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 <linux/config.h>
14 #include <asm/processor.h>
15 #include <asm/pgtable.h>
18 #include <asm/types.h>
19 #include <asm/ppc_asm.h>
20 #include <asm/offsets.h>
21 #include <asm/cputable.h>
28 * +-> Back chain (SP + 256)
29 * | General register save area (SP + 112)
30 * | Parameter save area (SP + 48)
31 * | TOC save area (SP + 40)
32 * | link editor doubleword (SP + 32)
33 * | compiler doubleword (SP + 24)
34 * | LR save area (SP + 16)
35 * | CR save area (SP + 8)
36 * SP ---> +-- Back chain (SP + 0)
38 #define STACKFRAMESIZE 256
40 /* Save parameters offsets */
41 #define STK_PARM(i) (STACKFRAMESIZE + 48 + ((i)-3)*8)
43 /* Save non-volatile offsets */
44 #define STK_REG(i) (112 + ((i)-14)*8)
47 * _hash_page(unsigned long ea, unsigned long access, unsigned long vsid,
48 * pte_t *ptep, unsigned long trap, int local)
50 * Adds a page to the hash table. This is the non-LPAR version for now
56 stdu r1,-STACKFRAMESIZE(r1)
57 /* Save all params that we need after a function call */
58 std r6,STK_PARM(r6)(r1)
59 std r8,STK_PARM(r8)(r1)
61 /* Add _PAGE_PRESENT to access */
62 ori r4,r4,_PAGE_PRESENT
64 /* Save non-volatile registers.
65 * r31 will hold "old PTE"
69 * r27 is hashtab mask (maybe dynamic patched instead ?)
71 std r27,STK_REG(r27)(r1)
72 std r28,STK_REG(r28)(r1)
73 std r29,STK_REG(r29)(r1)
74 std r30,STK_REG(r30)(r1)
75 std r31,STK_REG(r31)(r1)
79 * Check permissions, atomically mark the linux PTE busy
84 /* Check access rights (access & ~(pte_val(*ptep))) */
86 bne- htab_wrong_access
87 /* Check if PTE is busy */
88 andi. r0,r31,_PAGE_BUSY
90 /* Prepare new PTE value (turn access RW into DIRTY, then
91 * add BUSY,HASHPTE and ACCESSED)
93 rlwinm r30,r4,5,24,24 /* _PAGE_RW -> _PAGE_DIRTY */
95 ori r30,r30,_PAGE_BUSY | _PAGE_ACCESSED | _PAGE_HASHPTE
96 /* Write the linux PTE atomically (setting busy) */
103 * Insert/Update the HPTE in the hash table. At this point,
104 * r4 (access) is re-useable, we use it for the new HPTE flags
107 /* Calc va and put it in r29 */
108 rldicr r29,r5,28,63-28
112 /* Calculate hash value for primary slot and store it in r28 */
113 rldicl r5,r5,0,25 /* vsid & 0x0000007fffffffff */
114 rldicl r0,r3,64-12,48 /* (ea >> 12) & 0xffff */
117 /* Convert linux PTE bits into HW equivalents
119 andi. r3,r30,0x1fa /* Get basic set of flags */
120 rlwinm r0,r30,32-2+1,30,30 /* _PAGE_RW -> _PAGE_USER (r0) */
121 rlwinm r4,r30,32-7+1,30,30 /* _PAGE_DIRTY -> _PAGE_USER (r4) */
122 and r0,r0,r4 /* _PAGE_RW & _PAGE_DIRTY -> r0 bit 30 */
123 andc r0,r30,r0 /* r0 = pte & ~r0 */
124 rlwimi r3,r0,32-1,31,31 /* Insert result into PP lsb */
126 /* We eventually do the icache sync here (maybe inline that
127 * code rather than call a C function...)
132 bl .hash_page_do_lazy_icache
133 END_FTR_SECTION_IFSET(CPU_FTR_NOEXECUTE)
135 /* At this point, r3 contains new PP bits, save them in
136 * place of "access" in the param area (sic)
138 std r3,STK_PARM(r4)(r1)
140 /* Get htab_hash_mask */
141 ld r4,htab_data@got(2)
142 ld r27,16(r4) /* htab_data.htab_hash_mask -> r27 */
144 /* Check if we may already be in the hashtable, in this case, we
145 * go to out-of-line code to try to modify the HPTE
147 andi. r0,r31,_PAGE_HASHPTE
151 /* Clear hpte bits in new pte (we also clear BUSY btw) and
154 lis r0,_PAGE_HPTEFLAGS@h
155 ori r0,r0,_PAGE_HPTEFLAGS@l
157 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 cmpi 0,r3,-2 /* Critical failure */
178 beq- htab_pte_insert_failure
180 /* Now try secondary slot */
181 ori r30,r30,_PAGE_SECONDARY
183 /* page number in r5 */
184 rldicl r5,r31,64-PTE_SHIFT,PTE_SHIFT
186 /* Calculate secondary group hash */
189 rldicr r3,r0,3,63-3 /* r0 = (~hash & mask) << 3 */
191 /* Call ppc_md.hpte_insert */
192 ld r7,STK_PARM(r4)(r1) /* Retreive new pp bits */
193 mr r4,r29 /* Retreive va */
194 li r6,1 /* secondary slot *
195 li r8,0 /* not bolted and not large */
197 _GLOBAL(htab_call_hpte_insert2)
198 bl . /* Will be patched by htab_finish_init() */
200 bge+ htab_pte_insert_ok /* Insertion successful */
201 cmpi 0,r3,-2 /* Critical failure */
202 beq- htab_pte_insert_failure
204 /* Both are full, we need to evict something */
206 /* Pick a random group based on TB */
212 rldicr r3,r0,3,63-3 /* r0 = (hash & mask) << 3 */
213 /* Call ppc_md.hpte_remove */
214 _GLOBAL(htab_call_hpte_remove)
215 bl . /* Will be patched by htab_finish_init() */
221 /* Insert slot number in PTE */
222 rldimi r30,r3,12,63-14
224 /* Write out the PTE with a normal write
225 * (maybe add eieio may be good still ?)
228 ld r6,STK_PARM(r6)(r1)
232 ld r27,STK_REG(r27)(r1)
233 ld r28,STK_REG(r28)(r1)
234 ld r29,STK_REG(r29)(r1)
235 ld r30,STK_REG(r30)(r1)
236 ld r31,STK_REG(r31)(r1)
237 addi r1,r1,STACKFRAMESIZE
243 /* Keep PP bits in r4 and slot idx from the PTE around in r3 */
245 rlwinm r3,r31,32-12,29,31
247 /* Secondary group ? if yes, get a inverted hash value */
249 andi. r0,r31,_PAGE_SECONDARY
253 /* Calculate proper slot value for ppc_md.hpte_updatepp */
255 rldicr r0,r0,3,63-3 /* r0 = (hash & mask) << 3 */
256 add r3,r0,r3 /* add slot idx */
258 /* Call ppc_md.hpte_updatepp */
260 li r6,0 /* large is 0 */
261 ld r7,STK_PARM(r8)(r1) /* get "local" param */
262 _GLOBAL(htab_call_hpte_updatepp)
263 bl . /* Will be patched by htab_finish_init() */
265 /* if we failed because typically the HPTE wasn't really here
266 * we try an insertion.
271 /* Clear the BUSY bit and Write out the PTE */
277 /* Bail out clearing reservation */
282 htab_pte_insert_failure:
283 b .htab_insert_failure