ppc/hash32: Rework R and C bit updates

With MT-TCG, we are now running translation in a racy way, thus
we need to mimic hardware when it comes to updating the R and
C bits, by doing byte stores.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190411080004.8690-5-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This commit is contained in:
Benjamin Herrenschmidt 2019-04-11 10:00:02 +02:00 committed by David Gibson
parent a2dd4e83e7
commit 6e8a65abbb

View File

@ -345,6 +345,24 @@ static hwaddr ppc_hash32_pteg_search(PowerPCCPU *cpu, hwaddr pteg_off,
return -1; return -1;
} }
static void ppc_hash32_set_r(PowerPCCPU *cpu, hwaddr pte_offset, uint32_t pte1)
{
target_ulong base = ppc_hash32_hpt_base(cpu);
hwaddr offset = pte_offset + 6;
/* The HW performs a non-atomic byte update */
stb_phys(CPU(cpu)->as, base + offset, ((pte1 >> 8) & 0xff) | 0x01);
}
static void ppc_hash32_set_c(PowerPCCPU *cpu, hwaddr pte_offset, uint64_t pte1)
{
target_ulong base = ppc_hash32_hpt_base(cpu);
hwaddr offset = pte_offset + 7;
/* The HW performs a non-atomic byte update */
stb_phys(CPU(cpu)->as, base + offset, (pte1 & 0xff) | 0x80);
}
static hwaddr ppc_hash32_htab_lookup(PowerPCCPU *cpu, static hwaddr ppc_hash32_htab_lookup(PowerPCCPU *cpu,
target_ulong sr, target_ulong eaddr, target_ulong sr, target_ulong eaddr,
ppc_hash_pte32_t *pte) ppc_hash_pte32_t *pte)
@ -403,7 +421,6 @@ int ppc_hash32_handle_mmu_fault(PowerPCCPU *cpu, vaddr eaddr, int rwx,
hwaddr pte_offset; hwaddr pte_offset;
ppc_hash_pte32_t pte; ppc_hash_pte32_t pte;
int prot; int prot;
uint32_t new_pte1;
const int need_prot[] = {PAGE_READ, PAGE_WRITE, PAGE_EXEC}; const int need_prot[] = {PAGE_READ, PAGE_WRITE, PAGE_EXEC};
hwaddr raddr; hwaddr raddr;
@ -519,9 +536,12 @@ int ppc_hash32_handle_mmu_fault(PowerPCCPU *cpu, vaddr eaddr, int rwx,
/* 8. Update PTE referenced and changed bits if necessary */ /* 8. Update PTE referenced and changed bits if necessary */
new_pte1 = pte.pte1 | HPTE32_R_R; /* set referenced bit */ if (!(pte.pte1 & HPTE32_R_R)) {
ppc_hash32_set_r(cpu, pte_offset, pte.pte1);
}
if (!(pte.pte1 & HPTE32_R_C)) {
if (rwx == 1) { if (rwx == 1) {
new_pte1 |= HPTE32_R_C; /* set changed (dirty) bit */ ppc_hash32_set_c(cpu, pte_offset, pte.pte1);
} else { } else {
/* /*
* Treat the page as read-only for now, so that a later write * Treat the page as read-only for now, so that a later write
@ -529,9 +549,6 @@ int ppc_hash32_handle_mmu_fault(PowerPCCPU *cpu, vaddr eaddr, int rwx,
*/ */
prot &= ~PAGE_WRITE; prot &= ~PAGE_WRITE;
} }
if (new_pte1 != pte.pte1) {
ppc_hash32_store_hpte1(cpu, pte_offset, new_pte1);
} }
/* 9. Determine the real address from the PTE */ /* 9. Determine the real address from the PTE */