Author: wmb Date: Thu Jul 14 01:07:54 2011 New Revision: 2348 URL: http://tracker.coreboot.org/trac/openfirmware/changeset/2348
Log: Checked in some experimental code for testing the speed of MMP2 memory to memory DMA; it serves as an example for how to drive said hardware.
Added: cpu/arm/mmp2/mdma.fth
Added: cpu/arm/mmp2/mdma.fth ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ cpu/arm/mmp2/mdma.fth Thu Jul 14 01:07:54 2011 (r2348) @@ -0,0 +1,71 @@ +purpose: Test code to determine the speed of MMP2 memory to memory DMA + +\ Copy from cache to cache - 1.3 GB/sec +\ Copy from memory to memory - 323 MB/sec +\ DMA from memory to memory - 425 MB/sec +\ Read from cache (address constant) 4.2 GB/sec +\ Read from memory (advancing address) 390 MB/sec + +h# d42a.0a00 value mdma0-base + +: mdma! ( n offset -- ) mdma0-base + l! ; +: mdma@ ( offset -- n ) mdma0-base + l@ ; + +h# 0010.0000 constant mdma-ram +h# ffc0 constant /mdma-buf +mdma-ram constant mdma-desc0 +h# 10 constant /dma-desc + +\ Descriptor format: +\ Byte count +\ Source +\ Destination +\ link + +: set-descriptor ( next dest source length adr -- ) + >r r@ l! r@ la1+ l! r@ 2 la+ l! r> 3 la+ l! +; + +code cmake-test-ring ( src-adr dst-adr len desc -- ) + \ tos: desc + pop r4,sp \ r4: Total length + pop r2,sp \ r2: dst + pop r1,sp \ r1: src + set r0,#0xffc0 + begin + add r3,tos,#0x10 + stmia tos!,{r0,r1,r2,r3} + inc r1,r0 + inc r2,r0 + decs r4,r0 + 0<= until + \ Go back to last descriptor + dec tos,#0x10 + mov r3,#0 + str r3,[tos,#0x0c] \ Last link is 0 + inc r4,r0 + str r4,[tos] \ Fixup last length + pop tos,sp +c; +0 value dst-adr +0 value src-adr +0 value desc-adr +: make-test-ring ( src-adr dst-adr len -- ) + swap to dst-adr swap to src-adr + mdma-desc0 to desc-adr + 0 ?do + desc-adr /dma-desc + dst-adr i + src-adr i + /mdma-buf desc-adr set-descriptor + desc-adr /dma-desc + to desc-adr + /mdma-buf +loop + + desc-adr /dma-desc - to desc-adr + 0 desc-adr 3 la+ l! \ Put null in last link + + mdma-desc0 h# 30 mdma! \ Link to first descriptor +; +: start-test-ring ( -- ) +\ 8 h# d428.2864 l! \ Enable DMA clock + 1 h# 80 mdma! \ Enable DMA completion interrupts + h# 0000.3d80 h# 40 mdma! \ fetch next, enable, chain, 32 bytes, inc dest, inc src +; +: abort-test-ring ( -- ) h# 10.0000 h# 40 mdma! ;