2 * Copyright (C) 2006 Chris Dearman (chris@mips.com),
4 #include <linux/init.h>
5 #include <linux/kernel.h>
6 #include <linux/sched.h>
9 #include <asm/cpu-type.h>
10 #include <asm/mipsregs.h>
11 #include <asm/bcache.h>
12 #include <asm/cacheops.h>
14 #include <asm/pgtable.h>
15 #include <asm/mmu_context.h>
16 #include <asm/r4kcache.h>
17 #include <asm/mips-cm.h>
20 * MIPS32/MIPS64 L2 cache handling
24 * Writeback and invalidate the secondary cache before DMA.
26 static void mips_sc_wback_inv(unsigned long addr
, unsigned long size
)
28 blast_scache_range(addr
, addr
+ size
);
32 * Invalidate the secondary cache before DMA.
34 static void mips_sc_inv(unsigned long addr
, unsigned long size
)
36 unsigned long lsize
= cpu_scache_line_size();
37 unsigned long almask
= ~(lsize
- 1);
39 cache_op(Hit_Writeback_Inv_SD
, addr
& almask
);
40 cache_op(Hit_Writeback_Inv_SD
, (addr
+ size
- 1) & almask
);
41 blast_inv_scache_range(addr
, addr
+ size
);
44 static void mips_sc_enable(void)
46 /* L2 cache is permanently enabled */
49 static void mips_sc_disable(void)
51 /* L2 cache is permanently enabled */
54 static void mips_sc_prefetch_enable(void)
58 if (mips_cm_revision() < CM_REV_CM2_5
)
62 * If there is one or more L2 prefetch unit present then enable
63 * prefetching for both code & data, for all ports.
65 pftctl
= read_gcr_l2_pft_control();
66 if (pftctl
& CM_GCR_L2_PFT_CONTROL_NPFT_MSK
) {
67 pftctl
&= ~CM_GCR_L2_PFT_CONTROL_PAGEMASK_MSK
;
68 pftctl
|= PAGE_MASK
& CM_GCR_L2_PFT_CONTROL_PAGEMASK_MSK
;
69 pftctl
|= CM_GCR_L2_PFT_CONTROL_PFTEN_MSK
;
70 write_gcr_l2_pft_control(pftctl
);
72 pftctl
= read_gcr_l2_pft_control_b();
73 pftctl
|= CM_GCR_L2_PFT_CONTROL_B_PORTID_MSK
;
74 pftctl
|= CM_GCR_L2_PFT_CONTROL_B_CEN_MSK
;
75 write_gcr_l2_pft_control_b(pftctl
);
79 static void mips_sc_prefetch_disable(void)
83 if (mips_cm_revision() < CM_REV_CM2_5
)
86 pftctl
= read_gcr_l2_pft_control();
87 pftctl
&= ~CM_GCR_L2_PFT_CONTROL_PFTEN_MSK
;
88 write_gcr_l2_pft_control(pftctl
);
90 pftctl
= read_gcr_l2_pft_control_b();
91 pftctl
&= ~CM_GCR_L2_PFT_CONTROL_B_PORTID_MSK
;
92 pftctl
&= ~CM_GCR_L2_PFT_CONTROL_B_CEN_MSK
;
93 write_gcr_l2_pft_control_b(pftctl
);
96 static bool mips_sc_prefetch_is_enabled(void)
100 if (mips_cm_revision() < CM_REV_CM2_5
)
103 pftctl
= read_gcr_l2_pft_control();
104 if (!(pftctl
& CM_GCR_L2_PFT_CONTROL_NPFT_MSK
))
106 return !!(pftctl
& CM_GCR_L2_PFT_CONTROL_PFTEN_MSK
);
109 static struct bcache_ops mips_sc_ops
= {
110 .bc_enable
= mips_sc_enable
,
111 .bc_disable
= mips_sc_disable
,
112 .bc_wback_inv
= mips_sc_wback_inv
,
113 .bc_inv
= mips_sc_inv
,
114 .bc_prefetch_enable
= mips_sc_prefetch_enable
,
115 .bc_prefetch_disable
= mips_sc_prefetch_disable
,
116 .bc_prefetch_is_enabled
= mips_sc_prefetch_is_enabled
,
120 * Check if the L2 cache controller is activated on a particular platform.
121 * MTI's L2 controller and the L2 cache controller of Broadcom's BMIPS
122 * cores both use c0_config2's bit 12 as "L2 Bypass" bit, that is the
123 * cache being disabled. However there is no guarantee for this to be
124 * true on all platforms. In an act of stupidity the spec defined bits
125 * 12..15 as implementation defined so below function will eventually have
126 * to be replaced by a platform specific probe.
128 static inline int mips_sc_is_activated(struct cpuinfo_mips
*c
)
130 unsigned int config2
= read_c0_config2();
133 /* Check the bypass bit (L2B) */
134 switch (current_cpu_type()) {
143 case CPU_QEMU_GENERIC
:
144 if (config2
& (1 << 12))
148 tmp
= (config2
>> 4) & 0x0f;
149 if (0 < tmp
&& tmp
<= 7)
150 c
->scache
.linesz
= 2 << tmp
;
156 static int __init
mips_sc_probe_cm3(void)
158 struct cpuinfo_mips
*c
= ¤t_cpu_data
;
159 unsigned long cfg
= read_gcr_l2_config();
160 unsigned long sets
, line_sz
, assoc
;
162 if (cfg
& CM_GCR_L2_CONFIG_BYPASS_MSK
)
165 sets
= cfg
& CM_GCR_L2_CONFIG_SET_SIZE_MSK
;
166 sets
>>= CM_GCR_L2_CONFIG_SET_SIZE_SHF
;
168 c
->scache
.sets
= 64 << sets
;
170 line_sz
= cfg
& CM_GCR_L2_CONFIG_LINE_SIZE_MSK
;
171 line_sz
>>= CM_GCR_L2_CONFIG_LINE_SIZE_SHF
;
173 c
->scache
.linesz
= 2 << line_sz
;
175 assoc
= cfg
& CM_GCR_L2_CONFIG_ASSOC_MSK
;
176 assoc
>>= CM_GCR_L2_CONFIG_ASSOC_SHF
;
177 c
->scache
.ways
= assoc
+ 1;
178 c
->scache
.waysize
= c
->scache
.sets
* c
->scache
.linesz
;
179 c
->scache
.waybit
= __ffs(c
->scache
.waysize
);
181 if (c
->scache
.linesz
) {
182 c
->scache
.flags
&= ~MIPS_CACHE_NOT_PRESENT
;
189 static inline int __init
mips_sc_probe(void)
191 struct cpuinfo_mips
*c
= ¤t_cpu_data
;
192 unsigned int config1
, config2
;
195 /* Mark as not present until probe completed */
196 c
->scache
.flags
|= MIPS_CACHE_NOT_PRESENT
;
198 if (mips_cm_revision() >= CM_REV_CM3
)
199 return mips_sc_probe_cm3();
201 /* Ignore anything but MIPSxx processors */
202 if (!(c
->isa_level
& (MIPS_CPU_ISA_M32R1
| MIPS_CPU_ISA_M32R2
|
203 MIPS_CPU_ISA_M32R6
| MIPS_CPU_ISA_M64R1
|
204 MIPS_CPU_ISA_M64R2
| MIPS_CPU_ISA_M64R6
)))
207 /* Does this MIPS32/MIPS64 CPU have a config2 register? */
208 config1
= read_c0_config1();
209 if (!(config1
& MIPS_CONF_M
))
212 config2
= read_c0_config2();
214 if (!mips_sc_is_activated(c
))
217 tmp
= (config2
>> 8) & 0x0f;
219 c
->scache
.sets
= 64 << tmp
;
223 tmp
= (config2
>> 0) & 0x0f;
225 c
->scache
.ways
= tmp
+ 1;
229 c
->scache
.waysize
= c
->scache
.sets
* c
->scache
.linesz
;
230 c
->scache
.waybit
= __ffs(c
->scache
.waysize
);
232 c
->scache
.flags
&= ~MIPS_CACHE_NOT_PRESENT
;
237 int mips_sc_init(void)
239 int found
= mips_sc_probe();
242 mips_sc_prefetch_enable();
243 bcops
= &mips_sc_ops
;