From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Mallick, Asit K" Date: Sun, 30 Jul 2000 17:27:54 +0000 Subject: RE: [Linux-ia64] kernel update [relative to 2.4.0-test4] Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org > Here is the latest kernel update. Before I go on, two major caveats: > > BIG CAVEAT > To run this kernel on a system with a SCSI controller that > uses the PCI DMA interface (e.g, adaptec), you'll have to > specific boot option mem=4G to force the kernel to ignore > memory above 4GB. This is a temporary issue and will be fixed > in the next version. > > BIG CAVEAT > This kernel will work fine with the qla1280 SCSI driver, even > if there is memory above 4GB. However, you must make sure > that "64 bit addressing" is enabled in the Qlogic BIOS setup > (press "Alt-Q" during system initialization to get into the > SCSI controller configuration menu). If your system is unable > to mount the root filesystem, chances are you forgot to > do this. > > OK, having said that, here are the major goodies: > > - Support for software I/O TLB is in, thanks to Goutham and Asit > (Intel). This support allows to DMA from 32-bit PCI devices to any > place in the physical memory. However, the transfer size is > currently limited to one page and this is the reason SCSI drivers > such as the adaptec drivers do not work yet All the SCSI devices will work as long as it is a 64-bit PCI SCSI device and the dma_mask is set to 0xFFFFFFFFFFFFFFFF. We have a prototype working that supports I/O TLB mapping of more than a page size and will get the patch out as soon as possible. Thanks, Asit