It turns out that the logical CPU mapping is useful even when !CONFIG_SMP
for manipulation of devices like interrupt and power controllers when
running a UP kernel on a CPU other than 0. This can happen when kexecing
a UP image from an SMP kernel.
In the future, multi-cluster systems running AMP configurations will
require something similar for mapping cluster IDs, so it makes sense to
decouple this logic in preparation for this support.
Acked-by: Yang Bai <hamo.by@gmail.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Reported-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* 'next/cross-platform' of git://git.linaro.org/people/arnd/arm-soc:
arm/imx: use Kconfig choice for low-level debug UART selection
ARM: realview: use Kconfig choice for debug UART selection
ARM: plat-samsung: use Kconfig choice for debug UART selection
ARM: versatile: convert logical CPU numbers to physical numbers
ARM: ux500: convert logical CPU numbers to physical numbers
ARM: shmobile: convert logical CPU numbers to physical numbers
ARM: msm: convert logical CPU numbers to physical numbers
ARM: exynos4: convert logical CPU numbers to physical numbers
Fix up trivial conflict (config DEBUG_S3C_UART move/split vs addition of
ARM_KPROBES_TEST option) in arch/arm/Kconfig.debug
Rather than clipping the number of CPUs using the compile-time NR_CPUS
constant, use the runtime nr_cpu_ids value instead. This allows the
nr_cpus command line option to work as expected.
Cc: <stable@kernel.org>
Reported-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch uses the new cpu_logical_map() macro for converting logical
CPU numbers into physical numbers when dealing with the pen_release
variable in the SMP boot and CPU hotplug paths.
Tested-and-acked-by: David Brown <davidb@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
* 'next/fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/linux-arm-soc: (35 commits)
ARM: msm: platsmp: determine number of CPU cores at boot time
ARM: Tegra: Seaboard: Fix I2C bus numbering for ADT7461
ARM: Tegra: Trimslice: Tri-state DAP3 pinmux
ARM: orion5x: fixup 5181 MPP mask check
ARM: mxs-dma: include <linux/dmaengine.h>
ARM: i.MX53: consistently use MX53_UART_PAD_CTRL for uart txd/rxd/rts/cts
ARM: i.MX53: UARTn_CTS pin should not change RTS input select
ARM: i.MX53: UARTn_TXD pin should not change RXD input select
ARM: mx25: Fix typo on CAN1_RX pad setting
iomux-mx53: add missing 'IOMUX_CONFIG_SION' for some I2C pad definitions
ARM: NUC93X: add UL suffix to VMALLOC_END to ensure it is properly typed
ARM: LPC32XXX: add UL suffix to VMALLOC_END to ensure it is properly typed
ARM: CNS3XXX: add UL suffix to VMALLOC_END to ensure it is properly typed
ARM: i.MX53: Fix IOMUX type o's
ARM i.MX dma: Fix burstsize settings
mach-mx5: fix the I2C clock parents
ARM: mxs/tx28: according to the TX28's datasheet D4-D7 are not used for MMC0
ARM i.MX23/28: platform-mxsfb: Add missing include of linux/dma-mapping.h
ARM: mx53: Fix some interrupts marked as reserved.
MXC: iomux-v3: correct NO_PAD_CTRL definition
...
Fix up trivial conflict in arch/arm/mach-imx/mach-mx31_3ds.c
Previously we just assumed there were CONFIG_NR_CPUS cpus present in
the system. Instead, figure out the number of cpus from the MIDR
register.
Signed-off-by: Jeff Ohlstein <johlstei@codeaurora.org>
Signed-off-by: David Brown <davidb@codeaurora.org>
[arnd: clarified patch title]
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
If an ARM system has multiple cpus in the same socket and the
kernel is booted with maxcpus=1, secondary cpus are possible but
not present due to how platform_smp_prepare_cpus() is called.
Since most typical ARM processors don't actually support physical
hotplug, initialize the present map to be equal to the possible
map in generic ARM SMP code. Also, always call
platform_smp_prepare_cpus() as long as max_cpus is non-zero (0
means no SMP) to allow platform code to do any SMP setup.
After applying this patch it's possible to boot an ARM system
with maxcpus=1 on the command line and then hotplug in secondary
cpus via sysfs. This is more in line with how x86 does things.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: David Brown <davidb@codeaurora.org>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Cc: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Rather than having each platform class provide a mach/smp.h header for
smp_cross_call(), arrange for them to register the function with the
core ARM SMP code instead.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Will Deacon