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Re: [PATCH 06/31] target/loongarch: Add mmu support for Loongarch CPU.
From: |
Richard Henderson |
Subject: |
Re: [PATCH 06/31] target/loongarch: Add mmu support for Loongarch CPU. |
Date: |
Tue, 19 Oct 2021 14:11:06 -0700 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 |
On 10/19/21 12:34 AM, Xiaojuan Yang wrote:
@@ -272,6 +288,7 @@ static const struct SysemuCPUOps loongarch_sysemu_ops = {
#ifdef CONFIG_TCG
#include "hw/core/tcg-cpu-ops.h"
+#ifdef CONFIG_USER_ONLY
static bool loongarch_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
MMUAccessType access_type, int mmu_idx,
bool probe, uintptr_t retaddr)
@@ -280,9 +297,14 @@ static bool loongarch_cpu_tlb_fill(CPUState *cs, vaddr
address, int size,
CPULoongArchState *env = &cpu->env;
env->badaddr = address;
- cs->exception_index = EXCP_ADE;
+ if (access_type == MMU_DATA_STORE) {
+ cs->exception_index = EXCP_ADES;
+ } else {
+ cs->exception_index = EXCP_ADEL;
+ }
do_raise_exception(env, cs->exception_index, retaddr);
}
+#endif
It's too early to add this ifdef. With what's upstream at the moment, you've broken
loongarch-linux-user build by removing loongarch_cpu_tlb_fill.
There are patches out for review that would require tlb_fill be a system-only hook, but
they have not landed yet.
+#define LOONGARCH_HFLAG_KU 0x00003 /* kernel/user mode mask */
+#define LOONGARCH_HFLAG_UM 0x00003 /* user mode flag */
+#define LOONGARCH_HFLAG_KM 0x00000 /* kernel mode flag */
I think you might as well represent all 3 priv levels: it's not a "kernel/user"
mask.
+#define EXCP_TLB_NOMATCH 0x1
+#define EXCP_INST_NOTAVAIL 0x2 /* No valid instruction word for BadInstr */
These should be with the other EXCP values in the enum.
At the moment you're overlapping EXCP_ADES and EXCP_SYSCALL.
@@ -130,7 +139,11 @@ void loongarch_cpu_list(void);
static inline int cpu_mmu_index(CPULoongArchState *env, bool ifetch)
{
+#ifdef CONFIG_USER_ONLY
return MMU_USER_IDX;
+#else
+ return env->CSR_CRMD & LOONGARCH_HFLAG_KU;
Better would be
return FIELD_EX64(env->CSR_CRMD, CSR_CRMD, PLV);
since that's the field you're extracting from CRMD.
+typedef struct ls3a5k_tlb_t ls3a5k_tlb_t;
Types should be in CamelCase, without _t suffix.
+struct ls3a5k_tlb_t {
+ target_ulong VPN;
+ uint64_t PageMask;
+ uint32_t PageSize;
+ uint16_t ASID;
+ unsigned int V0:1; /* CSR_TLBLO[0] */
+ unsigned int V1:1;
+
+ unsigned int D0:1; /* CSR_TLBLO[1] */
+ unsigned int D1:1;
+
+ unsigned int PLV0:2; /* CSR_TLBLO[3:2] */
+ unsigned int PLV1:2;
+
+ unsigned int MAT0:3; /* CSR_TLBLO[5:4] */
+ unsigned int MAT1:3;
+
+ unsigned int G:1; /* CSR_TLBLO[6] */
+
+ uint64_t PPN0; /* CSR_TLBLO[47:12] */
+ uint64_t PPN1;
+
+ unsigned int NR0:1; /* CSR_TLBLO[61] */
+ unsigned int NR1:1;
+
+ unsigned int NX0:1; /* CSR_TLBLO[62] */
+ unsigned int NX1:1;
+
+ unsigned int NE:1; /* CSR_TLBIDX[31] */
+
+ unsigned int RPLV0:1;
+ unsigned int RPLV1:1; /* CSR_TLBLO[63] */
+};
It would be much better if you didn't use bitfields at all. This was a bad idea when mips
did it; let us not compound the error.
Just use the format defined by the architecture for the CSRs: a couple of uint64_t. Use
FIELD definitions to give the parts intelligible names.
+typedef struct ls3a5k_tlb_t ls3a5k_tlb_t;
+
+struct CPULoongArchTLBContext {
+ uint32_t nb_tlb;
+ int (*map_address)(struct CPULoongArchState *env, hwaddr *physical,
+ int *prot, target_ulong address,
+ MMUAccessType access_type);
+ struct {
+ uint64_t stlb_mask;
+ uint32_t stlb_size; /* at most : 8 * 256 = 2048 */
+ uint32_t mtlb_size; /* at most : 64 */
+ ls3a5k_tlb_t tlb[LOONGARCH_TLB_MAX];
+ } ls3a5k;
+};
There's probably no point in using an indirect function call until you've got more than
one mmu implementation. You're copying too much from mips.
+/* TLB state */
+static int get_tlb(QEMUFile *f, void *pv, size_t size,
+ const VMStateField *field)
+{
+ ls3a5k_tlb_t *v = pv;
+ uint32_t flags;
+
+ qemu_get_betls(f, &v->VPN);
+ qemu_get_be64s(f, &v->PageMask);
+ qemu_get_be32s(f, &v->PageSize);
+ qemu_get_be16s(f, &v->ASID);
+ qemu_get_be32s(f, &flags);
+ v->RPLV1 = (flags >> 21) & 1;
+ v->RPLV0 = (flags >> 20) & 1;
+ v->PLV1 = (flags >> 18) & 3;
+ v->PLV0 = (flags >> 16) & 3;
+ v->NE = (flags >> 15) & 1;
+ v->NR1 = (flags >> 14) & 1;
+ v->NR0 = (flags >> 13) & 1;
+ v->NX1 = (flags >> 12) & 1;
+ v->NX0 = (flags >> 11) & 1;
+ v->D1 = (flags >> 10) & 1;
+ v->D0 = (flags >> 9) & 1;
+ v->V1 = (flags >> 8) & 1;
+ v->V0 = (flags >> 7) & 1;
+ v->MAT1 = (flags >> 4) & 7;
+ v->MAT0 = (flags >> 1) & 7;
+ v->G = (flags >> 0) & 1;
+ qemu_get_be64s(f, &v->PPN0);
+ qemu_get_be64s(f, &v->PPN1);
Some of the ugly things that go away if you don't use bitfields.
+const VMStateDescription vmstate_tlb = {
+ .name = "cpu/tlb",
+ .version_id = 2,
+ .minimum_version_id = 2,
Too much copying again: version numbers do not start at 2.
+void ls3a5k_mmu_init(CPULoongArchState *env)
+{
+ env->tlb = g_malloc0(sizeof(CPULoongArchTLBContext));
I think you should not make this a separate structure, and instead allocate this with
CPULoongArchState.
diff --git a/target/loongarch/translate.c b/target/loongarch/translate.c
index bea290df66..0be29994f9 100644
--- a/target/loongarch/translate.c
+++ b/target/loongarch/translate.c
@@ -61,9 +61,10 @@ static void loongarch_tr_init_disas_context(DisasContextBase
*dcbase,
{
int64_t bound;
DisasContext *ctx = container_of(dcbase, DisasContext, base);
+ CPULoongArchState *env = cs->env_ptr;
ctx->page_start = ctx->base.pc_first & TARGET_PAGE_MASK;
- ctx->mem_idx = MMU_USER_IDX;
+ ctx->mem_idx = cpu_mmu_index(env, false);
This is incorrect. You want
tb_flags = ctx->base.tb->flags;
mem_idx = tb_flags & LOONGARCH_HFLAG_PRIV.
It is almost always incorrect to dereference env at this point. Everything should have
been encoded into tb_flags so that when we do the hashing of the TranslationBlocks we find
the one that has been compiled for the correct privilege level, etc.
r~
- [PATCH 17/31] hw/intc: Add loongarch ls7a interrupt controller support(PCH-PIC), (continued)
- [PATCH 17/31] hw/intc: Add loongarch ls7a interrupt controller support(PCH-PIC), Xiaojuan Yang, 2021/10/19
- [PATCH 16/31] hw/loongarch: Add loongarch ipi interrupt support(IPI), Xiaojuan Yang, 2021/10/19
- [PATCH 20/31] hw/loongarch: Add irq hierarchy for the system, Xiaojuan Yang, 2021/10/19
- [PATCH 14/31] hw/loongarch: Add a virt loongarch 3A5000 board support, Xiaojuan Yang, 2021/10/19
- [PATCH 15/31] hw/loongarch: Add loongarch cpu interrupt support(CPUINTC), Xiaojuan Yang, 2021/10/19
- Re: [PATCH 00/31] Add Loongarch softmmu support., WANG Xuerui, 2021/10/19
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- Re: [PATCH 06/31] target/loongarch: Add mmu support for Loongarch CPU.,
Richard Henderson <=
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