1 menu "Memory management options"
7 bool "Support for memory management hardware"
11 Some SH processors (such as SH-2/SH-2A) lack an MMU. In order to
12 boot on these systems, this option must not be set.
14 On other systems (such as the SH-3 and 4) where an MMU exists,
15 turning this off will boot the kernel on these machines with the
16 MMU implicitly switched off.
20 default "0x80000000" if MMU && SUPERH32
21 default "0x20000000" if MMU && SUPERH64
24 config FORCE_MAX_ZONEORDER
25 int "Maximum zone order"
26 range 9 64 if PAGE_SIZE_16KB
27 default "9" if PAGE_SIZE_16KB
28 range 7 64 if PAGE_SIZE_64KB
29 default "7" if PAGE_SIZE_64KB
34 The kernel memory allocator divides physically contiguous memory
35 blocks into "zones", where each zone is a power of two number of
36 pages. This option selects the largest power of two that the kernel
37 keeps in the memory allocator. If you need to allocate very large
38 blocks of physically contiguous memory, then you may need to
41 This config option is actually maximum order plus one. For example,
42 a value of 11 means that the largest free memory block is 2^10 pages.
44 The page size is not necessarily 4KB. Keep this in mind when
45 choosing a value for this option.
48 hex "Physical memory start address"
51 Computers built with Hitachi SuperH processors always
52 map the ROM starting at address zero. But the processor
53 does not specify the range that RAM takes.
55 The physical memory (RAM) start address will be automatically
56 set to 08000000. Other platforms, such as the Solution Engine
57 boards typically map RAM at 0C000000.
59 Tweak this only when porting to a new machine which does not
60 already have a defconfig. Changing it from the known correct
61 value on any of the known systems will only lead to disaster.
64 hex "Physical memory size"
67 This sets the default memory size assumed by your SH kernel. It can
68 be overridden as normal by the 'mem=' argument on the kernel command
69 line. If unsure, consult your board specifications or just leave it
70 as 0x04000000 which was the default value before this became
73 # Physical addressing modes
78 select UNCACHED_MAPPING
82 default y if CPU_SH5 || !MMU
85 bool "Support 32-bit physical addressing through PMB"
86 depends on MMU && CPU_SH4A && !CPU_SH4AL_DSP
88 select UNCACHED_MAPPING
90 If you say Y here, physical addressing will be extended to
91 32-bits through the SH-4A PMB. If this is not set, legacy
92 29-bit physical addressing will be used.
96 depends on (CPU_SHX2 || CPU_SHX3) && MMU
99 bool "Support vsyscall page"
100 depends on MMU && (CPU_SH3 || CPU_SH4)
103 This will enable support for the kernel mapping a vDSO page
104 in process space, and subsequently handing down the entry point
105 to the libc through the ELF auxiliary vector.
107 From the kernel side this is used for the signal trampoline.
108 For systems with an MMU that can afford to give up a page,
109 (the default value) say Y.
112 bool "Non Uniform Memory Access (NUMA) Support"
113 depends on MMU && SYS_SUPPORTS_NUMA
114 select ARCH_WANT_NUMA_VARIABLE_LOCALITY
117 Some SH systems have many various memories scattered around
118 the address space, each with varying latencies. This enables
119 support for these blocks by binding them to nodes and allowing
120 memory policies to be used for prioritizing and controlling
121 allocation behaviour.
125 default "3" if CPU_SUBTYPE_SHX3
127 depends on NEED_MULTIPLE_NODES
129 config ARCH_FLATMEM_ENABLE
133 config ARCH_SPARSEMEM_ENABLE
135 select SPARSEMEM_STATIC
137 config ARCH_SPARSEMEM_DEFAULT
140 config ARCH_SELECT_MEMORY_MODEL
143 config ARCH_ENABLE_MEMORY_HOTPLUG
145 depends on SPARSEMEM && MMU
147 config ARCH_ENABLE_MEMORY_HOTREMOVE
149 depends on SPARSEMEM && MMU
151 config ARCH_MEMORY_PROBE
153 depends on MEMORY_HOTPLUG
157 depends on X2TLB || SUPERH64
159 config UNCACHED_MAPPING
162 config HAVE_SRAM_POOL
164 select GENERIC_ALLOCATOR
167 prompt "Kernel page size"
168 default PAGE_SIZE_4KB
173 This is the default page size used by all SuperH CPUs.
177 depends on !MMU || X2TLB
179 This enables 8kB pages as supported by SH-X2 and later MMUs.
181 config PAGE_SIZE_16KB
185 This enables 16kB pages on MMU-less SH systems.
187 config PAGE_SIZE_64KB
189 depends on !MMU || CPU_SH4 || CPU_SH5
191 This enables support for 64kB pages, possible on all SH-4
197 prompt "HugeTLB page size"
198 depends on HUGETLB_PAGE
199 default HUGETLB_PAGE_SIZE_1MB if PAGE_SIZE_64KB
200 default HUGETLB_PAGE_SIZE_64K
202 config HUGETLB_PAGE_SIZE_64K
204 depends on !PAGE_SIZE_64KB
206 config HUGETLB_PAGE_SIZE_256K
210 config HUGETLB_PAGE_SIZE_1MB
213 config HUGETLB_PAGE_SIZE_4MB
217 config HUGETLB_PAGE_SIZE_64MB
221 config HUGETLB_PAGE_SIZE_512MB
230 bool "Multi-core scheduler support"
234 Multi-core scheduler support improves the CPU scheduler's decision
235 making when dealing with multi-core CPU chips at a cost of slightly
236 increased overhead in some places. If unsure say N here.
240 menu "Cache configuration"
242 config SH7705_CACHE_32KB
243 bool "Enable 32KB cache size for SH7705"
244 depends on CPU_SUBTYPE_SH7705
249 default CACHE_WRITEBACK if CPU_SH2A || CPU_SH3 || CPU_SH4 || CPU_SH5
250 default CACHE_WRITETHROUGH if (CPU_SH2 && !CPU_SH2A)
252 config CACHE_WRITEBACK
255 config CACHE_WRITETHROUGH
258 Selecting this option will configure the caches in write-through
259 mode, as opposed to the default write-back configuration.
261 Since there's sill some aliasing issues on SH-4, this option will
262 unfortunately still require the majority of flushing functions to
263 be implemented to deal with aliasing.