Skip to main content

Browse the archive

Revision 729739b754affa482e92fa7836e4066096089d11 authored by Alexander Duyck on 08 February 2012, 07:51:06 UTC, committed by Jeff Kirsher on 17 March 2012, 08:41:49 UTC 
ixgbe: always write DMA for single_mapped value with skb
 
This change makes it so that we always write the DMA address for the skb
itself on the same tx_buffer struct that the skb is written on.  This way
we don't need the MAPPED_AS_PAGE flag and we always know it will be the
first DMA value that we will have to unmap.

In addition I have found an issue in which we were leaking a DMA mapping if
the value happened to be 0 which is possible on some platforms.  In order
to resolve that I have updated the transmit path to use the length instead
of the DMA mapping in order to determine if a mapping is actually present.

One other tweak in this patch is that it only writes the olinfo information
on the first descriptor.  As it turns out it isn't necessary to write it
for anything but the first descriptor so there is no need to carry it
forward.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Stephen Ko <stephen.s.ko@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
1 parent 091a624
Raw File
system.c 
/*
 * system.c - a driver for reserving pnp system resources
 *
 * Some code is based on pnpbios_core.c
 * Copyright 2002 Adam Belay <ambx1@neo.rr.com>
 * (c) Copyright 2007 Hewlett-Packard Development Company, L.P.
 *	Bjorn Helgaas <bjorn.helgaas@hp.com>
 */

#include <linux/pnp.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/ioport.h>

static const struct pnp_device_id pnp_dev_table[] = {
	/* General ID for reserving resources */
	{"PNP0c02", 0},
	/* memory controller */
	{"PNP0c01", 0},
	{"", 0}
};

static void reserve_range(struct pnp_dev *dev, struct resource *r, int port)
{
	char *regionid;
	const char *pnpid = dev_name(&dev->dev);
	resource_size_t start = r->start, end = r->end;
	struct resource *res;

	regionid = kmalloc(16, GFP_KERNEL);
	if (!regionid)
		return;

	snprintf(regionid, 16, "pnp %s", pnpid);
	if (port)
		res = request_region(start, end - start + 1, regionid);
	else
		res = request_mem_region(start, end - start + 1, regionid);
	if (res)
		res->flags &= ~IORESOURCE_BUSY;
	else
		kfree(regionid);

	/*
	 * Failures at this point are usually harmless. pci quirks for
	 * example do reserve stuff they know about too, so we may well
	 * have double reservations.
	 */
	dev_info(&dev->dev, "%pR %s reserved\n", r,
		 res ? "has been" : "could not be");
}

static void reserve_resources_of_dev(struct pnp_dev *dev)
{
	struct resource *res;
	int i;

	for (i = 0; (res = pnp_get_resource(dev, IORESOURCE_IO, i)); i++) {
		if (res->flags & IORESOURCE_DISABLED)
			continue;
		if (res->start == 0)
			continue;	/* disabled */
		if (res->start < 0x100)
			/*
			 * Below 0x100 is only standard PC hardware
			 * (pics, kbd, timer, dma, ...)
			 * We should not get resource conflicts there,
			 * and the kernel reserves these anyway
			 * (see arch/i386/kernel/setup.c).
			 * So, do nothing
			 */
			continue;
		if (res->end < res->start)
			continue;	/* invalid */

		reserve_range(dev, res, 1);
	}

	for (i = 0; (res = pnp_get_resource(dev, IORESOURCE_MEM, i)); i++) {
		if (res->flags & IORESOURCE_DISABLED)
			continue;

		reserve_range(dev, res, 0);
	}
}

static int system_pnp_probe(struct pnp_dev *dev,
			    const struct pnp_device_id *dev_id)
{
	reserve_resources_of_dev(dev);
	return 0;
}

static struct pnp_driver system_pnp_driver = {
	.name     = "system",
	.id_table = pnp_dev_table,
	.flags    = PNP_DRIVER_RES_DO_NOT_CHANGE,
	.probe    = system_pnp_probe,
};

static int __init pnp_system_init(void)
{
	return pnp_register_driver(&system_pnp_driver);
}

/**
 * Reserve motherboard resources after PCI claim BARs,
 * but before PCI assign resources for uninitialized PCI devices
 */
fs_initcall(pnp_system_init);
back to top