|
| From: | LIU Zhiwei |
| Subject: | Re: [RFC PATCH 01/11] target/riscv: Add CLIC CSR mintstatus |
| Date: | Fri, 2 Jul 2021 14:09:50 +0800 |
| User-agent: | Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 |
On 2021/7/2 下午1:38, Alistair Francis wrote:
On Thu, Jul 1, 2021 at 6:45 PM Frank Chang <frank.chang@sifive.com> wrote:LIU Zhiwei <zhiwei_liu@c-sky.com> 於 2021年4月20日 週二 上午8:49寫道：On 2021/4/20 上午7:23, Alistair Francis wrote:On Fri, Apr 9, 2021 at 5:52 PM LIU Zhiwei <zhiwei_liu@c-sky.com> wrote:CSR mintstatus holds the active interrupt level for each supported privilege mode. sintstatus, and user, uintstatus, provide restricted views of mintstatus. Signed-off-by: LIU Zhiwei <zhiwei_liu@c-sky.com> --- target/riscv/cpu.h | 2 ++ target/riscv/cpu_bits.h | 11 +++++++++++ target/riscv/csr.c | 26 ++++++++++++++++++++++++++ 3 files changed, 39 insertions(+) diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h index 0a33d387ba..1a44ca62c7 100644 --- a/target/riscv/cpu.h +++ b/target/riscv/cpu.h @@ -159,6 +159,7 @@ struct CPURISCVState { target_ulong mip; uint32_t miclaim; + uint32_t mintstatus; /* clic-spec */ target_ulong mie; target_ulong mideleg; @@ -243,6 +244,7 @@ struct CPURISCVState { /* Fields from here on are preserved across CPU reset. */ QEMUTimer *timer; /* Internal timer */ + void *clic; /* clic interrupt controller */This should be the CLIC type.OK. Actually there are many versions of CLIC in my branch as different devices. But it is better to use CLIC type for the upstream version.Hi Alistair and Zhiwei, Replacing void *clic with RISCVCLICState *clic may create a circular loop because CPURISCVState is also referenced in riscv_clic.h. However, I would like to ask what is the best approach to add the reference of CLIC device in CPURISCVState struct? There may be different kinds of CLIC devices. AFAK, there was another RFC patchset trying to add void *eclic for Nuclei processor into CPURISCVState struct: https://patchwork.kernel.org/project/qemu-devel/patch/20210507081654.11056-2-wangjunqiang@iscas.ac.cn/ Is it okay to add the device reference directly into CPURISCVState struct like that, or we should create some abstraction for these CLIC devices? (However, I'm not sure how big the differences are for these CLIC devices...)I would prefer to not have the CLIC in the struct at all. Why is the CLIC required from the CPU?
In my opinion, the tight coupled interrupt controller, like NVIC in ARM, is much different from other devices.
CPU harts need to communicate with it through many ways.We can store the CLIC instance in the struct CPURISCVState or a global variable. Is that any other way?
I'm guessing we at least need it for CLIC CSR accesses. Could we handle that in the CPU and avoid needing a reference to the CLIC?
CSR access is one case. Other cases are:1. When process an interrupt and decide ISP address, we need to know current interrupt is vectored or not.
2. When interrupt returned, we need to choose another interrupt to serve, so that it will not miss any interrupt.
Thanks, Zhiwei
AlistairThanks, Frank Chang}; OBJECT_DECLARE_TYPE(RISCVCPU, RISCVCPUClass, diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h index caf4599207..c4ce6ec3d9 100644 --- a/target/riscv/cpu_bits.h +++ b/target/riscv/cpu_bits.h @@ -165,6 +165,7 @@ #define CSR_MCAUSE 0x342 #define CSR_MTVAL 0x343 #define CSR_MIP 0x344 +#define CSR_MINTSTATUS 0x346 /* clic-spec-draft */ /* Legacy Machine Trap Handling (priv v1.9.1) */ #define CSR_MBADADDR 0x343 @@ -183,6 +184,7 @@ #define CSR_SCAUSE 0x142 #define CSR_STVAL 0x143 #define CSR_SIP 0x144 +#define CSR_SINTSTATUS 0x146 /* clic-spec-draft */ /* Legacy Supervisor Trap Handling (priv v1.9.1) */ #define CSR_SBADADDR 0x143 @@ -585,6 +587,15 @@ #define SIP_STIP MIP_STIP #define SIP_SEIP MIP_SEIP +/* mintstatus */ +#define MINTSTATUS_MIL 0xff000000 /* mil[7:0] */ +#define MINTSTATUS_SIL 0x0000ff00 /* sil[7:0] */ +#define MINTSTATUS_UIL 0x000000ff /* uil[7:0] */ + +/* sintstatus */ +#define SINTSTATUS_SIL 0x0000ff00 /* sil[7:0] */ +#define SINTSTATUS_UIL 0x000000ff /* uil[7:0] */The bit fields in the comments are out of date.I didn't notice it. Fix it in next version. Thanks. ZhiweiAlistair+ /* MIE masks */ #define MIE_SEIE (1 << IRQ_S_EXT) #define MIE_UEIE (1 << IRQ_U_EXT) diff --git a/target/riscv/csr.c b/target/riscv/csr.c index d2585395bf..320b18ab60 100644 --- a/target/riscv/csr.c +++ b/target/riscv/csr.c @@ -188,6 +188,12 @@ static int pmp(CPURISCVState *env, int csrno) { return -!riscv_feature(env, RISCV_FEATURE_PMP); } + +static int clic(CPURISCVState *env, int csrno) +{ + return !!env->clic; +} + #endif /* User Floating-Point CSRs */ @@ -734,6 +740,12 @@ static int rmw_mip(CPURISCVState *env, int csrno, target_ulong *ret_value, return 0; } +static int read_mintstatus(CPURISCVState *env, int csrno, target_ulong *val) +{ + *val = env->mintstatus; + return 0; +} + /* Supervisor Trap Setup */ static int read_sstatus(CPURISCVState *env, int csrno, target_ulong *val) { @@ -893,6 +905,13 @@ static int rmw_sip(CPURISCVState *env, int csrno, target_ulong *ret_value, return ret; } +static int read_sintstatus(CPURISCVState *env, int csrno, target_ulong *val) +{ + target_ulong mask = SINTSTATUS_SIL | SINTSTATUS_UIL; + *val = env->mintstatus & mask; + return 0; +} + /* Supervisor Protection and Translation */ static int read_satp(CPURISCVState *env, int csrno, target_ulong *val) { @@ -1644,5 +1663,12 @@ riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = { [CSR_MHPMCOUNTER29H] = { "mhpmcounter29h", any32, read_zero }, [CSR_MHPMCOUNTER30H] = { "mhpmcounter30h", any32, read_zero }, [CSR_MHPMCOUNTER31H] = { "mhpmcounter31h", any32, read_zero }, + + /* Machine Mode Core Level Interrupt Controller */ + [CSR_MINTSTATUS] = { "mintstatus", clic, read_mintstatus }, + + /* Supervisor Mode Core Level Interrupt Controller */ + [CSR_SINTSTATUS] = { "sintstatus", clic, read_sintstatus }, + #endif /* !CONFIG_USER_ONLY */ }; -- 2.25.1
| [Prev in Thread] | Current Thread | [Next in Thread] |