Date: Thu, 11 Jan 2001 17:35:37 -0800 From: Jeff Roberson <jeff@midstream.com> To: "'freebsd-current@freebsd.org'" <freebsd-current@freebsd.org> Subject: Broken mmap in current? Message-ID: <31E4B6337A4FD411BD45000102472E0C05E729@EMAIL_SERVER>
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[-- Attachment #1 --] I have written a character device driver for a proprietary PCI device that has a large sum of mapable memory. The character device supports mmap() which I use to export the memory into a user process. I have no problems accessing the memory on this device, but I notice that my mmap routine is called for every access! Is this a problem with current, or a problem with my mmap? I use bus_alloc_resource and then rman_get_start to get the physical address in my attach, and then the mmap just returns atop(physical address). I assumed this is correct since I have verified with a logical analyzer that I am indeed writing to the memory on the device. Also, I noticed that the device's mmap interface does not provide any way to limit the size of the block being mapped? Can I specify the length of the region? Thanks, Jeff [-- Attachment #2 --] <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN"> <HTML> <HEAD> <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1"> <META NAME="Generator" CONTENT="MS Exchange Server version 5.5.2650.12"> <TITLE>Broken mmap in current?</TITLE> </HEAD> <BODY> <P><FONT SIZE=2>I have written a character device driver for a proprietary PCI device that has a large sum of mapable memory. The character device supports mmap() which I use to export the memory into a user process. I have no problems accessing the memory on this device, but I notice that my mmap routine is called for every access! Is this a problem with current, or a problem with my mmap?</FONT></P> <P><FONT SIZE=2>I use bus_alloc_resource and then rman_get_start to get the physical address in my attach, and then the mmap just returns atop(physical address). I assumed this is correct since I have verified with a logical analyzer that I am indeed writing to the memory on the device. Also, I noticed that the device's mmap interface does not provide any way to limit the size of the block being mapped? Can I specify the length of the region?</FONT></P> <P><FONT SIZE=2>Thanks,</FONT> <BR><FONT SIZE=2>Jeff</FONT> </P> </BODY> </HTML>home | help
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