From b77e5228849fdcd7a5d73beb16b9ad99395236ec Mon Sep 17 00:00:00 2001 From: Risto Suominen Date: Wed, 10 Jun 2009 09:55:00 +0000 Subject: [PATCH] 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: Risto Suominen Cc: Grant Grundler Signed-off-by: Andrew Morton Signed-off-by: David S. Miller --- drivers/net/tulip/Kconfig | 12 ++++++++++++ drivers/net/tulip/de2104x.c | 13 ++++++++++++- 2 files changed, 24 insertions(+), 1 deletion(-) diff --git a/drivers/net/tulip/Kconfig b/drivers/net/tulip/Kconfig index d913405bc39..1cc8cf4425d 100644 --- a/drivers/net/tulip/Kconfig +++ b/drivers/net/tulip/Kconfig @@ -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 diff --git a/drivers/net/tulip/de2104x.c b/drivers/net/tulip/de2104x.c index d4c5ecc51f7..e7609a05032 100644 --- a/drivers/net/tulip/de2104x.c +++ b/drivers/net/tulip/de2104x.c @@ -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 { -- 2.41.0