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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/infiniband/hw/hfi1/pin_system.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/infiniband/hw/hfi1/pin_system.c')
-rw-r--r--drivers/infiniband/hw/hfi1/pin_system.c474
1 files changed, 474 insertions, 0 deletions
diff --git a/drivers/infiniband/hw/hfi1/pin_system.c b/drivers/infiniband/hw/hfi1/pin_system.c
new file mode 100644
index 0000000000..384f722093
--- /dev/null
+++ b/drivers/infiniband/hw/hfi1/pin_system.c
@@ -0,0 +1,474 @@
+// SPDX-License-Identifier: GPL-2.0 or BSD-3-Clause
+/*
+ * Copyright(c) 2023 - Cornelis Networks, Inc.
+ */
+
+#include <linux/types.h>
+
+#include "hfi.h"
+#include "common.h"
+#include "device.h"
+#include "pinning.h"
+#include "mmu_rb.h"
+#include "user_sdma.h"
+#include "trace.h"
+
+struct sdma_mmu_node {
+ struct mmu_rb_node rb;
+ struct hfi1_user_sdma_pkt_q *pq;
+ struct page **pages;
+ unsigned int npages;
+};
+
+static bool sdma_rb_filter(struct mmu_rb_node *node, unsigned long addr,
+ unsigned long len);
+static int sdma_rb_evict(void *arg, struct mmu_rb_node *mnode, void *arg2,
+ bool *stop);
+static void sdma_rb_remove(void *arg, struct mmu_rb_node *mnode);
+
+static struct mmu_rb_ops sdma_rb_ops = {
+ .filter = sdma_rb_filter,
+ .evict = sdma_rb_evict,
+ .remove = sdma_rb_remove,
+};
+
+int hfi1_init_system_pinning(struct hfi1_user_sdma_pkt_q *pq)
+{
+ struct hfi1_devdata *dd = pq->dd;
+ int ret;
+
+ ret = hfi1_mmu_rb_register(pq, &sdma_rb_ops, dd->pport->hfi1_wq,
+ &pq->handler);
+ if (ret)
+ dd_dev_err(dd,
+ "[%u:%u] Failed to register system memory DMA support with MMU: %d\n",
+ pq->ctxt, pq->subctxt, ret);
+ return ret;
+}
+
+void hfi1_free_system_pinning(struct hfi1_user_sdma_pkt_q *pq)
+{
+ if (pq->handler)
+ hfi1_mmu_rb_unregister(pq->handler);
+}
+
+static u32 sdma_cache_evict(struct hfi1_user_sdma_pkt_q *pq, u32 npages)
+{
+ struct evict_data evict_data;
+
+ evict_data.cleared = 0;
+ evict_data.target = npages;
+ hfi1_mmu_rb_evict(pq->handler, &evict_data);
+ return evict_data.cleared;
+}
+
+static void unpin_vector_pages(struct mm_struct *mm, struct page **pages,
+ unsigned int start, unsigned int npages)
+{
+ hfi1_release_user_pages(mm, pages + start, npages, false);
+ kfree(pages);
+}
+
+static inline struct mm_struct *mm_from_sdma_node(struct sdma_mmu_node *node)
+{
+ return node->rb.handler->mn.mm;
+}
+
+static void free_system_node(struct sdma_mmu_node *node)
+{
+ if (node->npages) {
+ unpin_vector_pages(mm_from_sdma_node(node), node->pages, 0,
+ node->npages);
+ atomic_sub(node->npages, &node->pq->n_locked);
+ }
+ kfree(node);
+}
+
+/*
+ * kref_get()'s an additional kref on the returned rb_node to prevent rb_node
+ * from being released until after rb_node is assigned to an SDMA descriptor
+ * (struct sdma_desc) under add_system_iovec_to_sdma_packet(), even if the
+ * virtual address range for rb_node is invalidated between now and then.
+ */
+static struct sdma_mmu_node *find_system_node(struct mmu_rb_handler *handler,
+ unsigned long start,
+ unsigned long end)
+{
+ struct mmu_rb_node *rb_node;
+ unsigned long flags;
+
+ spin_lock_irqsave(&handler->lock, flags);
+ rb_node = hfi1_mmu_rb_get_first(handler, start, (end - start));
+ if (!rb_node) {
+ spin_unlock_irqrestore(&handler->lock, flags);
+ return NULL;
+ }
+
+ /* "safety" kref to prevent release before add_system_iovec_to_sdma_packet() */
+ kref_get(&rb_node->refcount);
+ spin_unlock_irqrestore(&handler->lock, flags);
+
+ return container_of(rb_node, struct sdma_mmu_node, rb);
+}
+
+static int pin_system_pages(struct user_sdma_request *req,
+ uintptr_t start_address, size_t length,
+ struct sdma_mmu_node *node, int npages)
+{
+ struct hfi1_user_sdma_pkt_q *pq = req->pq;
+ int pinned, cleared;
+ struct page **pages;
+
+ pages = kcalloc(npages, sizeof(*pages), GFP_KERNEL);
+ if (!pages)
+ return -ENOMEM;
+
+retry:
+ if (!hfi1_can_pin_pages(pq->dd, current->mm, atomic_read(&pq->n_locked),
+ npages)) {
+ SDMA_DBG(req, "Evicting: nlocked %u npages %u",
+ atomic_read(&pq->n_locked), npages);
+ cleared = sdma_cache_evict(pq, npages);
+ if (cleared >= npages)
+ goto retry;
+ }
+
+ SDMA_DBG(req, "Acquire user pages start_address %lx node->npages %u npages %u",
+ start_address, node->npages, npages);
+ pinned = hfi1_acquire_user_pages(current->mm, start_address, npages, 0,
+ pages);
+
+ if (pinned < 0) {
+ kfree(pages);
+ SDMA_DBG(req, "pinned %d", pinned);
+ return pinned;
+ }
+ if (pinned != npages) {
+ unpin_vector_pages(current->mm, pages, node->npages, pinned);
+ SDMA_DBG(req, "npages %u pinned %d", npages, pinned);
+ return -EFAULT;
+ }
+ node->rb.addr = start_address;
+ node->rb.len = length;
+ node->pages = pages;
+ node->npages = npages;
+ atomic_add(pinned, &pq->n_locked);
+ SDMA_DBG(req, "done. pinned %d", pinned);
+ return 0;
+}
+
+/*
+ * kref refcount on *node_p will be 2 on successful addition: one kref from
+ * kref_init() for mmu_rb_handler and one kref to prevent *node_p from being
+ * released until after *node_p is assigned to an SDMA descriptor (struct
+ * sdma_desc) under add_system_iovec_to_sdma_packet(), even if the virtual
+ * address range for *node_p is invalidated between now and then.
+ */
+static int add_system_pinning(struct user_sdma_request *req,
+ struct sdma_mmu_node **node_p,
+ unsigned long start, unsigned long len)
+
+{
+ struct hfi1_user_sdma_pkt_q *pq = req->pq;
+ struct sdma_mmu_node *node;
+ int ret;
+
+ node = kzalloc(sizeof(*node), GFP_KERNEL);
+ if (!node)
+ return -ENOMEM;
+
+ /* First kref "moves" to mmu_rb_handler */
+ kref_init(&node->rb.refcount);
+
+ /* "safety" kref to prevent release before add_system_iovec_to_sdma_packet() */
+ kref_get(&node->rb.refcount);
+
+ node->pq = pq;
+ ret = pin_system_pages(req, start, len, node, PFN_DOWN(len));
+ if (ret == 0) {
+ ret = hfi1_mmu_rb_insert(pq->handler, &node->rb);
+ if (ret)
+ free_system_node(node);
+ else
+ *node_p = node;
+
+ return ret;
+ }
+
+ kfree(node);
+ return ret;
+}
+
+static int get_system_cache_entry(struct user_sdma_request *req,
+ struct sdma_mmu_node **node_p,
+ size_t req_start, size_t req_len)
+{
+ struct hfi1_user_sdma_pkt_q *pq = req->pq;
+ u64 start = ALIGN_DOWN(req_start, PAGE_SIZE);
+ u64 end = PFN_ALIGN(req_start + req_len);
+ int ret;
+
+ if ((end - start) == 0) {
+ SDMA_DBG(req,
+ "Request for empty cache entry req_start %lx req_len %lx start %llx end %llx",
+ req_start, req_len, start, end);
+ return -EINVAL;
+ }
+
+ SDMA_DBG(req, "req_start %lx req_len %lu", req_start, req_len);
+
+ while (1) {
+ struct sdma_mmu_node *node =
+ find_system_node(pq->handler, start, end);
+ u64 prepend_len = 0;
+
+ SDMA_DBG(req, "node %p start %llx end %llu", node, start, end);
+ if (!node) {
+ ret = add_system_pinning(req, node_p, start,
+ end - start);
+ if (ret == -EEXIST) {
+ /*
+ * Another execution context has inserted a
+ * conficting entry first.
+ */
+ continue;
+ }
+ return ret;
+ }
+
+ if (node->rb.addr <= start) {
+ /*
+ * This entry covers at least part of the region. If it doesn't extend
+ * to the end, then this will be called again for the next segment.
+ */
+ *node_p = node;
+ return 0;
+ }
+
+ SDMA_DBG(req, "prepend: node->rb.addr %lx, node->rb.refcount %d",
+ node->rb.addr, kref_read(&node->rb.refcount));
+ prepend_len = node->rb.addr - start;
+
+ /*
+ * This node will not be returned, instead a new node
+ * will be. So release the reference.
+ */
+ kref_put(&node->rb.refcount, hfi1_mmu_rb_release);
+
+ /* Prepend a node to cover the beginning of the allocation */
+ ret = add_system_pinning(req, node_p, start, prepend_len);
+ if (ret == -EEXIST) {
+ /* Another execution context has inserted a conficting entry first. */
+ continue;
+ }
+ return ret;
+ }
+}
+
+static void sdma_mmu_rb_node_get(void *ctx)
+{
+ struct mmu_rb_node *node = ctx;
+
+ kref_get(&node->refcount);
+}
+
+static void sdma_mmu_rb_node_put(void *ctx)
+{
+ struct sdma_mmu_node *node = ctx;
+
+ kref_put(&node->rb.refcount, hfi1_mmu_rb_release);
+}
+
+static int add_mapping_to_sdma_packet(struct user_sdma_request *req,
+ struct user_sdma_txreq *tx,
+ struct sdma_mmu_node *cache_entry,
+ size_t start,
+ size_t from_this_cache_entry)
+{
+ struct hfi1_user_sdma_pkt_q *pq = req->pq;
+ unsigned int page_offset;
+ unsigned int from_this_page;
+ size_t page_index;
+ void *ctx;
+ int ret;
+
+ /*
+ * Because the cache may be more fragmented than the memory that is being accessed,
+ * it's not strictly necessary to have a descriptor per cache entry.
+ */
+
+ while (from_this_cache_entry) {
+ page_index = PFN_DOWN(start - cache_entry->rb.addr);
+
+ if (page_index >= cache_entry->npages) {
+ SDMA_DBG(req,
+ "Request for page_index %zu >= cache_entry->npages %u",
+ page_index, cache_entry->npages);
+ return -EINVAL;
+ }
+
+ page_offset = start - ALIGN_DOWN(start, PAGE_SIZE);
+ from_this_page = PAGE_SIZE - page_offset;
+
+ if (from_this_page < from_this_cache_entry) {
+ ctx = NULL;
+ } else {
+ /*
+ * In the case they are equal the next line has no practical effect,
+ * but it's better to do a register to register copy than a conditional
+ * branch.
+ */
+ from_this_page = from_this_cache_entry;
+ ctx = cache_entry;
+ }
+
+ ret = sdma_txadd_page(pq->dd, &tx->txreq,
+ cache_entry->pages[page_index],
+ page_offset, from_this_page,
+ ctx,
+ sdma_mmu_rb_node_get,
+ sdma_mmu_rb_node_put);
+ if (ret) {
+ /*
+ * When there's a failure, the entire request is freed by
+ * user_sdma_send_pkts().
+ */
+ SDMA_DBG(req,
+ "sdma_txadd_page failed %d page_index %lu page_offset %u from_this_page %u",
+ ret, page_index, page_offset, from_this_page);
+ return ret;
+ }
+ start += from_this_page;
+ from_this_cache_entry -= from_this_page;
+ }
+ return 0;
+}
+
+static int add_system_iovec_to_sdma_packet(struct user_sdma_request *req,
+ struct user_sdma_txreq *tx,
+ struct user_sdma_iovec *iovec,
+ size_t from_this_iovec)
+{
+ while (from_this_iovec > 0) {
+ struct sdma_mmu_node *cache_entry;
+ size_t from_this_cache_entry;
+ size_t start;
+ int ret;
+
+ start = (uintptr_t)iovec->iov.iov_base + iovec->offset;
+ ret = get_system_cache_entry(req, &cache_entry, start,
+ from_this_iovec);
+ if (ret) {
+ SDMA_DBG(req, "pin system segment failed %d", ret);
+ return ret;
+ }
+
+ from_this_cache_entry = cache_entry->rb.len - (start - cache_entry->rb.addr);
+ if (from_this_cache_entry > from_this_iovec)
+ from_this_cache_entry = from_this_iovec;
+
+ ret = add_mapping_to_sdma_packet(req, tx, cache_entry, start,
+ from_this_cache_entry);
+
+ /*
+ * Done adding cache_entry to zero or more sdma_desc. Can
+ * kref_put() the "safety" kref taken under
+ * get_system_cache_entry().
+ */
+ kref_put(&cache_entry->rb.refcount, hfi1_mmu_rb_release);
+
+ if (ret) {
+ SDMA_DBG(req, "add system segment failed %d", ret);
+ return ret;
+ }
+
+ iovec->offset += from_this_cache_entry;
+ from_this_iovec -= from_this_cache_entry;
+ }
+
+ return 0;
+}
+
+/*
+ * Add up to pkt_data_remaining bytes to the txreq, starting at the current
+ * offset in the given iovec entry and continuing until all data has been added
+ * to the iovec or the iovec entry type changes.
+ *
+ * On success, prior to returning, adjust pkt_data_remaining, req->iov_idx, and
+ * the offset value in req->iov[req->iov_idx] to reflect the data that has been
+ * consumed.
+ */
+int hfi1_add_pages_to_sdma_packet(struct user_sdma_request *req,
+ struct user_sdma_txreq *tx,
+ struct user_sdma_iovec *iovec,
+ u32 *pkt_data_remaining)
+{
+ size_t remaining_to_add = *pkt_data_remaining;
+ /*
+ * Walk through iovec entries, ensure the associated pages
+ * are pinned and mapped, add data to the packet until no more
+ * data remains to be added or the iovec entry type changes.
+ */
+ while (remaining_to_add > 0) {
+ struct user_sdma_iovec *cur_iovec;
+ size_t from_this_iovec;
+ int ret;
+
+ cur_iovec = iovec;
+ from_this_iovec = iovec->iov.iov_len - iovec->offset;
+
+ if (from_this_iovec > remaining_to_add) {
+ from_this_iovec = remaining_to_add;
+ } else {
+ /* The current iovec entry will be consumed by this pass. */
+ req->iov_idx++;
+ iovec++;
+ }
+
+ ret = add_system_iovec_to_sdma_packet(req, tx, cur_iovec,
+ from_this_iovec);
+ if (ret)
+ return ret;
+
+ remaining_to_add -= from_this_iovec;
+ }
+ *pkt_data_remaining = remaining_to_add;
+
+ return 0;
+}
+
+static bool sdma_rb_filter(struct mmu_rb_node *node, unsigned long addr,
+ unsigned long len)
+{
+ return (bool)(node->addr == addr);
+}
+
+/*
+ * Return 1 to remove the node from the rb tree and call the remove op.
+ *
+ * Called with the rb tree lock held.
+ */
+static int sdma_rb_evict(void *arg, struct mmu_rb_node *mnode,
+ void *evict_arg, bool *stop)
+{
+ struct sdma_mmu_node *node =
+ container_of(mnode, struct sdma_mmu_node, rb);
+ struct evict_data *evict_data = evict_arg;
+
+ /* this node will be evicted, add its pages to our count */
+ evict_data->cleared += node->npages;
+
+ /* have enough pages been cleared? */
+ if (evict_data->cleared >= evict_data->target)
+ *stop = true;
+
+ return 1; /* remove this node */
+}
+
+static void sdma_rb_remove(void *arg, struct mmu_rb_node *mnode)
+{
+ struct sdma_mmu_node *node =
+ container_of(mnode, struct sdma_mmu_node, rb);
+
+ free_system_node(node);
+}