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Re: [PATCH v6 11/18] target/ppc: Only calculate RMLS derived RMA limit o
From: |
David Gibson |
Subject: |
Re: [PATCH v6 11/18] target/ppc: Only calculate RMLS derived RMA limit on demand |
Date: |
Thu, 27 Feb 2020 15:33:41 +1100 |
On Wed, Feb 26, 2020 at 02:24:53PM +0100, Greg Kurz wrote:
> On Tue, 25 Feb 2020 10:37:17 +1100
> David Gibson <address@hidden> wrote:
>
> > When the LPCR is written, we update the env->rmls field with the RMA limit
> > it implies. Simplify things by just calculating the value directly from
> > the LPCR value when we need it.
> >
> > It's possible this is a little slower, but it's unlikely to be significant,
> > since this is only for real mode accesses in a translation configuration
> > that's not used very often, and the whole thing is behind the qemu TLB
> > anyway. Therefore, keeping the number of state variables down and not
> > having to worry about making sure it's always in sync seems the better
> > option.
> >
>
> This patch also refactors the code of ppc_hash64_update_vrma(), which
> is definitely an improvement, but seems a bit unrelated to the title...
> I'd personally make it a separate patch but you decide of course :)
Ah, dang it, botched rebase damage. There are a couple of hunks here
that are supposed to be in the next patch. I think I've sorted it out
now.
>
> Also, a cosmetic remark. See below.
>
> > Signed-off-by: David Gibson <address@hidden>
> > Reviewed-by: Cédric Le Goater <address@hidden>
> > ---
> > target/ppc/cpu.h | 1 -
> > target/ppc/mmu-hash64.c | 84 ++++++++++++++++++++---------------------
> > 2 files changed, 40 insertions(+), 45 deletions(-)
> >
> > diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h
> > index 8077fdb068..f9871b1233 100644
> > --- a/target/ppc/cpu.h
> > +++ b/target/ppc/cpu.h
> > @@ -1046,7 +1046,6 @@ struct CPUPPCState {
> > uint64_t insns_flags2;
> > #if defined(TARGET_PPC64)
> > ppc_slb_t vrma_slb;
> > - target_ulong rmls;
> > #endif
> >
> > int error_code;
> > diff --git a/target/ppc/mmu-hash64.c b/target/ppc/mmu-hash64.c
> > index dd0df6fd01..ac21c14f68 100644
> > --- a/target/ppc/mmu-hash64.c
> > +++ b/target/ppc/mmu-hash64.c
> > @@ -791,6 +791,35 @@ static target_ulong rmls_limit(PowerPCCPU *cpu)
> > }
> > }
> >
> > +static int build_vrma_slbe(PowerPCCPU *cpu, ppc_slb_t *slb)
> > +{
> > + CPUPPCState *env = &cpu->env;
> > + target_ulong lpcr = env->spr[SPR_LPCR];
> > + uint32_t vrmasd = (lpcr & LPCR_VRMASD) >> LPCR_VRMASD_SHIFT;
> > + target_ulong vsid = SLB_VSID_VRMA | ((vrmasd << 4) &
> > SLB_VSID_LLP_MASK);
> > + int i;
> > +
> > + for (i = 0; i < PPC_PAGE_SIZES_MAX_SZ; i++) {
> > + const PPCHash64SegmentPageSizes *sps = &cpu->hash64_opts->sps[i];
> > +
> > + if (!sps->page_shift) {
> > + break;
> > + }
> > +
> > + if ((vsid & SLB_VSID_LLP_MASK) == sps->slb_enc) {
> > + slb->esid = SLB_ESID_V;
> > + slb->vsid = vsid;
> > + slb->sps = sps;
> > + return 0;
> > + }
> > + }
> > +
> > + error_report("Bad page size encoding in LPCR[VRMASD]; LPCR=0x"
> > + TARGET_FMT_lx"\n", lpcr);
> > +
> > + return -1;
> > +}
> > +
> > int ppc_hash64_handle_mmu_fault(PowerPCCPU *cpu, vaddr eaddr,
> > int rwx, int mmu_idx)
> > {
> > @@ -844,8 +873,10 @@ int ppc_hash64_handle_mmu_fault(PowerPCCPU *cpu, vaddr
> > eaddr,
> >
> > goto skip_slb_search;
> > } else {
> > + target_ulong limit = rmls_limit(cpu);
> > +
> > /* Emulated old-style RMO mode, bounds check against RMLS */
> > - if (raddr >= env->rmls) {
> > + if (raddr >= limit) {
> > if (rwx == 2) {
> > ppc_hash64_set_isi(cs, SRR1_PROTFAULT);
> > } else {
> > @@ -1007,8 +1038,9 @@ hwaddr ppc_hash64_get_phys_page_debug(PowerPCCPU
> > *cpu, target_ulong addr)
> > return -1;
> > }
> > } else {
> > + target_ulong limit = rmls_limit(cpu);
>
> Maybe add an empty line like you did above for consistency and better
> readability ?
Ok, done.
>
> Anyway, feel free to add:
>
> Reviewed-by: Greg Kurz <address@hidden>
>
> > /* Emulated old-style RMO mode, bounds check against RMLS */
> > - if (raddr >= env->rmls) {
> > + if (raddr >= limit) {
> > return -1;
> > }
> > return raddr | env->spr[SPR_RMOR];
> > @@ -1043,53 +1075,18 @@ void ppc_hash64_tlb_flush_hpte(PowerPCCPU *cpu,
> > target_ulong ptex,
> > static void ppc_hash64_update_vrma(PowerPCCPU *cpu)
> > {
> > CPUPPCState *env = &cpu->env;
> > - const PPCHash64SegmentPageSizes *sps = NULL;
> > - target_ulong esid, vsid, lpcr;
> > ppc_slb_t *slb = &env->vrma_slb;
> > - uint32_t vrmasd;
> > - int i;
> > -
> > - /* First clear it */
> > - slb->esid = slb->vsid = 0;
> > - slb->sps = NULL;
> >
> > /* Is VRMA enabled ? */
> > - if (!ppc_hash64_use_vrma(env)) {
> > - return;
> > - }
> > -
> > - /*
> > - * Make one up. Mostly ignore the ESID which will not be needed
> > - * for translation
> > - */
> > - lpcr = env->spr[SPR_LPCR];
> > - vsid = SLB_VSID_VRMA;
> > - vrmasd = (lpcr & LPCR_VRMASD) >> LPCR_VRMASD_SHIFT;
> > - vsid |= (vrmasd << 4) & (SLB_VSID_L | SLB_VSID_LP);
> > - esid = SLB_ESID_V;
> > -
> > - for (i = 0; i < PPC_PAGE_SIZES_MAX_SZ; i++) {
> > - const PPCHash64SegmentPageSizes *sps1 = &cpu->hash64_opts->sps[i];
> > -
> > - if (!sps1->page_shift) {
> > - break;
> > + if (ppc_hash64_use_vrma(env)) {
> > + if (build_vrma_slbe(cpu, slb) == 0) {
> > + return;
> > }
> > -
> > - if ((vsid & SLB_VSID_LLP_MASK) == sps1->slb_enc) {
> > - sps = sps1;
> > - break;
> > - }
> > - }
> > -
> > - if (!sps) {
> > - error_report("Bad page size encoding esid 0x"TARGET_FMT_lx
> > - " vsid 0x"TARGET_FMT_lx, esid, vsid);
> > - return;
> > }
> >
> > - slb->vsid = vsid;
> > - slb->esid = esid;
> > - slb->sps = sps;
> > + /* Otherwise, clear it to indicate error */
> > + slb->esid = slb->vsid = 0;
> > + slb->sps = NULL;
> > }
> >
> > void ppc_store_lpcr(PowerPCCPU *cpu, target_ulong val)
> > @@ -1098,7 +1095,6 @@ void ppc_store_lpcr(PowerPCCPU *cpu, target_ulong val)
> > CPUPPCState *env = &cpu->env;
> >
> > env->spr[SPR_LPCR] = val & pcc->lpcr_mask;
> > - env->rmls = rmls_limit(cpu);
> > ppc_hash64_update_vrma(cpu);
> > }
> >
>
--
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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- [PATCH v6 10/18] target/ppc: Correct RMLS table, (continued)
- [PATCH v6 10/18] target/ppc: Correct RMLS table, David Gibson, 2020/02/24
- [PATCH v6 13/18] spapr: Don't use weird units for MIN_RMA_SLOF, David Gibson, 2020/02/24
- [PATCH v6 12/18] target/ppc: Don't store VRMA SLBE persistently, David Gibson, 2020/02/24
- [PATCH v6 11/18] target/ppc: Only calculate RMLS derived RMA limit on demand, David Gibson, 2020/02/24
- [PATCH v6 09/18] target/ppc: Streamline calculation of RMA limit from LPCR[RMLS], David Gibson, 2020/02/24
[PATCH v6 17/18] spapr: Clean up RMA size calculation, David Gibson, 2020/02/24