linux/arch/microblaze/Kconfig

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# SPDX-License-Identifier: GPL-2.0-only
config MICROBLAZE
def_bool y
select ARCH_32BIT_OFF_T
select ARCH_NO_SWAP
select ARCH_HAS_DMA_PREP_COHERENT
select ARCH_HAS_GCOV_PROFILE_ALL
select ARCH_HAS_SYNC_DMA_FOR_CPU
select ARCH_HAS_SYNC_DMA_FOR_DEVICE
select ARCH_MIGHT_HAVE_PC_PARPORT
select ARCH_WANT_IPC_PARSE_VERSION
select BUILDTIME_TABLE_SORT
select TIMER_OF
select CLONE_BACKWARDS3
select COMMON_CLK
select DMA_DIRECT_REMAP
select GENERIC_ATOMIC64
select GENERIC_CPU_DEVICES
select GENERIC_IDLE_POLL_SETUP
select GENERIC_IRQ_PROBE
select GENERIC_IRQ_SHOW
select GENERIC_PCI_IOMAP
select GENERIC_SCHED_CLOCK
select HAVE_ARCH_HASH
select HAVE_ARCH_KGDB
select HAVE_ARCH_SECCOMP
select HAVE_DEBUG_KMEMLEAK
select HAVE_DMA_CONTIGUOUS
select HAVE_DYNAMIC_FTRACE
select HAVE_FTRACE_MCOUNT_RECORD
select HAVE_FUNCTION_GRAPH_TRACER
select HAVE_FUNCTION_TRACER
select HAVE_PCI
select IRQ_DOMAIN
select XILINX_INTC
2012-09-28 05:01:03 +00:00
select MODULES_USE_ELF_RELA
select OF
select OF_EARLY_FLATTREE
select PCI_DOMAINS_GENERIC if PCI
select PCI_SYSCALL if PCI
select VIRT_TO_BUS
lib/GCD.c: use binary GCD algorithm instead of Euclidean The binary GCD algorithm is based on the following facts: 1. If a and b are all evens, then gcd(a,b) = 2 * gcd(a/2, b/2) 2. If a is even and b is odd, then gcd(a,b) = gcd(a/2, b) 3. If a and b are all odds, then gcd(a,b) = gcd((a-b)/2, b) = gcd((a+b)/2, b) Even on x86 machines with reasonable division hardware, the binary algorithm runs about 25% faster (80% the execution time) than the division-based Euclidian algorithm. On platforms like Alpha and ARMv6 where division is a function call to emulation code, it's even more significant. There are two variants of the code here, depending on whether a fast __ffs (find least significant set bit) instruction is available. This allows the unpredictable branches in the bit-at-a-time shifting loop to be eliminated. If fast __ffs is not available, the "even/odd" GCD variant is used. I use the following code to benchmark: #include <stdio.h> #include <stdlib.h> #include <stdint.h> #include <string.h> #include <time.h> #include <unistd.h> #define swap(a, b) \ do { \ a ^= b; \ b ^= a; \ a ^= b; \ } while (0) unsigned long gcd0(unsigned long a, unsigned long b) { unsigned long r; if (a < b) { swap(a, b); } if (b == 0) return a; while ((r = a % b) != 0) { a = b; b = r; } return b; } unsigned long gcd1(unsigned long a, unsigned long b) { unsigned long r = a | b; if (!a || !b) return r; b >>= __builtin_ctzl(b); for (;;) { a >>= __builtin_ctzl(a); if (a == b) return a << __builtin_ctzl(r); if (a < b) swap(a, b); a -= b; } } unsigned long gcd2(unsigned long a, unsigned long b) { unsigned long r = a | b; if (!a || !b) return r; r &= -r; while (!(b & r)) b >>= 1; for (;;) { while (!(a & r)) a >>= 1; if (a == b) return a; if (a < b) swap(a, b); a -= b; a >>= 1; if (a & r) a += b; a >>= 1; } } unsigned long gcd3(unsigned long a, unsigned long b) { unsigned long r = a | b; if (!a || !b) return r; b >>= __builtin_ctzl(b); if (b == 1) return r & -r; for (;;) { a >>= __builtin_ctzl(a); if (a == 1) return r & -r; if (a == b) return a << __builtin_ctzl(r); if (a < b) swap(a, b); a -= b; } } unsigned long gcd4(unsigned long a, unsigned long b) { unsigned long r = a | b; if (!a || !b) return r; r &= -r; while (!(b & r)) b >>= 1; if (b == r) return r; for (;;) { while (!(a & r)) a >>= 1; if (a == r) return r; if (a == b) return a; if (a < b) swap(a, b); a -= b; a >>= 1; if (a & r) a += b; a >>= 1; } } static unsigned long (*gcd_func[])(unsigned long a, unsigned long b) = { gcd0, gcd1, gcd2, gcd3, gcd4, }; #define TEST_ENTRIES (sizeof(gcd_func) / sizeof(gcd_func[0])) #if defined(__x86_64__) #define rdtscll(val) do { \ unsigned long __a,__d; \ __asm__ __volatile__("rdtsc" : "=a" (__a), "=d" (__d)); \ (val) = ((unsigned long long)__a) | (((unsigned long long)__d)<<32); \ } while(0) static unsigned long long benchmark_gcd_func(unsigned long (*gcd)(unsigned long, unsigned long), unsigned long a, unsigned long b, unsigned long *res) { unsigned long long start, end; unsigned long long ret; unsigned long gcd_res; rdtscll(start); gcd_res = gcd(a, b); rdtscll(end); if (end >= start) ret = end - start; else ret = ~0ULL - start + 1 + end; *res = gcd_res; return ret; } #else static inline struct timespec read_time(void) { struct timespec time; clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &time); return time; } static inline unsigned long long diff_time(struct timespec start, struct timespec end) { struct timespec temp; if ((end.tv_nsec - start.tv_nsec) < 0) { temp.tv_sec = end.tv_sec - start.tv_sec - 1; temp.tv_nsec = 1000000000ULL + end.tv_nsec - start.tv_nsec; } else { temp.tv_sec = end.tv_sec - start.tv_sec; temp.tv_nsec = end.tv_nsec - start.tv_nsec; } return temp.tv_sec * 1000000000ULL + temp.tv_nsec; } static unsigned long long benchmark_gcd_func(unsigned long (*gcd)(unsigned long, unsigned long), unsigned long a, unsigned long b, unsigned long *res) { struct timespec start, end; unsigned long gcd_res; start = read_time(); gcd_res = gcd(a, b); end = read_time(); *res = gcd_res; return diff_time(start, end); } #endif static inline unsigned long get_rand() { if (sizeof(long) == 8) return (unsigned long)rand() << 32 | rand(); else return rand(); } int main(int argc, char **argv) { unsigned int seed = time(0); int loops = 100; int repeats = 1000; unsigned long (*res)[TEST_ENTRIES]; unsigned long long elapsed[TEST_ENTRIES]; int i, j, k; for (;;) { int opt = getopt(argc, argv, "n:r:s:"); /* End condition always first */ if (opt == -1) break; switch (opt) { case 'n': loops = atoi(optarg); break; case 'r': repeats = atoi(optarg); break; case 's': seed = strtoul(optarg, NULL, 10); break; default: /* You won't actually get here. */ break; } } res = malloc(sizeof(unsigned long) * TEST_ENTRIES * loops); memset(elapsed, 0, sizeof(elapsed)); srand(seed); for (j = 0; j < loops; j++) { unsigned long a = get_rand(); /* Do we have args? */ unsigned long b = argc > optind ? strtoul(argv[optind], NULL, 10) : get_rand(); unsigned long long min_elapsed[TEST_ENTRIES]; for (k = 0; k < repeats; k++) { for (i = 0; i < TEST_ENTRIES; i++) { unsigned long long tmp = benchmark_gcd_func(gcd_func[i], a, b, &res[j][i]); if (k == 0 || min_elapsed[i] > tmp) min_elapsed[i] = tmp; } } for (i = 0; i < TEST_ENTRIES; i++) elapsed[i] += min_elapsed[i]; } for (i = 0; i < TEST_ENTRIES; i++) printf("gcd%d: elapsed %llu\n", i, elapsed[i]); k = 0; srand(seed); for (j = 0; j < loops; j++) { unsigned long a = get_rand(); unsigned long b = argc > optind ? strtoul(argv[optind], NULL, 10) : get_rand(); for (i = 1; i < TEST_ENTRIES; i++) { if (res[j][i] != res[j][0]) break; } if (i < TEST_ENTRIES) { if (k == 0) { k = 1; fprintf(stderr, "Error:\n"); } fprintf(stderr, "gcd(%lu, %lu): ", a, b); for (i = 0; i < TEST_ENTRIES; i++) fprintf(stderr, "%ld%s", res[j][i], i < TEST_ENTRIES - 1 ? ", " : "\n"); } } if (k == 0) fprintf(stderr, "PASS\n"); free(res); return 0; } Compiled with "-O2", on "VirtualBox 4.4.0-22-generic #38-Ubuntu x86_64" got: zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10 gcd0: elapsed 10174 gcd1: elapsed 2120 gcd2: elapsed 2902 gcd3: elapsed 2039 gcd4: elapsed 2812 PASS zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10 gcd0: elapsed 9309 gcd1: elapsed 2280 gcd2: elapsed 2822 gcd3: elapsed 2217 gcd4: elapsed 2710 PASS zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10 gcd0: elapsed 9589 gcd1: elapsed 2098 gcd2: elapsed 2815 gcd3: elapsed 2030 gcd4: elapsed 2718 PASS zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10 gcd0: elapsed 9914 gcd1: elapsed 2309 gcd2: elapsed 2779 gcd3: elapsed 2228 gcd4: elapsed 2709 PASS [akpm@linux-foundation.org: avoid #defining a CONFIG_ variable] Signed-off-by: Zhaoxiu Zeng <zhaoxiu.zeng@gmail.com> Signed-off-by: George Spelvin <linux@horizon.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-21 00:03:57 +00:00
select CPU_NO_EFFICIENT_FFS
select MMU_GATHER_NO_RANGE
select SPARSE_IRQ
select ZONE_DMA
select TRACE_IRQFLAGS_SUPPORT
select GENERIC_IRQ_MULTI_HANDLER
select HANDLE_DOMAIN_IRQ
# Endianness selection
choice
prompt "Endianness selection"
default CPU_LITTLE_ENDIAN
help
microblaze architectures can be configured for either little or
big endian formats. Be sure to select the appropriate mode.
config CPU_BIG_ENDIAN
bool "Big endian"
config CPU_LITTLE_ENDIAN
bool "Little endian"
endchoice
config ARCH_HAS_ILOG2_U32
def_bool n
config ARCH_HAS_ILOG2_U64
def_bool n
config GENERIC_HWEIGHT
def_bool y
config GENERIC_CALIBRATE_DELAY
def_bool y
config GENERIC_CSUM
def_bool y
config STACKTRACE_SUPPORT
def_bool y
config LOCKDEP_SUPPORT
def_bool y
source "arch/microblaze/Kconfig.platform"
menu "Processor type and features"
source "kernel/Kconfig.hz"
config MMU
def_bool y
comment "Boot options"
config CMDLINE_BOOL
bool "Default bootloader kernel arguments"
config CMDLINE
string "Default kernel command string"
depends on CMDLINE_BOOL
default "console=ttyUL0,115200"
help
On some architectures there is currently no way for the boot loader
to pass arguments to the kernel. For these architectures, you should
supply some command-line options at build time by entering them
here.
config CMDLINE_FORCE
bool "Force default kernel command string"
depends on CMDLINE_BOOL
default n
help
Set this to have arguments from the default kernel command string
override those passed by the boot loader.
endmenu
menu "Kernel features"
config NR_CPUS
int
default "1"
config ADVANCED_OPTIONS
bool "Prompt for advanced kernel configuration options"
help
This option will enable prompting for a variety of advanced kernel
configuration options. These options can cause the kernel to not
work if they are set incorrectly, but can be used to optimize certain
aspects of kernel memory management.
Unless you know what you are doing, say N here.
comment "Default settings for advanced configuration options are used"
depends on !ADVANCED_OPTIONS
config HIGHMEM
bool "High memory support"
select KMAP_LOCAL
help
The address space of Microblaze processors is only 4 Gigabytes large
and it has to accommodate user address space, kernel address
space as well as some memory mapped IO. That means that, if you
have a large amount of physical memory and/or IO, not all of the
memory can be "permanently mapped" by the kernel. The physical
memory that is not permanently mapped is called "high memory".
If unsure, say n.
config LOWMEM_SIZE_BOOL
bool "Set maximum low memory"
depends on ADVANCED_OPTIONS
help
This option allows you to set the maximum amount of memory which
will be used as "low memory", that is, memory which the kernel can
access directly, without having to set up a kernel virtual mapping.
This can be useful in optimizing the layout of kernel virtual
memory.
Say N here unless you know what you are doing.
config LOWMEM_SIZE
hex "Maximum low memory size (in bytes)" if LOWMEM_SIZE_BOOL
default "0x30000000"
config MANUAL_RESET_VECTOR
hex "Microblaze reset vector address setup"
default "0x0"
help
Set this option to have the kernel override the CPU Reset vector.
If zero, no change will be made to the MicroBlaze reset vector at
address 0x0.
If non-zero, a jump instruction to this address, will be written
to the reset vector at address 0x0.
If you are unsure, set it to default value 0x0.
config KERNEL_START_BOOL
bool "Set custom kernel base address"
depends on ADVANCED_OPTIONS
help
This option allows you to set the kernel virtual address at which
the kernel will map low memory (the kernel image will be linked at
this address). This can be useful in optimizing the virtual memory
layout of the system.
Say N here unless you know what you are doing.
config KERNEL_START
hex "Virtual address of kernel base" if KERNEL_START_BOOL
default "0xc0000000"
config TASK_SIZE_BOOL
bool "Set custom user task size"
depends on ADVANCED_OPTIONS
help
This option allows you to set the amount of virtual address space
allocated to user tasks. This can be useful in optimizing the
virtual memory layout of the system.
Say N here unless you know what you are doing.
config TASK_SIZE
hex "Size of user task space" if TASK_SIZE_BOOL
default "0x80000000"
endmenu
menu "Bus Options"
config PCI_XILINX
bool "Xilinx PCI host bridge support"
depends on PCI
endmenu