--- /dev/null
+/*
+ * Copyright IBM Corporation, 2015
+ * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2 of the GNU Lesser General Public License
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ */
+
+#include <linux/mm.h>
+#include <asm/machdep.h>
+#include <asm/mmu.h>
+
+int __hash_page_4K(unsigned long ea, unsigned long access, unsigned long vsid,
+ pte_t *ptep, unsigned long trap, unsigned long flags,
+ int ssize, int subpg_prot)
+{
+ real_pte_t rpte;
+ unsigned long *hidxp;
+ unsigned long hpte_group;
+ unsigned int subpg_index;
+ unsigned long rflags, pa, hidx;
+ unsigned long old_pte, new_pte, subpg_pte;
+ unsigned long vpn, hash, slot;
+ unsigned long shift = mmu_psize_defs[MMU_PAGE_4K].shift;
+
+ /*
+ * atomically mark the linux large page PTE busy and dirty
+ */
+ do {
+ pte_t pte = READ_ONCE(*ptep);
+
+ old_pte = pte_val(pte);
+ /* If PTE busy, retry the access */
+ if (unlikely(old_pte & _PAGE_BUSY))
+ return 0;
+ /* If PTE permissions don't match, take page fault */
+ if (unlikely(access & ~old_pte))
+ return 1;
+ /*
+ * Try to lock the PTE, add ACCESSED and DIRTY if it was
+ * a write access. Since this is 4K insert of 64K page size
+ * also add _PAGE_COMBO
+ */
+ new_pte = old_pte | _PAGE_BUSY | _PAGE_ACCESSED | _PAGE_COMBO;
+ if (access & _PAGE_RW)
+ new_pte |= _PAGE_DIRTY;
+ } while (old_pte != __cmpxchg_u64((unsigned long *)ptep,
+ old_pte, new_pte));
+ /*
+ * Handle the subpage protection bits
+ */
+ subpg_pte = new_pte & ~subpg_prot;
+ /*
+ * PP bits. _PAGE_USER is already PP bit 0x2, so we only
+ * need to add in 0x1 if it's a read-only user page
+ */
+ rflags = subpg_pte & _PAGE_USER;
+ if ((subpg_pte & _PAGE_USER) && !((subpg_pte & _PAGE_RW) &&
+ (subpg_pte & _PAGE_DIRTY)))
+ rflags |= 0x1;
+ /*
+ * _PAGE_EXEC -> HW_NO_EXEC since it's inverted
+ */
+ rflags |= ((subpg_pte & _PAGE_EXEC) ? 0 : HPTE_R_N);
+ /*
+ * Always add C and Memory coherence bit
+ */
+ rflags |= HPTE_R_C | HPTE_R_M;
+ /*
+ * Add in WIMG bits
+ */
+ rflags |= (subpg_pte & (_PAGE_WRITETHRU | _PAGE_NO_CACHE |
+ _PAGE_COHERENT | _PAGE_GUARDED));
+
+ if (!cpu_has_feature(CPU_FTR_NOEXECUTE) &&
+ !cpu_has_feature(CPU_FTR_COHERENT_ICACHE)) {
+
+ /*
+ * No CPU has hugepages but lacks no execute, so we
+ * don't need to worry about that case
+ */
+ rflags = hash_page_do_lazy_icache(rflags, __pte(old_pte), trap);
+ }
+
+ subpg_index = (ea & (PAGE_SIZE - 1)) >> shift;
+ vpn = hpt_vpn(ea, vsid, ssize);
+ rpte = __real_pte(__pte(old_pte), ptep);
+ /*
+ *None of the sub 4k page is hashed
+ */
+ if (!(old_pte & _PAGE_HASHPTE))
+ goto htab_insert_hpte;
+ /*
+ * Check if the pte was already inserted into the hash table
+ * as a 64k HW page, and invalidate the 64k HPTE if so.
+ */
+ if (!(old_pte & _PAGE_COMBO)) {
+ flush_hash_page(vpn, rpte, MMU_PAGE_64K, ssize, flags);
+ old_pte &= ~_PAGE_HPTE_SUB;
+ goto htab_insert_hpte;
+ }
+ /*
+ * Check for sub page valid and update
+ */
+ if (__rpte_sub_valid(rpte, subpg_index)) {
+ int ret;
+
+ hash = hpt_hash(vpn, shift, ssize);
+ hidx = __rpte_to_hidx(rpte, subpg_index);
+ if (hidx & _PTEIDX_SECONDARY)
+ hash = ~hash;
+ slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
+ slot += hidx & _PTEIDX_GROUP_IX;
+
+ ret = ppc_md.hpte_updatepp(slot, rflags, vpn,
+ MMU_PAGE_4K, MMU_PAGE_4K,
+ ssize, flags);
+ /*
+ *if we failed because typically the HPTE wasn't really here
+ * we try an insertion.
+ */
+ if (ret == -1)
+ goto htab_insert_hpte;
+
+ *ptep = __pte(new_pte & ~_PAGE_BUSY);
+ return 0;
+ }
+
+htab_insert_hpte:
+ /*
+ * handle _PAGE_4K_PFN case
+ */
+ if (old_pte & _PAGE_4K_PFN) {
+ /*
+ * All the sub 4k page have the same
+ * physical address.
+ */
+ pa = pte_pfn(__pte(old_pte)) << HW_PAGE_SHIFT;
+ } else {
+ pa = pte_pfn(__pte(old_pte)) << PAGE_SHIFT;
+ pa += (subpg_index << shift);
+ }
+ hash = hpt_hash(vpn, shift, ssize);
+repeat:
+ hpte_group = ((hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL;
+
+ /* Insert into the hash table, primary slot */
+ slot = ppc_md.hpte_insert(hpte_group, vpn, pa, rflags, 0,
+ MMU_PAGE_4K, MMU_PAGE_4K, ssize);
+ /*
+ * Primary is full, try the secondary
+ */
+ if (unlikely(slot == -1)) {
+ hpte_group = ((~hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL;
+ slot = ppc_md.hpte_insert(hpte_group, vpn, pa,
+ rflags, HPTE_V_SECONDARY,
+ MMU_PAGE_4K, MMU_PAGE_4K, ssize);
+ if (slot == -1) {
+ if (mftb() & 0x1)
+ hpte_group = ((hash & htab_hash_mask) *
+ HPTES_PER_GROUP) & ~0x7UL;
+ ppc_md.hpte_remove(hpte_group);
+ /*
+ * FIXME!! Should be try the group from which we removed ?
+ */
+ goto repeat;
+ }
+ }
+ /*
+ * Hypervisor failure. Restore old pmd and return -1
+ * similar to __hash_page_*
+ */
+ if (unlikely(slot == -2)) {
+ *ptep = __pte(old_pte);
+ hash_failure_debug(ea, access, vsid, trap, ssize,
+ MMU_PAGE_4K, MMU_PAGE_4K, old_pte);
+ return -1;
+ }
+ /*
+ * Insert slot number & secondary bit in PTE second half,
+ * clear _PAGE_BUSY and set appropriate HPTE slot bit
+ * Since we have _PAGE_BUSY set on ptep, we can be sure
+ * nobody is undating hidx.
+ */
+ hidxp = (unsigned long *)(ptep + PTRS_PER_PTE);
+ /* __real_pte use pte_val() any idea why ? FIXME!! */
+ rpte.hidx &= ~(0xfUL << (subpg_index << 2));
+ *hidxp = rpte.hidx | (slot << (subpg_index << 2));
+ new_pte |= (_PAGE_HPTE_SUB0 >> subpg_index);
+ /*
+ * check __real_pte for details on matching smp_rmb()
+ */
+ smp_wmb();
+ *ptep = __pte(new_pte & ~_PAGE_BUSY);
+ return 0;
+}
li r3,-1
b htab_bail
-
#else /* CONFIG_PPC_64K_PAGES */
-
-/*****************************************************************************
- * *
- * 64K SW & 4K or 64K HW in a 4K segment pages implementation *
- * *
- *****************************************************************************/
-
-/* _hash_page_4K(unsigned long ea, unsigned long access, unsigned long vsid,
- * pte_t *ptep, unsigned long trap, unsigned local flags,
- * int ssize, int subpg_prot)
- */
-
-/*
- * For now, we do NOT implement Admixed pages
- */
-_GLOBAL(__hash_page_4K)
- mflr r0
- std r0,16(r1)
- stdu r1,-STACKFRAMESIZE(r1)
- /* Save all params that we need after a function call */
- std r6,STK_PARAM(R6)(r1)
- std r8,STK_PARAM(R8)(r1)
- std r9,STK_PARAM(R9)(r1)
-
- /* Save non-volatile registers.
- * r31 will hold "old PTE"
- * r30 is "new PTE"
- * r29 is vpn
- * r28 is a hash value
- * r27 is hashtab mask (maybe dynamic patched instead ?)
- * r26 is the hidx mask
- * r25 is the index in combo page
- */
- std r25,STK_REG(R25)(r1)
- std r26,STK_REG(R26)(r1)
- std r27,STK_REG(R27)(r1)
- std r28,STK_REG(R28)(r1)
- std r29,STK_REG(R29)(r1)
- std r30,STK_REG(R30)(r1)
- std r31,STK_REG(R31)(r1)
-
- /* Step 1:
- *
- * Check permissions, atomically mark the linux PTE busy
- * and hashed.
- */
-1:
- ldarx r31,0,r6
- /* Check access rights (access & ~(pte_val(*ptep))) */
- andc. r0,r4,r31
- bne- htab_wrong_access
- /* Check if PTE is busy */
- andi. r0,r31,_PAGE_BUSY
- /* If so, just bail out and refault if needed. Someone else
- * is changing this PTE anyway and might hash it.
- */
- bne- htab_bail_ok
- /* Prepare new PTE value (turn access RW into DIRTY, then
- * add BUSY and ACCESSED)
- */
- rlwinm r30,r4,32-9+7,31-7,31-7 /* _PAGE_RW -> _PAGE_DIRTY */
- or r30,r30,r31
- ori r30,r30,_PAGE_BUSY | _PAGE_ACCESSED
- oris r30,r30,_PAGE_COMBO@h
- /* Write the linux PTE atomically (setting busy) */
- stdcx. r30,0,r6
- bne- 1b
- isync
-
- /* Step 2:
- *
- * Insert/Update the HPTE in the hash table. At this point,
- * r4 (access) is re-useable, we use it for the new HPTE flags
- */
-
- /* Load the hidx index */
- rldicl r25,r3,64-12,60
-
-BEGIN_FTR_SECTION
- cmpdi r9,0 /* check segment size */
- bne 3f
-END_MMU_FTR_SECTION_IFSET(MMU_FTR_1T_SEGMENT)
- /* Calc vpn and put it in r29 */
- sldi r29,r5,SID_SHIFT - VPN_SHIFT
- /*
- * clrldi r3,r3,64 - SID_SHIFT --> ea & 0xfffffff
- * srdi r28,r3,VPN_SHIFT
- */
- rldicl r28,r3,64 - VPN_SHIFT,64 - (SID_SHIFT - VPN_SHIFT)
- or r29,r28,r29
- /*
- * Calculate hash value for primary slot and store it in r28
- * r3 = va, r5 = vsid
- * r0 = (va >> 12) & ((1ul << (28 - 12)) -1)
- */
- rldicl r0,r3,64-12,48
- xor r28,r5,r0 /* hash */
- b 4f
-
-3: /* Calc vpn and put it in r29 */
- sldi r29,r5,SID_SHIFT_1T - VPN_SHIFT
- /*
- * clrldi r3,r3,64 - SID_SHIFT_1T --> ea & 0xffffffffff
- * srdi r28,r3,VPN_SHIFT
- */
- rldicl r28,r3,64 - VPN_SHIFT,64 - (SID_SHIFT_1T - VPN_SHIFT)
- or r29,r28,r29
-
- /*
- * Calculate hash value for primary slot and
- * store it in r28 for 1T segment
- * r3 = va, r5 = vsid
- */
- sldi r28,r5,25 /* vsid << 25 */
- /* r0 = (va >> 12) & ((1ul << (40 - 12)) -1) */
- rldicl r0,r3,64-12,36
- xor r28,r28,r5 /* vsid ^ ( vsid << 25) */
- xor r28,r28,r0 /* hash */
-
- /* Convert linux PTE bits into HW equivalents */
-4:
-#ifdef CONFIG_PPC_SUBPAGE_PROT
- andc r10,r30,r10
- andi. r3,r10,0x1fe /* Get basic set of flags */
- rlwinm r0,r10,32-9+1,30,30 /* _PAGE_RW -> _PAGE_USER (r0) */
-#else
- andi. r3,r30,0x1fe /* Get basic set of flags */
- rlwinm r0,r30,32-9+1,30,30 /* _PAGE_RW -> _PAGE_USER (r0) */
-#endif
- xori r3,r3,HPTE_R_N /* _PAGE_EXEC -> NOEXEC */
- rlwinm r4,r30,32-7+1,30,30 /* _PAGE_DIRTY -> _PAGE_USER (r4) */
- and r0,r0,r4 /* _PAGE_RW & _PAGE_DIRTY ->r0 bit 30*/
- andc r0,r3,r0 /* r0 = pte & ~r0 */
- rlwimi r3,r0,32-1,31,31 /* Insert result into PP lsb */
- /*
- * Always add "C" bit for perf. Memory coherence is always enabled
- */
- ori r3,r3,HPTE_R_C | HPTE_R_M
-
- /* We eventually do the icache sync here (maybe inline that
- * code rather than call a C function...)
- */
-BEGIN_FTR_SECTION
- mr r4,r30
- mr r5,r7
- bl hash_page_do_lazy_icache
-END_FTR_SECTION(CPU_FTR_NOEXECUTE|CPU_FTR_COHERENT_ICACHE, CPU_FTR_NOEXECUTE)
-
- /* At this point, r3 contains new PP bits, save them in
- * place of "access" in the param area (sic)
- */
- std r3,STK_PARAM(R4)(r1)
-
- /* Get htab_hash_mask */
- ld r4,htab_hash_mask@got(2)
- ld r27,0(r4) /* htab_hash_mask -> r27 */
-
- /* Check if we may already be in the hashtable, in this case, we
- * go to out-of-line code to try to modify the HPTE. We look for
- * the bit at (1 >> (index + 32))
- */
- rldicl. r0,r31,64-12,48
- li r26,0 /* Default hidx */
- beq htab_insert_pte
-
- /*
- * Check if the pte was already inserted into the hash table
- * as a 64k HW page, and invalidate the 64k HPTE if so.
- */
- andis. r0,r31,_PAGE_COMBO@h
- beq htab_inval_old_hpte
-
- ld r6,STK_PARAM(R6)(r1)
- ori r26,r6,PTE_PAGE_HIDX_OFFSET /* Load the hidx mask. */
- ld r26,0(r26)
- addi r5,r25,36 /* Check actual HPTE_SUB bit, this */
- rldcr. r0,r31,r5,0 /* must match pgtable.h definition */
- bne htab_modify_pte
-
-htab_insert_pte:
- /* real page number in r5, PTE RPN value + index */
- andis. r0,r31,_PAGE_4K_PFN@h
- srdi r5,r31,PTE_RPN_SHIFT
- bne- htab_special_pfn
- sldi r5,r5,PAGE_FACTOR
- add r5,r5,r25
-htab_special_pfn:
- sldi r5,r5,HW_PAGE_SHIFT
-
- /* Calculate primary group hash */
- and r0,r28,r27
- rldicr r3,r0,3,63-3 /* r0 = (hash & mask) << 3 */
-
- /* Call ppc_md.hpte_insert */
- ld r6,STK_PARAM(R4)(r1) /* Retrieve new pp bits */
- mr r4,r29 /* Retrieve vpn */
- li r7,0 /* !bolted, !secondary */
- li r8,MMU_PAGE_4K /* page size */
- li r9,MMU_PAGE_4K /* actual page size */
- ld r10,STK_PARAM(R9)(r1) /* segment size */
-.globl htab_call_hpte_insert1
-htab_call_hpte_insert1:
- bl . /* patched by htab_finish_init() */
- cmpdi 0,r3,0
- bge htab_pte_insert_ok /* Insertion successful */
- cmpdi 0,r3,-2 /* Critical failure */
- beq- htab_pte_insert_failure
-
- /* Now try secondary slot */
-
- /* real page number in r5, PTE RPN value + index */
- andis. r0,r31,_PAGE_4K_PFN@h
- srdi r5,r31,PTE_RPN_SHIFT
- bne- 3f
- sldi r5,r5,PAGE_FACTOR
- add r5,r5,r25
-3: sldi r5,r5,HW_PAGE_SHIFT
-
- /* Calculate secondary group hash */
- andc r0,r27,r28
- rldicr r3,r0,3,63-3 /* r0 = (~hash & mask) << 3 */
-
- /* Call ppc_md.hpte_insert */
- ld r6,STK_PARAM(R4)(r1) /* Retrieve new pp bits */
- mr r4,r29 /* Retrieve vpn */
- li r7,HPTE_V_SECONDARY /* !bolted, secondary */
- li r8,MMU_PAGE_4K /* page size */
- li r9,MMU_PAGE_4K /* actual page size */
- ld r10,STK_PARAM(R9)(r1) /* segment size */
-.globl htab_call_hpte_insert2
-htab_call_hpte_insert2:
- bl . /* patched by htab_finish_init() */
- cmpdi 0,r3,0
- bge+ htab_pte_insert_ok /* Insertion successful */
- cmpdi 0,r3,-2 /* Critical failure */
- beq- htab_pte_insert_failure
-
- /* Both are full, we need to evict something */
- mftb r0
- /* Pick a random group based on TB */
- andi. r0,r0,1
- mr r5,r28
- bne 2f
- not r5,r5
-2: and r0,r5,r27
- rldicr r3,r0,3,63-3 /* r0 = (hash & mask) << 3 */
- /* Call ppc_md.hpte_remove */
-.globl htab_call_hpte_remove
-htab_call_hpte_remove:
- bl . /* patched by htab_finish_init() */
-
- /* Try all again */
- b htab_insert_pte
-
- /*
- * Call out to C code to invalidate an 64k HW HPTE that is
- * useless now that the segment has been switched to 4k pages.
- */
-htab_inval_old_hpte:
- mr r3,r29 /* vpn */
- mr r4,r31 /* PTE.pte */
- li r5,0 /* PTE.hidx */
- li r6,MMU_PAGE_64K /* psize */
- ld r7,STK_PARAM(R9)(r1) /* ssize */
- ld r8,STK_PARAM(R8)(r1) /* flags */
- bl flush_hash_page
- /* Clear out _PAGE_HPTE_SUB bits in the new linux PTE */
- lis r0,_PAGE_HPTE_SUB@h
- ori r0,r0,_PAGE_HPTE_SUB@l
- andc r30,r30,r0
- b htab_insert_pte
-
-htab_bail_ok:
- li r3,0
- b htab_bail
-
-htab_pte_insert_ok:
- /* Insert slot number & secondary bit in PTE second half,
- * clear _PAGE_BUSY and set approriate HPTE slot bit
- */
- ld r6,STK_PARAM(R6)(r1)
- li r0,_PAGE_BUSY
- andc r30,r30,r0
- /* HPTE SUB bit */
- li r0,1
- subfic r5,r25,27 /* Must match bit position in */
- sld r0,r0,r5 /* pgtable.h */
- or r30,r30,r0
- /* hindx */
- sldi r5,r25,2
- sld r3,r3,r5
- li r4,0xf
- sld r4,r4,r5
- andc r26,r26,r4
- or r26,r26,r3
- ori r5,r6,PTE_PAGE_HIDX_OFFSET
- std r26,0(r5)
- lwsync
- std r30,0(r6)
- li r3, 0
-htab_bail:
- ld r25,STK_REG(R25)(r1)
- ld r26,STK_REG(R26)(r1)
- ld r27,STK_REG(R27)(r1)
- ld r28,STK_REG(R28)(r1)
- ld r29,STK_REG(R29)(r1)
- ld r30,STK_REG(R30)(r1)
- ld r31,STK_REG(R31)(r1)
- addi r1,r1,STACKFRAMESIZE
- ld r0,16(r1)
- mtlr r0
- blr
-
-htab_modify_pte:
- /* Keep PP bits in r4 and slot idx from the PTE around in r3 */
- mr r4,r3
- sldi r5,r25,2
- srd r3,r26,r5
-
- /* Secondary group ? if yes, get a inverted hash value */
- mr r5,r28
- andi. r0,r3,0x8 /* page secondary ? */
- beq 1f
- not r5,r5
-1: andi. r3,r3,0x7 /* extract idx alone */
-
- /* Calculate proper slot value for ppc_md.hpte_updatepp */
- and r0,r5,r27
- rldicr r0,r0,3,63-3 /* r0 = (hash & mask) << 3 */
- add r3,r0,r3 /* add slot idx */
-
- /* Call ppc_md.hpte_updatepp */
- mr r5,r29 /* vpn */
- li r6,MMU_PAGE_4K /* base page size */
- li r7,MMU_PAGE_4K /* actual page size */
- ld r8,STK_PARAM(R9)(r1) /* segment size */
- ld r9,STK_PARAM(R8)(r1) /* get "flags" param */
-.globl htab_call_hpte_updatepp
-htab_call_hpte_updatepp:
- bl . /* patched by htab_finish_init() */
-
- /* if we failed because typically the HPTE wasn't really here
- * we try an insertion.
- */
- cmpdi 0,r3,-1
- beq- htab_insert_pte
-
- /* Clear the BUSY bit and Write out the PTE */
- li r0,_PAGE_BUSY
- andc r30,r30,r0
- ld r6,STK_PARAM(R6)(r1)
- std r30,0(r6)
- li r3,0
- b htab_bail
-
-htab_wrong_access:
- /* Bail out clearing reservation */
- stdcx. r31,0,r6
- li r3,1
- b htab_bail
-
-htab_pte_insert_failure:
- /* Bail out restoring old PTE */
- ld r6,STK_PARAM(R6)(r1)
- std r31,0(r6)
- li r3,-1
- b htab_bail
-
-#endif /* CONFIG_PPC_64K_PAGES */
-
-#ifdef CONFIG_PPC_64K_PAGES
-
/*****************************************************************************
* *
* 64K SW & 64K HW in a 64K segment pages implementation *
#endif /* CONFIG_PPC_64K_PAGES */
-
-
-/*****************************************************************************
- * *
- * Huge pages implementation is in hugetlbpage.c *
- * *
- *****************************************************************************/
projects / GitHub / moto-9609 / android_kernel_motorola_exynos9610.git / commitdiff