xref: /openbmc/linux/arch/sh/mm/Kconfig (revision b830f94f) 
1# SPDX-License-Identifier: GPL-2.0
2menu "Memory management options"
3
4config QUICKLIST
5	def_bool y
6
7config MMU
8        bool "Support for memory management hardware"
9	depends on !CPU_SH2
10	default y
11	help
12	  Some SH processors (such as SH-2/SH-2A) lack an MMU. In order to
13	  boot on these systems, this option must not be set.
14
15	  On other systems (such as the SH-3 and 4) where an MMU exists,
16	  turning this off will boot the kernel on these machines with the
17	  MMU implicitly switched off.
18
19config PAGE_OFFSET
20	hex
21	default "0x80000000" if MMU && SUPERH32
22	default "0x20000000" if MMU && SUPERH64
23	default "0x00000000"
24
25config FORCE_MAX_ZONEORDER
26	int "Maximum zone order"
27	range 9 64 if PAGE_SIZE_16KB
28	default "9" if PAGE_SIZE_16KB
29	range 7 64 if PAGE_SIZE_64KB
30	default "7" if PAGE_SIZE_64KB
31	range 11 64
32	default "14" if !MMU
33	default "11"
34	help
35	  The kernel memory allocator divides physically contiguous memory
36	  blocks into "zones", where each zone is a power of two number of
37	  pages.  This option selects the largest power of two that the kernel
38	  keeps in the memory allocator.  If you need to allocate very large
39	  blocks of physically contiguous memory, then you may need to
40	  increase this value.
41
42	  This config option is actually maximum order plus one. For example,
43	  a value of 11 means that the largest free memory block is 2^10 pages.
44
45	  The page size is not necessarily 4KB. Keep this in mind when
46	  choosing a value for this option.
47
48config MEMORY_START
49	hex "Physical memory start address"
50	default "0x08000000"
51	---help---
52	  Computers built with Hitachi SuperH processors always
53	  map the ROM starting at address zero.  But the processor
54	  does not specify the range that RAM takes.
55
56	  The physical memory (RAM) start address will be automatically
57	  set to 08000000. Other platforms, such as the Solution Engine
58	  boards typically map RAM at 0C000000.
59
60	  Tweak this only when porting to a new machine which does not
61	  already have a defconfig. Changing it from the known correct
62	  value on any of the known systems will only lead to disaster.
63
64config MEMORY_SIZE
65	hex "Physical memory size"
66	default "0x04000000"
67	help
68	  This sets the default memory size assumed by your SH kernel. It can
69	  be overridden as normal by the 'mem=' argument on the kernel command
70	  line. If unsure, consult your board specifications or just leave it
71	  as 0x04000000 which was the default value before this became
72	  configurable.
73
74# Physical addressing modes
75
76config 29BIT
77	def_bool !32BIT
78	depends on SUPERH32
79	select UNCACHED_MAPPING
80
81config 32BIT
82	bool
83	default y if CPU_SH5 || !MMU
84
85config PMB
86	bool "Support 32-bit physical addressing through PMB"
87	depends on MMU && CPU_SH4A && !CPU_SH4AL_DSP
88	select 32BIT
89	select UNCACHED_MAPPING
90	help
91	  If you say Y here, physical addressing will be extended to
92	  32-bits through the SH-4A PMB. If this is not set, legacy
93	  29-bit physical addressing will be used.
94
95config X2TLB
96	def_bool y
97	depends on (CPU_SHX2 || CPU_SHX3) && MMU
98
99config VSYSCALL
100	bool "Support vsyscall page"
101	depends on MMU && (CPU_SH3 || CPU_SH4)
102	default y
103	help
104	  This will enable support for the kernel mapping a vDSO page
105	  in process space, and subsequently handing down the entry point
106	  to the libc through the ELF auxiliary vector.
107
108	  From the kernel side this is used for the signal trampoline.
109	  For systems with an MMU that can afford to give up a page,
110	  (the default value) say Y.
111
112config NUMA
113	bool "Non Uniform Memory Access (NUMA) Support"
114	depends on MMU && SYS_SUPPORTS_NUMA
115	select ARCH_WANT_NUMA_VARIABLE_LOCALITY
116	default n
117	help
118	  Some SH systems have many various memories scattered around
119	  the address space, each with varying latencies. This enables
120	  support for these blocks by binding them to nodes and allowing
121	  memory policies to be used for prioritizing and controlling
122	  allocation behaviour.
123
124config NODES_SHIFT
125	int
126	default "3" if CPU_SUBTYPE_SHX3
127	default "1"
128	depends on NEED_MULTIPLE_NODES
129
130config ARCH_FLATMEM_ENABLE
131	def_bool y
132	depends on !NUMA
133
134config ARCH_SPARSEMEM_ENABLE
135	def_bool y
136	select SPARSEMEM_STATIC
137
138config ARCH_SPARSEMEM_DEFAULT
139	def_bool y
140
141config ARCH_SELECT_MEMORY_MODEL
142	def_bool y
143
144config ARCH_ENABLE_MEMORY_HOTPLUG
145	def_bool y
146	depends on SPARSEMEM && MMU
147
148config ARCH_ENABLE_MEMORY_HOTREMOVE
149	def_bool y
150	depends on SPARSEMEM && MMU
151
152config ARCH_MEMORY_PROBE
153	def_bool y
154	depends on MEMORY_HOTPLUG
155
156config IOREMAP_FIXED
157       def_bool y
158       depends on X2TLB || SUPERH64
159
160config UNCACHED_MAPPING
161	bool
162
163config HAVE_SRAM_POOL
164	bool
165	select GENERIC_ALLOCATOR
166
167choice
168	prompt "Kernel page size"
169	default PAGE_SIZE_4KB
170
171config PAGE_SIZE_4KB
172	bool "4kB"
173	help
174	  This is the default page size used by all SuperH CPUs.
175
176config PAGE_SIZE_8KB
177	bool "8kB"
178	depends on !MMU || X2TLB
179	help
180	  This enables 8kB pages as supported by SH-X2 and later MMUs.
181
182config PAGE_SIZE_16KB
183	bool "16kB"
184	depends on !MMU
185	help
186	  This enables 16kB pages on MMU-less SH systems.
187
188config PAGE_SIZE_64KB
189	bool "64kB"
190	depends on !MMU || CPU_SH4 || CPU_SH5
191	help
192	  This enables support for 64kB pages, possible on all SH-4
193	  CPUs and later.
194
195endchoice
196
197choice
198	prompt "HugeTLB page size"
199	depends on HUGETLB_PAGE
200	default HUGETLB_PAGE_SIZE_1MB if PAGE_SIZE_64KB
201	default HUGETLB_PAGE_SIZE_64K
202
203config HUGETLB_PAGE_SIZE_64K
204	bool "64kB"
205	depends on !PAGE_SIZE_64KB
206
207config HUGETLB_PAGE_SIZE_256K
208	bool "256kB"
209	depends on X2TLB
210
211config HUGETLB_PAGE_SIZE_1MB
212	bool "1MB"
213
214config HUGETLB_PAGE_SIZE_4MB
215	bool "4MB"
216	depends on X2TLB
217
218config HUGETLB_PAGE_SIZE_64MB
219	bool "64MB"
220	depends on X2TLB
221
222config HUGETLB_PAGE_SIZE_512MB
223	bool "512MB"
224	depends on CPU_SH5
225
226endchoice
227
228config SCHED_MC
229	bool "Multi-core scheduler support"
230	depends on SMP
231	default y
232	help
233	  Multi-core scheduler support improves the CPU scheduler's decision
234	  making when dealing with multi-core CPU chips at a cost of slightly
235	  increased overhead in some places. If unsure say N here.
236
237endmenu
238
239menu "Cache configuration"
240
241config SH7705_CACHE_32KB
242	bool "Enable 32KB cache size for SH7705"
243	depends on CPU_SUBTYPE_SH7705
244	default y
245
246choice
247	prompt "Cache mode"
248	default CACHE_WRITEBACK if CPU_SH2A || CPU_SH3 || CPU_SH4 || CPU_SH5
249	default CACHE_WRITETHROUGH if (CPU_SH2 && !CPU_SH2A)
250
251config CACHE_WRITEBACK
252	bool "Write-back"
253
254config CACHE_WRITETHROUGH
255	bool "Write-through"
256	help
257	  Selecting this option will configure the caches in write-through
258	  mode, as opposed to the default write-back configuration.
259
260	  Since there's sill some aliasing issues on SH-4, this option will
261	  unfortunately still require the majority of flushing functions to
262	  be implemented to deal with aliasing.
263
264	  If unsure, say N.
265
266config CACHE_OFF
267	bool "Off"
268
269endchoice
270
271endmenu
272