+ dest += SOP_DISTANCE;
+
+ /* write final bytes, if any */
+ if (carry_write8(pbuf, dest)) {
+ dest += sizeof(u64);
+ /*
+ * NOTE: We do not need to recalculate whether dest needs
+ * SOP_DISTANCE or not.
+ *
+ * If we are in the first block and the dangle write
+ * keeps us in the same block, dest will need
+ * to retain SOP_DISTANCE in the loop below.
+ *
+ * If we are in the first block and the dangle write pushes
+ * us to the next block, then loop below will not run
+ * and dest is not used. Hence we do not need to update
+ * it.
+ *
+ * If we are past the first block, then SOP_DISTANCE
+ * was never added, so there is nothing to do.
+ */
+ }
+
+ /* fill in rest of block */
+ while (((unsigned long)dest & PIO_BLOCK_MASK) != 0) {
+ writeq(0, dest);
+ dest += sizeof(u64);
+ }
+
+ /* finished with this buffer */
+ atomic_dec(&pbuf->sc->buffers_allocated);