- IOPhysicalAddress pageAddr = pageList[ind].phys_addr;
- address = ptoa_32(pageAddr) + offset;
-
- // Check for the remaining data in this upl being longer than the
- // remainder on the current page. This should be checked for
- // contiguous pages
- if (length > PAGE_SIZE - offset) {
- // See if the next page is contiguous. Stop looking when we hit
- // the end of this upl, which is indicated by the
- // contigLength >= length.
- IOByteCount contigLength = PAGE_SIZE - offset;
-
- // Look for contiguous segment
- while (contigLength < length
- && ++pageAddr == pageList[++ind].phys_addr) {
- contigLength += PAGE_SIZE;
- }
- if (length > contigLength)
- length = contigLength;
- }
-
- assert(address);
- assert(length);
+ // Scan through iopl info blocks looking for block containing offset
+ while (ind < numIOPLs && offset >= ioplList[ind].fIOMDOffset)
+ ind++;
+
+ // Go back to actual range as search goes past it
+ ioPLBlock ioplInfo = ioplList[ind - 1];
+ off2Ind = ioplInfo.fIOMDOffset;
+
+ if (ind < numIOPLs)
+ length = ioplList[ind].fIOMDOffset;
+ else
+ length = _length;
+ length -= offset; // Remainder within iopl
+
+ // Subtract offset till this iopl in total list
+ offset -= off2Ind;
+
+ // If a mapped address is requested and this is a pre-mapped IOPL
+ // then just need to compute an offset relative to the mapped base.
+ if (mapped && ioplInfo.fMappedBase) {
+ offset += (ioplInfo.fPageOffset & PAGE_MASK);
+ address = ptoa_64(ioplInfo.fMappedBase) + offset;
+ continue; // Done leave do/while(false) now
+ }
+
+ // The offset is rebased into the current iopl.
+ // Now add the iopl 1st page offset.
+ offset += ioplInfo.fPageOffset;
+
+ // For external UPLs the fPageInfo field points directly to
+ // the upl's upl_page_info_t array.
+ if (ioplInfo.fFlags & kIOPLExternUPL)
+ pageList = (upl_page_info_t *) ioplInfo.fPageInfo;
+ else
+ pageList = &pageList[ioplInfo.fPageInfo];
+
+ // Check for direct device non-paged memory
+ if ( ioplInfo.fFlags & kIOPLOnDevice ) {
+ address = ptoa_64(pageList->phys_addr) + offset;
+ continue; // Done leave do/while(false) now
+ }
+
+ // Now we need compute the index into the pageList
+ UInt pageInd = atop_32(offset);
+ offset &= PAGE_MASK;
+
+ // Compute the starting address of this segment
+ IOPhysicalAddress pageAddr = pageList[pageInd].phys_addr;
+ address = ptoa_64(pageAddr) + offset;
+
+ // length is currently set to the length of the remainider of the iopl.
+ // We need to check that the remainder of the iopl is contiguous.
+ // This is indicated by pageList[ind].phys_addr being sequential.
+ IOByteCount contigLength = PAGE_SIZE - offset;
+ while (contigLength < length
+ && ++pageAddr == pageList[++pageInd].phys_addr)
+ {
+ contigLength += PAGE_SIZE;
+ }
+
+ if (contigLength < length)
+ length = contigLength;
+
+
+ assert(address);
+ assert(length);
+
+ } while (false);
+
+ // Update return values and state
+ isP->fIO.fIOVMAddr = address;
+ isP->fIO.fLength = length;
+ isP->fIndex = ind;
+ isP->fOffset2Index = off2Ind;
+ isP->fNextOffset = isP->fIO.fOffset + length;
+
+ return kIOReturnSuccess;
+}
projects / apple / xnu.git / blobdiff