Re: [PATCH for-next 2/4] RDMA/hns: Add IOMMU enable support in hip08

From: Wei Hu (Xavier)
Date: Thu Oct 12 2017 - 08:32:23 EST




On 2017/10/1 0:10, Leon Romanovsky wrote:
On Sat, Sep 30, 2017 at 05:28:59PM +0800, Wei Hu (Xavier) wrote:
If the IOMMU is enabled, the length of sg obtained from
__iommu_map_sg_attrs is not 4kB. When the IOVA is set with the sg
dma address, the IOVA will not be page continuous. and the VA
returned from dma_alloc_coherent is a vmalloc address. However,
the VA obtained by the page_address is a discontinuous VA. Under
these circumstances, the IOVA should be calculated based on the
sg length, and record the VA returned from dma_alloc_coherent
in the struct of hem.

Signed-off-by: Wei Hu (Xavier) <xavier.huwei@xxxxxxxxxx>
Signed-off-by: Shaobo Xu <xushaobo2@xxxxxxxxxx>
Signed-off-by: Lijun Ou <oulijun@xxxxxxxxxx>
---
Doug,

I didn't invest time in reviewing it, but having "is_vmalloc_addr" in
driver code to deal with dma_alloc_coherent is most probably wrong.

Thanks
Hi, Leon & Doug
We refered the function named __ttm_dma_alloc_page in the kernel code as below:
And there are similar methods in bch_bio_map and mem_to_page functions in current 4.14-rcx.

static struct dma_page *__ttm_dma_alloc_page(struct dma_pool *pool)
{
struct dma_page *d_page;

d_page = kmalloc(sizeof(struct dma_page), GFP_KERNEL);
if (!d_page)
return NULL;

d_page->vaddr = dma_alloc_coherent(pool->dev, pool->size,
&d_page->dma,
pool->gfp_flags);
if (d_page->vaddr) {
if (is_vmalloc_addr(d_page->vaddr))
d_page->p = vmalloc_to_page(d_page->vaddr);
else
d_page->p = virt_to_page(d_page->vaddr);
} else {
kfree(d_page);
d_page = NULL;
}
return d_page;
}

Regards
Wei Hu

drivers/infiniband/hw/hns/hns_roce_alloc.c | 5 ++++-
drivers/infiniband/hw/hns/hns_roce_hem.c | 30 +++++++++++++++++++++++++++---
drivers/infiniband/hw/hns/hns_roce_hem.h | 6 ++++++
drivers/infiniband/hw/hns/hns_roce_hw_v2.c | 22 +++++++++++++++-------
4 files changed, 52 insertions(+), 11 deletions(-)

diff --git a/drivers/infiniband/hw/hns/hns_roce_alloc.c b/drivers/infiniband/hw/hns/hns_roce_alloc.c
index 3e4c525..a69cd4b 100644
--- a/drivers/infiniband/hw/hns/hns_roce_alloc.c
+++ b/drivers/infiniband/hw/hns/hns_roce_alloc.c
@@ -243,7 +243,10 @@ int hns_roce_buf_alloc(struct hns_roce_dev *hr_dev, u32 size, u32 max_direct,
goto err_free;

for (i = 0; i < buf->nbufs; ++i)
- pages[i] = virt_to_page(buf->page_list[i].buf);
+ pages[i] =
+ is_vmalloc_addr(buf->page_list[i].buf) ?
+ vmalloc_to_page(buf->page_list[i].buf) :
+ virt_to_page(buf->page_list[i].buf);

buf->direct.buf = vmap(pages, buf->nbufs, VM_MAP,
PAGE_KERNEL);
diff --git a/drivers/infiniband/hw/hns/hns_roce_hem.c b/drivers/infiniband/hw/hns/hns_roce_hem.c
index 8388ae2..4a3d1d4 100644
--- a/drivers/infiniband/hw/hns/hns_roce_hem.c
+++ b/drivers/infiniband/hw/hns/hns_roce_hem.c
@@ -200,6 +200,7 @@ static struct hns_roce_hem *hns_roce_alloc_hem(struct hns_roce_dev *hr_dev,
gfp_t gfp_mask)
{
struct hns_roce_hem_chunk *chunk = NULL;
+ struct hns_roce_vmalloc *vmalloc;
struct hns_roce_hem *hem;
struct scatterlist *mem;
int order;
@@ -227,6 +228,7 @@ static struct hns_roce_hem *hns_roce_alloc_hem(struct hns_roce_dev *hr_dev,
sg_init_table(chunk->mem, HNS_ROCE_HEM_CHUNK_LEN);
chunk->npages = 0;
chunk->nsg = 0;
+ memset(chunk->vmalloc, 0, sizeof(chunk->vmalloc));
list_add_tail(&chunk->list, &hem->chunk_list);
}

@@ -243,7 +245,15 @@ static struct hns_roce_hem *hns_roce_alloc_hem(struct hns_roce_dev *hr_dev,
if (!buf)
goto fail;

- sg_set_buf(mem, buf, PAGE_SIZE << order);
+ if (is_vmalloc_addr(buf)) {
+ vmalloc = &chunk->vmalloc[chunk->npages];
+ vmalloc->is_vmalloc_addr = true;
+ vmalloc->vmalloc_addr = buf;
+ sg_set_page(mem, vmalloc_to_page(buf),
+ PAGE_SIZE << order, offset_in_page(buf));
+ } else {
+ sg_set_buf(mem, buf, PAGE_SIZE << order);
+ }
WARN_ON(mem->offset);
sg_dma_len(mem) = PAGE_SIZE << order;

@@ -262,17 +272,25 @@ static struct hns_roce_hem *hns_roce_alloc_hem(struct hns_roce_dev *hr_dev,
void hns_roce_free_hem(struct hns_roce_dev *hr_dev, struct hns_roce_hem *hem)
{
struct hns_roce_hem_chunk *chunk, *tmp;
+ void *cpu_addr;
int i;

if (!hem)
return;

list_for_each_entry_safe(chunk, tmp, &hem->chunk_list, list) {
- for (i = 0; i < chunk->npages; ++i)
+ for (i = 0; i < chunk->npages; ++i) {
+ if (chunk->vmalloc[i].is_vmalloc_addr)
+ cpu_addr = chunk->vmalloc[i].vmalloc_addr;
+ else
+ cpu_addr =
+ lowmem_page_address(sg_page(&chunk->mem[i]));
+
dma_free_coherent(hr_dev->dev,
chunk->mem[i].length,
- lowmem_page_address(sg_page(&chunk->mem[i])),
+ cpu_addr,
sg_dma_address(&chunk->mem[i]));
+ }
kfree(chunk);
}

@@ -774,6 +792,12 @@ void *hns_roce_table_find(struct hns_roce_dev *hr_dev,

if (chunk->mem[i].length > (u32)offset) {
page = sg_page(&chunk->mem[i]);
+ if (chunk->vmalloc[i].is_vmalloc_addr) {
+ mutex_unlock(&table->mutex);
+ return page ?
+ chunk->vmalloc[i].vmalloc_addr
+ + offset : NULL;
+ }
goto out;
}
offset -= chunk->mem[i].length;
diff --git a/drivers/infiniband/hw/hns/hns_roce_hem.h b/drivers/infiniband/hw/hns/hns_roce_hem.h
index af28bbf..62d712a 100644
--- a/drivers/infiniband/hw/hns/hns_roce_hem.h
+++ b/drivers/infiniband/hw/hns/hns_roce_hem.h
@@ -72,11 +72,17 @@ enum {
HNS_ROCE_HEM_PAGE_SIZE = 1 << HNS_ROCE_HEM_PAGE_SHIFT,
};

+struct hns_roce_vmalloc {
+ bool is_vmalloc_addr;
+ void *vmalloc_addr;
+};
+
struct hns_roce_hem_chunk {
struct list_head list;
int npages;
int nsg;
struct scatterlist mem[HNS_ROCE_HEM_CHUNK_LEN];
+ struct hns_roce_vmalloc vmalloc[HNS_ROCE_HEM_CHUNK_LEN];
};

struct hns_roce_hem {
diff --git a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
index b99d70a..9e19bf1 100644
--- a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
+++ b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
@@ -1093,9 +1093,11 @@ static int hns_roce_v2_write_mtpt(void *mb_buf, struct hns_roce_mr *mr,
{
struct hns_roce_v2_mpt_entry *mpt_entry;
struct scatterlist *sg;
+ u64 page_addr = 0;
u64 *pages;
+ int i = 0, j = 0;
+ int len = 0;
int entry;
- int i;

mpt_entry = mb_buf;
memset(mpt_entry, 0, sizeof(*mpt_entry));
@@ -1153,14 +1155,20 @@ static int hns_roce_v2_write_mtpt(void *mb_buf, struct hns_roce_mr *mr,

i = 0;
for_each_sg(mr->umem->sg_head.sgl, sg, mr->umem->nmap, entry) {
- pages[i] = ((u64)sg_dma_address(sg)) >> 6;
-
- /* Record the first 2 entry directly to MTPT table */
- if (i >= HNS_ROCE_V2_MAX_INNER_MTPT_NUM - 1)
- break;
- i++;
+ len = sg_dma_len(sg) >> PAGE_SHIFT;
+ for (j = 0; j < len; ++j) {
+ page_addr = sg_dma_address(sg) +
+ (j << mr->umem->page_shift);
+ pages[i] = page_addr >> 6;
+
+ /* Record the first 2 entry directly to MTPT table */
+ if (i >= HNS_ROCE_V2_MAX_INNER_MTPT_NUM - 1)
+ goto found;
+ i++;
+ }
}

+found:
mpt_entry->pa0_l = cpu_to_le32(lower_32_bits(pages[0]));
roce_set_field(mpt_entry->byte_56_pa0_h, V2_MPT_BYTE_56_PA0_H_M,
V2_MPT_BYTE_56_PA0_H_S,
--
1.9.1