Currently we use a big switch statement in ppc_hash64_update_rmls() to work out what the right RMA limit is based on the LPCR[RMLS] field. There's no formula for this - it's just an arbitrary mapping defined by the existing CPU implementations - but we can make it a bit more readable by using a lookup table rather than a switch. In addition we can use the MiB/GiB symbols to make it a bit clearer.
While there we add a bit of clarity and rationale to the comment about what happens if the LPCR[RMLS] doesn't contain a valid value. Signed-off-by: David Gibson <da...@gibson.dropbear.id.au> Reviewed-by: Cédric Le Goater <c...@kaod.org> --- target/ppc/mmu-hash64.c | 63 ++++++++++++++++++----------------------- 1 file changed, 27 insertions(+), 36 deletions(-) diff --git a/target/ppc/mmu-hash64.c b/target/ppc/mmu-hash64.c index 0ef330a614..934989e6d9 100644 --- a/target/ppc/mmu-hash64.c +++ b/target/ppc/mmu-hash64.c @@ -18,6 +18,7 @@ * License along with this library; if not, see <http://www.gnu.org/licenses/>. */ #include "qemu/osdep.h" +#include "qemu/units.h" #include "cpu.h" #include "exec/exec-all.h" #include "exec/helper-proto.h" @@ -757,6 +758,31 @@ static void ppc_hash64_set_c(PowerPCCPU *cpu, hwaddr ptex, uint64_t pte1) stb_phys(CPU(cpu)->as, base + offset, (pte1 & 0xff) | 0x80); } +static target_ulong rmls_limit(PowerPCCPU *cpu) +{ + CPUPPCState *env = &cpu->env; + /* + * This is the full 4 bits encoding of POWER8. Previous + * CPUs only support a subset of these but the filtering + * is done when writing LPCR. + * + * Unsupported values mean the OS has shot itself in the + * foot. Return a 0-sized RMA in this case, which we expect + * to trigger an immediate DSI or ISI + */ + static const target_ulong rma_sizes[16] = { + [1] = 16 * GiB, + [2] = 1 * GiB, + [3] = 64 * MiB, + [4] = 256 * MiB, + [7] = 128 * MiB, + [8] = 32 * MiB, + }; + target_ulong rmls = (env->spr[SPR_LPCR] & LPCR_RMLS) >> LPCR_RMLS_SHIFT; + + return rma_sizes[rmls]; +} + int ppc_hash64_handle_mmu_fault(PowerPCCPU *cpu, vaddr eaddr, int rwx, int mmu_idx) { @@ -1006,41 +1032,6 @@ void ppc_hash64_tlb_flush_hpte(PowerPCCPU *cpu, target_ulong ptex, cpu->env.tlb_need_flush = TLB_NEED_GLOBAL_FLUSH | TLB_NEED_LOCAL_FLUSH; } -static void ppc_hash64_update_rmls(PowerPCCPU *cpu) -{ - CPUPPCState *env = &cpu->env; - uint64_t lpcr = env->spr[SPR_LPCR]; - - /* - * This is the full 4 bits encoding of POWER8. Previous - * CPUs only support a subset of these but the filtering - * is done when writing LPCR - */ - switch ((lpcr & LPCR_RMLS) >> LPCR_RMLS_SHIFT) { - case 0x8: /* 32MB */ - env->rmls = 0x2000000ull; - break; - case 0x3: /* 64MB */ - env->rmls = 0x4000000ull; - break; - case 0x7: /* 128MB */ - env->rmls = 0x8000000ull; - break; - case 0x4: /* 256MB */ - env->rmls = 0x10000000ull; - break; - case 0x2: /* 1GB */ - env->rmls = 0x40000000ull; - break; - case 0x1: /* 16GB */ - env->rmls = 0x400000000ull; - break; - default: - /* What to do here ??? */ - env->rmls = 0; - } -} - static void ppc_hash64_update_vrma(PowerPCCPU *cpu) { CPUPPCState *env = &cpu->env; @@ -1099,7 +1090,7 @@ void ppc_store_lpcr(PowerPCCPU *cpu, target_ulong val) CPUPPCState *env = &cpu->env; env->spr[SPR_LPCR] = val & pcc->lpcr_mask; - ppc_hash64_update_rmls(cpu); + env->rmls = rmls_limit(cpu); ppc_hash64_update_vrma(cpu); } -- 2.24.1
