android_kernel_xiaomi_sm8350/arch/riscv/Kconfig
Alexandre Ghiti 54c95a11cc riscv: make mmap allocation top-down by default
In order to avoid wasting user address space by using bottom-up mmap
allocation scheme, prefer top-down scheme when possible.

Before:
root@qemuriscv64:~# cat /proc/self/maps
00010000-00016000 r-xp 00000000 fe:00 6389       /bin/cat.coreutils
00016000-00017000 r--p 00005000 fe:00 6389       /bin/cat.coreutils
00017000-00018000 rw-p 00006000 fe:00 6389       /bin/cat.coreutils
00018000-00039000 rw-p 00000000 00:00 0          [heap]
1555556000-155556d000 r-xp 00000000 fe:00 7193   /lib/ld-2.28.so
155556d000-155556e000 r--p 00016000 fe:00 7193   /lib/ld-2.28.so
155556e000-155556f000 rw-p 00017000 fe:00 7193   /lib/ld-2.28.so
155556f000-1555570000 rw-p 00000000 00:00 0
1555570000-1555572000 r-xp 00000000 00:00 0      [vdso]
1555574000-1555576000 rw-p 00000000 00:00 0
1555576000-1555674000 r-xp 00000000 fe:00 7187   /lib/libc-2.28.so
1555674000-1555678000 r--p 000fd000 fe:00 7187   /lib/libc-2.28.so
1555678000-155567a000 rw-p 00101000 fe:00 7187   /lib/libc-2.28.so
155567a000-15556a0000 rw-p 00000000 00:00 0
3fffb90000-3fffbb1000 rw-p 00000000 00:00 0      [stack]

After:
root@qemuriscv64:~# cat /proc/self/maps
00010000-00016000 r-xp 00000000 fe:00 6389       /bin/cat.coreutils
00016000-00017000 r--p 00005000 fe:00 6389       /bin/cat.coreutils
00017000-00018000 rw-p 00006000 fe:00 6389       /bin/cat.coreutils
2de81000-2dea2000 rw-p 00000000 00:00 0          [heap]
3ff7eb6000-3ff7ed8000 rw-p 00000000 00:00 0
3ff7ed8000-3ff7fd6000 r-xp 00000000 fe:00 7187   /lib/libc-2.28.so
3ff7fd6000-3ff7fda000 r--p 000fd000 fe:00 7187   /lib/libc-2.28.so
3ff7fda000-3ff7fdc000 rw-p 00101000 fe:00 7187   /lib/libc-2.28.so
3ff7fdc000-3ff7fe2000 rw-p 00000000 00:00 0
3ff7fe4000-3ff7fe6000 r-xp 00000000 00:00 0      [vdso]
3ff7fe6000-3ff7ffd000 r-xp 00000000 fe:00 7193   /lib/ld-2.28.so
3ff7ffd000-3ff7ffe000 r--p 00016000 fe:00 7193   /lib/ld-2.28.so
3ff7ffe000-3ff7fff000 rw-p 00017000 fe:00 7193   /lib/ld-2.28.so
3ff7fff000-3ff8000000 rw-p 00000000 00:00 0
3fff888000-3fff8a9000 rw-p 00000000 00:00 0      [stack]

[alex@ghiti.fr: v6]
  Link: http://lkml.kernel.org/r/20190808061756.19712-15-alex@ghiti.fr
Link: http://lkml.kernel.org/r/20190730055113.23635-15-alex@ghiti.fr
Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Acked-by: Paul Walmsley <paul.walmsley@sifive.com>	[arch/riscv]
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24 15:54:12 -07:00

329 lines
7.3 KiB
Plaintext

# SPDX-License-Identifier: GPL-2.0-only
#
# For a description of the syntax of this configuration file,
# see Documentation/kbuild/kconfig-language.rst.
#
config 64BIT
bool
config 32BIT
bool
config RISCV
def_bool y
# even on 32-bit, physical (and DMA) addresses are > 32-bits
select PHYS_ADDR_T_64BIT
select OF
select OF_EARLY_FLATTREE
select OF_IRQ
select ARCH_HAS_BINFMT_FLAT
select ARCH_WANT_FRAME_POINTERS
select CLONE_BACKWARDS
select COMMON_CLK
select GENERIC_CLOCKEVENTS
select GENERIC_CPU_DEVICES
select GENERIC_IRQ_SHOW
select GENERIC_PCI_IOMAP
select GENERIC_SCHED_CLOCK
select GENERIC_STRNCPY_FROM_USER
select GENERIC_STRNLEN_USER
select GENERIC_SMP_IDLE_THREAD
select GENERIC_ATOMIC64 if !64BIT
select HAVE_ARCH_AUDITSYSCALL
select HAVE_ASM_MODVERSIONS
select HAVE_MEMBLOCK_NODE_MAP
select HAVE_DMA_CONTIGUOUS
select HAVE_FUTEX_CMPXCHG if FUTEX
select HAVE_PERF_EVENTS
select HAVE_PERF_REGS
select HAVE_PERF_USER_STACK_DUMP
select HAVE_SYSCALL_TRACEPOINTS
select IRQ_DOMAIN
select SPARSE_IRQ
select SYSCTL_EXCEPTION_TRACE
select HAVE_ARCH_TRACEHOOK
select HAVE_PCI
select MODULES_USE_ELF_RELA if MODULES
select MODULE_SECTIONS if MODULES
select THREAD_INFO_IN_TASK
select PCI_DOMAINS_GENERIC if PCI
select PCI_MSI if PCI
select RISCV_TIMER
select GENERIC_IRQ_MULTI_HANDLER
select GENERIC_ARCH_TOPOLOGY if SMP
select ARCH_HAS_PTE_SPECIAL
select ARCH_HAS_MMIOWB
select HAVE_EBPF_JIT if 64BIT
select EDAC_SUPPORT
select ARCH_HAS_GIGANTIC_PAGE
select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
select SPARSEMEM_STATIC if 32BIT
select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
select HAVE_ARCH_MMAP_RND_BITS
config ARCH_MMAP_RND_BITS_MIN
default 18 if 64BIT
default 8
# max bits determined by the following formula:
# VA_BITS - PAGE_SHIFT - 3
config ARCH_MMAP_RND_BITS_MAX
default 24 if 64BIT # SV39 based
default 17
config MMU
def_bool y
config ZONE_DMA32
bool
default y if 64BIT
config VA_BITS
int
default 32 if 32BIT
default 39 if 64BIT
config PA_BITS
int
default 34 if 32BIT
default 56 if 64BIT
config PAGE_OFFSET
hex
default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
config ARCH_FLATMEM_ENABLE
def_bool y
config ARCH_SPARSEMEM_ENABLE
def_bool y
select SPARSEMEM_VMEMMAP_ENABLE
config ARCH_SELECT_MEMORY_MODEL
def_bool ARCH_SPARSEMEM_ENABLE
config ARCH_WANT_GENERAL_HUGETLB
def_bool y
config SYS_SUPPORTS_HUGETLBFS
def_bool y
config STACKTRACE_SUPPORT
def_bool y
config TRACE_IRQFLAGS_SUPPORT
def_bool y
config GENERIC_BUG
def_bool y
depends on BUG
select GENERIC_BUG_RELATIVE_POINTERS if 64BIT
config GENERIC_BUG_RELATIVE_POINTERS
bool
config GENERIC_CALIBRATE_DELAY
def_bool y
config GENERIC_CSUM
def_bool y
config GENERIC_HWEIGHT
def_bool y
config FIX_EARLYCON_MEM
def_bool y
config PGTABLE_LEVELS
int
default 3 if 64BIT
default 2
source "arch/riscv/Kconfig.socs"
menu "Platform type"
choice
prompt "Base ISA"
default ARCH_RV64I
help
This selects the base ISA that this kernel will target and must match
the target platform.
config ARCH_RV32I
bool "RV32I"
select 32BIT
select GENERIC_LIB_ASHLDI3
select GENERIC_LIB_ASHRDI3
select GENERIC_LIB_LSHRDI3
select GENERIC_LIB_UCMPDI2
config ARCH_RV64I
bool "RV64I"
select 64BIT
select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000
select HAVE_FUNCTION_TRACER
select HAVE_FUNCTION_GRAPH_TRACER
select HAVE_FTRACE_MCOUNT_RECORD
select HAVE_DYNAMIC_FTRACE
select HAVE_DYNAMIC_FTRACE_WITH_REGS
select SWIOTLB
endchoice
# We must be able to map all physical memory into the kernel, but the compiler
# is still a bit more efficient when generating code if it's setup in a manner
# such that it can only map 2GiB of memory.
choice
prompt "Kernel Code Model"
default CMODEL_MEDLOW if 32BIT
default CMODEL_MEDANY if 64BIT
config CMODEL_MEDLOW
bool "medium low code model"
config CMODEL_MEDANY
bool "medium any code model"
endchoice
config MODULE_SECTIONS
bool
select HAVE_MOD_ARCH_SPECIFIC
choice
prompt "Maximum Physical Memory"
default MAXPHYSMEM_2GB if 32BIT
default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
config MAXPHYSMEM_2GB
bool "2GiB"
config MAXPHYSMEM_128GB
depends on 64BIT && CMODEL_MEDANY
bool "128GiB"
endchoice
config SMP
bool "Symmetric Multi-Processing"
help
This enables support for systems with more than one CPU. If
you say N here, the kernel will run on single and
multiprocessor machines, but will use only one CPU of a
multiprocessor machine. If you say Y here, the kernel will run
on many, but not all, single processor machines. On a single
processor machine, the kernel will run faster if you say N
here.
If you don't know what to do here, say N.
config NR_CPUS
int "Maximum number of CPUs (2-32)"
range 2 32
depends on SMP
default "8"
choice
prompt "CPU Tuning"
default TUNE_GENERIC
config TUNE_GENERIC
bool "generic"
endchoice
config RISCV_ISA_C
bool "Emit compressed instructions when building Linux"
default y
help
Adds "C" to the ISA subsets that the toolchain is allowed to emit
when building Linux, which results in compressed instructions in the
Linux binary.
If you don't know what to do here, say Y.
menu "supported PMU type"
depends on PERF_EVENTS
config RISCV_BASE_PMU
bool "Base Performance Monitoring Unit"
def_bool y
help
A base PMU that serves as a reference implementation and has limited
feature of perf. It can run on any RISC-V machines so serves as the
fallback, but this option can also be disable to reduce kernel size.
endmenu
config FPU
bool "FPU support"
default y
help
Say N here if you want to disable all floating-point related procedure
in the kernel.
If you don't know what to do here, say Y.
endmenu
menu "Kernel features"
source "kernel/Kconfig.hz"
endmenu
menu "Boot options"
config CMDLINE
string "Built-in kernel command line"
help
For most platforms, the arguments for the kernel's command line
are provided at run-time, during boot. However, there are cases
where either no arguments are being provided or the provided
arguments are insufficient or even invalid.
When that occurs, it is possible to define a built-in command
line here and choose how the kernel should use it later on.
choice
prompt "Built-in command line usage" if CMDLINE != ""
default CMDLINE_FALLBACK
help
Choose how the kernel will handle the provided built-in command
line.
config CMDLINE_FALLBACK
bool "Use bootloader kernel arguments if available"
help
Use the built-in command line as fallback in case we get nothing
during boot. This is the default behaviour.
config CMDLINE_EXTEND
bool "Extend bootloader kernel arguments"
help
The command-line arguments provided during boot will be
appended to the built-in command line. This is useful in
cases where the provided arguments are insufficient and
you don't want to or cannot modify them.
config CMDLINE_FORCE
bool "Always use the default kernel command string"
help
Always use the built-in command line, even if we get one during
boot. This is useful in case you need to override the provided
command line on systems where you don't have or want control
over it.
endchoice
endmenu
menu "Power management options"
source "kernel/power/Kconfig"
endmenu