powerpc: Optimize hugepage invalidate

Hugepage invalidate involves invalidating multiple hpte entries.
Optimize the operation using H_BULK_REMOVE on lpar platforms.
On native, reduce the number of tlb flush.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

4 files changed, 201 insertions, 9 deletions

diff --git a/arch/powerpc/include/asm/machdep.h b/arch/powerpc/include/asm/machdep.h
index 801e3c61395f..8b480901165a 100644
--- a/arch/powerpc/include/asm/machdep.h
+++ b/arch/powerpc/include/asm/machdep.h
@@ -57,6 +57,9 @@ struct machdep_calls {
         void            (*hpte_removebolted)(unsigned long ea,
                                              int psize, int ssize);
         void            (*flush_hash_range)(unsigned long number, int local);
+        void            (*hugepage_invalidate)(struct mm_struct *mm,
+                                               unsigned char *hpte_slot_array,
+                                               unsigned long addr, int psize);
 
         /* special for kexec, to be called in real mode, linear mapping is
          * destroyed as well */
diff --git a/arch/powerpc/mm/hash_native_64.c b/arch/powerpc/mm/hash_native_64.c
index 6d152bc993e5..3f0c30ae4791 100644
--- a/arch/powerpc/mm/hash_native_64.c
+++ b/arch/powerpc/mm/hash_native_64.c
@@ -407,6 +407,78 @@ static void native_hpte_invalidate(unsigned long slot, unsigned long vpn,
         local_irq_restore(flags);
 }
 
+static void native_hugepage_invalidate(struct mm_struct *mm,
+                                       unsigned char *hpte_slot_array,
+                                       unsigned long addr, int psize)
+{
+        int ssize = 0, i;
+        int lock_tlbie;
+        struct hash_pte *hptep;
+        int actual_psize = MMU_PAGE_16M;
+        unsigned int max_hpte_count, valid;
+        unsigned long flags, s_addr = addr;
+        unsigned long hpte_v, want_v, shift;
+        unsigned long hidx, vpn = 0, vsid, hash, slot;
+
+        shift = mmu_psize_defs[psize].shift;
+        max_hpte_count = 1U << (PMD_SHIFT - shift);
+
+        local_irq_save(flags);
+        for (i = 0; i < max_hpte_count; i++) {
+                valid = hpte_valid(hpte_slot_array, i);
+                if (!valid)
+                        continue;
+                hidx =  hpte_hash_index(hpte_slot_array, i);
+
+                /* get the vpn */
+                addr = s_addr + (i * (1ul << shift));
+                if (!is_kernel_addr(addr)) {
+                        ssize = user_segment_size(addr);
+                        vsid = get_vsid(mm->context.id, addr, ssize);
+                        WARN_ON(vsid == 0);
+                } else {
+                        vsid = get_kernel_vsid(addr, mmu_kernel_ssize);
+                        ssize = mmu_kernel_ssize;
+                }
+
+                vpn = hpt_vpn(addr, vsid, ssize);
+                hash = hpt_hash(vpn, shift, ssize);
+                if (hidx & _PTEIDX_SECONDARY)
+                        hash = ~hash;
+
+                slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
+                slot += hidx & _PTEIDX_GROUP_IX;
+
+                hptep = htab_address + slot;
+                want_v = hpte_encode_avpn(vpn, psize, ssize);
+                native_lock_hpte(hptep);
+                hpte_v = hptep->v;
+
+                /* Even if we miss, we need to invalidate the TLB */
+                if (!HPTE_V_COMPARE(hpte_v, want_v) || !(hpte_v & HPTE_V_VALID))
+                        native_unlock_hpte(hptep);
+                else
+                        /* Invalidate the hpte. NOTE: this also unlocks it */
+                        hptep->v = 0;
+        }
+        /*
+         * Since this is a hugepage, we just need a single tlbie.
+         * use the last vpn.
+         */
+        lock_tlbie = !mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE);
+        if (lock_tlbie)
+                raw_spin_lock(&native_tlbie_lock);
+
+        asm volatile("ptesync":::"memory");
+        __tlbie(vpn, psize, actual_psize, ssize);
+        asm volatile("eieio; tlbsync; ptesync":::"memory");
+
+        if (lock_tlbie)
+                raw_spin_unlock(&native_tlbie_lock);
+
+        local_irq_restore(flags);
+}
+
 static inline int __hpte_actual_psize(unsigned int lp, int psize)
 {
         int i, shift;
@@ -640,4 +712,5 @@ void __init hpte_init_native(void)
         ppc_md.hpte_remove      = native_hpte_remove;
         ppc_md.hpte_clear_all   = native_hpte_clear;
         ppc_md.flush_hash_range = native_flush_hash_range;
+        ppc_md.hugepage_invalidate   = native_hugepage_invalidate;
 }
diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c
index 074a4a225054..536eec72c0f7 100644
--- a/arch/powerpc/mm/pgtable_64.c
+++ b/arch/powerpc/mm/pgtable_64.c
@@ -708,6 +708,7 @@ void hpte_do_hugepage_flush(struct mm_struct *mm, unsigned long addr,
 {
         int ssize, i;
         unsigned long s_addr;
+        int max_hpte_count;
         unsigned int psize, valid;
         unsigned char *hpte_slot_array;
         unsigned long hidx, vpn, vsid, hash, shift, slot;
@@ -727,9 +728,16 @@ void hpte_do_hugepage_flush(struct mm_struct *mm, unsigned long addr,
 
         /* get the base page size */
         psize = get_slice_psize(mm, s_addr);
-        shift = mmu_psize_defs[psize].shift;
 
-        for (i = 0; i < (HPAGE_PMD_SIZE >> shift); i++) {
+        if (ppc_md.hugepage_invalidate)
+                return ppc_md.hugepage_invalidate(mm, hpte_slot_array,
+                                                  s_addr, psize);
+        /*
+         * No bluk hpte removal support, invalidate each entry
+         */
+        shift = mmu_psize_defs[psize].shift;
+        max_hpte_count = HPAGE_PMD_SIZE >> shift;
+        for (i = 0; i < max_hpte_count; i++) {
                 /*
                  * 8 bits per each hpte entries
                  * 000| [ secondary group (one bit) | hidx (3 bits) | valid bit]
diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c
index ca45c8f3c0ba..fd0f2f2a9b90 100644
--- a/arch/powerpc/platforms/pseries/lpar.c
+++ b/arch/powerpc/platforms/pseries/lpar.c
@@ -45,6 +45,13 @@
 #include "plpar_wrappers.h"
 #include "pseries.h"
 
+/* Flag bits for H_BULK_REMOVE */
+#define HBR_REQUEST     0x4000000000000000UL
+#define HBR_RESPONSE    0x8000000000000000UL
+#define HBR_END         0xc000000000000000UL
+#define HBR_AVPN        0x0200000000000000UL
+#define HBR_ANDCOND     0x0100000000000000UL
+
 
 /* in hvCall.S */
 EXPORT_SYMBOL(plpar_hcall);
@@ -347,6 +354,113 @@ static void pSeries_lpar_hpte_invalidate(unsigned long slot, unsigned long vpn,
         BUG_ON(lpar_rc != H_SUCCESS);
 }
 
+/*
+ * Limit iterations holding pSeries_lpar_tlbie_lock to 3. We also need
+ * to make sure that we avoid bouncing the hypervisor tlbie lock.
+ */
+#define PPC64_HUGE_HPTE_BATCH 12
+
+static void __pSeries_lpar_hugepage_invalidate(unsigned long *slot,
+                                             unsigned long *vpn, int count,
+                                             int psize, int ssize)
+{
+        unsigned long param[8];
+        int i = 0, pix = 0, rc;
+        unsigned long flags = 0;
+        int lock_tlbie = !mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE);
+
+        if (lock_tlbie)
+                spin_lock_irqsave(&pSeries_lpar_tlbie_lock, flags);
+
+        for (i = 0; i < count; i++) {
+
+                if (!firmware_has_feature(FW_FEATURE_BULK_REMOVE)) {
+                        pSeries_lpar_hpte_invalidate(slot[i], vpn[i], psize, 0,
+                                                     ssize, 0);
+                } else {
+                        param[pix] = HBR_REQUEST | HBR_AVPN | slot[i];
+                        param[pix+1] = hpte_encode_avpn(vpn[i], psize, ssize);
+                        pix += 2;
+                        if (pix == 8) {
+                                rc = plpar_hcall9(H_BULK_REMOVE, param,
+                                                  param[0], param[1], param[2],
+                                                  param[3], param[4], param[5],
+                                                  param[6], param[7]);
+                                BUG_ON(rc != H_SUCCESS);
+                                pix = 0;
+                        }
+                }
+        }
+        if (pix) {
+                param[pix] = HBR_END;
+                rc = plpar_hcall9(H_BULK_REMOVE, param, param[0], param[1],
+                                  param[2], param[3], param[4], param[5],
+                                  param[6], param[7]);
+                BUG_ON(rc != H_SUCCESS);
+        }
+
+        if (lock_tlbie)
+                spin_unlock_irqrestore(&pSeries_lpar_tlbie_lock, flags);
+}
+
+static void pSeries_lpar_hugepage_invalidate(struct mm_struct *mm,
+                                       unsigned char *hpte_slot_array,
+                                       unsigned long addr, int psize)
+{
+        int ssize = 0, i, index = 0;
+        unsigned long s_addr = addr;
+        unsigned int max_hpte_count, valid;
+        unsigned long vpn_array[PPC64_HUGE_HPTE_BATCH];
+        unsigned long slot_array[PPC64_HUGE_HPTE_BATCH];
+        unsigned long shift, hidx, vpn = 0, vsid, hash, slot;
+
+        shift = mmu_psize_defs[psize].shift;
+        max_hpte_count = 1U << (PMD_SHIFT - shift);
+
+        for (i = 0; i < max_hpte_count; i++) {
+                valid = hpte_valid(hpte_slot_array, i);
+                if (!valid)
+                        continue;
+                hidx =  hpte_hash_index(hpte_slot_array, i);
+
+                /* get the vpn */
+                addr = s_addr + (i * (1ul << shift));
+                if (!is_kernel_addr(addr)) {
+                        ssize = user_segment_size(addr);
+                        vsid = get_vsid(mm->context.id, addr, ssize);
+                        WARN_ON(vsid == 0);
+                } else {
+                        vsid = get_kernel_vsid(addr, mmu_kernel_ssize);
+                        ssize = mmu_kernel_ssize;
+                }
+
+                vpn = hpt_vpn(addr, vsid, ssize);
+                hash = hpt_hash(vpn, shift, ssize);
+                if (hidx & _PTEIDX_SECONDARY)
+                        hash = ~hash;
+
+                slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
+                slot += hidx & _PTEIDX_GROUP_IX;
+
+                slot_array[index] = slot;
+                vpn_array[index] = vpn;
+                if (index == PPC64_HUGE_HPTE_BATCH - 1) {
+                        /*
+                         * Now do a bluk invalidate
+                         */
+                        __pSeries_lpar_hugepage_invalidate(slot_array,
+                                                           vpn_array,
+                                                           PPC64_HUGE_HPTE_BATCH,
+                                                           psize, ssize);
+                        index = 0;
+                } else
+                        index++;
+        }
+        if (index)
+                __pSeries_lpar_hugepage_invalidate(slot_array, vpn_array,
+                                                   index, psize, ssize);
+}
+
 static void pSeries_lpar_hpte_removebolted(unsigned long ea,
                                            int psize, int ssize)
 {
@@ -364,13 +478,6 @@ static void pSeries_lpar_hpte_removebolted(unsigned long ea,
         pSeries_lpar_hpte_invalidate(slot, vpn, psize, 0, ssize, 0);
 }
 
-/* Flag bits for H_BULK_REMOVE */
-#define HBR_REQUEST     0x4000000000000000UL
-#define HBR_RESPONSE    0x8000000000000000UL
-#define HBR_END         0xc000000000000000UL
-#define HBR_AVPN        0x0200000000000000UL
-#define HBR_ANDCOND     0x0100000000000000UL
-
 /*
  * Take a spinlock around flushes to avoid bouncing the hypervisor tlbie
  * lock.
@@ -459,6 +566,7 @@ void __init hpte_init_lpar(void)
         ppc_md.hpte_removebolted = pSeries_lpar_hpte_removebolted;
         ppc_md.flush_hash_range = pSeries_lpar_flush_hash_range;
         ppc_md.hpte_clear_all   = pSeries_lpar_hptab_clear;
+        ppc_md.hugepage_invalidate = pSeries_lpar_hugepage_invalidate;
 }
 
 #ifdef CONFIG_PPC_SMLPAR