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Diffstat (limited to 'arch/nds32/Kconfig.cpu')
| -rw-r--r-- | arch/nds32/Kconfig.cpu | 217 |
1 files changed, 217 insertions, 0 deletions
diff --git a/arch/nds32/Kconfig.cpu b/arch/nds32/Kconfig.cpu new file mode 100644 index 000000000..f88a12fdf --- /dev/null +++ b/arch/nds32/Kconfig.cpu @@ -0,0 +1,217 @@ +# SPDX-License-Identifier: GPL-2.0-only +comment "Processor Features" + +config CPU_BIG_ENDIAN + def_bool !CPU_LITTLE_ENDIAN + +config CPU_LITTLE_ENDIAN + bool "Little endian" + default y + +config FPU + bool "FPU support" + default n + help + If FPU ISA is used in user space, this configuration shall be Y to + enable required support in kernel such as fpu context switch and + fpu exception handler. + + If no FPU ISA is used in user space, say N. + +config LAZY_FPU + bool "lazy FPU support" + depends on FPU + default y + help + Say Y here to enable the lazy FPU scheme. The lazy FPU scheme can + enhance system performance by reducing the context switch + frequency of the FPU register. + + For normal case, say Y. + +config SUPPORT_DENORMAL_ARITHMETIC + bool "Denormal arithmetic support" + depends on FPU + default n + help + Say Y here to enable arithmetic of denormalized number. Enabling + this feature can enhance the precision for tininess number. + However, performance loss in float point calculations is + possibly significant due to additional FPU exception. + + If the calculated tolerance for tininess number is not critical, + say N to prevent performance loss. + +config HWZOL + bool "hardware zero overhead loop support" + depends on CPU_D10 || CPU_D15 + default n + help + A set of Zero-Overhead Loop mechanism is provided to reduce the + instruction fetch and execution overhead of loop-control instructions. + It will save 3 registers($LB, $LC, $LE) for context saving if say Y. + You don't need to save these registers if you can make sure your user + program doesn't use these registers. + + If unsure, say N. + +config CPU_CACHE_ALIASING + bool "Aliasing cache" + depends on CPU_N10 || CPU_D10 || CPU_N13 || CPU_V3 + default y + help + If this CPU is using VIPT data cache and its cache way size is larger + than page size, say Y. If it is using PIPT data cache, say N. + + If unsure, say Y. + +choice + prompt "minimum CPU type" + default CPU_V3 + help + The data cache of N15/D15 is implemented as PIPT and it will not cause + the cache aliasing issue. The rest cpus(N13, N10 and D10) are + implemented as VIPT data cache. It may cause the cache aliasing issue + if its cache way size is larger than page size. You can specify the + CPU type directly or choose CPU_V3 if unsure. + + A kernel built for N10 is able to run on N15, D15, N13, N10 or D10. + A kernel built for N15 is able to run on N15 or D15. + A kernel built for D10 is able to run on D10 or D15. + A kernel built for D15 is able to run on D15. + A kernel built for N13 is able to run on N15, N13 or D15. + +config CPU_N15 + bool "AndesCore N15" +config CPU_N13 + bool "AndesCore N13" + select CPU_CACHE_ALIASING if ANDES_PAGE_SIZE_4KB +config CPU_N10 + bool "AndesCore N10" + select CPU_CACHE_ALIASING +config CPU_D15 + bool "AndesCore D15" +config CPU_D10 + bool "AndesCore D10" + select CPU_CACHE_ALIASING +config CPU_V3 + bool "AndesCore v3 compatible" + select CPU_CACHE_ALIASING +endchoice +choice + prompt "Paging -- page size " + default ANDES_PAGE_SIZE_4KB +config ANDES_PAGE_SIZE_4KB + bool "use 4KB page size" +config ANDES_PAGE_SIZE_8KB + bool "use 8KB page size" +endchoice + +config CPU_ICACHE_DISABLE + bool "Disable I-Cache" + help + Say Y here to disable the processor instruction cache. Unless + you have a reason not to or are unsure, say N. + +config CPU_DCACHE_DISABLE + bool "Disable D-Cache" + help + Say Y here to disable the processor data cache. Unless + you have a reason not to or are unsure, say N. + +config CPU_DCACHE_WRITETHROUGH + bool "Force write through D-cache" + depends on !CPU_DCACHE_DISABLE + help + Say Y here to use the data cache in writethrough mode. Unless you + specifically require this or are unsure, say N. + +config WBNA + bool "WBNA" + default n + help + Say Y here to enable write-back memory with no-write-allocation policy. + +config ALIGNMENT_TRAP + bool "Kernel support unaligned access handling by sw" + depends on PROC_FS + default n + help + Andes processors cannot load/store information which is not + naturally aligned on the bus, i.e., a 4 byte load must start at an + address divisible by 4. On 32-bit Andes processors, these non-aligned + load/store instructions will be emulated in software if you say Y + here, which has a severe performance impact. With an IP-only + configuration it is safe to say N, otherwise say Y. + +config HW_SUPPORT_UNALIGNMENT_ACCESS + bool "Kernel support unaligned access handling by hw" + depends on !ALIGNMENT_TRAP + default n + help + Andes processors load/store world/half-word instructions can access + unaligned memory locations without generating the Data Alignment + Check exceptions. With an IP-only configuration it is safe to say N, + otherwise say Y. + +config HIGHMEM + bool "High Memory Support" + depends on MMU && !CPU_CACHE_ALIASING + help + The address space of Andes 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". + + Depending on the selected kernel/user memory split, minimum + vmalloc space and actual amount of RAM, you may not need this + option which should result in a slightly faster kernel. + + If unsure, say N. + +config CACHE_L2 + bool "Support L2 cache" + default y + help + Say Y here to enable L2 cache if your SoC are integrated with L2CC. + If unsure, say N. + +config HW_PRE + bool "Enable hardware prefetcher" + default y + help + Say Y here to enable hardware prefetcher feature. + Only when CPU_VER.REV >= 0x09 can support. + +menu "Memory configuration" + +choice + prompt "Memory split" + depends on MMU + default VMSPLIT_3G_OPT + help + Select the desired split between kernel and user memory. + + If you are not absolutely sure what you are doing, leave this + option alone! + + config VMSPLIT_3G + bool "3G/1G user/kernel split" + config VMSPLIT_3G_OPT + bool "3G/1G user/kernel split (for full 1G low memory)" + config VMSPLIT_2G + bool "2G/2G user/kernel split" + config VMSPLIT_1G + bool "1G/3G user/kernel split" +endchoice + +config PAGE_OFFSET + hex + default 0x40000000 if VMSPLIT_1G + default 0x80000000 if VMSPLIT_2G + default 0xB0000000 if VMSPLIT_3G_OPT + default 0xC0000000 + +endmenu |