Revision b811ce9104a7f7663ddae4f7795a194a103b8f90 authored by Jesse Brandeburg on 20 September 2011, 15:13:03 UTC, committed by David S. Miller on 21 September 2011, 06:14:13 UTC
It seems that at least one PPC machine would occasionally give a (valid) 0 as
the return value from dma_map, this caused the ixgbe code to not work
correctly.  A fix is pending in the PPC tree to not return 0 from dma map, but
we can also fix the driver to make sure we don't mess up in other arches as
well.

This patch is applicable to all current stable kernels.

Ref: https://bugzilla.redhat.com/show_bug.cgi?id=683611

Reported-by: Neil Horman <nhorman@redhat.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
CC: Alexander Duyck <alexander.h.duyck@intel.com>
CC: stable@kernel.org
Tested-by: Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent 5c1e688
Raw File
zatm.h
/* drivers/atm/zatm.h - ZeitNet ZN122x device driver declarations */

/* Written 1995-1998 by Werner Almesberger, EPFL LRC/ICA */


#ifndef DRIVER_ATM_ZATM_H
#define DRIVER_ATM_ZATM_H

#include <linux/skbuff.h>
#include <linux/atm.h>
#include <linux/atmdev.h>
#include <linux/sonet.h>
#include <linux/pci.h>


#define DEV_LABEL	"zatm"

#define MAX_AAL5_PDU	10240	/* allocate for AAL5 PDUs of this size */
#define MAX_RX_SIZE_LD	14	/* ceil(log2((MAX_AAL5_PDU+47)/48)) */

#define LOW_MARK	12	/* start adding new buffers if less than 12 */
#define HIGH_MARK	30	/* stop adding buffers after reaching 30 */
#define OFF_CNG_THRES	5	/* threshold for offset changes */

#define RX_SIZE		2	/* RX lookup entry size (in bytes) */
#define NR_POOLS	32	/* number of free buffer pointers */
#define POOL_SIZE	8	/* buffer entry size (in bytes) */
#define NR_SHAPERS	16	/* number of shapers */
#define SHAPER_SIZE	4	/* shaper entry size (in bytes) */
#define VC_SIZE		32	/* VC dsc (TX or RX) size (in bytes) */

#define RING_ENTRIES	32	/* ring entries (without back pointer) */
#define RING_WORDS	4	/* ring element size */
#define RING_SIZE	(sizeof(unsigned long)*(RING_ENTRIES+1)*RING_WORDS)

#define NR_MBX		4	/* four mailboxes */
#define MBX_RX_0	0	/* mailbox indices */
#define MBX_RX_1	1
#define MBX_TX_0	2
#define MBX_TX_1	3

struct zatm_vcc {
	/*-------------------------------- RX part */
	int rx_chan;			/* RX channel, 0 if none */
	int pool;			/* free buffer pool */
	/*-------------------------------- TX part */
	int tx_chan;			/* TX channel, 0 if none */
	int shaper;			/* shaper, <0 if none */
	struct sk_buff_head tx_queue;	/* list of buffers in transit */
	wait_queue_head_t tx_wait;	/* for close */
	u32 *ring;			/* transmit ring */
	int ring_curr;			/* current write position */
	int txing;			/* number of transmits in progress */
	struct sk_buff_head backlog;	/* list of buffers waiting for ring */
};

struct zatm_dev {
	/*-------------------------------- TX part */
	int tx_bw;			/* remaining bandwidth */
	u32 free_shapers;		/* bit set */
	int ubr;			/* UBR shaper; -1 if none */
	int ubr_ref_cnt;		/* number of VCs using UBR shaper */
	/*-------------------------------- RX part */
	int pool_ref[NR_POOLS];		/* free buffer pool usage counters */
	volatile struct sk_buff *last_free[NR_POOLS];
					/* last entry in respective pool */
	struct sk_buff_head pool[NR_POOLS];/* free buffer pools */
	struct zatm_pool_info pool_info[NR_POOLS]; /* pool information */
	/*-------------------------------- maps */
	struct atm_vcc **tx_map;	/* TX VCCs */
	struct atm_vcc **rx_map;	/* RX VCCs */
	int chans;			/* map size, must be 2^n */
	/*-------------------------------- mailboxes */
	unsigned long mbx_start[NR_MBX];/* start addresses */
	dma_addr_t mbx_dma[NR_MBX];
	u16 mbx_end[NR_MBX];		/* end offset (in bytes) */
	/*-------------------------------- other pointers */
	u32 pool_base;			/* Free buffer pool dsc (word addr) */
	/*-------------------------------- ZATM links */
	struct atm_dev *more;		/* other ZATM devices */
	/*-------------------------------- general information */
	int mem;			/* RAM on board (in bytes) */
	int khz;			/* timer clock */
	int copper;			/* PHY type */
	unsigned char irq;		/* IRQ */
	unsigned int base;		/* IO base address */
	struct pci_dev *pci_dev;	/* PCI stuff */
	spinlock_t lock;
};


#define ZATM_DEV(d) ((struct zatm_dev *) (d)->dev_data)
#define ZATM_VCC(d) ((struct zatm_vcc *) (d)->dev_data)


struct zatm_skb_prv {
	struct atm_skb_data _;		/* reserved */
	u32 *dsc;			/* pointer to skb's descriptor */
};

#define ZATM_PRV_DSC(skb) (((struct zatm_skb_prv *) (skb)->cb)->dsc)

#endif
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