Date: Mon, 23 Nov 1998 16:38:09 -0500 (EST) From: Simon Shapiro <shimon@simon-shapiro.org> To: freebsd-alpha@FreeBSD.ORG Subject: UnAligned Access, but why? Message-ID: <XFMail.981123163809.shimon@simon-shapiro.org>
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Am trying to get the DPT driver running on alpha.
Narrowed down the problem to this:
In sys/alpha/include/bus.h there is a series of static inline functions to
do the equivalient of inb, inw, and inl, as well as outb, outw, outl. they
are called bus_space_{read,write}_[124].
The bus_space_read_[14] are causing unaligned access panics. These panics
can be eliminated by casting explicitly:
return (inb((u_int32_t)(handle + offset)));
and
return (inl((u_int32_t)(handle + offset)));
However, bus_space_write_[14] will panic on unaligned access even when
modified to be:
outb((u_int32_t)(bsh + offset), (u_int8_t)value);
and
outl((u_int32_t)(bsh + offset), (u_int32_t)value);
I even tried to modify bus_space_write_4 to be:
/* static __inline void */
void
bus_space_write_4(bus_space_tag_t tag, bus_space_handle_t bsh,
bus_size_t offset, u_int32_t value)
{
#if defined(_ALPHA_BUS_PIO_H_)
#if defined(_ALPHA_BUS_MEMIO_H_)
if (tag == ALPHA_BUS_SPACE_IO)
#endif
{
u_int32_t port, data;
port = (u_int32_t)bsh + (u_int32_t)offset;
data = (u_int32_t)value;
outl(port, data);
}
#endif
#if defined(_ALPHA_BUS_MEMIO_H_)
#if defined(_ALPHA_BUS_PIO_H_)
else
#endif
writel(bsh + offset, value);
#endif
}
I.E made the function non static, not inline and copied the values to local
variables before doing the outl thing. The panic occurs right at the outl
line. I can get the kernel to printf exactly to that point.
Any help will be appreciated. I tried to trace the functions but end at
the chipset structure. IS there a set of functions in ROM that is mapped
in this manner?
Simon
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