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
84 bool "Support 32-bit physical addressing through PMB"
85 depends on MMU && EXPERIMENTAL && (CPU_SUBTYPE_SH7757 || CPU_SUBTYPE_SH7780 || CPU_SUBTYPE_SH7785)
89 If you say Y here, physical addressing will be extended to
90 32-bits through the SH-4A PMB. If this is not set, legacy
91 29-bit physical addressing will be used.
94 prompt "PMB handling type"
100 depends on MMU && EXPERIMENTAL && (CPU_SUBTYPE_SH7757 || CPU_SUBTYPE_SH7780 || CPU_SUBTYPE_SH7785)
103 If you say Y here, physical addressing will be extended to
104 32-bits through the SH-4A PMB. If this is not set, legacy
105 29-bit physical addressing will be used.
109 depends on MMU && EXPERIMENTAL && (CPU_SUBTYPE_SH7757 || \
110 CPU_SUBTYPE_SH7780 || \
114 If this option is enabled, fixed PMB mappings are inherited
115 from the boot loader, and the kernel does not attempt dynamic
116 management. This is the closest to legacy 29-bit physical mode,
117 and allows systems to support up to 512MiB of system memory.
122 bool "Enable extended TLB mode"
123 depends on (CPU_SHX2 || CPU_SHX3) && MMU && EXPERIMENTAL
125 Selecting this option will enable the extended mode of the SH-X2
126 TLB. For legacy SH-X behaviour and interoperability, say N. For
127 all of the fun new features and a willingless to submit bug reports,
131 bool "Support vsyscall page"
132 depends on MMU && (CPU_SH3 || CPU_SH4)
135 This will enable support for the kernel mapping a vDSO page
136 in process space, and subsequently handing down the entry point
137 to the libc through the ELF auxiliary vector.
139 From the kernel side this is used for the signal trampoline.
140 For systems with an MMU that can afford to give up a page,
141 (the default value) say Y.
144 bool "Non Uniform Memory Access (NUMA) Support"
145 depends on MMU && SYS_SUPPORTS_NUMA && EXPERIMENTAL
148 Some SH systems have many various memories scattered around
149 the address space, each with varying latencies. This enables
150 support for these blocks by binding them to nodes and allowing
151 memory policies to be used for prioritizing and controlling
152 allocation behaviour.
156 default "3" if CPU_SUBTYPE_SHX3
158 depends on NEED_MULTIPLE_NODES
160 config ARCH_FLATMEM_ENABLE
164 config ARCH_SPARSEMEM_ENABLE
166 select SPARSEMEM_STATIC
168 config ARCH_SPARSEMEM_DEFAULT
171 config MAX_ACTIVE_REGIONS
173 default "6" if (CPU_SUBTYPE_SHX3 && SPARSEMEM)
174 default "2" if SPARSEMEM && (CPU_SUBTYPE_SH7722 || \
178 config ARCH_POPULATES_NODE_MAP
181 config ARCH_SELECT_MEMORY_MODEL
184 config ARCH_ENABLE_MEMORY_HOTPLUG
186 depends on SPARSEMEM && MMU
188 config ARCH_ENABLE_MEMORY_HOTREMOVE
190 depends on SPARSEMEM && MMU
192 config ARCH_MEMORY_PROBE
194 depends on MEMORY_HOTPLUG
197 prompt "Kernel page size"
198 default PAGE_SIZE_8KB if X2TLB
199 default PAGE_SIZE_4KB
203 depends on !MMU || !X2TLB
205 This is the default page size used by all SuperH CPUs.
209 depends on !MMU || X2TLB
211 This enables 8kB pages as supported by SH-X2 and later MMUs.
213 config PAGE_SIZE_16KB
217 This enables 16kB pages on MMU-less SH systems.
219 config PAGE_SIZE_64KB
221 depends on !MMU || CPU_SH4 || CPU_SH5
223 This enables support for 64kB pages, possible on all SH-4
229 prompt "HugeTLB page size"
230 depends on HUGETLB_PAGE && (CPU_SH4 || CPU_SH5) && MMU
231 default HUGETLB_PAGE_SIZE_1MB if PAGE_SIZE_64KB
232 default HUGETLB_PAGE_SIZE_64K
234 config HUGETLB_PAGE_SIZE_64K
236 depends on !PAGE_SIZE_64KB
238 config HUGETLB_PAGE_SIZE_256K
242 config HUGETLB_PAGE_SIZE_1MB
245 config HUGETLB_PAGE_SIZE_4MB
249 config HUGETLB_PAGE_SIZE_64MB
253 config HUGETLB_PAGE_SIZE_512MB
263 menu "Cache configuration"
265 config SH7705_CACHE_32KB
266 bool "Enable 32KB cache size for SH7705"
267 depends on CPU_SUBTYPE_SH7705
272 default CACHE_WRITEBACK if CPU_SH2A || CPU_SH3 || CPU_SH4 || CPU_SH5
273 default CACHE_WRITETHROUGH if (CPU_SH2 && !CPU_SH2A)
275 config CACHE_WRITEBACK
278 config CACHE_WRITETHROUGH
281 Selecting this option will configure the caches in write-through
282 mode, as opposed to the default write-back configuration.
284 Since there's sill some aliasing issues on SH-4, this option will
285 unfortunately still require the majority of flushing functions to
286 be implemented to deal with aliasing.