Hi! Thanks for answers! There is one more thing. This is Linux 2.4.x kernel driver, may be in 2.4 this way (allocate_resource) was right. I've read pci.txt and referenced IO-mapping.txt, which was more informative! Am I right, that allocate_resource searches first free and compatible (by func parameters) region and reserve it for us? And if we start from some address in PCI space this func will return window in PCI address space for us? With Regards, Michael > On Tue, Aug 05, 2008 at 04:23:10PM +0400, Michael Kolesov wrote: >> Hello! >> >> I'm writing QNX6 Tundra Tsi148 VME manager. And currently I'm based on >> Tsi148 linux driver. >> I have some questions about pci-relative function calls. > To start with, have you read Documentation/pci.txt ? >> So. In Tundra spec there is requestment of : >> "STAL (Start Address Lower): This field determines the start address of a particular memory >> area on the PCI/X bus which is used to access VMEbus resources. The value of this field is >> compared with A31-A16 of the PCI/X bus address" >> Please see source code of this part in linux driver,with comments >> bellow: >> (full source can be found on http://www-zeuthen.desy.de/pitz/control_doc/MVME6100/Tsi148driver.tar) >> //---------------------------------------------------------------------------- >> // vmeSetOutBound >> // Set attributes of an outbound window. >> //---------------------------------------------------------------------------- >> int >> vmeSetOutBound( vmeOutWindowCfg_t *vmeOut) >> { >> int windowNbr = vmeOut->windowNbr; >> unsigned int existingSize; >> >> if(vmepcimem == 0) >> return(-ENOMEM); >> if(vmeOut->windowSizeL == 0) >> return(-EINVAL); >> >> // Allocate and map PCI memory space for this window. >> existingSize = out_resource[windowNbr].end - out_resource[windowNbr].start; >> if(existingSize != vmeOut->windowSizeL){ >> if(existingSize != 0){ >> iounmap((char *)out_image_va[windowNbr]); >> release_resource(&out_resource[windowNbr]); >> memset(&out_resource[windowNbr], 0, sizeof(struct resource)); >> } >> if(allocate_resource(vmepcimem, &out_resource[windowNbr], >> vmeOut->windowSizeL, 0, 0xFFFFFFFF, 0x10000, 0,0)) { >> printk("allocation failed for 0x%x-0x%x (0x%x)\n", out_resource[windowNbr].start, >> out_resource[windowNbr].end, vmeOut->windowSizeL); >> return(-ENOMEM); >> } >> >> out_image_va[windowNbr] = >> (int )ioremap(out_resource[windowNbr].start, vmeOut->windowSizeL); >> if(out_image_va[windowNbr] == 0){ >> release_resource(&out_resource[windowNbr]); >> memset(&out_resource[windowNbr], 0, sizeof(struct resource)); >> return(-ENOMEM); >> } >> } >> >> vmeOut->pciBusAddrL = out_resource[windowNbr].start >> - pci_bus_mem_base_phys(vmechip_bus); >> >> switch(vmechip_devid) { >> case PCI_DEVICE_ID_TUNDRA_CA91C042: >> return(uniSetOutBound(vmeOut)); >> break; >> case PCI_DEVICE_ID_TUNDRA_TEMPE: >> return(tempeSetOutBound(vmeOut)); >> break; >> } >> return(-ENODEV); >> } >> >> >> >> In linux code I see three main functions doing spec's requirements >> >> >> 1. allocate_resource >> >> allocate_resource(vmepcimem, &out_resource[windowNbr], >> vmeOut->windowSizeL, 0, 0xFFFFFFFF, 0x10000, 0,0) > drivers should generally not need to directly call this. > See pci.txt for the pci_resource interfaces. >> vmepcimem - is 'struct resource' and before it was >> assigned by pci_find_parent_resource(vme_pci_dev, &pcimemres), where >> vme_pci_dev is Tundra Tsi148 pci_dev structure. >> >> windowSizeL - size of needed memory window >> >> out_resource is 'struct resource' too, for new mem area. >> ----------- >> Where out_resource's start and end fields will be? >> My opinion, right after Tsi148 PCI address space region. >> What allocate_resource realy do in linux? >> Why we just can't do mmap-like function with pci-address, as example? > "pci-address" might not be 1:1 with the "host bus" address that the CPU > should be using. e.g. MMIO 0x10000 on the PCI bus might be accessed through > 0x8 0010 0000 host physical address (assumes 64-bit arch). >> ----------- >> >> 2. ioremap >> >> out_image_va[windowNbr] = >> (int )ioremap(out_resource[windowNbr].start, vmeOut->windowSizeL); >> >> out_image_va - virtual address of previously allocated mem space, >> throught which we can access new allocated space. >> >> I read, it used for making special kernel virtual space address, and >> it maps high PCI addresses. >> >> 3. pci_bus_mem_base_phys >> >> vmeOut->pciBusAddrL = out_resource[windowNbr].start >> - pci_bus_mem_base_phys(vmechip_bus); >> >> vmechip_bus == 0. >> -------------- >> So we can get start address of PCI range, right? > Yes, but unless the device is doing Peer-to-Peer transfers on the PCI bus, > the driver should be using the resource_start() values. >> ------------- >> >> ////////////////////////// >> >> Please correct me, if I got wrong understanding of functions above. > hth, > grant >> >> With Best Regards, >> Michael Kolesov >> software developer >> CBD BC, Saint-Petersburg, Russia >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-pci" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html -- С уважением, Michael mailto:M.Kolesov@xxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
