From e03bc654f85604bcd5304debb597f398d1d03778 Mon Sep 17 00:00:00 2001 From: Thomas Petazzoni Date: Mon, 29 Jul 2013 17:42:14 +0200 Subject: [PATCH] mv_xor: support big endian systems using descriptor swap feature The mv_xor driver had never been used in a big-endian context, and therefore was not using the hardware features to support such an execution environment. The hardware provides a "descriptor swap" bit that automatically swaps the bytes of the DMA descriptors, within blocks of 8 bytes. This requires a different DMA descriptor layout on big-endian systems, as well as enabling this "descriptor swap" bit. This mechanism is exactly identical to the one already used in the mv643xx_eth network driver and the mvneta network driver. Signed-off-by: Thomas Petazzoni Signed-off-by: Dan Williams --- drivers/dma/mv_xor.c | 11 +++++++++-- drivers/dma/mv_xor.h | 28 +++++++++++++++++++++++++++- 2 files changed, 36 insertions(+), 3 deletions(-) diff --git a/drivers/dma/mv_xor.c b/drivers/dma/mv_xor.c index c026b27f76e1..d332b9e3f9ce 100644 --- a/drivers/dma/mv_xor.c +++ b/drivers/dma/mv_xor.c @@ -64,7 +64,7 @@ static u32 mv_desc_get_src_addr(struct mv_xor_desc_slot *desc, int src_idx) { struct mv_xor_desc *hw_desc = desc->hw_desc; - return hw_desc->phy_src_addr[src_idx]; + return hw_desc->phy_src_addr[mv_phy_src_idx(src_idx)]; } @@ -107,7 +107,7 @@ static void mv_desc_set_src_addr(struct mv_xor_desc_slot *desc, int index, dma_addr_t addr) { struct mv_xor_desc *hw_desc = desc->hw_desc; - hw_desc->phy_src_addr[index] = addr; + hw_desc->phy_src_addr[mv_phy_src_idx(index)] = addr; if (desc->type == DMA_XOR) hw_desc->desc_command |= (1 << index); } @@ -192,6 +192,13 @@ static void mv_set_mode(struct mv_xor_chan *chan, config &= ~0x7; config |= op_mode; + +#if defined(__BIG_ENDIAN) + config |= XOR_DESCRIPTOR_SWAP; +#else + config &= ~XOR_DESCRIPTOR_SWAP; +#endif + writel_relaxed(config, XOR_CONFIG(chan)); chan->current_type = type; } diff --git a/drivers/dma/mv_xor.h b/drivers/dma/mv_xor.h index c619359cb7fe..06b067f24c9b 100644 --- a/drivers/dma/mv_xor.h +++ b/drivers/dma/mv_xor.h @@ -29,8 +29,10 @@ #define MV_XOR_THRESHOLD 1 #define MV_XOR_MAX_CHANNELS 2 +/* Values for the XOR_CONFIG register */ #define XOR_OPERATION_MODE_XOR 0 #define XOR_OPERATION_MODE_MEMCPY 2 +#define XOR_DESCRIPTOR_SWAP BIT(14) #define XOR_CURR_DESC(chan) (chan->mmr_base + 0x210 + (chan->idx * 4)) #define XOR_NEXT_DESC(chan) (chan->mmr_base + 0x200 + (chan->idx * 4)) @@ -143,7 +145,16 @@ struct mv_xor_desc_slot { #endif }; -/* This structure describes XOR descriptor size 64bytes */ +/* + * This structure describes XOR descriptor size 64bytes. The + * mv_phy_src_idx() macro must be used when indexing the values of the + * phy_src_addr[] array. This is due to the fact that the 'descriptor + * swap' feature, used on big endian systems, swaps descriptors data + * within blocks of 8 bytes. So two consecutive values of the + * phy_src_addr[] array are actually swapped in big-endian, which + * explains the different mv_phy_src_idx() implementation. + */ +#if defined(__LITTLE_ENDIAN) struct mv_xor_desc { u32 status; /* descriptor execution status */ u32 crc32_result; /* result of CRC-32 calculation */ @@ -155,6 +166,21 @@ struct mv_xor_desc { u32 reserved0; u32 reserved1; }; +#define mv_phy_src_idx(src_idx) (src_idx) +#else +struct mv_xor_desc { + u32 crc32_result; /* result of CRC-32 calculation */ + u32 status; /* descriptor execution status */ + u32 phy_next_desc; /* next descriptor address pointer */ + u32 desc_command; /* type of operation to be carried out */ + u32 phy_dest_addr; /* destination block address */ + u32 byte_count; /* size of src/dst blocks in bytes */ + u32 phy_src_addr[8]; /* source block addresses */ + u32 reserved1; + u32 reserved0; +}; +#define mv_phy_src_idx(src_idx) (src_idx ^ 1) +#endif #define to_mv_sw_desc(addr_hw_desc) \ container_of(addr_hw_desc, struct mv_xor_desc_slot, hw_desc)