| Message ID | 1464960552-6645-7-git-send-email-edgar.iglesias@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Edgar, On 03/06/16 14:29, Edgar E. Iglesias wrote: > From: "Edgar E. Iglesias" <edgar.iglesias@xilinx.com> > > Add an mmio-sram bus that prevents sram sub areas from > being re-mapped. These sub-areas describe allocations and > not mappings. mmio-sram is not a bus and the region below should point to a valid physical address. So why do you want that? Regards,
On Mon, Jun 06, 2016 at 07:05:20PM +0100, Julien Grall wrote: > Hi Edgar, > > On 03/06/16 14:29, Edgar E. Iglesias wrote: > >From: "Edgar E. Iglesias" <edgar.iglesias@xilinx.com> > > > >Add an mmio-sram bus that prevents sram sub areas from > >being re-mapped. These sub-areas describe allocations and > >not mappings. > > mmio-sram is not a bus and the region below should point to a valid physical > address. > > So why do you want that? Hi, Yes, I briefly mentioned this in the cover letter. It's a hack to avoid the mapping of sub allocations. The regions under mmio-sram point to valid addresses but they point into the same space that the outer mmio-sram node maps in. They also don't need to be page aligned. AFAICT, Xen should ignore these sub-regions allthough I think things work anyway (at least with my dts). Maybe I should just drop this until we have a real problem or come up with a nicer way of dealing with this. Cheers, Edgar > > Regards, > > -- > Julien Grall
Hi Edgar, On 08/06/2016 01:21, Edgar E. Iglesias wrote: > On Mon, Jun 06, 2016 at 07:05:20PM +0100, Julien Grall wrote: >> Hi Edgar, >> >> On 03/06/16 14:29, Edgar E. Iglesias wrote: >>> From: "Edgar E. Iglesias" <edgar.iglesias@xilinx.com> >>> >>> Add an mmio-sram bus that prevents sram sub areas from >>> being re-mapped. These sub-areas describe allocations and >>> not mappings. >> >> mmio-sram is not a bus and the region below should point to a valid physical >> address. >> >> So why do you want that? > > Hi, > > Yes, I briefly mentioned this in the cover letter. It's a hack > to avoid the mapping of sub allocations. The regions under mmio-sram > point to valid addresses but they point into the same space that > the outer mmio-sram node maps in. They also don't need to be page > aligned. AFAICT, Xen should ignore these sub-regions allthough I > think things work anyway (at least with my dts). Sorry I haven't fully read the cover letter. I agree that going through those sub-regions are pointless because it already mapped by the parent. However, it is harmless as they should be part of the parent MMIO. It also makes the code simpler. > > Maybe I should just drop this until we have a real problem or > come up with a nicer way of dealing with this. Sounds good to me. Regards,
diff --git a/xen/common/device_tree.c b/xen/common/device_tree.c index fbee354..698d4da 100644 --- a/xen/common/device_tree.c +++ b/xen/common/device_tree.c @@ -616,10 +616,47 @@ static int dt_bus_pci_translate(__be32 *addr, u64 offset, int na) } /* + * MMIO-SRAM bus specific translator + */ + +static bool_t dt_bus_mmio_sram_match(const struct dt_device_node *np) +{ + static const struct dt_device_match match[] __initconst = + { + DT_MATCH_COMPATIBLE("mmio-sram"), + { /* sentinel */ }, + }; + + return dt_match_node(match, np) != NULL; +} + +static void dt_bus_mmio_sram_count_cells(const struct dt_device_node *np, + int *addrc, int *sizec) +{ + /* + * Child areas describe allocations, not mappings. Don't map anything. + */ + if (addrc) + *addrc = 0; + if (sizec) + *sizec = 0; +} + +/* * Array of bus specific translators */ static const struct dt_bus dt_busses[] = { + /* MMIO-SRAM */ + { + .name = "mmio-sram", + .addresses = "reg", + .match = dt_bus_mmio_sram_match, + .count_cells = dt_bus_mmio_sram_count_cells, + .map = dt_bus_default_map, + .translate = dt_bus_default_translate, + .get_flags = dt_bus_default_get_flags, + }, /* PCI */ { .name = "pci",