the following patch was just integrated into master: commit 305b1f0d30b68c310d4dfa7e1a5f432769a65b31 Author: Aaron Durbin adurbin@chromium.org Date: Tue Jan 15 08:27:05 2013 -0600
haswell: Parallel AP bringup
This patch parallelizes the AP startup for Haswell-based devices. It does not touch the generic secondary startup code. Instead it provides its own MP support matching up with the Haswell BWG. It seemed to be too much trouble to support the old startup way and this new way. Because of that parallel loading is the only thing supported.
A couple of things to note: 1. Micrcode needs to be loaded twice. Once before MTRR and caching is enabled. And a second time after SMM relocation. 2. The sipi_vector is entirely self-contained. Once it is loaded and written back to RAM the APs do not access memory outside of the sipi_vector load location until a sync up in ramstage. 3. SMM relocation is kicked off by an IPI to self w/ SMI set as the destination mode.
The following are timings from cbmem with dev mode disabled and recovery mode enabled to boot directly into the kernel. This was done on the baskingridge CRB with a 4-core 8-thread CPU and 2 DIMMs 1GiB each. The kernel has console enabled on the serial port. Entry 70 is the device initialization, and that is where the APs are brought up. With these two examples it looks to shave off ~200 ms of boot time.
Before: 1:55,382 2:57,606 (2,223) 3:3,108,983 (3,051,377) 4:3,110,084 (1,101) 8:3,113,109 (3,024) 9:3,156,694 (43,585) 10:3,156,815 (120) 30:3,157,110 (295) 40:3,158,180 (1,069) 50:3,160,157 (1,977) 60:3,160,366 (208) 70:4,221,044 (1,060,677) 75:4,221,062 (18) 80:4,227,185 (6,122) 90:4,227,669 (484) 99:4,265,596 (37,927) 1000:4,267,822 (2,225) 1001:4,268,507 (685) 1002:4,268,780 (272) 1003:4,398,676 (129,896) 1004:4,398,979 (303) 1100:7,477,601 (3,078,621) 1101:7,480,210 (2,608)
After: 1:49,518 2:51,778 (2,259) 3:3,081,186 (3,029,407) 4:3,082,252 (1,066) 8:3,085,137 (2,884) 9:3,130,339 (45,202) 10:3,130,518 (178) 30:3,130,544 (26) 40:3,131,125 (580) 50:3,133,023 (1,897) 60:3,133,278 (255) 70:4,009,259 (875,980) 75:4,009,273 (13) 80:4,015,947 (6,674) 90:4,016,430 (482) 99:4,056,265 (39,835) 1000:4,058,492 (2,226) 1001:4,059,176 (684) 1002:4,059,450 (273) 1003:4,189,333 (129,883) 1004:4,189,770 (436) 1100:7,262,358 (3,072,588) 1101:7,263,926 (1,567)
Booted the baskingridge board as noted above. Also analyzed serial messages with pcserial enabled.
Change-Id: Ifedc7f787953647c228b11afdb725686e38c4098 Signed-off-by: Aaron Durbin adurbin@chromium.org Reviewed-on: http://review.coreboot.org/2779 Tested-by: build bot (Jenkins) Reviewed-by: Ronald G. Minnich rminnich@gmail.com
Build-Tested: build bot (Jenkins) at Tue Mar 19 02:20:03 2013, giving +1 Reviewed-By: Ronald G. Minnich rminnich@gmail.com at Tue Mar 19 05:15:22 2013, giving +2 See http://review.coreboot.org/2779 for details.
-gerrit