dsa: b53: fix big-endian register access

The b53 dsa register access confusingly uses __raw register accessors
when both the CPU and the device are big-endian, but it uses little-
endian accessors when the same device is used from a little-endian
CPU, which makes no sense.

This uses normal accessors in device-endianess all the time, which
will work in all four combinations of register and CPU endianess,
and it will have the same barrier semantics in all cases.

This also seems to take care of a (false positive) warning I'm getting:

drivers/net/dsa/b53/b53_mmap.c: In function 'b53_mmap_read64':
drivers/net/dsa/b53/b53_mmap.c:109:10: error: 'hi' may be used uninitialized in this function [-Werror=maybe-uninitialized]
  *val = ((u64)hi << 32) | lo;

I originally planned to submit another patch for that warning
and did this one as a preparation cleanup, but it does seem to be
sufficient by itself.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/dsa/b53/b53_mmap.c b/drivers/net/dsa/b53/b53_mmap.c
index f115ee25c0e83716bb43d6d7b46c51fd1b86ec13..b70daf9174d44040f28cab3d6996bf698a314ad6 100644 (file)
--- a/drivers/net/dsa/b53/b53_mmap.c
+++ b/drivers/net/dsa/b53/b53_mmap.c
@@ -45,9 +45,8 @@ static int b53_mmap_read16(struct b53_device *dev, u8 page, u8 reg, u16 *val)
        if (WARN_ON(reg % 2))
                return -EINVAL;
 
-       if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) && dev->pdata &&
-           dev->pdata->big_endian)
-               *val = __raw_readw(regs + (page << 8) + reg);
+       if (dev->pdata && dev->pdata->big_endian)
+               *val = ioread16be(regs + (page << 8) + reg);
        else
                *val = readw(regs + (page << 8) + reg);
 
@@ -61,9 +60,8 @@ static int b53_mmap_read32(struct b53_device *dev, u8 page, u8 reg, u32 *val)
        if (WARN_ON(reg % 4))
                return -EINVAL;
 
-       if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) && dev->pdata &&
-           dev->pdata->big_endian)
-               *val = __raw_readl(regs + (page << 8) + reg);
+       if (dev->pdata && dev->pdata->big_endian)
+               *val = ioread32be(regs + (page << 8) + reg);
        else
                *val = readl(regs + (page << 8) + reg);
 
@@ -128,9 +126,8 @@ static int b53_mmap_write16(struct b53_device *dev, u8 page, u8 reg,
        if (WARN_ON(reg % 2))
                return -EINVAL;
 
-       if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) && dev->pdata &&
-           dev->pdata->big_endian)
-               __raw_writew(value, regs + (page << 8) + reg);
+       if (dev->pdata && dev->pdata->big_endian)
+               iowrite16be(value, regs + (page << 8) + reg);
        else
                writew(value, regs + (page << 8) + reg);
 
@@ -145,9 +142,8 @@ static int b53_mmap_write32(struct b53_device *dev, u8 page, u8 reg,
        if (WARN_ON(reg % 4))
                return -EINVAL;
 
-       if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) && dev->pdata &&
-           dev->pdata->big_endian)
-               __raw_writel(value, regs + (page << 8) + reg);
+       if (dev->pdata && dev->pdata->big_endian)
+               iowrite32be(value, regs + (page << 8) + reg);
        else
                writel(value, regs + (page << 8) + reg);