#include "q_struct.h"
#include "nicvf_queues.h"
-#define NICVF_PAGE_ORDER ((PAGE_SIZE <= 4096) ? PAGE_ALLOC_COSTLY_ORDER : 0)
-
static inline u64 nicvf_iova_to_phys(struct nicvf *nic, dma_addr_t dma_addr)
{
/* Translation is installed only when IOMMU is present */
dmem->base = NULL;
}
-/* Allocate buffer for packet reception
- * HW returns memory address where packet is DMA'ed but not a pointer
- * into RBDR ring, so save buffer address at the start of fragment and
- * align the start address to a cache aligned address
+/* Allocate a new page or recycle one if possible
+ *
+ * We cannot optimize dma mapping here, since
+ * 1. It's only one RBDR ring for 8 Rx queues.
+ * 2. CQE_RX gives address of the buffer where pkt has been DMA'ed
+ * and not idx into RBDR ring, so can't refer to saved info.
+ * 3. There are multiple receive buffers per page
*/
-static inline int nicvf_alloc_rcv_buffer(struct nicvf *nic, gfp_t gfp,
- u32 buf_len, u64 **rbuf)
+static struct pgcache *nicvf_alloc_page(struct nicvf *nic,
+ struct rbdr *rbdr, gfp_t gfp)
{
- int order = NICVF_PAGE_ORDER;
+ struct page *page = NULL;
+ struct pgcache *pgcache, *next;
+
+ /* Check if page is already allocated */
+ pgcache = &rbdr->pgcache[rbdr->pgidx];
+ page = pgcache->page;
+ /* Check if page can be recycled */
+ if (page && (page_ref_count(page) != 1))
+ page = NULL;
+
+ if (!page) {
+ page = alloc_pages(gfp | __GFP_COMP | __GFP_NOWARN, 0);
+ if (!page)
+ return NULL;
+
+ this_cpu_inc(nic->pnicvf->drv_stats->page_alloc);
+
+ /* Check for space */
+ if (rbdr->pgalloc >= rbdr->pgcnt) {
+ /* Page can still be used */
+ nic->rb_page = page;
+ return NULL;
+ }
+
+ /* Save the page in page cache */
+ pgcache->page = page;
+ rbdr->pgalloc++;
+ }
+
+ /* Take extra page reference for recycling */
+ page_ref_add(page, 1);
+
+ rbdr->pgidx++;
+ rbdr->pgidx &= (rbdr->pgcnt - 1);
+
+ /* Prefetch refcount of next page in page cache */
+ next = &rbdr->pgcache[rbdr->pgidx];
+ page = next->page;
+ if (page)
+ prefetch(&page->_refcount);
+
+ return pgcache;
+}
+
+/* Allocate buffer for packet reception */
+static inline int nicvf_alloc_rcv_buffer(struct nicvf *nic, struct rbdr *rbdr,
+ gfp_t gfp, u32 buf_len, u64 **rbuf)
+{
+ struct pgcache *pgcache = NULL;
/* Check if request can be accomodated in previous allocated page */
if (nic->rb_page &&
- ((nic->rb_page_offset + buf_len) < (PAGE_SIZE << order))) {
+ ((nic->rb_page_offset + buf_len) <= PAGE_SIZE)) {
nic->rb_pageref++;
goto ret;
}
nicvf_get_page(nic);
+ nic->rb_page = NULL;
- /* Allocate a new page */
- nic->rb_page = alloc_pages(gfp | __GFP_COMP | __GFP_NOWARN,
- order);
- if (!nic->rb_page) {
+ /* Get new page, either recycled or new one */
+ pgcache = nicvf_alloc_page(nic, rbdr, gfp);
+ if (!pgcache && !nic->rb_page) {
this_cpu_inc(nic->pnicvf->drv_stats->rcv_buffer_alloc_failures);
return -ENOMEM;
}
+
nic->rb_page_offset = 0;
+ /* Check if it's recycled */
+ if (pgcache)
+ nic->rb_page = pgcache->page;
ret:
/* HW will ensure data coherency, CPU sync not required */
*rbuf = (u64 *)((u64)dma_map_page_attrs(&nic->pdev->dev, nic->rb_page,
DMA_ATTR_SKIP_CPU_SYNC));
if (dma_mapping_error(&nic->pdev->dev, (dma_addr_t)*rbuf)) {
if (!nic->rb_page_offset)
- __free_pages(nic->rb_page, order);
+ __free_pages(nic->rb_page, 0);
nic->rb_page = NULL;
return -ENOMEM;
}
rbdr->head = 0;
rbdr->tail = 0;
+ /* Initialize page recycling stuff.
+ *
+ * Can't use single buffer per page especially with 64K pages.
+ * On embedded platforms i.e 81xx/83xx available memory itself
+ * is low and minimum ring size of RBDR is 8K, that takes away
+ * lots of memory.
+ */
+ rbdr->pgcnt = ring_len / (PAGE_SIZE / buf_size);
+ rbdr->pgcnt = roundup_pow_of_two(rbdr->pgcnt);
+ rbdr->pgcache = kzalloc(sizeof(*rbdr->pgcache) *
+ rbdr->pgcnt, GFP_KERNEL);
+ if (!rbdr->pgcache)
+ return -ENOMEM;
+ rbdr->pgidx = 0;
+ rbdr->pgalloc = 0;
+
nic->rb_page = NULL;
for (idx = 0; idx < ring_len; idx++) {
- err = nicvf_alloc_rcv_buffer(nic, GFP_KERNEL, RCV_FRAG_LEN,
- &rbuf);
+ err = nicvf_alloc_rcv_buffer(nic, rbdr, GFP_KERNEL,
+ RCV_FRAG_LEN, &rbuf);
if (err) {
/* To free already allocated and mapped ones */
rbdr->tail = idx - 1;
{
int head, tail;
u64 buf_addr, phys_addr;
+ struct pgcache *pgcache;
struct rbdr_entry_t *desc;
if (!rbdr)
if (phys_addr)
put_page(virt_to_page(phys_to_virt(phys_addr)));
+ /* Sync page cache info */
+ smp_rmb();
+
+ /* Release additional page references held for recycling */
+ head = 0;
+ while (head < rbdr->pgcnt) {
+ pgcache = &rbdr->pgcache[head];
+ if (pgcache->page && page_ref_count(pgcache->page) != 0)
+ put_page(pgcache->page);
+ head++;
+ }
+
/* Free RBDR ring */
nicvf_free_q_desc_mem(nic, &rbdr->dmem);
}
else
refill_rb_cnt = qs->rbdr_len - qcount - 1;
+ /* Sync page cache info */
+ smp_rmb();
+
/* Start filling descs from tail */
tail = nicvf_queue_reg_read(nic, NIC_QSET_RBDR_0_1_TAIL, rbdr_idx) >> 3;
while (refill_rb_cnt) {
tail++;
tail &= (rbdr->dmem.q_len - 1);
- if (nicvf_alloc_rcv_buffer(nic, gfp, RCV_FRAG_LEN, &rbuf))
+ if (nicvf_alloc_rcv_buffer(nic, rbdr, gfp, RCV_FRAG_LEN, &rbuf))
break;
desc = GET_RBDR_DESC(rbdr, tail);
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