Hi Angelo, CC commit relations On Sat, Apr 27, 2019 at 10:22 PM Angelo Dureghello <angelo@xxxxxxxx> wrote: > On Sat, Apr 27, 2019 at 05:32:22PM +0200, Angelo Dureghello wrote: > > as you may know, i am working on mcf5441x. > > Sorry for not following carefully all the threads, but from a certain > > kernel version (likely 4.19 or near there), seems ioread32be > > reads the bytes swapped in endianness (mcf-edma dma driver not working > > anymore). > > > > Has there been a change about this in the architecture I/O access ? > > How should i proceed now ? Fixing the DMA driver read/write, or what ? > looks like the reason of my ioread32be now swapped is: > > https://patchwork.kernel.org/patch/10766673/ > > Trying to figure out what to do now. This is commit aecc787c06f4300f ("iomap: Use non-raw io functions for io{read|write}XXbe"): --- a/lib/iomap.c +++ b/lib/iomap.c @@ -65,8 +65,8 @@ static void bad_io_access(unsigned long port, const char *access) #endif #ifndef mmio_read16be -#define mmio_read16be(addr) be16_to_cpu(__raw_readw(addr)) -#define mmio_read32be(addr) be32_to_cpu(__raw_readl(addr)) +#define mmio_read16be(addr) swab16(readw(addr)) +#define mmio_read32be(addr) swab32(readl(addr)) #endif unsigned int ioread8(void __iomem *addr) @@ -106,8 +106,8 @@ EXPORT_SYMBOL(ioread32be); #endif #ifndef mmio_write16be -#define mmio_write16be(val,port) __raw_writew(be16_to_cpu(val),port) -#define mmio_write32be(val,port) __raw_writel(be32_to_cpu(val),port) +#define mmio_write16be(val,port) writew(swab16(val),port) +#define mmio_write32be(val,port) writel(swab32(val),port) On big endian, the raw accessors are assumed to be non-swapping, while non-raw accessors are assumed to be swapping. The latter is not true for Coldfire internal registers, cfr. arch/m68k/include/asm/io_no.h: static inline u16 readw(const volatile void __iomem *addr) { if (cf_internalio(addr)) return __raw_readw(addr); return __le16_to_cpu(__raw_readw(addr)); } Orthogonal to how Coldfire's read[wl]() should be fixed, I find it a bit questionable to swap data twice on big endian architectures. Fortunately we can avoid that by defining our own mmio_{read,write}{16,32}be()... Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
