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code / linux / torvalds / linux / 8808981baf96e1b3dea1f08461e4d958aa0dbde1 / . / drivers / infiniband / hw / mlx5 / odp.c
blob: 1ab676b6689408005eb357717e62f1b39b3b1bff [file] [log] [blame]
/*
* Copyright (c) 2013-2015, Mellanox Technologies. All rights reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the
* OpenIB.org BSD license below:
*
* 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.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#include <rdma/ib_umem.h>
#include <rdma/ib_umem_odp.h>
#include <linux/kernel.h>
#include "mlx5_ib.h"
#include "cmd.h"
#include "qp.h"
#include <linux/mlx5/eq.h>
/* Contains the details of a pagefault. */
struct mlx5_pagefault {
u32 bytes_committed;
u32 token;
u8 event_subtype;
u8 type;
union {
/* Initiator or send message responder pagefault details. */
struct {
/* Received packet size, only valid for responders. */
u32 packet_size;
/*
* Number of resource holding WQE, depends on type.
*/
u32 wq_num;
/*
* WQE index. Refers to either the send queue or
* receive queue, according to event_subtype.
*/
u16 wqe_index;
} wqe;
/* RDMA responder pagefault details */
struct {
u32 r_key;
/*
* Received packet size, minimal size page fault
* resolution required for forward progress.
*/
u32 packet_size;
u32 rdma_op_len;
u64 rdma_va;
} rdma;
};
struct mlx5_ib_pf_eq *eq;
struct work_struct work;
};
#define MAX_PREFETCH_LEN (4*1024*1024U)
/* Timeout in ms to wait for an active mmu notifier to complete when handling
* a pagefault. */
#define MMU_NOTIFIER_TIMEOUT 1000
#define MLX5_IMR_MTT_BITS (30 - PAGE_SHIFT)
#define MLX5_IMR_MTT_SHIFT (MLX5_IMR_MTT_BITS + PAGE_SHIFT)
#define MLX5_IMR_MTT_ENTRIES BIT_ULL(MLX5_IMR_MTT_BITS)
#define MLX5_IMR_MTT_SIZE BIT_ULL(MLX5_IMR_MTT_SHIFT)
#define MLX5_IMR_MTT_MASK (~(MLX5_IMR_MTT_SIZE - 1))
#define MLX5_KSM_PAGE_SHIFT MLX5_IMR_MTT_SHIFT
static u64 mlx5_imr_ksm_entries;
static void populate_klm(struct mlx5_klm *pklm, size_t idx, size_t nentries,
struct mlx5_ib_mr *imr, int flags)
{
struct mlx5_klm *end = pklm + nentries;
if (flags & MLX5_IB_UPD_XLT_ZAP) {
for (; pklm != end; pklm++, idx++) {
pklm->bcount = cpu_to_be32(MLX5_IMR_MTT_SIZE);
pklm->key = cpu_to_be32(imr->dev->null_mkey);
pklm->va = 0;
}
return;
}
/*
* The locking here is pretty subtle. Ideally the implicit_children
* xarray would be protected by the umem_mutex, however that is not
* possible. Instead this uses a weaker update-then-lock pattern:
*
* srcu_read_lock()
* xa_store()
* mutex_lock(umem_mutex)
* mlx5_ib_update_xlt()
* mutex_unlock(umem_mutex)
* destroy lkey
*
* ie any change the xarray must be followed by the locked update_xlt
* before destroying.
*
* The umem_mutex provides the acquire/release semantic needed to make
* the xa_store() visible to a racing thread. While SRCU is not
* technically required, using it gives consistent use of the SRCU
* locking around the xarray.
*/
lockdep_assert_held(&to_ib_umem_odp(imr->umem)->umem_mutex);
lockdep_assert_held(&imr->dev->odp_srcu);
for (; pklm != end; pklm++, idx++) {
struct mlx5_ib_mr *mtt = xa_load(&imr->implicit_children, idx);
pklm->bcount = cpu_to_be32(MLX5_IMR_MTT_SIZE);
if (mtt) {
pklm->key = cpu_to_be32(mtt->ibmr.lkey);
pklm->va = cpu_to_be64(idx * MLX5_IMR_MTT_SIZE);
} else {
pklm->key = cpu_to_be32(imr->dev->null_mkey);
pklm->va = 0;
}
}
}
static u64 umem_dma_to_mtt(dma_addr_t umem_dma)
{
u64 mtt_entry = umem_dma & ODP_DMA_ADDR_MASK;
if (umem_dma & ODP_READ_ALLOWED_BIT)
mtt_entry |= MLX5_IB_MTT_READ;
if (umem_dma & ODP_WRITE_ALLOWED_BIT)
mtt_entry |= MLX5_IB_MTT_WRITE;
return mtt_entry;
}
static void populate_mtt(__be64 *pas, size_t idx, size_t nentries,
struct mlx5_ib_mr *mr, int flags)
{
struct ib_umem_odp *odp = to_ib_umem_odp(mr->umem);
dma_addr_t pa;
size_t i;
if (flags & MLX5_IB_UPD_XLT_ZAP)
return;
for (i = 0; i < nentries; i++) {
pa = odp->dma_list[idx + i];
pas[i] = cpu_to_be64(umem_dma_to_mtt(pa));
}
}
void mlx5_odp_populate_xlt(void *xlt, size_t idx, size_t nentries,
struct mlx5_ib_mr *mr, int flags)
{
if (flags & MLX5_IB_UPD_XLT_INDIRECT) {
populate_klm(xlt, idx, nentries, mr, flags);
} else {
populate_mtt(xlt, idx, nentries, mr, flags);
}
}
static void dma_fence_odp_mr(struct mlx5_ib_mr *mr)
{
struct ib_umem_odp *odp = to_ib_umem_odp(mr->umem);
/* Ensure mlx5_ib_invalidate_range() will not touch the MR any more */
mutex_lock(&odp->umem_mutex);
if (odp->npages) {
mlx5_mr_cache_invalidate(mr);
ib_umem_odp_unmap_dma_pages(odp, ib_umem_start(odp),
ib_umem_end(odp));
WARN_ON(odp->npages);
}
odp->private = NULL;
mutex_unlock(&odp->umem_mutex);
if (!mr->cache_ent) {
mlx5_core_destroy_mkey(mr->dev->mdev, &mr->mmkey);
WARN_ON(mr->descs);
}
}
/*
* This must be called after the mr has been removed from implicit_children
* and the SRCU synchronized. NOTE: The MR does not necessarily have to be
* empty here, parallel page faults could have raced with the free process and
* added pages to it.
*/
static void free_implicit_child_mr(struct mlx5_ib_mr *mr, bool need_imr_xlt)
{
struct mlx5_ib_mr *imr = mr->parent;
struct ib_umem_odp *odp_imr = to_ib_umem_odp(imr->umem);
struct ib_umem_odp *odp = to_ib_umem_odp(mr->umem);
unsigned long idx = ib_umem_start(odp) >> MLX5_IMR_MTT_SHIFT;
int srcu_key;
/* implicit_child_mr's are not allowed to have deferred work */
WARN_ON(atomic_read(&mr->num_deferred_work));
if (need_imr_xlt) {
srcu_key = srcu_read_lock(&mr->dev->odp_srcu);
mutex_lock(&odp_imr->umem_mutex);
mlx5_ib_update_xlt(mr->parent, idx, 1, 0,
MLX5_IB_UPD_XLT_INDIRECT |
MLX5_IB_UPD_XLT_ATOMIC);
mutex_unlock(&odp_imr->umem_mutex);
srcu_read_unlock(&mr->dev->odp_srcu, srcu_key);
}
dma_fence_odp_mr(mr);
mr->parent = NULL;
mlx5_mr_cache_free(mr->dev, mr);
ib_umem_odp_release(odp);
if (atomic_dec_and_test(&imr->num_deferred_work))
wake_up(&imr->q_deferred_work);
}
static void free_implicit_child_mr_work(struct work_struct *work)
{
struct mlx5_ib_mr *mr =
container_of(work, struct mlx5_ib_mr, odp_destroy.work);
free_implicit_child_mr(mr, true);
}
static void free_implicit_child_mr_rcu(struct rcu_head *head)
{
struct mlx5_ib_mr *mr =
container_of(head, struct mlx5_ib_mr, odp_destroy.rcu);
/* Freeing a MR is a sleeping operation, so bounce to a work queue */
INIT_WORK(&mr->odp_destroy.work, free_implicit_child_mr_work);
queue_work(system_unbound_wq, &mr->odp_destroy.work);
}
static void destroy_unused_implicit_child_mr(struct mlx5_ib_mr *mr)
{
struct ib_umem_odp *odp = to_ib_umem_odp(mr->umem);
unsigned long idx = ib_umem_start(odp) >> MLX5_IMR_MTT_SHIFT;
struct mlx5_ib_mr *imr = mr->parent;
xa_lock(&imr->implicit_children);
/*
* This can race with mlx5_ib_free_implicit_mr(), the first one to
* reach the xa lock wins the race and destroys the MR.
*/
if (__xa_cmpxchg(&imr->implicit_children, idx, mr, NULL, GFP_ATOMIC) !=
mr)
goto out_unlock;
atomic_inc(&imr->num_deferred_work);
call_srcu(&mr->dev->odp_srcu, &mr->odp_destroy.rcu,
free_implicit_child_mr_rcu);
out_unlock:
xa_unlock(&imr->implicit_children);
}
static bool mlx5_ib_invalidate_range(struct mmu_interval_notifier *mni,
const struct mmu_notifier_range *range,
unsigned long cur_seq)
{
struct ib_umem_odp *umem_odp =
container_of(mni, struct ib_umem_odp, notifier);
struct mlx5_ib_mr *mr;
const u64 umr_block_mask = (MLX5_UMR_MTT_ALIGNMENT /
sizeof(struct mlx5_mtt)) - 1;
u64 idx = 0, blk_start_idx = 0;
u64 invalidations = 0;
unsigned long start;
unsigned long end;
int in_block = 0;
u64 addr;
if (!mmu_notifier_range_blockable(range))
return false;
mutex_lock(&umem_odp->umem_mutex);
mmu_interval_set_seq(mni, cur_seq);
/*
* If npages is zero then umem_odp->private may not be setup yet. This
* does not complete until after the first page is mapped for DMA.
*/
if (!umem_odp->npages)
goto out;
mr = umem_odp->private;
start = max_t(u64, ib_umem_start(umem_odp), range->start);
end = min_t(u64, ib_umem_end(umem_odp), range->end);
/*
* Iteration one - zap the HW's MTTs. The notifiers_count ensures that
* while we are doing the invalidation, no page fault will attempt to
* overwrite the same MTTs. Concurent invalidations might race us,
* but they will write 0s as well, so no difference in the end result.
*/
for (addr = start; addr < end; addr += BIT(umem_odp->page_shift)) {
idx = (addr - ib_umem_start(umem_odp)) >> umem_odp->page_shift;
/*
* Strive to write the MTTs in chunks, but avoid overwriting
* non-existing MTTs. The huristic here can be improved to
* estimate the cost of another UMR vs. the cost of bigger
* UMR.
*/
if (umem_odp->dma_list[idx] &
(ODP_READ_ALLOWED_BIT | ODP_WRITE_ALLOWED_BIT)) {
if (!in_block) {
blk_start_idx = idx;
in_block = 1;
}
/* Count page invalidations */
invalidations += idx - blk_start_idx + 1;
} else {
u64 umr_offset = idx & umr_block_mask;
if (in_block && umr_offset == 0) {
mlx5_ib_update_xlt(mr, blk_start_idx,
idx - blk_start_idx, 0,
MLX5_IB_UPD_XLT_ZAP |
MLX5_IB_UPD_XLT_ATOMIC);
in_block = 0;
}
}
}
if (in_block)
mlx5_ib_update_xlt(mr, blk_start_idx,
idx - blk_start_idx + 1, 0,
MLX5_IB_UPD_XLT_ZAP |
MLX5_IB_UPD_XLT_ATOMIC);
mlx5_update_odp_stats(mr, invalidations, invalidations);
/*
* We are now sure that the device will not access the
* memory. We can safely unmap it, and mark it as dirty if
* needed.
*/
ib_umem_odp_unmap_dma_pages(umem_odp, start, end);
if (unlikely(!umem_odp->npages && mr->parent))
destroy_unused_implicit_child_mr(mr);
out:
mutex_unlock(&umem_odp->umem_mutex);
return true;
}
const struct mmu_interval_notifier_ops mlx5_mn_ops = {
.invalidate = mlx5_ib_invalidate_range,
};
void mlx5_ib_internal_fill_odp_caps(struct mlx5_ib_dev *dev)
{
struct ib_odp_caps *caps = &dev->odp_caps;
memset(caps, 0, sizeof(*caps));
if (!MLX5_CAP_GEN(dev->mdev, pg) ||
!mlx5_ib_can_use_umr(dev, true, 0))
return;
caps->general_caps = IB_ODP_SUPPORT;
if (MLX5_CAP_GEN(dev->mdev, umr_extended_translation_offset))
dev->odp_max_size = U64_MAX;
else
dev->odp_max_size = BIT_ULL(MLX5_MAX_UMR_SHIFT + PAGE_SHIFT);
if (MLX5_CAP_ODP(dev->mdev, ud_odp_caps.send))
caps->per_transport_caps.ud_odp_caps |= IB_ODP_SUPPORT_SEND;
if (MLX5_CAP_ODP(dev->mdev, ud_odp_caps.srq_receive))
caps->per_transport_caps.ud_odp_caps |= IB_ODP_SUPPORT_SRQ_RECV;
if (MLX5_CAP_ODP(dev->mdev, rc_odp_caps.send))
caps->per_transport_caps.rc_odp_caps |= IB_ODP_SUPPORT_SEND;
if (MLX5_CAP_ODP(dev->mdev, rc_odp_caps.receive))
caps->per_transport_caps.rc_odp_caps |= IB_ODP_SUPPORT_RECV;
if (MLX5_CAP_ODP(dev->mdev, rc_odp_caps.write))
caps->per_transport_caps.rc_odp_caps |= IB_ODP_SUPPORT_WRITE;
if (MLX5_CAP_ODP(dev->mdev, rc_odp_caps.read))
caps->per_transport_caps.rc_odp_caps |= IB_ODP_SUPPORT_READ;
if (MLX5_CAP_ODP(dev->mdev, rc_odp_caps.atomic))
caps->per_transport_caps.rc_odp_caps |= IB_ODP_SUPPORT_ATOMIC;
if (MLX5_CAP_ODP(dev->mdev, rc_odp_caps.srq_receive))
caps->per_transport_caps.rc_odp_caps |= IB_ODP_SUPPORT_SRQ_RECV;
if (MLX5_CAP_ODP(dev->mdev, xrc_odp_caps.send))
caps->per_transport_caps.xrc_odp_caps |= IB_ODP_SUPPORT_SEND;
if (MLX5_CAP_ODP(dev->mdev, xrc_odp_caps.receive))
caps->per_transport_caps.xrc_odp_caps |= IB_ODP_SUPPORT_RECV;
if (MLX5_CAP_ODP(dev->mdev, xrc_odp_caps.write))
caps->per_transport_caps.xrc_odp_caps |= IB_ODP_SUPPORT_WRITE;
if (MLX5_CAP_ODP(dev->mdev, xrc_odp_caps.read))
caps->per_transport_caps.xrc_odp_caps |= IB_ODP_SUPPORT_READ;
if (MLX5_CAP_ODP(dev->mdev, xrc_odp_caps.atomic))
caps->per_transport_caps.xrc_odp_caps |= IB_ODP_SUPPORT_ATOMIC;
if (MLX5_CAP_ODP(dev->mdev, xrc_odp_caps.srq_receive))
caps->per_transport_caps.xrc_odp_caps |= IB_ODP_SUPPORT_SRQ_RECV;
if (MLX5_CAP_GEN(dev->mdev, fixed_buffer_size) &&
MLX5_CAP_GEN(dev->mdev, null_mkey) &&
MLX5_CAP_GEN(dev->mdev, umr_extended_translation_offset) &&
!MLX5_CAP_GEN(dev->mdev, umr_indirect_mkey_disabled))
caps->general_caps |= IB_ODP_SUPPORT_IMPLICIT;
}
static void mlx5_ib_page_fault_resume(struct mlx5_ib_dev *dev,
struct mlx5_pagefault *pfault,
int error)
{
int wq_num = pfault->event_subtype == MLX5_PFAULT_SUBTYPE_WQE ?
pfault->wqe.wq_num : pfault->token;
u32 in[MLX5_ST_SZ_DW(page_fault_resume_in)] = {};
int err;
MLX5_SET(page_fault_resume_in, in, opcode, MLX5_CMD_OP_PAGE_FAULT_RESUME);
MLX5_SET(page_fault_resume_in, in, page_fault_type, pfault->type);
MLX5_SET(page_fault_resume_in, in, token, pfault->token);
MLX5_SET(page_fault_resume_in, in, wq_number, wq_num);
MLX5_SET(page_fault_resume_in, in, error, !!error);
err = mlx5_cmd_exec_in(dev->mdev, page_fault_resume, in);
if (err)
mlx5_ib_err(dev, "Failed to resolve the page fault on WQ 0x%x err %d\n",
wq_num, err);
}
static struct mlx5_ib_mr *implicit_get_child_mr(struct mlx5_ib_mr *imr,
unsigned long idx)
{
struct ib_umem_odp *odp;
struct mlx5_ib_mr *mr;
struct mlx5_ib_mr *ret;
int err;
odp = ib_umem_odp_alloc_child(to_ib_umem_odp(imr->umem),
idx * MLX5_IMR_MTT_SIZE,
MLX5_IMR_MTT_SIZE, &mlx5_mn_ops);
if (IS_ERR(odp))
return ERR_CAST(odp);
ret = mr = mlx5_mr_cache_alloc(imr->dev, MLX5_IMR_MTT_CACHE_ENTRY);
if (IS_ERR(mr))
goto out_umem;
mr->ibmr.pd = imr->ibmr.pd;
mr->access_flags = imr->access_flags;
mr->umem = &odp->umem;
mr->ibmr.lkey = mr->mmkey.key;
mr->ibmr.rkey = mr->mmkey.key;
mr->mmkey.iova = idx * MLX5_IMR_MTT_SIZE;
mr->parent = imr;
odp->private = mr;
err = mlx5_ib_update_xlt(mr, 0,
MLX5_IMR_MTT_ENTRIES,
PAGE_SHIFT,
MLX5_IB_UPD_XLT_ZAP |
MLX5_IB_UPD_XLT_ENABLE);
if (err) {
ret = ERR_PTR(err);
goto out_mr;
}
/*
* Once the store to either xarray completes any error unwind has to
* use synchronize_srcu(). Avoid this with xa_reserve()
*/
ret = xa_cmpxchg(&imr->implicit_children, idx, NULL, mr,
GFP_KERNEL);
if (unlikely(ret)) {
if (xa_is_err(ret)) {
ret = ERR_PTR(xa_err(ret));
goto out_mr;
}
/*
* Another thread beat us to creating the child mr, use
* theirs.
*/
goto out_mr;
}
mlx5_ib_dbg(imr->dev, "key %x mr %p\n", mr->mmkey.key, mr);
return mr;
out_mr:
mlx5_mr_cache_free(imr->dev, mr);
out_umem:
ib_umem_odp_release(odp);
return ret;
}
struct mlx5_ib_mr *mlx5_ib_alloc_implicit_mr(struct mlx5_ib_pd *pd,
struct ib_udata *udata,
int access_flags)
{
struct mlx5_ib_dev *dev = to_mdev(pd->ibpd.device);
struct ib_umem_odp *umem_odp;
struct mlx5_ib_mr *imr;
int err;
umem_odp = ib_umem_odp_alloc_implicit(&dev->ib_dev, access_flags);
if (IS_ERR(umem_odp))
return ERR_CAST(umem_odp);
imr = mlx5_mr_cache_alloc(dev, MLX5_IMR_KSM_CACHE_ENTRY);
if (IS_ERR(imr)) {
err = PTR_ERR(imr);
goto out_umem;
}
imr->ibmr.pd = &pd->ibpd;
imr->access_flags = access_flags;
imr->mmkey.iova = 0;
imr->umem = &umem_odp->umem;
imr->ibmr.lkey = imr->mmkey.key;
imr->ibmr.rkey = imr->mmkey.key;
imr->umem = &umem_odp->umem;
imr->is_odp_implicit = true;
atomic_set(&imr->num_deferred_work, 0);
init_waitqueue_head(&imr->q_deferred_work);
xa_init(&imr->implicit_children);
err = mlx5_ib_update_xlt(imr, 0,
mlx5_imr_ksm_entries,
MLX5_KSM_PAGE_SHIFT,
MLX5_IB_UPD_XLT_INDIRECT |
MLX5_IB_UPD_XLT_ZAP |
MLX5_IB_UPD_XLT_ENABLE);
if (err)
goto out_mr;
err = xa_err(xa_store(&dev->odp_mkeys, mlx5_base_mkey(imr->mmkey.key),
&imr->mmkey, GFP_KERNEL));
if (err)
goto out_mr;
mlx5_ib_dbg(dev, "key %x mr %p\n", imr->mmkey.key, imr);
return imr;
out_mr:
mlx5_ib_err(dev, "Failed to register MKEY %d\n", err);
mlx5_mr_cache_free(dev, imr);
out_umem:
ib_umem_odp_release(umem_odp);
return ERR_PTR(err);
}
void mlx5_ib_free_implicit_mr(struct mlx5_ib_mr *imr)
{
struct ib_umem_odp *odp_imr = to_ib_umem_odp(imr->umem);
struct mlx5_ib_dev *dev = imr->dev;
struct list_head destroy_list;
struct mlx5_ib_mr *mtt;
struct mlx5_ib_mr *tmp;
unsigned long idx;
INIT_LIST_HEAD(&destroy_list);
xa_erase(&dev->odp_mkeys, mlx5_base_mkey(imr->mmkey.key));
/*
* This stops the SRCU protected page fault path from touching either
* the imr or any children. The page fault path can only reach the
* children xarray via the imr.
*/
synchronize_srcu(&dev->odp_srcu);
/*
* All work on the prefetch list must be completed, xa_erase() prevented
* new work from being created.
*/
wait_event(imr->q_deferred_work, !atomic_read(&imr->num_deferred_work));
/*
* At this point it is forbidden for any other thread to enter
* pagefault_mr() on this imr. It is already forbidden to call
* pagefault_mr() on an implicit child. Due to this additions to
* implicit_children are prevented.
*/
/*
* Block destroy_unused_implicit_child_mr() from incrementing
* num_deferred_work.
*/
xa_lock(&imr->implicit_children);
xa_for_each (&imr->implicit_children, idx, mtt) {
__xa_erase(&imr->implicit_children, idx);
list_add(&mtt->odp_destroy.elm, &destroy_list);
}
xa_unlock(&imr->implicit_children);
/*
* Wait for any concurrent destroy_unused_implicit_child_mr() to
* complete.
*/
wait_event(imr->q_deferred_work, !atomic_read(&imr->num_deferred_work));
/*
* Fence the imr before we destroy the children. This allows us to
* skip updating the XLT of the imr during destroy of the child mkey
* the imr points to.
*/
mlx5_mr_cache_invalidate(imr);
list_for_each_entry_safe (mtt, tmp, &destroy_list, odp_destroy.elm)
free_implicit_child_mr(mtt, false);
mlx5_mr_cache_free(dev, imr);
ib_umem_odp_release(odp_imr);
}
/**
* mlx5_ib_fence_odp_mr - Stop all access to the ODP MR
* @mr: to fence
*
* On return no parallel threads will be touching this MR and no DMA will be
* active.
*/
void mlx5_ib_fence_odp_mr(struct mlx5_ib_mr *mr)
{
/* Prevent new page faults and prefetch requests from succeeding */
xa_erase(&mr->dev->odp_mkeys, mlx5_base_mkey(mr->mmkey.key));
/* Wait for all running page-fault handlers to finish. */
synchronize_srcu(&mr->dev->odp_srcu);
wait_event(mr->q_deferred_work, !atomic_read(&mr->num_deferred_work));
dma_fence_odp_mr(mr);
}
#define MLX5_PF_FLAGS_DOWNGRADE BIT(1)
static int pagefault_real_mr(struct mlx5_ib_mr *mr, struct ib_umem_odp *odp,
u64 user_va, size_t bcnt, u32 *bytes_mapped,
u32 flags)
{
int page_shift, ret, np;
bool downgrade = flags & MLX5_PF_FLAGS_DOWNGRADE;
unsigned long current_seq;
u64 access_mask;
u64 start_idx;
page_shift = odp->page_shift;
start_idx = (user_va - ib_umem_start(odp)) >> page_shift;
access_mask = ODP_READ_ALLOWED_BIT;
if (odp->umem.writable && !downgrade)
access_mask |= ODP_WRITE_ALLOWED_BIT;
current_seq = mmu_interval_read_begin(&odp->notifier);
np = ib_umem_odp_map_dma_pages(odp, user_va, bcnt, access_mask,
current_seq);
if (np < 0)
return np;
mutex_lock(&odp->umem_mutex);
if (!mmu_interval_read_retry(&odp->notifier, current_seq)) {
/*
* No need to check whether the MTTs really belong to
* this MR, since ib_umem_odp_map_dma_pages already
* checks this.
*/
ret = mlx5_ib_update_xlt(mr, start_idx, np,
page_shift, MLX5_IB_UPD_XLT_ATOMIC);
} else {
ret = -EAGAIN;
}
mutex_unlock(&odp->umem_mutex);
if (ret < 0) {
if (ret != -EAGAIN)
mlx5_ib_err(mr->dev,
"Failed to update mkey page tables\n");
goto out;
}
if (bytes_mapped) {
u32 new_mappings = (np << page_shift) -
(user_va - round_down(user_va, 1 << page_shift));
*bytes_mapped += min_t(u32, new_mappings, bcnt);
}
return np << (page_shift - PAGE_SHIFT);
out:
return ret;
}
static int pagefault_implicit_mr(struct mlx5_ib_mr *imr,
struct ib_umem_odp *odp_imr, u64 user_va,
size_t bcnt, u32 *bytes_mapped, u32 flags)
{
unsigned long end_idx = (user_va + bcnt - 1) >> MLX5_IMR_MTT_SHIFT;
unsigned long upd_start_idx = end_idx + 1;
unsigned long upd_len = 0;
unsigned long npages = 0;
int err;
int ret;
if (unlikely(user_va >= mlx5_imr_ksm_entries * MLX5_IMR_MTT_SIZE ||
mlx5_imr_ksm_entries * MLX5_IMR_MTT_SIZE - user_va < bcnt))
return -EFAULT;
/* Fault each child mr that intersects with our interval. */
while (bcnt) {
unsigned long idx = user_va >> MLX5_IMR_MTT_SHIFT;
struct ib_umem_odp *umem_odp;
struct mlx5_ib_mr *mtt;
u64 len;
mtt = xa_load(&imr->implicit_children, idx);
if (unlikely(!mtt)) {
mtt = implicit_get_child_mr(imr, idx);
if (IS_ERR(mtt)) {
ret = PTR_ERR(mtt);
goto out;
}
upd_start_idx = min(upd_start_idx, idx);
upd_len = idx - upd_start_idx + 1;
}
umem_odp = to_ib_umem_odp(mtt->umem);
len = min_t(u64, user_va + bcnt, ib_umem_end(umem_odp)) -
user_va;
ret = pagefault_real_mr(mtt, umem_odp, user_va, len,
bytes_mapped, flags);
if (ret < 0)
goto out;
user_va += len;
bcnt -= len;
npages += ret;
}
ret = npages;
/*
* Any time the implicit_children are changed we must perform an
* update of the xlt before exiting to ensure the HW and the
* implicit_children remains synchronized.
*/
out:
if (likely(!upd_len))
return ret;
/*
* Notice this is not strictly ordered right, the KSM is updated after
* the implicit_children is updated, so a parallel page fault could
* see a MR that is not yet visible in the KSM. This is similar to a
* parallel page fault seeing a MR that is being concurrently removed
* from the KSM. Both of these improbable situations are resolved
* safely by resuming the HW and then taking another page fault. The
* next pagefault handler will see the new information.
*/
mutex_lock(&odp_imr->umem_mutex);
err = mlx5_ib_update_xlt(imr, upd_start_idx, upd_len, 0,
MLX5_IB_UPD_XLT_INDIRECT |
MLX5_IB_UPD_XLT_ATOMIC);
mutex_unlock(&odp_imr->umem_mutex);
if (err) {
mlx5_ib_err(imr->dev, "Failed to update PAS\n");
return err;
}
return ret;
}
/*
* Returns:
* -EFAULT: The io_virt->bcnt is not within the MR, it covers pages that are
* not accessible, or the MR is no longer valid.
* -EAGAIN/-ENOMEM: The operation should be retried
*
* -EINVAL/others: General internal malfunction
* >0: Number of pages mapped
*/
static int pagefault_mr(struct mlx5_ib_mr *mr, u64 io_virt, size_t bcnt,
u32 *bytes_mapped, u32 flags)
{
struct ib_umem_odp *odp = to_ib_umem_odp(mr->umem);
if (unlikely(io_virt < mr->mmkey.iova))
return -EFAULT;
if (!odp->is_implicit_odp) {
u64 user_va;
if (check_add_overflow(io_virt - mr->mmkey.iova,
(u64)odp->umem.address, &user_va))
return -EFAULT;
if (unlikely(user_va >= ib_umem_end(odp) ||
ib_umem_end(odp) - user_va < bcnt))
return -EFAULT;
return pagefault_real_mr(mr, odp, user_va, bcnt, bytes_mapped,
flags);
}
return pagefault_implicit_mr(mr, odp, io_virt, bcnt, bytes_mapped,
flags);
}
struct pf_frame {
struct pf_frame *next;
u32 key;
u64 io_virt;
size_t bcnt;
int depth;
};
static bool mkey_is_eq(struct mlx5_core_mkey *mmkey, u32 key)
{
if (!mmkey)
return false;
if (mmkey->type == MLX5_MKEY_MW)
return mlx5_base_mkey(mmkey->key) == mlx5_base_mkey(key);
return mmkey->key == key;
}
static int get_indirect_num_descs(struct mlx5_core_mkey *mmkey)
{
struct mlx5_ib_mw *mw;
struct mlx5_ib_devx_mr *devx_mr;
if (mmkey->type == MLX5_MKEY_MW) {
mw = container_of(mmkey, struct mlx5_ib_mw, mmkey);
return mw->ndescs;
}
devx_mr = container_of(mmkey, struct mlx5_ib_devx_mr,
mmkey);
return devx_mr->ndescs;
}
/*
* Handle a single data segment in a page-fault WQE or RDMA region.
*
* Returns number of OS pages retrieved on success. The caller may continue to
* the next data segment.
* Can return the following error codes:
* -EAGAIN to designate a temporary error. The caller will abort handling the
* page fault and resolve it.
* -EFAULT when there's an error mapping the requested pages. The caller will
* abort the page fault handling.
*/
static int pagefault_single_data_segment(struct mlx5_ib_dev *dev,
struct ib_pd *pd, u32 key,
u64 io_virt, size_t bcnt,
u32 *bytes_committed,
u32 *bytes_mapped)
{
int npages = 0, srcu_key, ret, i, outlen, cur_outlen = 0, depth = 0;
struct pf_frame *head = NULL, *frame;
struct mlx5_core_mkey *mmkey;
struct mlx5_ib_mr *mr;
struct mlx5_klm *pklm;
u32 *out = NULL;
size_t offset;
int ndescs;
srcu_key = srcu_read_lock(&dev->odp_srcu);
io_virt += *bytes_committed;
bcnt -= *bytes_committed;
next_mr:
mmkey = xa_load(&dev->odp_mkeys, mlx5_base_mkey(key));
if (!mmkey) {
mlx5_ib_dbg(
dev,
"skipping non ODP MR (lkey=0x%06x) in page fault handler.\n",
key);
if (bytes_mapped)
*bytes_mapped += bcnt;
/*
* The user could specify a SGL with multiple lkeys and only
* some of them are ODP. Treat the non-ODP ones as fully
* faulted.
*/
ret = 0;
goto srcu_unlock;
}
if (!mkey_is_eq(mmkey, key)) {
mlx5_ib_dbg(dev, "failed to find mkey %x\n", key);
ret = -EFAULT;
goto srcu_unlock;
}
switch (mmkey->type) {
case MLX5_MKEY_MR:
mr = container_of(mmkey, struct mlx5_ib_mr, mmkey);
ret = pagefault_mr(mr, io_virt, bcnt, bytes_mapped, 0);
if (ret < 0)
goto srcu_unlock;
/*
* When prefetching a page, page fault is generated
* in order to bring the page to the main memory.
* In the current flow, page faults are being counted.
*/
mlx5_update_odp_stats(mr, faults, ret);
npages += ret;
ret = 0;
break;
case MLX5_MKEY_MW:
case MLX5_MKEY_INDIRECT_DEVX:
ndescs = get_indirect_num_descs(mmkey);
if (depth >= MLX5_CAP_GEN(dev->mdev, max_indirection)) {
mlx5_ib_dbg(dev, "indirection level exceeded\n");
ret = -EFAULT;
goto srcu_unlock;
}
outlen = MLX5_ST_SZ_BYTES(query_mkey_out) +
sizeof(*pklm) * (ndescs - 2);
if (outlen > cur_outlen) {
kfree(out);
out = kzalloc(outlen, GFP_KERNEL);
if (!out) {
ret = -ENOMEM;
goto srcu_unlock;
}
cur_outlen = outlen;
}
pklm = (struct mlx5_klm *)MLX5_ADDR_OF(query_mkey_out, out,
bsf0_klm0_pas_mtt0_1);
ret = mlx5_core_query_mkey(dev->mdev, mmkey, out, outlen);
if (ret)
goto srcu_unlock;
offset = io_virt - MLX5_GET64(query_mkey_out, out,
memory_key_mkey_entry.start_addr);
for (i = 0; bcnt && i < ndescs; i++, pklm++) {
if (offset >= be32_to_cpu(pklm->bcount)) {
offset -= be32_to_cpu(pklm->bcount);
continue;
}
frame = kzalloc(sizeof(*frame), GFP_KERNEL);
if (!frame) {
ret = -ENOMEM;
goto srcu_unlock;
}
frame->key = be32_to_cpu(pklm->key);
frame->io_virt = be64_to_cpu(pklm->va) + offset;
frame->bcnt = min_t(size_t, bcnt,
be32_to_cpu(pklm->bcount) - offset);
frame->depth = depth + 1;
frame->next = head;
head = frame;
bcnt -= frame->bcnt;
offset = 0;
}
break;
default:
mlx5_ib_dbg(dev, "wrong mkey type %d\n", mmkey->type);
ret = -EFAULT;
goto srcu_unlock;
}
if (head) {
frame = head;
head = frame->next;
key = frame->key;
io_virt = frame->io_virt;
bcnt = frame->bcnt;
depth = frame->depth;
kfree(frame);
goto next_mr;
}
srcu_unlock:
while (head) {
frame = head;
head = frame->next;
kfree(frame);
}
kfree(out);
srcu_read_unlock(&dev->odp_srcu, srcu_key);
*bytes_committed = 0;
return ret ? ret : npages;
}
/**
* Parse a series of data segments for page fault handling.
*
* @pfault contains page fault information.
* @wqe points at the first data segment in the WQE.
* @wqe_end points after the end of the WQE.
* @bytes_mapped receives the number of bytes that the function was able to
* map. This allows the caller to decide intelligently whether
* enough memory was mapped to resolve the page fault
* successfully (e.g. enough for the next MTU, or the entire
* WQE).
* @total_wqe_bytes receives the total data size of this WQE in bytes (minus
* the committed bytes).
*
* Returns the number of pages loaded if positive, zero for an empty WQE, or a
* negative error code.
*/
static int pagefault_data_segments(struct mlx5_ib_dev *dev,
struct mlx5_pagefault *pfault,
void *wqe,
void *wqe_end, u32 *bytes_mapped,
u32 *total_wqe_bytes, bool receive_queue)
{
int ret = 0, npages = 0;
u64 io_virt;
u32 key;
u32 byte_count;
size_t bcnt;
int inline_segment;
if (bytes_mapped)
*bytes_mapped = 0;
if (total_wqe_bytes)
*total_wqe_bytes = 0;
while (wqe < wqe_end) {
struct mlx5_wqe_data_seg *dseg = wqe;
io_virt = be64_to_cpu(dseg->addr);
key = be32_to_cpu(dseg->lkey);
byte_count = be32_to_cpu(dseg->byte_count);
inline_segment = !!(byte_count & MLX5_INLINE_SEG);
bcnt = byte_count & ~MLX5_INLINE_SEG;
if (inline_segment) {
bcnt = bcnt & MLX5_WQE_INLINE_SEG_BYTE_COUNT_MASK;
wqe += ALIGN(sizeof(struct mlx5_wqe_inline_seg) + bcnt,
16);
} else {
wqe += sizeof(*dseg);
}
/* receive WQE end of sg list. */
if (receive_queue && bcnt == 0 && key == MLX5_INVALID_LKEY &&
io_virt == 0)
break;
if (!inline_segment && total_wqe_bytes) {
*total_wqe_bytes += bcnt - min_t(size_t, bcnt,
pfault->bytes_committed);
}
/* A zero length data segment designates a length of 2GB. */
if (bcnt == 0)
bcnt = 1U << 31;
if (inline_segment || bcnt <= pfault->bytes_committed) {
pfault->bytes_committed -=
min_t(size_t, bcnt,
pfault->bytes_committed);
continue;
}
ret = pagefault_single_data_segment(dev, NULL, key,
io_virt, bcnt,
&pfault->bytes_committed,
bytes_mapped);
if (ret < 0)
break;
npages += ret;
}
return ret < 0 ? ret : npages;
}
/*
* Parse initiator WQE. Advances the wqe pointer to point at the
* scatter-gather list, and set wqe_end to the end of the WQE.
*/
static int mlx5_ib_mr_initiator_pfault_handler(
struct mlx5_ib_dev *dev, struct mlx5_pagefault *pfault,
struct mlx5_ib_qp *qp, void **wqe, void **wqe_end, int wqe_length)
{
struct mlx5_wqe_ctrl_seg *ctrl = *wqe;
u16 wqe_index = pfault->wqe.wqe_index;
struct mlx5_base_av *av;
unsigned ds, opcode;
u32 qpn = qp->trans_qp.base.mqp.qpn;
ds = be32_to_cpu(ctrl->qpn_ds) & MLX5_WQE_CTRL_DS_MASK;
if (ds * MLX5_WQE_DS_UNITS > wqe_length) {
mlx5_ib_err(dev, "Unable to read the complete WQE. ds = 0x%x, ret = 0x%x\n",
ds, wqe_length);
return -EFAULT;
}
if (ds == 0) {
mlx5_ib_err(dev, "Got WQE with zero DS. wqe_index=%x, qpn=%x\n",
wqe_index, qpn);
return -EFAULT;
}
*wqe_end = *wqe + ds * MLX5_WQE_DS_UNITS;
*wqe += sizeof(*ctrl);
opcode = be32_to_cpu(ctrl->opmod_idx_opcode) &
MLX5_WQE_CTRL_OPCODE_MASK;
if (qp->ibqp.qp_type == IB_QPT_XRC_INI)
*wqe += sizeof(struct mlx5_wqe_xrc_seg);
if (qp->type == IB_QPT_UD || qp->type == MLX5_IB_QPT_DCI) {
av = *wqe;
if (av->dqp_dct & cpu_to_be32(MLX5_EXTENDED_UD_AV))
*wqe += sizeof(struct mlx5_av);
else
*wqe += sizeof(struct mlx5_base_av);
}
switch (opcode) {
case MLX5_OPCODE_RDMA_WRITE:
case MLX5_OPCODE_RDMA_WRITE_IMM:
case MLX5_OPCODE_RDMA_READ:
*wqe += sizeof(struct mlx5_wqe_raddr_seg);
break;
case MLX5_OPCODE_ATOMIC_CS:
case MLX5_OPCODE_ATOMIC_FA:
*wqe += sizeof(struct mlx5_wqe_raddr_seg);
*wqe += sizeof(struct mlx5_wqe_atomic_seg);
break;
}
return 0;
}
/*
* Parse responder WQE and set wqe_end to the end of the WQE.
*/
static int mlx5_ib_mr_responder_pfault_handler_srq(struct mlx5_ib_dev *dev,
struct mlx5_ib_srq *srq,
void **wqe, void **wqe_end,
int wqe_length)
{
int wqe_size = 1 << srq->msrq.wqe_shift;
if (wqe_size > wqe_length) {
mlx5_ib_err(dev, "Couldn't read all of the receive WQE's content\n");
return -EFAULT;
}
*wqe_end = *wqe + wqe_size;
*wqe += sizeof(struct mlx5_wqe_srq_next_seg);
return 0;
}
static int mlx5_ib_mr_responder_pfault_handler_rq(struct mlx5_ib_dev *dev,
struct mlx5_ib_qp *qp,
void *wqe, void **wqe_end,
int wqe_length)
{
struct mlx5_ib_wq *wq = &qp->rq;
int wqe_size = 1 << wq->wqe_shift;
if (qp->flags_en & MLX5_QP_FLAG_SIGNATURE) {
mlx5_ib_err(dev, "ODP fault with WQE signatures is not supported\n");
return -EFAULT;
}
if (wqe_size > wqe_length) {
mlx5_ib_err(dev, "Couldn't read all of the receive WQE's content\n");
return -EFAULT;
}
*wqe_end = wqe + wqe_size;
return 0;
}
static inline struct mlx5_core_rsc_common *odp_get_rsc(struct mlx5_ib_dev *dev,
u32 wq_num, int pf_type)
{
struct mlx5_core_rsc_common *common = NULL;
struct mlx5_core_srq *srq;
switch (pf_type) {
case MLX5_WQE_PF_TYPE_RMP:
srq = mlx5_cmd_get_srq(dev, wq_num);
if (srq)
common = &srq->common;
break;
case MLX5_WQE_PF_TYPE_REQ_SEND_OR_WRITE:
case MLX5_WQE_PF_TYPE_RESP:
case MLX5_WQE_PF_TYPE_REQ_READ_OR_ATOMIC:
common = mlx5_core_res_hold(dev, wq_num, MLX5_RES_QP);
break;
default:
break;
}
return common;
}
static inline struct mlx5_ib_qp *res_to_qp(struct mlx5_core_rsc_common *res)
{
struct mlx5_core_qp *mqp = (struct mlx5_core_qp *)res;
return to_mibqp(mqp);
}
static inline struct mlx5_ib_srq *res_to_srq(struct mlx5_core_rsc_common *res)
{
struct mlx5_core_srq *msrq =
container_of(res, struct mlx5_core_srq, common);
return to_mibsrq(msrq);
}
static void mlx5_ib_mr_wqe_pfault_handler(struct mlx5_ib_dev *dev,
struct mlx5_pagefault *pfault)
{
bool sq = pfault->type & MLX5_PFAULT_REQUESTOR;
u16 wqe_index = pfault->wqe.wqe_index;
void *wqe, *wqe_start = NULL, *wqe_end = NULL;
u32 bytes_mapped, total_wqe_bytes;
struct mlx5_core_rsc_common *res;
int resume_with_error = 1;
struct mlx5_ib_qp *qp;
size_t bytes_copied;
int ret = 0;
res = odp_get_rsc(dev, pfault->wqe.wq_num, pfault->type);
if (!res) {
mlx5_ib_dbg(dev, "wqe page fault for missing resource %d\n", pfault->wqe.wq_num);
return;
}
if (res->res != MLX5_RES_QP && res->res != MLX5_RES_SRQ &&
res->res != MLX5_RES_XSRQ) {
mlx5_ib_err(dev, "wqe page fault for unsupported type %d\n",
pfault->type);
goto resolve_page_fault;
}
wqe_start = (void *)__get_free_page(GFP_KERNEL);
if (!wqe_start) {
mlx5_ib_err(dev, "Error allocating memory for IO page fault handling.\n");
goto resolve_page_fault;
}
wqe = wqe_start;
qp = (res->res == MLX5_RES_QP) ? res_to_qp(res) : NULL;
if (qp && sq) {
ret = mlx5_ib_read_wqe_sq(qp, wqe_index, wqe, PAGE_SIZE,
&bytes_copied);
if (ret)
goto read_user;
ret = mlx5_ib_mr_initiator_pfault_handler(
dev, pfault, qp, &wqe, &wqe_end, bytes_copied);
} else if (qp && !sq) {
ret = mlx5_ib_read_wqe_rq(qp, wqe_index, wqe, PAGE_SIZE,
&bytes_copied);
if (ret)
goto read_user;
ret = mlx5_ib_mr_responder_pfault_handler_rq(
dev, qp, wqe, &wqe_end, bytes_copied);
} else if (!qp) {
struct mlx5_ib_srq *srq = res_to_srq(res);
ret = mlx5_ib_read_wqe_srq(srq, wqe_index, wqe, PAGE_SIZE,
&bytes_copied);
if (ret)
goto read_user;
ret = mlx5_ib_mr_responder_pfault_handler_srq(
dev, srq, &wqe, &wqe_end, bytes_copied);
}
if (ret < 0 || wqe >= wqe_end)
goto resolve_page_fault;
ret = pagefault_data_segments(dev, pfault, wqe, wqe_end, &bytes_mapped,
&total_wqe_bytes, !sq);
if (ret == -EAGAIN)
goto out;
if (ret < 0 || total_wqe_bytes > bytes_mapped)
goto resolve_page_fault;
out:
ret = 0;
resume_with_error = 0;
read_user:
if (ret)
mlx5_ib_err(
dev,
"Failed reading a WQE following page fault, error %d, wqe_index %x, qpn %x\n",
ret, wqe_index, pfault->token);
resolve_page_fault:
mlx5_ib_page_fault_resume(dev, pfault, resume_with_error);
mlx5_ib_dbg(dev, "PAGE FAULT completed. QP 0x%x resume_with_error=%d, type: 0x%x\n",
pfault->wqe.wq_num, resume_with_error,
pfault->type);
mlx5_core_res_put(res);
free_page((unsigned long)wqe_start);
}
static int pages_in_range(u64 address, u32 length)
{
return (ALIGN(address + length, PAGE_SIZE) -
(address & PAGE_MASK)) >> PAGE_SHIFT;
}
static void mlx5_ib_mr_rdma_pfault_handler(struct mlx5_ib_dev *dev,
struct mlx5_pagefault *pfault)
{
u64 address;
u32 length;
u32 prefetch_len = pfault->bytes_committed;
int prefetch_activated = 0;
u32 rkey = pfault->rdma.r_key;
int ret;
/* The RDMA responder handler handles the page fault in two parts.
* First it brings the necessary pages for the current packet
* (and uses the pfault context), and then (after resuming the QP)
* prefetches more pages. The second operation cannot use the pfault
* context and therefore uses the dummy_pfault context allocated on
* the stack */
pfault->rdma.rdma_va += pfault->bytes_committed;
pfault->rdma.rdma_op_len -= min(pfault->bytes_committed,
pfault->rdma.rdma_op_len);
pfault->bytes_committed = 0;
address = pfault->rdma.rdma_va;
length = pfault->rdma.rdma_op_len;
/* For some operations, the hardware cannot tell the exact message
* length, and in those cases it reports zero. Use prefetch
* logic. */
if (length == 0) {
prefetch_activated = 1;
length = pfault->rdma.packet_size;
prefetch_len = min(MAX_PREFETCH_LEN, prefetch_len);
}
ret = pagefault_single_data_segment(dev, NULL, rkey, address, length,
&pfault->bytes_committed, NULL);
if (ret == -EAGAIN) {
/* We're racing with an invalidation, don't prefetch */
prefetch_activated = 0;
} else if (ret < 0 || pages_in_range(address, length) > ret) {
mlx5_ib_page_fault_resume(dev, pfault, 1);
if (ret != -ENOENT)
mlx5_ib_dbg(dev, "PAGE FAULT error %d. QP 0x%x, type: 0x%x\n",
ret, pfault->token, pfault->type);
return;
}
mlx5_ib_page_fault_resume(dev, pfault, 0);
mlx5_ib_dbg(dev, "PAGE FAULT completed. QP 0x%x, type: 0x%x, prefetch_activated: %d\n",
pfault->token, pfault->type,
prefetch_activated);
/* At this point, there might be a new pagefault already arriving in
* the eq, switch to the dummy pagefault for the rest of the
* processing. We're still OK with the objects being alive as the
* work-queue is being fenced. */
if (prefetch_activated) {
u32 bytes_committed = 0;
ret = pagefault_single_data_segment(dev, NULL, rkey, address,
prefetch_len,
&bytes_committed, NULL);
if (ret < 0 && ret != -EAGAIN) {
mlx5_ib_dbg(dev, "Prefetch failed. ret: %d, QP 0x%x, address: 0x%.16llx, length = 0x%.16x\n",
ret, pfault->token, address, prefetch_len);
}
}
}
static void mlx5_ib_pfault(struct mlx5_ib_dev *dev, struct mlx5_pagefault *pfault)
{
u8 event_subtype = pfault->event_subtype;
switch (event_subtype) {
case MLX5_PFAULT_SUBTYPE_WQE:
mlx5_ib_mr_wqe_pfault_handler(dev, pfault);
break;
case MLX5_PFAULT_SUBTYPE_RDMA:
mlx5_ib_mr_rdma_pfault_handler(dev, pfault);
break;
default:
mlx5_ib_err(dev, "Invalid page fault event subtype: 0x%x\n",
event_subtype);
mlx5_ib_page_fault_resume(dev, pfault, 1);
}
}
static void mlx5_ib_eqe_pf_action(struct work_struct *work)
{
struct mlx5_pagefault *pfault = container_of(work,
struct mlx5_pagefault,
work);
struct mlx5_ib_pf_eq *eq = pfault->eq;
mlx5_ib_pfault(eq->dev, pfault);
mempool_free(pfault, eq->pool);
}
static void mlx5_ib_eq_pf_process(struct mlx5_ib_pf_eq *eq)
{
struct mlx5_eqe_page_fault *pf_eqe;
struct mlx5_pagefault *pfault;
struct mlx5_eqe *eqe;
int cc = 0;
while ((eqe = mlx5_eq_get_eqe(eq->core, cc))) {
pfault = mempool_alloc(eq->pool, GFP_ATOMIC);
if (!pfault) {
schedule_work(&eq->work);
break;
}
pf_eqe = &eqe->data.page_fault;
pfault->event_subtype = eqe->sub_type;
pfault->bytes_committed = be32_to_cpu(pf_eqe->bytes_committed);
mlx5_ib_dbg(eq->dev,
"PAGE_FAULT: subtype: 0x%02x, bytes_committed: 0x%06x\n",
eqe->sub_type, pfault->bytes_committed);
switch (eqe->sub_type) {
case MLX5_PFAULT_SUBTYPE_RDMA:
/* RDMA based event */
pfault->type =
be32_to_cpu(pf_eqe->rdma.pftype_token) >> 24;
pfault->token =
be32_to_cpu(pf_eqe->rdma.pftype_token) &
MLX5_24BIT_MASK;
pfault->rdma.r_key =
be32_to_cpu(pf_eqe->rdma.r_key);
pfault->rdma.packet_size =
be16_to_cpu(pf_eqe->rdma.packet_length);
pfault->rdma.rdma_op_len =
be32_to_cpu(pf_eqe->rdma.rdma_op_len);
pfault->rdma.rdma_va =
be64_to_cpu(pf_eqe->rdma.rdma_va);
mlx5_ib_dbg(eq->dev,
"PAGE_FAULT: type:0x%x, token: 0x%06x, r_key: 0x%08x\n",
pfault->type, pfault->token,
pfault->rdma.r_key);
mlx5_ib_dbg(eq->dev,
"PAGE_FAULT: rdma_op_len: 0x%08x, rdma_va: 0x%016llx\n",
pfault->rdma.rdma_op_len,
pfault->rdma.rdma_va);
break;
case MLX5_PFAULT_SUBTYPE_WQE:
/* WQE based event */
pfault->type =
(be32_to_cpu(pf_eqe->wqe.pftype_wq) >> 24) & 0x7;
pfault->token =
be32_to_cpu(pf_eqe->wqe.token);
pfault->wqe.wq_num =
be32_to_cpu(pf_eqe->wqe.pftype_wq) &
MLX5_24BIT_MASK;
pfault->wqe.wqe_index =
be16_to_cpu(pf_eqe->wqe.wqe_index);
pfault->wqe.packet_size =
be16_to_cpu(pf_eqe->wqe.packet_length);
mlx5_ib_dbg(eq->dev,
"PAGE_FAULT: type:0x%x, token: 0x%06x, wq_num: 0x%06x, wqe_index: 0x%04x\n",
pfault->type, pfault->token,
pfault->wqe.wq_num,
pfault->wqe.wqe_index);
break;
default:
mlx5_ib_warn(eq->dev,
"Unsupported page fault event sub-type: 0x%02hhx\n",
eqe->sub_type);
/* Unsupported page faults should still be
* resolved by the page fault handler
*/
}
pfault->eq = eq;
INIT_WORK(&pfault->work, mlx5_ib_eqe_pf_action);
queue_work(eq->wq, &pfault->work);
cc = mlx5_eq_update_cc(eq->core, ++cc);
}
mlx5_eq_update_ci(eq->core, cc, 1);
}
static int mlx5_ib_eq_pf_int(struct notifier_block *nb, unsigned long type,
void *data)
{
struct mlx5_ib_pf_eq *eq =
container_of(nb, struct mlx5_ib_pf_eq, irq_nb);
unsigned long flags;
if (spin_trylock_irqsave(&eq->lock, flags)) {
mlx5_ib_eq_pf_process(eq);
spin_unlock_irqrestore(&eq->lock, flags);
} else {
schedule_work(&eq->work);
}
return IRQ_HANDLED;
}
/* mempool_refill() was proposed but unfortunately wasn't accepted
* http://lkml.iu.edu/hypermail/linux/kernel/1512.1/05073.html
* Cheap workaround.
*/
static void mempool_refill(mempool_t *pool)
{
while (pool->curr_nr < pool->min_nr)
mempool_free(mempool_alloc(pool, GFP_KERNEL), pool);
}
static void mlx5_ib_eq_pf_action(struct work_struct *work)
{
struct mlx5_ib_pf_eq *eq =
container_of(work, struct mlx5_ib_pf_eq, work);
mempool_refill(eq->pool);
spin_lock_irq(&eq->lock);
mlx5_ib_eq_pf_process(eq);
spin_unlock_irq(&eq->lock);
}
enum {
MLX5_IB_NUM_PF_EQE = 0x1000,
MLX5_IB_NUM_PF_DRAIN = 64,
};
static int
mlx5_ib_create_pf_eq(struct mlx5_ib_dev *dev, struct mlx5_ib_pf_eq *eq)
{
struct mlx5_eq_param param = {};
int err;
INIT_WORK(&eq->work, mlx5_ib_eq_pf_action);
spin_lock_init(&eq->lock);
eq->dev = dev;
eq->pool = mempool_create_kmalloc_pool(MLX5_IB_NUM_PF_DRAIN,
sizeof(struct mlx5_pagefault));
if (!eq->pool)
return -ENOMEM;
eq->wq = alloc_workqueue("mlx5_ib_page_fault",
WQ_HIGHPRI | WQ_UNBOUND | WQ_MEM_RECLAIM,
MLX5_NUM_CMD_EQE);
if (!eq->wq) {
err = -ENOMEM;
goto err_mempool;
}
eq->irq_nb.notifier_call = mlx5_ib_eq_pf_int;
param = (struct mlx5_eq_param) {
.irq_index = 0,
.nent = MLX5_IB_NUM_PF_EQE,
};
param.mask[0] = 1ull << MLX5_EVENT_TYPE_PAGE_FAULT;
eq->core = mlx5_eq_create_generic(dev->mdev, &param);
if (IS_ERR(eq->core)) {
err = PTR_ERR(eq->core);
goto err_wq;
}
err = mlx5_eq_enable(dev->mdev, eq->core, &eq->irq_nb);
if (err) {
mlx5_ib_err(dev, "failed to enable odp EQ %d\n", err);
goto err_eq;
}
return 0;
err_eq:
mlx5_eq_destroy_generic(dev->mdev, eq->core);
err_wq:
destroy_workqueue(eq->wq);
err_mempool:
mempool_destroy(eq->pool);
return err;
}
static int
mlx5_ib_destroy_pf_eq(struct mlx5_ib_dev *dev, struct mlx5_ib_pf_eq *eq)
{
int err;
mlx5_eq_disable(dev->mdev, eq->core, &eq->irq_nb);
err = mlx5_eq_destroy_generic(dev->mdev, eq->core);
cancel_work_sync(&eq->work);
destroy_workqueue(eq->wq);
mempool_destroy(eq->pool);
return err;
}
void mlx5_odp_init_mr_cache_entry(struct mlx5_cache_ent *ent)
{
if (!(ent->dev->odp_caps.general_caps & IB_ODP_SUPPORT_IMPLICIT))
return;
switch (ent->order - 2) {
case MLX5_IMR_MTT_CACHE_ENTRY:
ent->page = PAGE_SHIFT;
ent->xlt = MLX5_IMR_MTT_ENTRIES *
sizeof(struct mlx5_mtt) /
MLX5_IB_UMR_OCTOWORD;
ent->access_mode = MLX5_MKC_ACCESS_MODE_MTT;
ent->limit = 0;
break;
case MLX5_IMR_KSM_CACHE_ENTRY:
ent->page = MLX5_KSM_PAGE_SHIFT;
ent->xlt = mlx5_imr_ksm_entries *
sizeof(struct mlx5_klm) /
MLX5_IB_UMR_OCTOWORD;
ent->access_mode = MLX5_MKC_ACCESS_MODE_KSM;
ent->limit = 0;
break;
}
}
static const struct ib_device_ops mlx5_ib_dev_odp_ops = {
.advise_mr = mlx5_ib_advise_mr,
};
int mlx5_ib_odp_init_one(struct mlx5_ib_dev *dev)
{
int ret = 0;
if (!(dev->odp_caps.general_caps & IB_ODP_SUPPORT))
return ret;
ib_set_device_ops(&dev->ib_dev, &mlx5_ib_dev_odp_ops);
if (dev->odp_caps.general_caps & IB_ODP_SUPPORT_IMPLICIT) {
ret = mlx5_cmd_null_mkey(dev->mdev, &dev->null_mkey);
if (ret) {
mlx5_ib_err(dev, "Error getting null_mkey %d\n", ret);
return ret;
}
}
ret = mlx5_ib_create_pf_eq(dev, &dev->odp_pf_eq);
return ret;
}
void mlx5_ib_odp_cleanup_one(struct mlx5_ib_dev *dev)
{
if (!(dev->odp_caps.general_caps & IB_ODP_SUPPORT))
return;
mlx5_ib_destroy_pf_eq(dev, &dev->odp_pf_eq);
}
int mlx5_ib_odp_init(void)
{
mlx5_imr_ksm_entries = BIT_ULL(get_order(TASK_SIZE) -
MLX5_IMR_MTT_BITS);
return 0;
}
struct prefetch_mr_work {
struct work_struct work;
u32 pf_flags;
u32 num_sge;
struct {
u64 io_virt;
struct mlx5_ib_mr *mr;
size_t length;
} frags[];
};
static void destroy_prefetch_work(struct prefetch_mr_work *work)
{
u32 i;
for (i = 0; i < work->num_sge; ++i)
if (atomic_dec_and_test(&work->frags[i].mr->num_deferred_work))
wake_up(&work->frags[i].mr->q_deferred_work);
kvfree(work);
}
static struct mlx5_ib_mr *
get_prefetchable_mr(struct ib_pd *pd, enum ib_uverbs_advise_mr_advice advice,
u32 lkey)
{
struct mlx5_ib_dev *dev = to_mdev(pd->device);
struct mlx5_core_mkey *mmkey;
struct ib_umem_odp *odp;
struct mlx5_ib_mr *mr;
lockdep_assert_held(&dev->odp_srcu);
mmkey = xa_load(&dev->odp_mkeys, mlx5_base_mkey(lkey));
if (!mmkey || mmkey->key != lkey || mmkey->type != MLX5_MKEY_MR)
return NULL;
mr = container_of(mmkey, struct mlx5_ib_mr, mmkey);
if (mr->ibmr.pd != pd)
return NULL;
odp = to_ib_umem_odp(mr->umem);
/* prefetch with write-access must be supported by the MR */
if (advice == IB_UVERBS_ADVISE_MR_ADVICE_PREFETCH_WRITE &&
!odp->umem.writable)
return NULL;
return mr;
}
static void mlx5_ib_prefetch_mr_work(struct work_struct *w)
{
struct prefetch_mr_work *work =
container_of(w, struct prefetch_mr_work, work);
u32 bytes_mapped = 0;
u32 i;
for (i = 0; i < work->num_sge; ++i)
pagefault_mr(work->frags[i].mr, work->frags[i].io_virt,
work->frags[i].length, &bytes_mapped,
work->pf_flags);
destroy_prefetch_work(work);
}
static bool init_prefetch_work(struct ib_pd *pd,
enum ib_uverbs_advise_mr_advice advice,
u32 pf_flags, struct prefetch_mr_work *work,
struct ib_sge *sg_list, u32 num_sge)
{
u32 i;
INIT_WORK(&work->work, mlx5_ib_prefetch_mr_work);
work->pf_flags = pf_flags;
for (i = 0; i < num_sge; ++i) {
work->frags[i].io_virt = sg_list[i].addr;
work->frags[i].length = sg_list[i].length;
work->frags[i].mr =
get_prefetchable_mr(pd, advice, sg_list[i].lkey);
if (!work->frags[i].mr) {
work->num_sge = i - 1;
if (i)
destroy_prefetch_work(work);
return false;
}
/* Keep the MR pointer will valid outside the SRCU */
atomic_inc(&work->frags[i].mr->num_deferred_work);
}
work->num_sge = num_sge;
return true;
}
static int mlx5_ib_prefetch_sg_list(struct ib_pd *pd,
enum ib_uverbs_advise_mr_advice advice,
u32 pf_flags, struct ib_sge *sg_list,
u32 num_sge)
{
struct mlx5_ib_dev *dev = to_mdev(pd->device);
u32 bytes_mapped = 0;
int srcu_key;
int ret = 0;
u32 i;
srcu_key = srcu_read_lock(&dev->odp_srcu);
for (i = 0; i < num_sge; ++i) {
struct mlx5_ib_mr *mr;
mr = get_prefetchable_mr(pd, advice, sg_list[i].lkey);
if (!mr) {
ret = -ENOENT;
goto out;
}
ret = pagefault_mr(mr, sg_list[i].addr, sg_list[i].length,
&bytes_mapped, pf_flags);
if (ret < 0)
goto out;
}
ret = 0;
out:
srcu_read_unlock(&dev->odp_srcu, srcu_key);
return ret;
}
int mlx5_ib_advise_mr_prefetch(struct ib_pd *pd,
enum ib_uverbs_advise_mr_advice advice,
u32 flags, struct ib_sge *sg_list, u32 num_sge)
{
struct mlx5_ib_dev *dev = to_mdev(pd->device);
u32 pf_flags = 0;
struct prefetch_mr_work *work;
int srcu_key;
if (advice == IB_UVERBS_ADVISE_MR_ADVICE_PREFETCH)
pf_flags |= MLX5_PF_FLAGS_DOWNGRADE;
if (flags & IB_UVERBS_ADVISE_MR_FLAG_FLUSH)
return mlx5_ib_prefetch_sg_list(pd, advice, pf_flags, sg_list,
num_sge);
work = kvzalloc(struct_size(work, frags, num_sge), GFP_KERNEL);
if (!work)
return -ENOMEM;
srcu_key = srcu_read_lock(&dev->odp_srcu);
if (!init_prefetch_work(pd, advice, pf_flags, work, sg_list, num_sge)) {
srcu_read_unlock(&dev->odp_srcu, srcu_key);
return -EINVAL;
}
queue_work(system_unbound_wq, &work->work);
srcu_read_unlock(&dev->odp_srcu, srcu_key);
return 0;
}