[RFC PATCH v2 22/25] net/gve: Use PISA memory for RX buffers

[Luigi Rizzo <lrizzo@google.com>]

When dev->pisa_rx_bufs is enabled, allocate GQI-RDA RX packet buffers
with pisa_rx_gfp(dev) so they come from the per-node PISA
allocator, and evict plain pages when a free PISA RX block is available;
DQO-RDA uses page_pool, which checks dev->pisa_rx_bufs directly.

Signed-off-by: Luigi Rizzo <lrizzo@google.com>
---
 drivers/net/ethernet/google/gve/gve_rx.c | 32 ++++++++++++++++--------
 1 file changed, 22 insertions(+), 10 deletions(-)

diff --git a/drivers/net/ethernet/google/gve/gve_rx.c b/drivers/net/ethernet/google/gve/gve_rx.c
index 89f287b678bf0..85c243bbdeb33 100644
--- a/drivers/net/ethernet/google/gve/gve_rx.c
+++ b/drivers/net/ethernet/google/gve/gve_rx.c
@@ -4,6 +4,7 @@
  * Copyright (C) 2015-2021 Google, Inc.
  */
 
+#include <linux/pisa.h>
 #include "gve.h"
 #include "gve_adminq.h"
 #include "gve_utils.h"
@@ -170,6 +171,8 @@ static int gve_rx_alloc_buffer(struct gve_priv *priv, struct device *dev,
 	dma_addr_t dma;
 	int err;
 
+	if (rx->data.raw_addressing)
+		gfp |= pisa_rx_gfp(dev);
 	err = gve_alloc_page(priv, dev, &page, &dma, DMA_FROM_DEVICE, gfp);
 	if (err) {
 		u64_stats_update_begin(&rx->statss);
@@ -499,13 +502,19 @@ static void gve_rx_flip_buff(struct gve_rx_slot_page_info *page_info, __be64 *sl
 	*(slot_addr) ^= offset;
 }
 
-static int gve_rx_can_recycle_buffer(struct gve_rx_slot_page_info *page_info)
+static int gve_rx_can_recycle_buffer(struct gve_rx_ring *rx,
+				     struct gve_rx_slot_page_info *page_info)
 {
 	int pagecount = page_count(page_info->page);
 
 	/* This page is not being used by any SKBs - reuse */
-	if (pagecount == page_info->pagecnt_bias)
+	if (pagecount == page_info->pagecnt_bias) {
+		if (rx && rx->data.raw_addressing &&
+		    !is_pisa_page(page_info->page) &&
+		    pisa_has_free_blocks_rx(&rx->gve->pdev->dev, 0, rx->gve->numa_node))
+			return 0;
 		return 1;
+	}
 	/* This page is still being used by an SKB - we can't reuse */
 	else if (pagecount > page_info->pagecnt_bias)
 		return 0;
@@ -549,7 +558,7 @@ static struct sk_buff *gve_rx_copy_to_pool(struct gve_rx_ring *rx,
 
 	copy_page_info = &rx->qpl_copy_pool[pool_idx];
 	if (!copy_page_info->can_flip) {
-		int recycle = gve_rx_can_recycle_buffer(copy_page_info);
+		int recycle = gve_rx_can_recycle_buffer(NULL, copy_page_info);
 
 		if (unlikely(recycle < 0)) {
 			gve_schedule_reset(rx->gve);
@@ -669,7 +678,7 @@ static struct sk_buff *gve_rx_skb(struct gve_priv *priv, struct gve_rx_ring *rx,
 			u64_stats_update_end(&rx->statss);
 		}
 	} else {
-		int recycle = gve_rx_can_recycle_buffer(page_info);
+		int recycle = gve_rx_can_recycle_buffer(rx, page_info);
 
 		if (unlikely(recycle < 0)) {
 			gve_schedule_reset(priv);
@@ -975,7 +984,7 @@ static bool gve_rx_refill_buffers(struct gve_priv *priv, struct gve_rx_ring *rx)
 			 * owns half the page it is impossible to tell which half. Either
 			 * the whole page is free or it needs to be replaced.
 			 */
-			int recycle = gve_rx_can_recycle_buffer(page_info);
+			int recycle = gve_rx_can_recycle_buffer(rx, page_info);
 
 			if (recycle < 0) {
 				if (!rx->data.raw_addressing)
@@ -987,12 +996,15 @@ static bool gve_rx_refill_buffers(struct gve_priv *priv, struct gve_rx_ring *rx)
 				union gve_rx_data_slot *data_slot =
 						&rx->data.data_ring[idx];
 				struct device *dev = &priv->pdev->dev;
-				gve_rx_free_buffer(dev, page_info, data_slot);
-				page_info->page = NULL;
-				if (gve_rx_alloc_buffer(priv, dev, page_info,
-							data_slot, rx)) {
+				struct gve_rx_slot_page_info new_info;
+				union gve_rx_data_slot new_slot;
+
+				if (gve_rx_alloc_buffer(priv, dev, &new_info,
+							&new_slot, rx))
 					break;
-				}
+				gve_rx_free_buffer(dev, page_info, data_slot);
+				*page_info = new_info;
+				*data_slot = new_slot;
 			}
 		}
 		fill_cnt++;
-- 
2.56.0.542.g3ef89b7020-goog