On Thu, Apr 04, 2013 at 11:28:02AM +0530, Aneesh Kumar K.V wrote:
> From: "Aneesh Kumar K.V" <aneesh.ku...@linux.vnet.ibm.com>
>
> 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.ku...@linux.vnet.ibm.com>
> ---
> arch/powerpc/include/asm/machdep.h | 3 +
> arch/powerpc/mm/hash_native_64.c | 78 ++++++++++++++++++++
> arch/powerpc/mm/pgtable.c | 13 +++-
> arch/powerpc/platforms/pseries/lpar.c | 126
> +++++++++++++++++++++++++++++++--
> 4 files changed, 210 insertions(+), 10 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/machdep.h
> b/arch/powerpc/include/asm/machdep.h
> index 6cee6e0..3bc7816 100644
> --- a/arch/powerpc/include/asm/machdep.h
> +++ b/arch/powerpc/include/asm/machdep.h
> @@ -56,6 +56,9 @@ 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 ac84fa6..59f29bf 100644
> --- a/arch/powerpc/mm/hash_native_64.c
> +++ b/arch/powerpc/mm/hash_native_64.c
> @@ -450,6 +450,83 @@ 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 = HUGE_PAGE_SIZE/(1ul << shift);
> +
> + local_irq_save(flags);
> + for (i = 0; i < max_hpte_count; i++) {
> + /*
> + * 8 bits per each hpte entries
> + * 000| [ secondary group (one bit) | hidx (3 bits) | valid bit]
> + */
> + valid = hpte_slot_array[i] & 0x1;
> + if (!valid)
> + continue;
> + hidx = hpte_slot_array[i] >> 1;
> +
> + /* 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;
Shouldn't you be clearing the entry from the slot_array once it is
invalidated in the hash table?
> + }
> + /*
> + * 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 void hpte_decode(struct hash_pte *hpte, unsigned long slot,
> int *psize, int *apsize, int *ssize, unsigned long *vpn)
> {
> @@ -678,4 +755,5 @@ 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.c b/arch/powerpc/mm/pgtable.c
> index fbff062..386cab8 100644
> --- a/arch/powerpc/mm/pgtable.c
> +++ b/arch/powerpc/mm/pgtable.c
> @@ -433,6 +433,7 @@ void hpte_need_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;
> @@ -446,12 +447,18 @@ void hpte_need_hugepage_flush(struct mm_struct *mm,
> unsigned long addr,
> * second half of the PMD
> */
> hpte_slot_array = *(char **)(pmdp + PTRS_PER_PMD);
> -
> /* get the base page size */
> psize = get_slice_psize(mm, s_addr);
> - shift = mmu_psize_defs[psize].shift;
>
> - for (i = 0; i < HUGE_PAGE_SIZE/(1ul << 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 = HUGE_PAGE_SIZE/(1ul << 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 3daced3..5fcc621 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);
> @@ -339,6 +346,117 @@ 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[9];
> + 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,
> + 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];
These are really too big to be allocating on the stack. You'd be
better off going direct from the char slot array to the data structure
for H_BULK_REMOVE, rather than introducing this intermediate structure.
> + unsigned long shift, hidx, vpn = 0, vsid, hash, slot;
> +
> + shift = mmu_psize_defs[psize].shift;
> + max_hpte_count = HUGE_PAGE_SIZE/(1ul << 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]
> + */
> + valid = hpte_slot_array[i] & 0x1;
> + if (!valid)
> + continue;
> + hidx = hpte_slot_array[i] >> 1;
> +
> + /* 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)
> {
> @@ -354,13 +472,6 @@ static void pSeries_lpar_hpte_removebolted(unsigned long
> ea,
> pSeries_lpar_hpte_invalidate(slot, vpn, psize, 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.
> @@ -446,6 +557,7 @@ 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
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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