net: ethernet: mtk_wed: add support for devices with more than 4GB of dram

Introduce WED offloading support for boards with more than 4GB of
memory.

Co-developed-by: Sujuan Chen <sujuan.chen@mediatek.com>
Signed-off-by: Sujuan Chen <sujuan.chen@mediatek.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/1c7efdf5d384ea7af3c0209723e40b2ee0f956bf.1700239272.git.lorenzo@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: LorenzoBianconi

drivers/net/ethernet/mediatek/mtk_eth_soc.c

@@ -1159,15 +1159,18 @@ static int mtk_init_fq_dma(struct mtk_eth *eth)
 	phy_ring_tail = eth->phy_scratch_ring + soc->txrx.txd_size * (cnt - 1);
 
 	for (i = 0; i < cnt; i++) {
+		dma_addr_t addr = dma_addr + i * MTK_QDMA_PAGE_SIZE;
 		struct mtk_tx_dma_v2 *txd;
 
 		txd = eth->scratch_ring + i * soc->txrx.txd_size;
-		txd->txd1 = dma_addr + i * MTK_QDMA_PAGE_SIZE;
+		txd->txd1 = addr;
 		if (i < cnt - 1)
 			txd->txd2 = eth->phy_scratch_ring +
 				    (i + 1) * soc->txrx.txd_size;
 
 		txd->txd3 = TX_DMA_PLEN0(MTK_QDMA_PAGE_SIZE);
+		if (MTK_HAS_CAPS(soc->caps, MTK_36BIT_DMA))
+			txd->txd3 |= TX_DMA_PREP_ADDR64(addr);
 		txd->txd4 = 0;
 		if (mtk_is_netsys_v2_or_greater(eth)) {
 			txd->txd5 = 0;

drivers/net/ethernet/mediatek/mtk_wed.c

@@ -691,10 +691,11 @@ mtk_wed_tx_buffer_alloc(struct mtk_wed_device *dev)
 
 		for (s = 0; s < MTK_WED_BUF_PER_PAGE; s++) {
 			struct mtk_wdma_desc *desc = desc_ptr;
+			u32 ctrl;
 
 			desc->buf0 = cpu_to_le32(buf_phys);
 			if (!mtk_wed_is_v3_or_greater(dev->hw)) {
-				u32 txd_size, ctrl;
+				u32 txd_size;
 
 				txd_size = dev->wlan.init_buf(buf, buf_phys,
 							      token++);
@@ -708,11 +709,11 @@ mtk_wed_tx_buffer_alloc(struct mtk_wed_device *dev)
 					ctrl |= MTK_WDMA_DESC_CTRL_LAST_SEG0 |
 						FIELD_PREP(MTK_WDMA_DESC_CTRL_LEN1_V2,
 							   MTK_WED_BUF_SIZE - txd_size);
-				desc->ctrl = cpu_to_le32(ctrl);
 				desc->info = 0;
 			} else {
-				desc->ctrl = cpu_to_le32(token << 16);
+				ctrl = token << 16 | TX_DMA_PREP_ADDR64(buf_phys);
 			}
+			desc->ctrl = cpu_to_le32(ctrl);
 
 			desc_ptr += desc_size;
 			buf += MTK_WED_BUF_SIZE;
@@ -811,6 +812,7 @@ mtk_wed_hwrro_buffer_alloc(struct mtk_wed_device *dev)
 		buf_phys = page_phys;
 		for (s = 0; s < MTK_WED_RX_BUF_PER_PAGE; s++) {
 			desc->buf0 = cpu_to_le32(buf_phys);
+			desc->token = cpu_to_le32(RX_DMA_PREP_ADDR64(buf_phys));
 			buf_phys += MTK_WED_PAGE_BUF_SIZE;
 			desc++;
 		}

drivers/net/ethernet/mediatek/mtk_wed_wo.c

@@ -142,7 +142,8 @@ mtk_wed_wo_queue_refill(struct mtk_wed_wo *wo, struct mtk_wed_wo_queue *q,
 		dma_addr_t addr;
 		void *buf;
 
-		buf = page_frag_alloc(&q->cache, q->buf_size, GFP_ATOMIC);
+		buf = page_frag_alloc(&q->cache, q->buf_size,
+				      GFP_ATOMIC | GFP_DMA32);
 		if (!buf)
 			break;