From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bin Meng Date: Mon, 13 Jul 2020 12:48:35 +0800 Subject: [PATCH v4 10/25] x86: mp: Support APs waiting for instructions In-Reply-To: <20200707193423.v4.10.I5cdb6d2b53a528eaebda2227b8cdfe26c4c73ceb@changeid> References: <20200708013446.2600256-1-sjg@chromium.org> <20200707193423.v4.10.I5cdb6d2b53a528eaebda2227b8cdfe26c4c73ceb@changeid> Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On Wed, Jul 8, 2020 at 9:37 AM Simon Glass wrote: > > At present the APs (non-boot CPUs) are inited once and then parked ready > for the OS to use them. However in some cases we want to send new requests > through, such as to change MTRRs and keep them consistent across CPUs. > > Change the last state of the flight plan to go into a wait loop, accepting > instructions from the main CPU. > > Drop cpu_map since it is not used. > > Signed-off-by: Simon Glass > Reviewed-by: Wolfgang Wallner > --- > > Changes in v4: > - Add a Kconfig to control this feature, enabled only on APL > > Changes in v3: > - s/slow/slot/ > - Use C code instead of assembler to read/write callback pointers > - Update commit message to mention dropping of cpu_map > > Changes in v2: > - Add more comments > > arch/x86/Kconfig | 7 ++ > arch/x86/cpu/apollolake/Kconfig | 1 + > arch/x86/cpu/mp_init.c | 123 +++++++++++++++++++++++++++++--- > arch/x86/include/asm/mp.h | 11 +++ > 4 files changed, 134 insertions(+), 8 deletions(-) > Reviewed-by: Bin Meng