target-ppc: Rework SLB page size lookup
Currently, the ppc_hash64_page_shift() function looks up a page size based
on information in an SLB entry. It open codes the bit translation for
existing CPUs, however different CPU models can have different SLB
encodings. We already store those in the 'sps' table in CPUPPCState, but
we don't currently enforce that that actually matches the logic in
ppc_hash64_page_shift.
This patch reworks lookup of page size from SLB in several ways:
* ppc_store_slb() will now fail (triggering an illegal instruction
exception) if given a bad SLB page size encoding
* On success ppc_store_slb() stores a pointer to the relevant entry in
the page size table in the SLB entry. This is looked up directly from
the published table of page size encodings, so can't get out ot sync.
* ppc_hash64_htab_lookup() and others now use this precached page size
information rather than decoding the SLB values
* Now that callers have easy access to the page_shift,
ppc_hash64_pte_raddr() amounts to just a deposit64(), so remove it and
have the callers use deposit64() directly.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Alexander Graf <agraf@suse.de>
diff --git a/target-ppc/mmu-hash64.c b/target-ppc/mmu-hash64.c
index 788725c..9ad02f3 100644
--- a/target-ppc/mmu-hash64.c
+++ b/target-ppc/mmu-hash64.c
@@ -20,6 +20,7 @@
#include "qemu/osdep.h"
#include "cpu.h"
#include "exec/helper-proto.h"
+#include "qemu/error-report.h"
#include "sysemu/kvm.h"
#include "kvm_ppc.h"
#include "mmu-hash64.h"
@@ -141,6 +142,8 @@
{
CPUPPCState *env = &cpu->env;
ppc_slb_t *slb = &env->slb[slot];
+ const struct ppc_one_seg_page_size *sps = NULL;
+ int i;
if (slot >= env->slb_nr) {
return -1; /* Bad slot number */
@@ -155,8 +158,29 @@
return -1; /* 1T segment on MMU that doesn't support it */
}
+ for (i = 0; i < PPC_PAGE_SIZES_MAX_SZ; i++) {
+ const struct ppc_one_seg_page_size *sps1 = &env->sps.sps[i];
+
+ if (!sps1->page_shift) {
+ break;
+ }
+
+ if ((vsid & SLB_VSID_LLP_MASK) == sps1->slb_enc) {
+ sps = sps1;
+ break;
+ }
+ }
+
+ if (!sps) {
+ error_report("Bad page size encoding in SLB store: slot "TARGET_FMT_lu
+ " esid 0x"TARGET_FMT_lx" vsid 0x"TARGET_FMT_lx,
+ slot, esid, vsid);
+ return -1;
+ }
+
slb->esid = esid;
slb->vsid = vsid;
+ slb->sps = sps;
LOG_SLB("%s: %d " TARGET_FMT_lx " - " TARGET_FMT_lx " => %016" PRIx64
" %016" PRIx64 "\n", __func__, slot, esid, vsid,
@@ -395,24 +419,6 @@
return -1;
}
-static uint64_t ppc_hash64_page_shift(ppc_slb_t *slb)
-{
- uint64_t epnshift;
-
- /* Page size according to the SLB, which we use to generate the
- * EPN for hash table lookup.. When we implement more recent MMU
- * extensions this might be different from the actual page size
- * encoded in the PTE */
- if ((slb->vsid & SLB_VSID_LLP_MASK) == SLB_VSID_4K) {
- epnshift = TARGET_PAGE_BITS;
- } else if ((slb->vsid & SLB_VSID_LLP_MASK) == SLB_VSID_64K) {
- epnshift = TARGET_PAGE_BITS_64K;
- } else {
- epnshift = TARGET_PAGE_BITS_16M;
- }
- return epnshift;
-}
-
static hwaddr ppc_hash64_htab_lookup(PowerPCCPU *cpu,
ppc_slb_t *slb, target_ulong eaddr,
ppc_hash_pte64_t *pte)
@@ -420,21 +426,24 @@
CPUPPCState *env = &cpu->env;
hwaddr pte_offset;
hwaddr hash;
- uint64_t vsid, epnshift, epnmask, epn, ptem;
+ uint64_t vsid, epnmask, epn, ptem;
- epnshift = ppc_hash64_page_shift(slb);
- epnmask = ~((1ULL << epnshift) - 1);
+ /* The SLB store path should prevent any bad page size encodings
+ * getting in there, so: */
+ assert(slb->sps);
+
+ epnmask = ~((1ULL << slb->sps->page_shift) - 1);
if (slb->vsid & SLB_VSID_B) {
/* 1TB segment */
vsid = (slb->vsid & SLB_VSID_VSID) >> SLB_VSID_SHIFT_1T;
epn = (eaddr & ~SEGMENT_MASK_1T) & epnmask;
- hash = vsid ^ (vsid << 25) ^ (epn >> epnshift);
+ hash = vsid ^ (vsid << 25) ^ (epn >> slb->sps->page_shift);
} else {
/* 256M segment */
vsid = (slb->vsid & SLB_VSID_VSID) >> SLB_VSID_SHIFT;
epn = (eaddr & ~SEGMENT_MASK_256M) & epnmask;
- hash = vsid ^ (epn >> epnshift);
+ hash = vsid ^ (epn >> slb->sps->page_shift);
}
ptem = (slb->vsid & SLB_VSID_PTEM) | ((epn >> 16) & HPTE64_V_AVPN);
@@ -466,20 +475,6 @@
return pte_offset;
}
-static hwaddr ppc_hash64_pte_raddr(ppc_slb_t *slb, ppc_hash_pte64_t pte,
- target_ulong eaddr)
-{
- hwaddr mask;
- int target_page_bits;
- hwaddr rpn = pte.pte1 & HPTE64_R_RPN;
- /*
- * We support 4K, 64K and 16M now
- */
- target_page_bits = ppc_hash64_page_shift(slb);
- mask = (1ULL << target_page_bits) - 1;
- return (rpn & ~mask) | (eaddr & mask);
-}
-
int ppc_hash64_handle_mmu_fault(PowerPCCPU *cpu, target_ulong eaddr,
int rwx, int mmu_idx)
{
@@ -601,7 +596,7 @@
/* 7. Determine the real address from the PTE */
- raddr = ppc_hash64_pte_raddr(slb, pte, eaddr);
+ raddr = deposit64(pte.pte1 & HPTE64_R_RPN, 0, slb->sps->page_shift, eaddr);
tlb_set_page(cs, eaddr & TARGET_PAGE_MASK, raddr & TARGET_PAGE_MASK,
prot, mmu_idx, TARGET_PAGE_SIZE);
@@ -631,7 +626,8 @@
return -1;
}
- return ppc_hash64_pte_raddr(slb, pte, addr) & TARGET_PAGE_MASK;
+ return deposit64(pte.pte1 & HPTE64_R_RPN, 0, slb->sps->page_shift, addr)
+ & TARGET_PAGE_MASK;
}
void ppc_hash64_store_hpte(PowerPCCPU *cpu,
