From 0baa080c75cea6357bfba9b93ba598d747457cbd Mon Sep 17 00:00:00 2001 From: Thomas Chou Date: Sun, 4 Oct 2009 23:33:20 +0000 Subject: ethoc: use system memory as buffer This patch enabled the ethoc to allocate system memory as buffer when there is no dedicated buffer memory. Some hardware designs may not have dedicated buffer memory such as on chip or off chip SRAM. In this case, only one memory resource is supplied in the platform data instead of two. Then a DMA buffer can be allocated from system memory and used for the transfer. Signed-off-by: Thomas Chou Signed-off-by: David S. Miller --- drivers/net/ethoc.c | 64 ++++++++++++++++++++++++++++++++++++----------------- 1 file changed, 44 insertions(+), 20 deletions(-) diff --git a/drivers/net/ethoc.c b/drivers/net/ethoc.c index 0c6c7f47ace..6d82dc646ac 100644 --- a/drivers/net/ethoc.c +++ b/drivers/net/ethoc.c @@ -19,6 +19,10 @@ #include #include +static int buffer_size = 0x8000; /* 32 KBytes */ +module_param(buffer_size, int, 0); +MODULE_PARM_DESC(buffer_size, "DMA buffer allocation size"); + /* register offsets */ #define MODER 0x00 #define INT_SOURCE 0x04 @@ -167,6 +171,7 @@ * struct ethoc - driver-private device structure * @iobase: pointer to I/O memory region * @membase: pointer to buffer memory region + * @dma_alloc: dma allocated buffer size * @num_tx: number of send buffers * @cur_tx: last send buffer written * @dty_tx: last buffer actually sent @@ -185,6 +190,7 @@ struct ethoc { void __iomem *iobase; void __iomem *membase; + int dma_alloc; unsigned int num_tx; unsigned int cur_tx; @@ -906,22 +912,19 @@ static int ethoc_probe(struct platform_device *pdev) /* obtain buffer memory space */ res = platform_get_resource(pdev, IORESOURCE_MEM, 1); - if (!res) { - dev_err(&pdev->dev, "cannot obtain memory space\n"); - ret = -ENXIO; - goto free; - } - - mem = devm_request_mem_region(&pdev->dev, res->start, + if (res) { + mem = devm_request_mem_region(&pdev->dev, res->start, res->end - res->start + 1, res->name); - if (!mem) { - dev_err(&pdev->dev, "cannot request memory space\n"); - ret = -ENXIO; - goto free; + if (!mem) { + dev_err(&pdev->dev, "cannot request memory space\n"); + ret = -ENXIO; + goto free; + } + + netdev->mem_start = mem->start; + netdev->mem_end = mem->end; } - netdev->mem_start = mem->start; - netdev->mem_end = mem->end; /* obtain device IRQ number */ res = platform_get_resource(pdev, IORESOURCE_IRQ, 0); @@ -936,6 +939,7 @@ static int ethoc_probe(struct platform_device *pdev) /* setup driver-private data */ priv = netdev_priv(netdev); priv->netdev = netdev; + priv->dma_alloc = 0; priv->iobase = devm_ioremap_nocache(&pdev->dev, netdev->base_addr, mmio->end - mmio->start + 1); @@ -945,12 +949,27 @@ static int ethoc_probe(struct platform_device *pdev) goto error; } - priv->membase = devm_ioremap_nocache(&pdev->dev, netdev->mem_start, - mem->end - mem->start + 1); - if (!priv->membase) { - dev_err(&pdev->dev, "cannot remap memory space\n"); - ret = -ENXIO; - goto error; + if (netdev->mem_end) { + priv->membase = devm_ioremap_nocache(&pdev->dev, + netdev->mem_start, mem->end - mem->start + 1); + if (!priv->membase) { + dev_err(&pdev->dev, "cannot remap memory space\n"); + ret = -ENXIO; + goto error; + } + } else { + /* Allocate buffer memory */ + priv->membase = dma_alloc_coherent(NULL, + buffer_size, (void *)&netdev->mem_start, + GFP_KERNEL); + if (!priv->membase) { + dev_err(&pdev->dev, "cannot allocate %dB buffer\n", + buffer_size); + ret = -ENOMEM; + goto error; + } + netdev->mem_end = netdev->mem_start + buffer_size; + priv->dma_alloc = buffer_size; } /* Allow the platform setup code to pass in a MAC address. */ @@ -1037,6 +1056,9 @@ free_mdio: kfree(priv->mdio->irq); mdiobus_free(priv->mdio); free: + if (priv->dma_alloc) + dma_free_coherent(NULL, priv->dma_alloc, priv->membase, + netdev->mem_start); free_netdev(netdev); out: return ret; @@ -1062,7 +1084,9 @@ static int ethoc_remove(struct platform_device *pdev) kfree(priv->mdio->irq); mdiobus_free(priv->mdio); } - + if (priv->dma_alloc) + dma_free_coherent(NULL, priv->dma_alloc, priv->membase, + netdev->mem_start); unregister_netdev(netdev); free_netdev(netdev); } -- cgit v1.2.3