2 * ppc64 MMU hashtable management routines
4 * (c) Copyright IBM Corp. 2003
6 * Maintained by: Benjamin Herrenschmidt
7 * <benh@kernel.crashing.org>
9 * This file is covered by the GNU Public Licence v2 as
10 * described in the kernel's COPYING file.
13 #include <asm/processor.h>
14 #include <asm/pgtable.h>
17 #include <asm/types.h>
18 #include <asm/ppc_asm.h>
19 #include <asm/offsets.h>
20 #include <asm/cputable.h>
27 * +-> Back chain (SP + 256)
28 * | General register save area (SP + 112)
29 * | Parameter save area (SP + 48)
30 * | TOC save area (SP + 40)
31 * | link editor doubleword (SP + 32)
32 * | compiler doubleword (SP + 24)
33 * | LR save area (SP + 16)
34 * | CR save area (SP + 8)
35 * SP ---> +-- Back chain (SP + 0)
37 #define STACKFRAMESIZE 256
39 /* Save parameters offsets */
40 #define STK_PARM(i) (STACKFRAMESIZE + 48 + ((i)-3)*8)
42 /* Save non-volatile offsets */
43 #define STK_REG(i) (112 + ((i)-14)*8)
46 * _hash_page(unsigned long ea, unsigned long access, unsigned long vsid,
47 * pte_t *ptep, unsigned long trap, int local)
49 * Adds a page to the hash table. This is the non-LPAR version for now
55 stdu r1,-STACKFRAMESIZE(r1)
56 /* Save all params that we need after a function call */
57 std r6,STK_PARM(r6)(r1)
58 std r8,STK_PARM(r8)(r1)
60 /* Add _PAGE_PRESENT to access */
61 ori r4,r4,_PAGE_PRESENT
63 /* Save non-volatile registers.
64 * r31 will hold "old PTE"
68 * r27 is hashtab mask (maybe dynamic patched instead ?)
70 std r27,STK_REG(r27)(r1)
71 std r28,STK_REG(r28)(r1)
72 std r29,STK_REG(r29)(r1)
73 std r30,STK_REG(r30)(r1)
74 std r31,STK_REG(r31)(r1)
78 * Check permissions, atomically mark the linux PTE busy
83 /* Check access rights (access & ~(pte_val(*ptep))) */
85 bne- htab_wrong_access
86 /* Check if PTE is busy */
87 andi. r0,r31,_PAGE_BUSY
89 /* Prepare new PTE value (turn access RW into DIRTY, then
90 * add BUSY,HASHPTE and ACCESSED)
92 rlwinm r30,r4,32-9+7,31-7,31-7 /* _PAGE_RW -> _PAGE_DIRTY */
94 ori r30,r30,_PAGE_BUSY | _PAGE_ACCESSED | _PAGE_HASHPTE
95 /* Write the linux PTE atomically (setting busy) */
102 * Insert/Update the HPTE in the hash table. At this point,
103 * r4 (access) is re-useable, we use it for the new HPTE flags
106 /* Calc va and put it in r29 */
107 rldicr r29,r5,28,63-28
111 /* Calculate hash value for primary slot and store it in r28 */
112 rldicl r5,r5,0,25 /* vsid & 0x0000007fffffffff */
113 rldicl r0,r3,64-12,48 /* (ea >> 12) & 0xffff */
116 /* Convert linux PTE bits into HW equivalents */
117 andi. r3,r30,0x1fe /* Get basic set of flags */
118 xori r3,r3,HW_NO_EXEC /* _PAGE_EXEC -> NOEXEC */
119 rlwinm r0,r30,32-9+1,30,30 /* _PAGE_RW -> _PAGE_USER (r0) */
120 rlwinm r4,r30,32-7+1,30,30 /* _PAGE_DIRTY -> _PAGE_USER (r4) */
121 and r0,r0,r4 /* _PAGE_RW & _PAGE_DIRTY -> r0 bit 30 */
122 andc r0,r30,r0 /* r0 = pte & ~r0 */
123 rlwimi r3,r0,32-1,31,31 /* Insert result into PP lsb */
125 /* We eventually do the icache sync here (maybe inline that
126 * code rather than call a C function...)
132 bl .hash_page_do_lazy_icache
133 END_FTR_SECTION_IFSET(CPU_FTR_NOEXECUTE)
134 END_FTR_SECTION_IFCLR(CPU_FTR_COHERENT_ICACHE)
136 /* At this point, r3 contains new PP bits, save them in
137 * place of "access" in the param area (sic)
139 std r3,STK_PARM(r4)(r1)
141 /* Get htab_hash_mask */
142 ld r4,htab_hash_mask@got(2)
143 ld r27,0(r4) /* htab_hash_mask -> r27 */
145 /* Check if we may already be in the hashtable, in this case, we
146 * go to out-of-line code to try to modify the HPTE
148 andi. r0,r31,_PAGE_HASHPTE
152 /* Clear hpte bits in new pte (we also clear BUSY btw) and
155 lis r0,_PAGE_HPTEFLAGS@h
156 ori r0,r0,_PAGE_HPTEFLAGS@l
158 ori r30,r30,_PAGE_HASHPTE
160 /* page number in r5 */
161 rldicl r5,r31,64-PTE_SHIFT,PTE_SHIFT
163 /* Calculate primary group hash */
165 rldicr r3,r0,3,63-3 /* r0 = (hash & mask) << 3 */
167 /* Call ppc_md.hpte_insert */
168 ld r7,STK_PARM(r4)(r1) /* Retreive new pp bits */
169 mr r4,r29 /* Retreive va */
170 li r6,0 /* primary slot */
171 li r8,0 /* not bolted and not large */
173 _GLOBAL(htab_call_hpte_insert1)
174 bl . /* Will be patched by htab_finish_init() */
176 bge htab_pte_insert_ok /* Insertion successful */
177 cmpdi 0,r3,-2 /* Critical failure */
178 beq- htab_pte_insert_failure
180 /* Now try secondary slot */
182 /* page number in r5 */
183 rldicl r5,r31,64-PTE_SHIFT,PTE_SHIFT
185 /* Calculate secondary group hash */
187 rldicr r3,r0,3,63-3 /* r0 = (~hash & mask) << 3 */
189 /* Call ppc_md.hpte_insert */
190 ld r7,STK_PARM(r4)(r1) /* Retreive new pp bits */
191 mr r4,r29 /* Retreive va */
192 li r6,1 /* secondary slot */
193 li r8,0 /* not bolted and not large */
195 _GLOBAL(htab_call_hpte_insert2)
196 bl . /* Will be patched by htab_finish_init() */
198 bge+ htab_pte_insert_ok /* Insertion successful */
199 cmpdi 0,r3,-2 /* Critical failure */
200 beq- htab_pte_insert_failure
202 /* Both are full, we need to evict something */
204 /* Pick a random group based on TB */
210 rldicr r3,r0,3,63-3 /* r0 = (hash & mask) << 3 */
211 /* Call ppc_md.hpte_remove */
212 _GLOBAL(htab_call_hpte_remove)
213 bl . /* Will be patched by htab_finish_init() */
219 /* Insert slot number & secondary bit in PTE */
220 rldimi r30,r3,12,63-15
222 /* Write out the PTE with a normal write
223 * (maybe add eieio may be good still ?)
226 ld r6,STK_PARM(r6)(r1)
230 ld r27,STK_REG(r27)(r1)
231 ld r28,STK_REG(r28)(r1)
232 ld r29,STK_REG(r29)(r1)
233 ld r30,STK_REG(r30)(r1)
234 ld r31,STK_REG(r31)(r1)
235 addi r1,r1,STACKFRAMESIZE
241 /* Keep PP bits in r4 and slot idx from the PTE around in r3 */
243 rlwinm r3,r31,32-12,29,31
245 /* Secondary group ? if yes, get a inverted hash value */
247 andi. r0,r31,_PAGE_SECONDARY
251 /* Calculate proper slot value for ppc_md.hpte_updatepp */
253 rldicr r0,r0,3,63-3 /* r0 = (hash & mask) << 3 */
254 add r3,r0,r3 /* add slot idx */
256 /* Call ppc_md.hpte_updatepp */
258 li r6,0 /* large is 0 */
259 ld r7,STK_PARM(r8)(r1) /* get "local" param */
260 _GLOBAL(htab_call_hpte_updatepp)
261 bl . /* Will be patched by htab_finish_init() */
263 /* if we failed because typically the HPTE wasn't really here
264 * we try an insertion.
269 /* Clear the BUSY bit and Write out the PTE */
275 /* Bail out clearing reservation */
280 htab_pte_insert_failure:
281 /* Bail out restoring old PTE */
282 ld r6,STK_PARM(r6)(r1)