Commit b77e5228 authored by Risto Suominen's avatar Risto Suominen Committed by David S. Miller

de2104x: support for systems lacking cache coherence

Add a configurable Descriptor Skip Length for systems that lack cache
coherence.

(akpm: I think this should be done as a module parameter, not a
compile-tinme option)
Signed-off-by: default avatarRisto Suominen <Risto.Suominen@gmail.com>
Cc: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ef5c8996
......@@ -27,6 +27,18 @@ config DE2104X
To compile this driver as a module, choose M here. The module will
be called de2104x.
config DE2104X_DSL
int "Descriptor Skip Length in 32 bit longwords"
depends on DE2104X
range 0 31
default 0
help
Setting this value allows to align ring buffer descriptors into their
own cache lines. Value of 4 corresponds to the typical 32 byte line
(the descriptor is 16 bytes). This is necessary on systems that lack
cache coherence, an example is PowerMac 5500. Otherwise 0 is safe.
Default is 0, and range is 0 to 31.
config TULIP
tristate "DECchip Tulip (dc2114x) PCI support"
depends on PCI
......
......@@ -82,6 +82,13 @@ MODULE_PARM_DESC (rx_copybreak, "de2104x Breakpoint at which Rx packets are copi
NETIF_MSG_RX_ERR | \
NETIF_MSG_TX_ERR)
/* Descriptor skip length in 32 bit longwords. */
#ifndef CONFIG_DE2104X_DSL
#define DSL 0
#else
#define DSL CONFIG_DE2104X_DSL
#endif
#define DE_RX_RING_SIZE 64
#define DE_TX_RING_SIZE 64
#define DE_RING_BYTES \
......@@ -153,6 +160,7 @@ enum {
CmdReset = (1 << 0),
CacheAlign16 = 0x00008000,
BurstLen4 = 0x00000400,
DescSkipLen = (DSL << 2),
/* Rx/TxPoll bits */
NormalTxPoll = (1 << 0),
......@@ -246,7 +254,7 @@ static const u32 de_intr_mask =
* Set the programmable burst length to 4 longwords for all:
* DMA errors result without these values. Cache align 16 long.
*/
static const u32 de_bus_mode = CacheAlign16 | BurstLen4;
static const u32 de_bus_mode = CacheAlign16 | BurstLen4 | DescSkipLen;
struct de_srom_media_block {
u8 opts;
......@@ -266,6 +274,9 @@ struct de_desc {
__le32 opts2;
__le32 addr1;
__le32 addr2;
#if DSL
__le32 skip[DSL];
#endif
};
struct media_info {
......
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