xref: /openbmc/linux/arch/sh/mm/Kconfig (revision a44e4f3a) 
1# SPDX-License-Identifier: GPL-2.0
2menu "Memory management options"
3
4config MMU
5        bool "Support for memory management hardware"
6	depends on !CPU_SH2
7	default y
8	help
9	  Some SH processors (such as SH-2/SH-2A) lack an MMU. In order to
10	  boot on these systems, this option must not be set.
11
12	  On other systems (such as the SH-3 and 4) where an MMU exists,
13	  turning this off will boot the kernel on these machines with the
14	  MMU implicitly switched off.
15
16config PAGE_OFFSET
17	hex
18	default "0x80000000" if MMU && SUPERH32
19	default "0x20000000" if MMU && SUPERH64
20	default "0x00000000"
21
22config FORCE_MAX_ZONEORDER
23	int "Maximum zone order"
24	range 9 64 if PAGE_SIZE_16KB
25	default "9" if PAGE_SIZE_16KB
26	range 7 64 if PAGE_SIZE_64KB
27	default "7" if PAGE_SIZE_64KB
28	range 11 64
29	default "14" if !MMU
30	default "11"
31	help
32	  The kernel memory allocator divides physically contiguous memory
33	  blocks into "zones", where each zone is a power of two number of
34	  pages.  This option selects the largest power of two that the kernel
35	  keeps in the memory allocator.  If you need to allocate very large
36	  blocks of physically contiguous memory, then you may need to
37	  increase this value.
38
39	  This config option is actually maximum order plus one. For example,
40	  a value of 11 means that the largest free memory block is 2^10 pages.
41
42	  The page size is not necessarily 4KB. Keep this in mind when
43	  choosing a value for this option.
44
45config MEMORY_START
46	hex "Physical memory start address"
47	default "0x08000000"
48	---help---
49	  Computers built with Hitachi SuperH processors always
50	  map the ROM starting at address zero.  But the processor
51	  does not specify the range that RAM takes.
52
53	  The physical memory (RAM) start address will be automatically
54	  set to 08000000. Other platforms, such as the Solution Engine
55	  boards typically map RAM at 0C000000.
56
57	  Tweak this only when porting to a new machine which does not
58	  already have a defconfig. Changing it from the known correct
59	  value on any of the known systems will only lead to disaster.
60
61config MEMORY_SIZE
62	hex "Physical memory size"
63	default "0x04000000"
64	help
65	  This sets the default memory size assumed by your SH kernel. It can
66	  be overridden as normal by the 'mem=' argument on the kernel command
67	  line. If unsure, consult your board specifications or just leave it
68	  as 0x04000000 which was the default value before this became
69	  configurable.
70
71# Physical addressing modes
72
73config 29BIT
74	def_bool !32BIT
75	depends on SUPERH32
76	select UNCACHED_MAPPING
77
78config 32BIT
79	bool
80	default y if CPU_SH5 || !MMU
81
82config PMB
83	bool "Support 32-bit physical addressing through PMB"
84	depends on MMU && CPU_SH4A && !CPU_SH4AL_DSP
85	select 32BIT
86	select UNCACHED_MAPPING
87	help
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.
91
92config X2TLB
93	def_bool y
94	depends on (CPU_SHX2 || CPU_SHX3) && MMU
95
96config VSYSCALL
97	bool "Support vsyscall page"
98	depends on MMU && (CPU_SH3 || CPU_SH4)
99	default y
100	help
101	  This will enable support for the kernel mapping a vDSO page
102	  in process space, and subsequently handing down the entry point
103	  to the libc through the ELF auxiliary vector.
104
105	  From the kernel side this is used for the signal trampoline.
106	  For systems with an MMU that can afford to give up a page,
107	  (the default value) say Y.
108
109config NUMA
110	bool "Non Uniform Memory Access (NUMA) Support"
111	depends on MMU && SYS_SUPPORTS_NUMA
112	select ARCH_WANT_NUMA_VARIABLE_LOCALITY
113	default n
114	help
115	  Some SH systems have many various memories scattered around
116	  the address space, each with varying latencies. This enables
117	  support for these blocks by binding them to nodes and allowing
118	  memory policies to be used for prioritizing and controlling
119	  allocation behaviour.
120
121config NODES_SHIFT
122	int
123	default "3" if CPU_SUBTYPE_SHX3
124	default "1"
125	depends on NEED_MULTIPLE_NODES
126
127config ARCH_FLATMEM_ENABLE
128	def_bool y
129	depends on !NUMA
130
131config ARCH_SPARSEMEM_ENABLE
132	def_bool y
133	select SPARSEMEM_STATIC
134
135config ARCH_SPARSEMEM_DEFAULT
136	def_bool y
137
138config ARCH_SELECT_MEMORY_MODEL
139	def_bool y
140
141config ARCH_ENABLE_MEMORY_HOTPLUG
142	def_bool y
143	depends on SPARSEMEM && MMU
144
145config ARCH_ENABLE_MEMORY_HOTREMOVE
146	def_bool y
147	depends on SPARSEMEM && MMU
148
149config ARCH_MEMORY_PROBE
150	def_bool y
151	depends on MEMORY_HOTPLUG
152
153config IOREMAP_FIXED
154       def_bool y
155       depends on X2TLB || SUPERH64
156
157config UNCACHED_MAPPING
158	bool
159
160config HAVE_SRAM_POOL
161	bool
162	select GENERIC_ALLOCATOR
163
164choice
165	prompt "Kernel page size"
166	default PAGE_SIZE_4KB
167
168config PAGE_SIZE_4KB
169	bool "4kB"
170	help
171	  This is the default page size used by all SuperH CPUs.
172
173config PAGE_SIZE_8KB
174	bool "8kB"
175	depends on !MMU || X2TLB
176	help
177	  This enables 8kB pages as supported by SH-X2 and later MMUs.
178
179config PAGE_SIZE_16KB
180	bool "16kB"
181	depends on !MMU
182	help
183	  This enables 16kB pages on MMU-less SH systems.
184
185config PAGE_SIZE_64KB
186	bool "64kB"
187	depends on !MMU || CPU_SH4 || CPU_SH5
188	help
189	  This enables support for 64kB pages, possible on all SH-4
190	  CPUs and later.
191
192endchoice
193
194choice
195	prompt "HugeTLB page size"
196	depends on HUGETLB_PAGE
197	default HUGETLB_PAGE_SIZE_1MB if PAGE_SIZE_64KB
198	default HUGETLB_PAGE_SIZE_64K
199
200config HUGETLB_PAGE_SIZE_64K
201	bool "64kB"
202	depends on !PAGE_SIZE_64KB
203
204config HUGETLB_PAGE_SIZE_256K
205	bool "256kB"
206	depends on X2TLB
207
208config HUGETLB_PAGE_SIZE_1MB
209	bool "1MB"
210
211config HUGETLB_PAGE_SIZE_4MB
212	bool "4MB"
213	depends on X2TLB
214
215config HUGETLB_PAGE_SIZE_64MB
216	bool "64MB"
217	depends on X2TLB
218
219config HUGETLB_PAGE_SIZE_512MB
220	bool "512MB"
221	depends on CPU_SH5
222
223endchoice
224
225config SCHED_MC
226	bool "Multi-core scheduler support"
227	depends on SMP
228	default y
229	help
230	  Multi-core scheduler support improves the CPU scheduler's decision
231	  making when dealing with multi-core CPU chips at a cost of slightly
232	  increased overhead in some places. If unsure say N here.
233
234endmenu
235
236menu "Cache configuration"
237
238config SH7705_CACHE_32KB
239	bool "Enable 32KB cache size for SH7705"
240	depends on CPU_SUBTYPE_SH7705
241	default y
242
243choice
244	prompt "Cache mode"
245	default CACHE_WRITEBACK if CPU_SH2A || CPU_SH3 || CPU_SH4 || CPU_SH5
246	default CACHE_WRITETHROUGH if (CPU_SH2 && !CPU_SH2A)
247
248config CACHE_WRITEBACK
249	bool "Write-back"
250
251config CACHE_WRITETHROUGH
252	bool "Write-through"
253	help
254	  Selecting this option will configure the caches in write-through
255	  mode, as opposed to the default write-back configuration.
256
257	  Since there's sill some aliasing issues on SH-4, this option will
258	  unfortunately still require the majority of flushing functions to
259	  be implemented to deal with aliasing.
260
261	  If unsure, say N.
262
263config CACHE_OFF
264	bool "Off"
265
266endchoice
267
268endmenu
269