--- /dev/null
- dmb_node->cpu_addr = kzalloc(dmb_node->len, GFP_KERNEL |
- __GFP_NOWARN | __GFP_NORETRY |
- __GFP_NOMEMALLOC);
- if (!dmb_node->cpu_addr) {
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Functions for dibs loopback/loopback-ism device.
+ *
+ * Copyright (c) 2024, Alibaba Inc.
+ *
+ * Author: Wen Gu <guwen@linux.alibaba.com>
+ * Tony Lu <tonylu@linux.alibaba.com>
+ *
+ */
+
+#include <linux/bitops.h>
+#include <linux/device.h>
+#include <linux/dibs.h>
++#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+#include "dibs_loopback.h"
+
+#define DIBS_LO_SUPPORT_NOCOPY 0x1
+#define DIBS_DMA_ADDR_INVALID (~(dma_addr_t)0)
+
+static const char dibs_lo_dev_name[] = "lo";
+/* global loopback device */
+static struct dibs_lo_dev *lo_dev;
+
+static u16 dibs_lo_get_fabric_id(struct dibs_dev *dibs)
+{
+ return DIBS_LOOPBACK_FABRIC;
+}
+
+static int dibs_lo_query_rgid(struct dibs_dev *dibs, const uuid_t *rgid,
+ u32 vid_valid, u32 vid)
+{
+ /* rgid should be the same as lgid */
+ if (!uuid_equal(rgid, &dibs->gid))
+ return -ENETUNREACH;
+ return 0;
+}
+
+static int dibs_lo_max_dmbs(void)
+{
+ return DIBS_LO_MAX_DMBS;
+}
+
+static int dibs_lo_register_dmb(struct dibs_dev *dibs, struct dibs_dmb *dmb,
+ struct dibs_client *client)
+{
+ struct dibs_lo_dmb_node *dmb_node, *tmp_node;
+ struct dibs_lo_dev *ldev;
++ struct folio *folio;
+ unsigned long flags;
+ int sba_idx, rc;
+
+ ldev = dibs->drv_priv;
+ sba_idx = dmb->idx;
+ /* check space for new dmb */
+ for_each_clear_bit(sba_idx, ldev->sba_idx_mask, DIBS_LO_MAX_DMBS) {
+ if (!test_and_set_bit(sba_idx, ldev->sba_idx_mask))
+ break;
+ }
+ if (sba_idx == DIBS_LO_MAX_DMBS)
+ return -ENOSPC;
+
+ dmb_node = kzalloc(sizeof(*dmb_node), GFP_KERNEL);
+ if (!dmb_node) {
+ rc = -ENOMEM;
+ goto err_bit;
+ }
+
+ dmb_node->sba_idx = sba_idx;
+ dmb_node->len = dmb->dmb_len;
- kfree(dmb_node->cpu_addr);
++
++ /* not critical; fail under memory pressure and fallback to TCP */
++ folio = folio_alloc(GFP_KERNEL | __GFP_NOWARN | __GFP_NOMEMALLOC |
++ __GFP_NORETRY | __GFP_ZERO,
++ get_order(dmb_node->len));
++ if (!folio) {
+ rc = -ENOMEM;
+ goto err_node;
+ }
++ dmb_node->cpu_addr = folio_address(folio);
+ dmb_node->dma_addr = DIBS_DMA_ADDR_INVALID;
+ refcount_set(&dmb_node->refcnt, 1);
+
+again:
+ /* add new dmb into hash table */
+ get_random_bytes(&dmb_node->token, sizeof(dmb_node->token));
+ write_lock_bh(&ldev->dmb_ht_lock);
+ hash_for_each_possible(ldev->dmb_ht, tmp_node, list, dmb_node->token) {
+ if (tmp_node->token == dmb_node->token) {
+ write_unlock_bh(&ldev->dmb_ht_lock);
+ goto again;
+ }
+ }
+ hash_add(ldev->dmb_ht, &dmb_node->list, dmb_node->token);
+ write_unlock_bh(&ldev->dmb_ht_lock);
+ atomic_inc(&ldev->dmb_cnt);
+
+ dmb->idx = dmb_node->sba_idx;
+ dmb->dmb_tok = dmb_node->token;
+ dmb->cpu_addr = dmb_node->cpu_addr;
+ dmb->dma_addr = dmb_node->dma_addr;
+ dmb->dmb_len = dmb_node->len;
+
+ spin_lock_irqsave(&dibs->lock, flags);
+ dibs->dmb_clientid_arr[sba_idx] = client->id;
+ spin_unlock_irqrestore(&dibs->lock, flags);
+
+ return 0;
+
+err_node:
+ kfree(dmb_node);
+err_bit:
+ clear_bit(sba_idx, ldev->sba_idx_mask);
+ return rc;
+}
+
+static void __dibs_lo_unregister_dmb(struct dibs_lo_dev *ldev,
+ struct dibs_lo_dmb_node *dmb_node)
+{
+ /* remove dmb from hash table */
+ write_lock_bh(&ldev->dmb_ht_lock);
+ hash_del(&dmb_node->list);
+ write_unlock_bh(&ldev->dmb_ht_lock);
+
+ clear_bit(dmb_node->sba_idx, ldev->sba_idx_mask);
++ folio_put(virt_to_folio(dmb_node->cpu_addr));
+ kfree(dmb_node);
+
+ if (atomic_dec_and_test(&ldev->dmb_cnt))
+ wake_up(&ldev->ldev_release);
+}
+
+static int dibs_lo_unregister_dmb(struct dibs_dev *dibs, struct dibs_dmb *dmb)
+{
+ struct dibs_lo_dmb_node *dmb_node = NULL, *tmp_node;
+ struct dibs_lo_dev *ldev;
+ unsigned long flags;
+
+ ldev = dibs->drv_priv;
+
+ /* find dmb from hash table */
+ read_lock_bh(&ldev->dmb_ht_lock);
+ hash_for_each_possible(ldev->dmb_ht, tmp_node, list, dmb->dmb_tok) {
+ if (tmp_node->token == dmb->dmb_tok) {
+ dmb_node = tmp_node;
+ break;
+ }
+ }
+ read_unlock_bh(&ldev->dmb_ht_lock);
+ if (!dmb_node)
+ return -EINVAL;
+
+ if (refcount_dec_and_test(&dmb_node->refcnt)) {
+ spin_lock_irqsave(&dibs->lock, flags);
+ dibs->dmb_clientid_arr[dmb_node->sba_idx] = NO_DIBS_CLIENT;
+ spin_unlock_irqrestore(&dibs->lock, flags);
+
+ __dibs_lo_unregister_dmb(ldev, dmb_node);
+ }
+ return 0;
+}
+
+static int dibs_lo_support_dmb_nocopy(struct dibs_dev *dibs)
+{
+ return DIBS_LO_SUPPORT_NOCOPY;
+}
+
+static int dibs_lo_attach_dmb(struct dibs_dev *dibs, struct dibs_dmb *dmb)
+{
+ struct dibs_lo_dmb_node *dmb_node = NULL, *tmp_node;
+ struct dibs_lo_dev *ldev;
+
+ ldev = dibs->drv_priv;
+
+ /* find dmb_node according to dmb->dmb_tok */
+ read_lock_bh(&ldev->dmb_ht_lock);
+ hash_for_each_possible(ldev->dmb_ht, tmp_node, list, dmb->dmb_tok) {
+ if (tmp_node->token == dmb->dmb_tok) {
+ dmb_node = tmp_node;
+ break;
+ }
+ }
+ if (!dmb_node) {
+ read_unlock_bh(&ldev->dmb_ht_lock);
+ return -EINVAL;
+ }
+ read_unlock_bh(&ldev->dmb_ht_lock);
+
+ if (!refcount_inc_not_zero(&dmb_node->refcnt))
+ /* the dmb is being unregistered, but has
+ * not been removed from the hash table.
+ */
+ return -EINVAL;
+
+ /* provide dmb information */
+ dmb->idx = dmb_node->sba_idx;
+ dmb->dmb_tok = dmb_node->token;
+ dmb->cpu_addr = dmb_node->cpu_addr;
+ dmb->dma_addr = dmb_node->dma_addr;
+ dmb->dmb_len = dmb_node->len;
+ return 0;
+}
+
+static int dibs_lo_detach_dmb(struct dibs_dev *dibs, u64 token)
+{
+ struct dibs_lo_dmb_node *dmb_node = NULL, *tmp_node;
+ struct dibs_lo_dev *ldev;
+
+ ldev = dibs->drv_priv;
+
+ /* find dmb_node according to dmb->dmb_tok */
+ read_lock_bh(&ldev->dmb_ht_lock);
+ hash_for_each_possible(ldev->dmb_ht, tmp_node, list, token) {
+ if (tmp_node->token == token) {
+ dmb_node = tmp_node;
+ break;
+ }
+ }
+ if (!dmb_node) {
+ read_unlock_bh(&ldev->dmb_ht_lock);
+ return -EINVAL;
+ }
+ read_unlock_bh(&ldev->dmb_ht_lock);
+
+ if (refcount_dec_and_test(&dmb_node->refcnt))
+ __dibs_lo_unregister_dmb(ldev, dmb_node);
+ return 0;
+}
+
+static int dibs_lo_move_data(struct dibs_dev *dibs, u64 dmb_tok,
+ unsigned int idx, bool sf, unsigned int offset,
+ void *data, unsigned int size)
+{
+ struct dibs_lo_dmb_node *rmb_node = NULL, *tmp_node;
+ struct dibs_lo_dev *ldev;
+ u16 s_mask;
+ u8 client_id;
+ u32 sba_idx;
+
+ ldev = dibs->drv_priv;
+
+ read_lock_bh(&ldev->dmb_ht_lock);
+ hash_for_each_possible(ldev->dmb_ht, tmp_node, list, dmb_tok) {
+ if (tmp_node->token == dmb_tok) {
+ rmb_node = tmp_node;
+ break;
+ }
+ }
+ if (!rmb_node) {
+ read_unlock_bh(&ldev->dmb_ht_lock);
+ return -EINVAL;
+ }
+ memcpy((char *)rmb_node->cpu_addr + offset, data, size);
+ sba_idx = rmb_node->sba_idx;
+ read_unlock_bh(&ldev->dmb_ht_lock);
+
+ if (!sf)
+ return 0;
+
+ spin_lock(&dibs->lock);
+ client_id = dibs->dmb_clientid_arr[sba_idx];
+ s_mask = ror16(0x1000, idx);
+ if (likely(client_id != NO_DIBS_CLIENT && dibs->subs[client_id]))
+ dibs->subs[client_id]->ops->handle_irq(dibs, sba_idx, s_mask);
+ spin_unlock(&dibs->lock);
+
+ return 0;
+}
+
+static const struct dibs_dev_ops dibs_lo_ops = {
+ .get_fabric_id = dibs_lo_get_fabric_id,
+ .query_remote_gid = dibs_lo_query_rgid,
+ .max_dmbs = dibs_lo_max_dmbs,
+ .register_dmb = dibs_lo_register_dmb,
+ .unregister_dmb = dibs_lo_unregister_dmb,
+ .move_data = dibs_lo_move_data,
+ .support_mmapped_rdmb = dibs_lo_support_dmb_nocopy,
+ .attach_dmb = dibs_lo_attach_dmb,
+ .detach_dmb = dibs_lo_detach_dmb,
+};
+
+static void dibs_lo_dev_init(struct dibs_lo_dev *ldev)
+{
+ rwlock_init(&ldev->dmb_ht_lock);
+ hash_init(ldev->dmb_ht);
+ atomic_set(&ldev->dmb_cnt, 0);
+ init_waitqueue_head(&ldev->ldev_release);
+}
+
+static void dibs_lo_dev_exit(struct dibs_lo_dev *ldev)
+{
+ if (atomic_read(&ldev->dmb_cnt))
+ wait_event(ldev->ldev_release, !atomic_read(&ldev->dmb_cnt));
+}
+
+static int dibs_lo_dev_probe(void)
+{
+ struct dibs_lo_dev *ldev;
+ struct dibs_dev *dibs;
+ int ret;
+
+ ldev = kzalloc(sizeof(*ldev), GFP_KERNEL);
+ if (!ldev)
+ return -ENOMEM;
+
+ dibs = dibs_dev_alloc();
+ if (!dibs) {
+ kfree(ldev);
+ return -ENOMEM;
+ }
+
+ ldev->dibs = dibs;
+ dibs->drv_priv = ldev;
+ dibs_lo_dev_init(ldev);
+ uuid_gen(&dibs->gid);
+ dibs->ops = &dibs_lo_ops;
+
+ dibs->dev.parent = NULL;
+ dev_set_name(&dibs->dev, "%s", dibs_lo_dev_name);
+
+ ret = dibs_dev_add(dibs);
+ if (ret)
+ goto err_reg;
+ lo_dev = ldev;
+ return 0;
+
+err_reg:
+ kfree(dibs->dmb_clientid_arr);
+ /* pairs with dibs_dev_alloc() */
+ put_device(&dibs->dev);
+ kfree(ldev);
+
+ return ret;
+}
+
+static void dibs_lo_dev_remove(void)
+{
+ if (!lo_dev)
+ return;
+
+ dibs_dev_del(lo_dev->dibs);
+ dibs_lo_dev_exit(lo_dev);
+ /* pairs with dibs_dev_alloc() */
+ put_device(&lo_dev->dibs->dev);
+ kfree(lo_dev);
+ lo_dev = NULL;
+}
+
+int dibs_loopback_init(void)
+{
+ return dibs_lo_dev_probe();
+}
+
+void dibs_loopback_exit(void)
+{
+ dibs_lo_dev_remove();
+}
projects / thirdparty / linux.git / commitdiff
