[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <566ca90fc59ad0d3aff8bc8dc22ebaf0544bce47.1751072868.git.daniel@makrotopia.org>
Date: Sat, 28 Jun 2025 02:30:40 +0100
From: Daniel Golle <daniel@...rotopia.org>
To: Felix Fietkau <nbd@....name>,
Frank Wunderlich <frank-w@...lic-files.de>,
Eric Woudstra <ericwouds@...il.com>, Elad Yifee <eladwf@...il.com>,
Bo-Cun Chen <bc-bocun.chen@...iatek.com>,
Sky Huang <skylake.huang@...iatek.com>,
Sean Wang <sean.wang@...iatek.com>,
Lorenzo Bianconi <lorenzo@...nel.org>,
Andrew Lunn <andrew+netdev@...n.ch>,
"David S. Miller" <davem@...emloft.net>,
Eric Dumazet <edumazet@...gle.com>,
Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>,
Matthias Brugger <matthias.bgg@...il.com>,
AngeloGioacchino Del Regno <angelogioacchino.delregno@...labora.com>,
netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
linux-arm-kernel@...ts.infradead.org,
linux-mediatek@...ts.infradead.org
Subject: [PATCH net/next 3/3] net: ethernet: mtk_eth_soc: use genpool
allocator for SRAM
Use a dedicated "mmio-sram" and the genpool allocator instead of
open-coding SRAM allocation for DMA rings.
Keep support for legacy device trees but notify the user via a
warning.
Co-developed-by: Frank Wunderlich <frank-w@...lic-files.de>
Signed-off-by: Frank Wunderlich <frank-w@...lic-files.de>
Signed-off-by: Daniel Golle <daniel@...rotopia.org>
---
drivers/net/ethernet/mediatek/mtk_eth_soc.c | 119 +++++++++++++-------
drivers/net/ethernet/mediatek/mtk_eth_soc.h | 4 +-
2 files changed, 83 insertions(+), 40 deletions(-)
diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index 8f55069441f4..adae59a3dfa4 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -27,6 +27,7 @@
#include <net/dsa.h>
#include <net/dst_metadata.h>
#include <net/page_pool/helpers.h>
+#include <linux/genalloc.h>
#include "mtk_eth_soc.h"
#include "mtk_wed.h"
@@ -1267,6 +1268,44 @@ static void *mtk_max_lro_buf_alloc(gfp_t gfp_mask)
return (void *)data;
}
+static bool mtk_use_legacy_sram(struct mtk_eth *eth)
+{
+ return !eth->sram_pool && MTK_HAS_CAPS(eth->soc->caps, MTK_SRAM);
+}
+
+static void *mtk_dma_ring_alloc(struct mtk_eth *eth, size_t size,
+ dma_addr_t *dma_handle)
+{
+ void *dma_ring;
+
+ if (WARN_ON(mtk_use_legacy_sram(eth)))
+ return -ENOMEM;
+
+ if (eth->sram_pool) {
+ dma_ring = (void *)gen_pool_alloc(eth->sram_pool, size);
+ if (!dma_ring)
+ return dma_ring;
+ *dma_handle = gen_pool_virt_to_phys(eth->sram_pool, (unsigned long)dma_ring);
+ } else {
+ dma_ring = dma_alloc_coherent(eth->dma_dev, size, dma_handle,
+ GFP_KERNEL);
+ }
+
+ return dma_ring;
+}
+
+static void mtk_dma_ring_free(struct mtk_eth *eth, size_t size, void *dma_ring,
+ dma_addr_t dma_handle)
+{
+ if (WARN_ON(mtk_use_legacy_sram(eth)))
+ return;
+
+ if (eth->sram_pool)
+ gen_pool_free(eth->sram_pool, (unsigned long)dma_ring, size);
+ else
+ dma_free_coherent(eth->dma_dev, size, dma_ring, dma_handle);
+}
+
/* the qdma core needs scratch memory to be setup */
static int mtk_init_fq_dma(struct mtk_eth *eth)
{
@@ -1276,13 +1315,12 @@ static int mtk_init_fq_dma(struct mtk_eth *eth)
dma_addr_t dma_addr;
int i, j, len;
- if (MTK_HAS_CAPS(eth->soc->caps, MTK_SRAM))
+ if (!mtk_use_legacy_sram(eth)) {
+ eth->scratch_ring = mtk_dma_ring_alloc(eth, cnt * soc->tx.desc_size,
+ ð->phy_scratch_ring);
+ } else {
eth->scratch_ring = eth->sram_base;
- else
- eth->scratch_ring = dma_alloc_coherent(eth->dma_dev,
- cnt * soc->tx.desc_size,
- ð->phy_scratch_ring,
- GFP_KERNEL);
+ }
if (unlikely(!eth->scratch_ring))
return -ENOMEM;
@@ -2620,12 +2658,11 @@ static int mtk_tx_alloc(struct mtk_eth *eth)
if (!ring->buf)
goto no_tx_mem;
- if (MTK_HAS_CAPS(soc->caps, MTK_SRAM)) {
+ if (!mtk_use_legacy_sram(eth)) {
+ ring->dma = mtk_dma_ring_alloc(eth, ring_size * sz, &ring->phys);
+ } else {
ring->dma = eth->sram_base + soc->tx.fq_dma_size * sz;
ring->phys = eth->phy_scratch_ring + soc->tx.fq_dma_size * (dma_addr_t)sz;
- } else {
- ring->dma = dma_alloc_coherent(eth->dma_dev, ring_size * sz,
- &ring->phys, GFP_KERNEL);
}
if (!ring->dma)
@@ -2726,9 +2763,9 @@ static void mtk_tx_clean(struct mtk_eth *eth)
kfree(ring->buf);
ring->buf = NULL;
}
- if (!MTK_HAS_CAPS(soc->caps, MTK_SRAM) && ring->dma) {
- dma_free_coherent(eth->dma_dev,
- ring->dma_size * soc->tx.desc_size,
+
+ if (!mtk_use_legacy_sram(eth) && ring->dma) {
+ mtk_dma_ring_free(eth, ring->dma_size * soc->tx.desc_size,
ring->dma, ring->phys);
ring->dma = NULL;
}
@@ -2793,6 +2830,9 @@ static int mtk_rx_alloc(struct mtk_eth *eth, int ring_no, int rx_flag)
ring->dma = dma_alloc_coherent(eth->dma_dev,
rx_dma_size * eth->soc->rx.desc_size,
&ring->phys, GFP_KERNEL);
+ } else if (eth->sram_pool) {
+ ring->dma = mtk_dma_ring_alloc(eth, rx_dma_size * eth->soc->rx.desc_size,
+ &ring->phys);
} else {
struct mtk_tx_ring *tx_ring = ð->tx_ring;
@@ -2921,6 +2961,11 @@ static void mtk_rx_clean(struct mtk_eth *eth, struct mtk_rx_ring *ring, bool in_
ring->dma_size * eth->soc->rx.desc_size,
ring->dma, ring->phys);
ring->dma = NULL;
+ } else if (!mtk_use_legacy_sram(eth) && ring->dma) {
+ mtk_dma_ring_free(eth,
+ ring->dma_size * eth->soc->rx.desc_size,
+ ring->dma, ring->phys);
+ ring->dma = NULL;
}
if (ring->page_pool) {
@@ -3287,9 +3332,8 @@ static void mtk_dma_free(struct mtk_eth *eth)
netdev_tx_reset_subqueue(eth->netdev[i], j);
}
- if (!MTK_HAS_CAPS(soc->caps, MTK_SRAM) && eth->scratch_ring) {
- dma_free_coherent(eth->dma_dev,
- MTK_QDMA_RING_SIZE * soc->tx.desc_size,
+ if (!mtk_use_legacy_sram(eth) && eth->scratch_ring) {
+ mtk_dma_ring_free(eth, soc->tx.fq_dma_size * soc->tx.desc_size,
eth->scratch_ring, eth->phy_scratch_ring);
eth->scratch_ring = NULL;
eth->phy_scratch_ring = 0;
@@ -5009,7 +5053,7 @@ static int mtk_sgmii_init(struct mtk_eth *eth)
static int mtk_probe(struct platform_device *pdev)
{
- struct resource *res = NULL, *res_sram;
+ struct resource *res = NULL;
struct device_node *mac_np;
struct mtk_eth *eth;
int err, i;
@@ -5029,20 +5073,6 @@ static int mtk_probe(struct platform_device *pdev)
if (MTK_HAS_CAPS(eth->soc->caps, MTK_SOC_MT7628))
eth->ip_align = NET_IP_ALIGN;
- if (MTK_HAS_CAPS(eth->soc->caps, MTK_SRAM)) {
- /* SRAM is actual memory and supports transparent access just like DRAM.
- * Hence we don't require __iomem being set and don't need to use accessor
- * functions to read from or write to SRAM.
- */
- if (mtk_is_netsys_v3_or_greater(eth)) {
- eth->sram_base = (void __force *)devm_platform_ioremap_resource(pdev, 1);
- if (IS_ERR(eth->sram_base))
- return PTR_ERR(eth->sram_base);
- } else {
- eth->sram_base = (void __force *)eth->base + MTK_ETH_SRAM_OFFSET;
- }
- }
-
if (MTK_HAS_CAPS(eth->soc->caps, MTK_36BIT_DMA)) {
err = dma_set_mask(&pdev->dev, DMA_BIT_MASK(36));
if (!err)
@@ -5117,16 +5147,27 @@ static int mtk_probe(struct platform_device *pdev)
err = -EINVAL;
goto err_destroy_sgmii;
}
+
if (MTK_HAS_CAPS(eth->soc->caps, MTK_SRAM)) {
- if (mtk_is_netsys_v3_or_greater(eth)) {
- res_sram = platform_get_resource(pdev, IORESOURCE_MEM, 1);
- if (!res_sram) {
- err = -EINVAL;
- goto err_destroy_sgmii;
+ eth->sram_pool = of_gen_pool_get(pdev->dev.of_node, "sram", 0);
+ if (!eth->sram_pool) {
+ if (!mtk_is_netsys_v3_or_greater(eth)) {
+ /*
+ * Legacy support for missing 'sram' node in DT.
+ * SRAM is actual memory and supports transparent access
+ * just like DRAM. Hence we don't require __iomem being
+ * set and don't need to use accessor functions to read from
+ * or write to SRAM.
+ */
+ eth->sram_base = (void __force *)eth->base +
+ MTK_ETH_SRAM_OFFSET;
+ eth->phy_scratch_ring = res->start + MTK_ETH_SRAM_OFFSET;
+ dev_warn(&pdev->dev,
+ "legacy DT: using hard-coded SRAM offset.\n");
+ } else {
+ dev_err(&pdev->dev, "Could not get SRAM pool\n");
+ return -ENODEV;
}
- eth->phy_scratch_ring = res_sram->start;
- } else {
- eth->phy_scratch_ring = res->start + MTK_ETH_SRAM_OFFSET;
}
}
}
diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
index 1ad9075a9b69..0104659e37f0 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
@@ -1245,7 +1245,8 @@ struct mtk_soc_data {
* @dev: The device pointer
* @dma_dev: The device pointer used for dma mapping/alloc
* @base: The mapped register i/o base
- * @sram_base: The mapped SRAM base
+ * @sram_base: The mapped SRAM base (deprecated)
+ * @sram_pool: Pointer to SRAM pool used for DMA descriptor rings
* @page_lock: Make sure that register operations are atomic
* @tx_irq__lock: Make sure that IRQ register operations are atomic
* @rx_irq__lock: Make sure that IRQ register operations are atomic
@@ -1292,6 +1293,7 @@ struct mtk_eth {
struct device *dma_dev;
void __iomem *base;
void *sram_base;
+ struct gen_pool *sram_pool;
spinlock_t page_lock;
spinlock_t tx_irq_lock;
spinlock_t rx_irq_lock;
--
2.50.0
Powered by blists - more mailing lists