Date: Thu, 29 Apr 2010 21:50:06 -0600 (MDT) From: "M. Warner Losh" <imp@bsdimp.com> To: jmallett@freebsd.org Cc: src-committers@freebsd.org, svn-src-user@freebsd.org Subject: Re: svn commit: r207417 - user/jmallett/octeon/sys/mips/mips Message-ID: <20100429.215006.342007108973685078.imp@bsdimp.com> In-Reply-To: <201004300314.o3U3Eluq041543@svn.freebsd.org> References: <201004300314.o3U3Eluq041543@svn.freebsd.org>
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In message: <201004300314.o3U3Eluq041543@svn.freebsd.org>
Juli Mallett <jmallett@freebsd.org> writes:
: That's just the uart code, which seems to use its own bus space
: anyway.
The UART code needs to have its own space. The uart*.c code is mostly
setup to read bytes from the uart device. We use bus space to spread
out the bytes (which uart could do itself, but we tell it not to), as
well as insure that the 64-bit registers are accessed as 64-bit
registers. This is important for the Octeon take on a 16550 since
byte reads/writes cause problems, at least on some members of the
family. The bus space code bridges these two worlds. It also solves
the 'big endian' issues that the atheros code still has...
Warner
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