[PATCH net-next 1/7] net: stmmac: provide plat_dat->dma_cfg in stmmac_plat_dat_alloc()
From: Russell King (Oracle) <hidden>
Date: 2026-03-07 11:02:54
Also in:
imx, linux-arm-kernel, linux-arm-msm, linux-mediatek, linux-sunxi, linux-tegra
Subsystem:
motorcomm dwmac glue driver, networking drivers, stmmac ethernet driver, the rest · Maintainers:
Yao Zi, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
plat_dat->dma_cfg is unconditionally required for the operation of the driver, so it would make sense to allocate it along with the plat_dat. On Arm64, sizeof(*plat_dat) has recently shrunk from 880 to 816 bytes and sizeof(*plat_dat->dma_cfg) has shrunk from 32 to 20 bytes. Given that dma_cfg is required, and it is now less than a cache line, It doesn't make sense to allocate this separateny, so place it at the end of struct plat_stmmacenet_data, and set plat_dat->dma_cfg to point at that to avoid mass changes. Signed-off-by: Russell King (Oracle) <redacted> --- drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c | 5 ----- drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c | 4 ---- drivers/net/ethernet/stmicro/stmmac/dwmac-motorcomm.c | 4 ---- drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 2 ++ drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c | 5 ----- drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c | 8 +------- include/linux/stmmac.h | 1 + 7 files changed, 4 insertions(+), 25 deletions(-)
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c
index fc13bfb47783..0b32560cd059 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c@@ -1251,11 +1251,6 @@ static int intel_eth_pci_probe(struct pci_dev *pdev, if (!plat->mdio_bus_data) return -ENOMEM; - plat->dma_cfg = devm_kzalloc(&pdev->dev, sizeof(*plat->dma_cfg), - GFP_KERNEL); - if (!plat->dma_cfg) - return -ENOMEM; - plat->safety_feat_cfg = devm_kzalloc(&pdev->dev, sizeof(*plat->safety_feat_cfg), GFP_KERNEL);
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c
index ada6c6ef1f5c..51b1562f84d1 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c@@ -513,10 +513,6 @@ static int loongson_dwmac_probe(struct pci_dev *pdev, const struct pci_device_id if (!plat->mdio_bus_data) return -ENOMEM; - plat->dma_cfg = devm_kzalloc(&pdev->dev, sizeof(*plat->dma_cfg), GFP_KERNEL); - if (!plat->dma_cfg) - return -ENOMEM; - ld = devm_kzalloc(&pdev->dev, sizeof(*ld), GFP_KERNEL); if (!ld) return -ENOMEM;
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-motorcomm.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-motorcomm.c
index 8b45b9cf7202..d245546b90db 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-motorcomm.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-motorcomm.c@@ -218,10 +218,6 @@ motorcomm_default_plat_data(struct pci_dev *pdev) if (!plat->mdio_bus_data) return NULL; - plat->dma_cfg = devm_kzalloc(dev, sizeof(*plat->dma_cfg), GFP_KERNEL); - if (!plat->dma_cfg) - return NULL; - plat->axi = devm_kzalloc(dev, sizeof(*plat->axi), GFP_KERNEL); if (!plat->axi) return NULL;
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index f0160ff54a59..87f43811faa0 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c@@ -7730,6 +7730,8 @@ struct plat_stmmacenet_data *stmmac_plat_dat_alloc(struct device *dev) if (!plat_dat) return NULL; + plat_dat->dma_cfg = &plat_dat->__dma_cfg; + /* Set the defaults: * - phy autodetection * - determine GMII_Address CR field from CSR clock
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c
index 270ad066ced3..836fed7d60ab 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c@@ -134,11 +134,6 @@ static int stmmac_pci_probe(struct pci_dev *pdev, if (!plat->mdio_bus_data) return -ENOMEM; - plat->dma_cfg = devm_kzalloc(&pdev->dev, sizeof(*plat->dma_cfg), - GFP_KERNEL); - if (!plat->dma_cfg) - return -ENOMEM; - plat->safety_feat_cfg = devm_kzalloc(&pdev->dev, sizeof(*plat->safety_feat_cfg), GFP_KERNEL);
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
index c34998486293..1aed48fe0db6 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c@@ -548,13 +548,7 @@ stmmac_probe_config_dt(struct platform_device *pdev, u8 *mac) &plat->multicast_filter_bins); } - dma_cfg = devm_kzalloc(&pdev->dev, sizeof(*dma_cfg), - GFP_KERNEL); - if (!dma_cfg) { - ret = ERR_PTR(-ENOMEM); - goto error_put_mdio; - } - plat->dma_cfg = dma_cfg; + dma_cfg = plat->dma_cfg; of_property_read_u32(np, "snps,pbl", &dma_cfg->pbl); if (!dma_cfg->pbl)
diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
index 965ada809fdf..919196713c05 100644
--- a/include/linux/stmmac.h
+++ b/include/linux/stmmac.h@@ -306,5 +306,6 @@ struct plat_stmmacenet_data { int msi_tx_base_vec; const struct dwmac4_addrs *dwmac4_addrs; unsigned int flags; + struct stmmac_dma_cfg __dma_cfg; }; #endif
--
2.47.3