Hi Richard, From: "ext Woodruff, Richard" <r-woodruff2@xxxxxx> Subject: RE: [PATCH 1/1] Use pmd_table() MACRO for unmap_area_sections() Date: Sun, 7 Sep 2008 21:04:56 -0500 > > > From: linux-omap-owner@xxxxxxxxxxxxxxx [mailto:linux-omap- > > owner@xxxxxxxxxxxxxxx] On Behalf Of Russell King - ARM Linux > > > Well, the first question is... where has this come from, and why. > > In OMAPs, a few devices have a local IO MMU. Their basic structure > is similar to an ARM MMU, but less featured. IVA & Camera have one > each on 3430/2430, a 2420 has those before mentioned and + 3rd in > its video accelerator. > > The usage in TI kernels has varied a bit. Some times they are just > load and lock TLB's, for others table walking can be enabled. In > all cases if a table walk miss happens it is fatal and the IP block > device will have to be reset. In *theory*, from this IOMMU hardware perspective, it's feasible to load something on memory dynamically("on-demand loading") when a table walk miss happens by notifying it to some memory manager through its assigned interrupt. Practically this latency may be a problem in some cases;) Hiroshi DOYU -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
