[PATCH] net: macb: Add big endian CPU support

Arun Chandran
2015-02-24T07:40:08Z

This patch converts all __raw_readl and __raw_writel function calls
to their corresponding readl_relaxed and writel_relaxed variants.

It also tells the driver to set ahb_endian_swp_mgmt_en bit in dma_cfg
when the cpu is configured in big endian mode.

Signed-off-by: Arun Chandran <achandran@mvista.com>
---
This patch is tested on xilinx ZC702 evaluation board with
CONFIG_CPU_BIG_ENDIAN=y and booting NFS rootfs
Added on the fly IP endianness detection according to
comments from Michal Simek.
---
---
drivers/net/ethernet/cadence/macb.c | 33 +++++++++++++++++++++++++++------
drivers/net/ethernet/cadence/macb.h | 15 ++++++++-------
2 files changed, 35 insertions(+), 13 deletions(-)

diff --git a/drivers/net/ethernet/cadence/macb.c b/drivers/net/ethernet/cadence/macb.c
index ad76b8e..1642911 100644
--- a/drivers/net/ethernet/cadence/macb.c
+++ b/drivers/net/ethernet/cadence/macb.c
@@ -449,7 +449,7 @@ static void macb_update_stats(struct macb *bp)
WARN_ON((unsigned long)(end - p - 1) != (MACB_TPF - MACB_PFR) / 4);

for(; p < end; p++, reg++)
- *p += __raw_readl(reg);
+ *p += readl_relaxed(reg);
}

static int macb_halt_tx(struct macb *bp)
@@ -1578,6 +1578,7 @@ static u32 macb_dbw(struct macb *bp)
static void macb_configure_dma(struct macb *bp)
{
u32 dmacfg;
+ u32 tmp, ncr;

if (macb_is_gem(bp)) {
dmacfg = gem_readl(bp, DMACFG) & ~GEM_BF(RXBS, -1L);
@@ -1585,7 +1586,25 @@ static void macb_configure_dma(struct macb *bp)
if (bp->dma_burst_length)
dmacfg = GEM_BFINS(FBLDO, bp->dma_burst_length, dmacfg);
dmacfg |= GEM_BIT(TXPBMS) | GEM_BF(RXBMS, -1L);
- dmacfg &= ~GEM_BIT(ENDIA);
+ dmacfg &= ~GEM_BIT(ENDIA_PKT);
+
+ /* Here we use the loopback bit of net_ctrl register to detect
+ * endianness on IP. save it first. Program swaped mode for
+ * management descriptor accesses if writing to loop back bit
+ * and reading it back brings no change in bit value.
+ */
+ ncr = macb_readl(bp, NCR);
+ __raw_writel(MACB_BIT(LLB), bp->regs + MACB_NCR);
+ tmp = __raw_readl(bp->regs + MACB_NCR);
+
+ if (tmp == MACB_BIT(LLB))
+ dmacfg &= ~GEM_BIT(ENDIA_DESC);
+ else
+ dmacfg |= GEM_BIT(ENDIA_DESC);
+
+ /* Restore net_ctrl */
+ macb_writel(bp, NCR, ncr);
+
if (bp->dev->features & NETIF_F_HW_CSUM)
dmacfg |= GEM_BIT(TXCOEN);
else
@@ -1832,14 +1851,14 @@ static void gem_update_stats(struct macb *bp)

for (i = 0; i < GEM_STATS_LEN; ++i, ++p) {
u32 offset = gem_statistics[i].offset;
- u64 val = __raw_readl(bp->regs + offset);
+ u64 val = readl_relaxed(bp->regs + offset);

bp->ethtool_stats[i] += val;
*p += val;

if (offset == GEM_OCTTXL || offset == GEM_OCTRXL) {
/* Add GEM_OCTTXH, GEM_OCTRXH */
- val = __raw_readl(bp->regs + offset + 4);
+ val = readl_relaxed(bp->regs + offset + 4);
bp->ethtool_stats[i] += ((u64)val) << 32;
*(++p) += val;
}
@@ -2191,12 +2210,14 @@ static void macb_probe_queues(void __iomem *mem,
*num_queues = 1;

/* is it macb or gem ? */
- mid = __raw_readl(mem + MACB_MID);
+ mid = readl_relaxed(mem + MACB_MID);
+
if (MACB_BFEXT(IDNUM, mid) != 0x2)
return;

/* bit 0 is never set but queue 0 always exists */
- *queue_mask = __raw_readl(mem + GEM_DCFG6) & 0xff;
+ *queue_mask = readl_relaxed(mem + GEM_DCFG6) & 0xff;
+
*queue_mask |= 0x1;

for (hw_q = 1; hw_q < MACB_MAX_QUEUES; ++hw_q)
diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h
index 31dc080..57f0a1a 100644
--- a/drivers/net/ethernet/cadence/macb.h
+++ b/drivers/net/ethernet/cadence/macb.h
@@ -229,7 +229,8 @@
/* Bitfields in DMACFG. */
#define GEM_FBLDO_OFFSET 0 /* fixed burst length for DMA */
#define GEM_FBLDO_SIZE 5
-#define GEM_ENDIA_OFFSET 7 /* endian swap mode for packet data access */
+#define GEM_ENDIA_DESC_OFFSET 6 /* endian swap mode for management descriptor access */
+#define GEM_ENDIA_PKT_OFFSET 7 /* endian swap mode for packet data access */
#define GEM_ENDIA_SIZE 1
#define GEM_RXBMS_OFFSET 8 /* RX packet buffer memory size select */
#define GEM_RXBMS_SIZE 2
@@ -423,17 +424,17 @@

/* Register access macros */
#define macb_readl(port,reg) \
- __raw_readl((port)->regs + MACB_##reg)
+ readl_relaxed((port)->regs + MACB_##reg)
#define macb_writel(port,reg,value) \
- __raw_writel((value), (port)->regs + MACB_##reg)
+ writel_relaxed((value), (port)->regs + MACB_##reg)
#define gem_readl(port, reg) \
- __raw_readl((port)->regs + GEM_##reg)
+ readl_relaxed((port)->regs + GEM_##reg)
#define gem_writel(port, reg, value) \
- __raw_writel((value), (port)->regs + GEM_##reg)
+ writel_relaxed((value), (port)->regs + GEM_##reg)
#define queue_readl(queue, reg) \
- __raw_readl((queue)->bp->regs + (queue)->reg)
+ readl_relaxed((queue)->bp->regs + (queue)->reg)
#define queue_writel(queue, reg, value) \
- __raw_writel((value), (queue)->bp->regs + (queue)->reg)
+ writel_relaxed((value), (queue)->bp->regs + (queue)->reg)

/* Conditional GEM/MACB macros. These perform the operation to the correct
* register dependent on whether the device is a GEM or a MACB. For registers
--
1.9.1