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)
88 If you say Y here, physical addressing will be extended to
89 32-bits through the SH-4A PMB. If this is not set, legacy
90 29-bit physical addressing will be used.
93 prompt "PMB handling type"
99 depends on MMU && EXPERIMENTAL && (CPU_SUBTYPE_SH7757 || CPU_SUBTYPE_SH7780 || CPU_SUBTYPE_SH7785)
101 If you say Y here, physical addressing will be extended to
102 32-bits through the SH-4A PMB. If this is not set, legacy
103 29-bit physical addressing will be used.
107 depends on MMU && EXPERIMENTAL && (CPU_SUBTYPE_SH7757 || \
108 CPU_SUBTYPE_SH7780 || \
112 If this option is enabled, fixed PMB mappings are inherited
113 from the boot loader, and the kernel does not attempt dynamic
114 management. This is the closest to legacy 29-bit physical mode,
115 and allows systems to support up to 512MiB of system memory.
120 bool "Enable extended TLB mode"
121 depends on (CPU_SHX2 || CPU_SHX3) && MMU && EXPERIMENTAL
123 Selecting this option will enable the extended mode of the SH-X2
124 TLB. For legacy SH-X behaviour and interoperability, say N. For
125 all of the fun new features and a willingless to submit bug reports,
129 bool "Support vsyscall page"
130 depends on MMU && (CPU_SH3 || CPU_SH4)
133 This will enable support for the kernel mapping a vDSO page
134 in process space, and subsequently handing down the entry point
135 to the libc through the ELF auxiliary vector.
137 From the kernel side this is used for the signal trampoline.
138 For systems with an MMU that can afford to give up a page,
139 (the default value) say Y.
142 bool "Non Uniform Memory Access (NUMA) Support"
143 depends on MMU && SYS_SUPPORTS_NUMA && EXPERIMENTAL
146 Some SH systems have many various memories scattered around
147 the address space, each with varying latencies. This enables
148 support for these blocks by binding them to nodes and allowing
149 memory policies to be used for prioritizing and controlling
150 allocation behaviour.
154 default "3" if CPU_SUBTYPE_SHX3
156 depends on NEED_MULTIPLE_NODES
158 config ARCH_FLATMEM_ENABLE
162 config ARCH_SPARSEMEM_ENABLE
164 select SPARSEMEM_STATIC
166 config ARCH_SPARSEMEM_DEFAULT
169 config MAX_ACTIVE_REGIONS
171 default "6" if (CPU_SUBTYPE_SHX3 && SPARSEMEM)
172 default "2" if SPARSEMEM && (CPU_SUBTYPE_SH7722 || \
176 config ARCH_POPULATES_NODE_MAP
179 config ARCH_SELECT_MEMORY_MODEL
182 config ARCH_ENABLE_MEMORY_HOTPLUG
184 depends on SPARSEMEM && MMU
186 config ARCH_ENABLE_MEMORY_HOTREMOVE
188 depends on SPARSEMEM && MMU
190 config ARCH_MEMORY_PROBE
192 depends on MEMORY_HOTPLUG
195 prompt "Kernel page size"
196 default PAGE_SIZE_8KB if X2TLB
197 default PAGE_SIZE_4KB
201 depends on !MMU || !X2TLB
203 This is the default page size used by all SuperH CPUs.
207 depends on !MMU || X2TLB
209 This enables 8kB pages as supported by SH-X2 and later MMUs.
211 config PAGE_SIZE_16KB
215 This enables 16kB pages on MMU-less SH systems.
217 config PAGE_SIZE_64KB
219 depends on !MMU || CPU_SH4 || CPU_SH5
221 This enables support for 64kB pages, possible on all SH-4
227 prompt "HugeTLB page size"
228 depends on HUGETLB_PAGE && (CPU_SH4 || CPU_SH5) && MMU
229 default HUGETLB_PAGE_SIZE_1MB if PAGE_SIZE_64KB
230 default HUGETLB_PAGE_SIZE_64K
232 config HUGETLB_PAGE_SIZE_64K
234 depends on !PAGE_SIZE_64KB
236 config HUGETLB_PAGE_SIZE_256K
240 config HUGETLB_PAGE_SIZE_1MB
243 config HUGETLB_PAGE_SIZE_4MB
247 config HUGETLB_PAGE_SIZE_64MB
251 config HUGETLB_PAGE_SIZE_512MB
261 menu "Cache configuration"
263 config SH7705_CACHE_32KB
264 bool "Enable 32KB cache size for SH7705"
265 depends on CPU_SUBTYPE_SH7705
270 default CACHE_WRITEBACK if CPU_SH2A || CPU_SH3 || CPU_SH4 || CPU_SH5
271 default CACHE_WRITETHROUGH if (CPU_SH2 && !CPU_SH2A)
273 config CACHE_WRITEBACK
276 config CACHE_WRITETHROUGH
279 Selecting this option will configure the caches in write-through
280 mode, as opposed to the default write-back configuration.
282 Since there's sill some aliasing issues on SH-4, this option will
283 unfortunately still require the majority of flushing functions to
284 be implemented to deal with aliasing.