| #
6213f70e |
|
13-Dec-2018 |
Russell King <rmk+kernel@armlinux.org.uk> |
ARM: smp: remove arch-provided "pen_release"
Consolidating the "pen_release" stuff amongst the various SoC
implementations gives credence to having a CPU holding pen for
secondary CPUs. However, this is far from the truth.
Many SoC implementations cargo-cult copied various bits of the pen
release implementation from the initial Realview/Versatile Express
implementation without understanding what it was or why it existed.
The reason it existed is because these are _development_ platforms,
and some board firmware is unable to individually control the
startup of secondary CPUs. Moreover, they do not have a way to
power down or reset secondary CPUs for hot-unplug. Hence, the
pen_release implementation was designed for ARM Ltd's development
platforms to provide a working implementation, even though it is
very far from what is required.
It was decided a while back to reduce the duplication by consolidating
the "pen_release" variable, but this only made the situation worse -
we have ended up with several implementations that read this variable
but do not write it - again, showing the cargo-cult mentality at work,
lack of proper review of new code, and in some cases a lack of testing.
While it would be preferable to remove pen_release entirely from the
kernel, this is not possible without help from the SoC maintainers,
which seems to be lacking. However, I want to remove pen_release from
arch code to remove the credence that having it gives.
This patch removes pen_release from the arch code entirely, adding
private per-SoC definitions for it instead, and explicitly stating
that write_pen_release() is cargo-cult copied and should not be
copied any further. Rename write_pen_release() in a similar fashion
as well.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
|
| #
b96fc2f3 |
|
19-Oct-2015 |
Stephen Boyd <sboyd@codeaurora.org> |
ARM: Remove __ref on hotplug cpu die path
Now that __cpuinit has been removed, the __ref markings on these
functions are useless. Remove them. This also reduces the size of
the multi_v7_defconfig image:
$ size before after
text data bss dec hex filename
12683578 1470996 348904 14503478 dd4e36 before
12683274 1470996 348904 14503174 dd4d06 after
presumably because now we don't have to jump to code in the
.ref.text section and/or the noinline marking is removed.
Cc: Shiraz Hashim <shiraz.linux.kernel@gmail.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: <linux-omap@vger.kernel.org>
Cc: <linux-arm-msm@vger.kernel.org>
Cc: <spear-devel@list.st.com>
Cc: <linux-tegra@vger.kernel.org>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Barry Song <baohua@kernel.org>
Acked-by: Andy Gross <agross@codeaurora.org>
Acked-by: Viresh Kumar <vireshk@kernel.org>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Olof Johansson <olof@lixom.net>
|