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 && EXPERIMENTAL && 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 && EXPERIMENTAL
116 Some SH systems have many various memories scattered around
117 the address space, each with varying latencies. This enables
118 support for these blocks by binding them to nodes and allowing
119 memory policies to be used for prioritizing and controlling
120 allocation behaviour.
124 default "3" if CPU_SUBTYPE_SHX3
126 depends on NEED_MULTIPLE_NODES
128 config ARCH_FLATMEM_ENABLE
132 config ARCH_SPARSEMEM_ENABLE
134 select SPARSEMEM_STATIC
136 config ARCH_SPARSEMEM_DEFAULT
139 config MAX_ACTIVE_REGIONS
141 default "6" if (CPU_SUBTYPE_SHX3 && SPARSEMEM)
142 default "2" if SPARSEMEM && (CPU_SUBTYPE_SH7722 || \
146 config ARCH_SELECT_MEMORY_MODEL
149 config ARCH_ENABLE_MEMORY_HOTPLUG
151 depends on SPARSEMEM && MMU
153 config ARCH_ENABLE_MEMORY_HOTREMOVE
155 depends on SPARSEMEM && MMU
157 config ARCH_MEMORY_PROBE
159 depends on MEMORY_HOTPLUG
163 depends on X2TLB || SUPERH64
165 config UNCACHED_MAPPING
168 config HAVE_SRAM_POOL
170 select GENERIC_ALLOCATOR
173 prompt "Kernel page size"
174 default PAGE_SIZE_4KB
179 This is the default page size used by all SuperH CPUs.
183 depends on !MMU || X2TLB
185 This enables 8kB pages as supported by SH-X2 and later MMUs.
187 config PAGE_SIZE_16KB
191 This enables 16kB pages on MMU-less SH systems.
193 config PAGE_SIZE_64KB
195 depends on !MMU || CPU_SH4 || CPU_SH5
197 This enables support for 64kB pages, possible on all SH-4
203 prompt "HugeTLB page size"
204 depends on HUGETLB_PAGE
205 default HUGETLB_PAGE_SIZE_1MB if PAGE_SIZE_64KB
206 default HUGETLB_PAGE_SIZE_64K
208 config HUGETLB_PAGE_SIZE_64K
210 depends on !PAGE_SIZE_64KB
212 config HUGETLB_PAGE_SIZE_256K
216 config HUGETLB_PAGE_SIZE_1MB
219 config HUGETLB_PAGE_SIZE_4MB
223 config HUGETLB_PAGE_SIZE_64MB
227 config HUGETLB_PAGE_SIZE_512MB
236 bool "Multi-core scheduler support"
240 Multi-core scheduler support improves the CPU scheduler's decision
241 making when dealing with multi-core CPU chips at a cost of slightly
242 increased overhead in some places. If unsure say N here.
246 menu "Cache configuration"
248 config SH7705_CACHE_32KB
249 bool "Enable 32KB cache size for SH7705"
250 depends on CPU_SUBTYPE_SH7705
255 default CACHE_WRITEBACK if CPU_SH2A || CPU_SH3 || CPU_SH4 || CPU_SH5
256 default CACHE_WRITETHROUGH if (CPU_SH2 && !CPU_SH2A)
258 config CACHE_WRITEBACK
261 config CACHE_WRITETHROUGH
264 Selecting this option will configure the caches in write-through
265 mode, as opposed to the default write-back configuration.
267 Since there's sill some aliasing issues on SH-4, this option will
268 unfortunately still require the majority of flushing functions to
269 be implemented to deal with aliasing.