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2015-06-05lib: Unify log2() and related functionsJulius Werner
This patch adds a few bit counting functions that are commonly needed for certain register calculations. We previously had a log2() implementation already, but it was awkwardly split between some C code that's only available in ramstage and an optimized x86-specific implementation in pre-RAM that prevented other archs from pulling it into earlier stages. Using __builtin_clz() as the baseline allows GCC to inline optimized assembly for most archs (including CLZ on ARM/ARM64 and BSR on x86), and to perform constant-folding if possible. What was previously named log2f on pre-RAM x86 is now ffs, since that's the standard name for that operation and I honestly don't have the slightest idea how it could've ever ended up being called log2f (which in POSIX is 'binary(2) LOGarithm with Float result, whereas the Find First Set operation has no direct correlation to logarithms that I know of). Make ffs result 0-based instead of the POSIX standard's 1-based since that is consistent with clz, log2 and the former log2f, and generally closer to what you want for most applications (a value that can directly be used as a shift to reach the found bit). Call it __ffs() instead of ffs() to avoid problems when importing code, since that's what Linux uses for the 0-based operation. CQ-DEPEND=CL:273023 BRANCH=None BUG=None TEST=Built on Big, Falco, Jerry, Oak and Urara. Compared old and new log2() and __ffs() results on Falco for a bunch of test values. Change-Id: I599209b342059e17b3130621edb6b6bbeae26876 Signed-off-by: Patrick Georgi <pgeorgi@chromium.org> Original-Commit-Id: 3701a16ae944ecff9c54fa9a50d28015690fcb2f Original-Change-Id: I60f7cf893792508188fa04d088401a8bca4b4af6 Original-Signed-off-by: Julius Werner <jwerner@chromium.org> Original-Reviewed-on: https://chromium-review.googlesource.com/273008 Original-Reviewed-by: Patrick Georgi <pgeorgi@chromium.org> Reviewed-on: http://review.coreboot.org/10394 Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
2014-06-20src/lib/clog2.c: Fix style and clarity, remove some cruftEdward O'Callaghan
Change-Id: I6b37cf945db12d2cf8096c9f49fff9e0bec139d6 Signed-off-by: Edward O'Callaghan <eocallaghan@alterapraxis.com> Reviewed-on: http://review.coreboot.org/6058 Tested-by: build bot (Jenkins) Reviewed-by: Idwer Vollering <vidwer@gmail.com>
2014-01-14lib: Add log2 ceiling functionAlexandru Gagniuc
Change-Id: Ifb41050e729a0ce314e4d4918e46f82bc7e16bed Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com> Reviewed-on: http://review.coreboot.org/4684 Tested-by: build bot (Jenkins) Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
2010-03-22printk_foo -> printk(BIOS_FOO, ...)Stefan Reinauer
Signed-off-by: Stefan Reinauer <stepan@coresystems.de> Acked-by: Ronald G. Minnich <rminnich@gmail.com> git-svn-id: svn://svn.coreboot.org/coreboot/trunk@5266 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
2009-10-28Create lib.h for homeless prototypes.Myles Watson
Signed-off-by: Myles Watson <mylesgw@gmail.com> Acked-by: Ronald G. Minnich <rminnich@gmail.com> git-svn-id: svn://svn.coreboot.org/coreboot/trunk@4878 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
2009-10-27Add few missing prototypes, and remove few unused (thus lonelly) variables.Maciej Pijanka
TODO - x86emu need (imo) some common header with prototypes at least - clog2, ulzma, hardwaremain prototypes added by this patch probably should be moved to some header too. - in src/devices/device_util.c prototype is before function because seems, it is used only within same file, if not it should be moved to debug section of prototypes in include/device/device.h Signed-off-by: Maciej Pijanka <maciej.pijanka@gmail.com> Acked-by: Myles Watson <mylesgw@gmail.com> git-svn-id: svn://svn.coreboot.org/coreboot/trunk@4871 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
2005-07-08eric patchYinghai Lu
1. x86_setup_mtrr take address bit. 2. generic ht, pcix, pcie beidge... 3. scan bus and reset_bus 4. ht read ctrl to decide if the ht chain is ready 5. Intel e7520 and e7525 support 6. new ich5r support 7. intel sb 6300 support. yhlu patch 1. split x86_setup_mtrrs to fixed and var 2. if (resource->flags & IORESOURCE_FIXED ) return; in device.c pick_largest_resource 3. in_conherent.c K8_SCAN_PCI_BUS git-svn-id: svn://svn.coreboot.org/coreboot/trunk@1982 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
2004-05-28This will never happen unless the code is buggy (in which case it's easy toStefan Reinauer
reenable debugging output). git-svn-id: svn://svn.coreboot.org/coreboot/trunk@1586 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
2003-04-22- Initial checkin of the freebios2 treeEric Biederman
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@784 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1