Date: Wed, 22 Nov 2000 00:03:35 -0700 From: Warner Losh <imp@village.org> To: "Justin T. Gibbs" <gibbs@scsiguy.com> Cc: Mike Smith <msmith@FreeBSD.ORG>, wpaul@FreeBSD.ORG (Bill Paul), freebsd-current@FreeBSD.ORG Subject: Re: Getting at cardbus CIS data from inside drivers Message-ID: <200011220703.AAA40559@harmony.village.org> In-Reply-To: Your message of "Tue, 21 Nov 2000 23:23:09 MST." <200011220623.eAM6N9473750@aslan.scsiguy.com> References: <200011220623.eAM6N9473750@aslan.scsiguy.com>
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In message <200011220623.eAM6N9473750@aslan.scsiguy.com> "Justin T. Gibbs" writes: : The ROM BAR is only implemented for function 0 and the ROM : contains information for all functions of the chip. So, functions : greater than 0 must have the flexibility to activate at least the ROM : BAR on function 0 as well as access that region. I think there's a difference between where the CIS actually lives, and the CIS chains for the each function. cardbus cards give each function its own CIS chain. These CIS chains can live in configuration space, in memory space or the expansion ROM (which I assume is the same thing as the ROM BAR on function 0, but maybe I'm mistaken) and the bridge is responsible for properlly mapping the last two. The config space presents the biggest problem because we don't have any way to access it with the bus_space(9) functions, so special code is needed in the cardbus bus driver to know where to read from. I talked with YAMAMOTO shigeru-san at BSDcon about an extension to the bus_space code to allow user defined regions/functions to be used so that one can write generic code to access each of these regions with bus_space_read/write_N. Since this is getting off topic, I'll leave it there, but it looked cool and many of the issues I could think of to bring up were handled well. I also made an error in a previous message. 16-bit and 32bit cis parsing is somewhat different. 16-bit cards effectively have the functions comingled with global entries, while cardbus segregates them. With cardbus the iterated chain would just contain CIS entries for that function. They designed things this way so that the functions could be completely separate, integrated only on an ASIC at the last minute before being placed on a cardbus card :-) Warner To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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