Re: [Qemu-devel] [PATCH 5/6] [RFC] Emulation of Leon3.

[Blue Swirl]

On Mon, Dec 6, 2010 at 9:26 AM, Fabien Chouteau <address@hidden> wrote:
>
> Signed-off-by: Fabien Chouteau <address@hidden>
> ---
>  Makefile.target          |    5 +-
>  hw/leon3.c               |  310 
> ++++++++++++++++++++++++++++++++++++++++++++++
>  target-sparc/cpu.h       |   10 ++
>  target-sparc/helper.c    |    2 +-
>  target-sparc/op_helper.c |   30 ++++-
>  5 files changed, 353 insertions(+), 4 deletions(-)
>
> diff --git a/Makefile.target b/Makefile.target
> index 2800f47..f40e04f 100644
> --- a/Makefile.target
> +++ b/Makefile.target
> @@ -290,7 +290,10 @@ obj-sparc-y += cirrus_vga.o
>  else
>  obj-sparc-y = sun4m.o lance.o tcx.o sun4m_iommu.o slavio_intctl.o
>  obj-sparc-y += slavio_timer.o slavio_misc.o sparc32_dma.o
> -obj-sparc-y += cs4231.o eccmemctl.o sbi.o sun4c_intctl.o
> +obj-sparc-y += cs4231.o eccmemctl.o sbi.o sun4c_intctl.o leon3.o
> +
> +# GRLIB
> +obj-sparc-y += grlib_gptimer.o grlib_irqmp.o grlib_apbuart.o
>  endif
>
>  obj-arm-y = integratorcp.o versatilepb.o arm_pic.o arm_timer.o
> diff --git a/hw/leon3.c b/hw/leon3.c
> new file mode 100644
> index 0000000..ba61081
> --- /dev/null
> +++ b/hw/leon3.c
> @@ -0,0 +1,310 @@
> +/*
> + * QEMU Leon3 System Emulator
> + *
> + * Copyright (c) 2010 AdaCore
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a 
> copy
> + * of this software and associated documentation files (the "Software"), to 
> deal
> + * in the Software without restriction, including without limitation the 
> rights
> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
> + * copies of the Software, and to permit persons to whom the Software is
> + * furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
> FROM,
> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
> + * THE SOFTWARE.
> + */
> +#include "hw.h"
> +#include "qemu-timer.h"
> +#include "qemu-char.h"
> +#include "sysemu.h"
> +#include "boards.h"
> +#include "loader.h"
> +#include "elf.h"
> +
> +#include "grlib.h"
> +
> +/* #define DEBUG_LEON3 */
> +
> +#ifdef DEBUG_LEON3
> +#define DPRINTF(fmt, ...)                                       \
> +    do { printf("Leon3: " fmt , ## __VA_ARGS__); } while (0)
> +#else
> +#define DPRINTF(fmt, ...)
> +#endif
> +
> +/* Default system clock.  */
> +#define CPU_CLK (40 * 1000 * 1000)
> +
> +#define PROM_FILENAME        "u-boot.bin"
> +
> +#define MAX_PILS 16
> +
> +typedef struct Leon3State
> +{
> +    uint32_t cache_control;
> +    uint32_t inst_cache_conf;
> +    uint32_t data_cache_conf;
> +
> +    uint64_t entry;             /* save kernel entry in case of reset */
> +} Leon3State;
> +
> +Leon3State leon3_state;

Again global state, please refactor. Perhaps most of the cache
handling code belong to target-sparc/op_helper.c and this structure to
CPUSPARCState.

> +
> +/* Cache control: emulate the behavior of cache control registers but without
> +   any effect on the emulated CPU */
> +
> +#define CACHE_DISABLED 0x0
> +#define CACHE_FROZEN   0x1
> +#define CACHE_ENABLED  0x3
> +
> +/* Cache Control register fields */
> +
> +#define CACHE_CTRL_IF (1 <<  4)  /* Instruction Cache Freeze on Interrupt */
> +#define CACHE_CTRL_DF (1 <<  5)  /* Data Cache Freeze on Interrupt */
> +#define CACHE_CTRL_DP (1 << 14)  /* Data cache flush pending */
> +#define CACHE_CTRL_IP (1 << 15)  /* Instruction cache flush pending */
> +#define CACHE_CTRL_IB (1 << 16)  /* Instruction burst fetch */
> +#define CACHE_CTRL_FI (1 << 21)  /* Flush Instruction cache (Write only) */
> +#define CACHE_CTRL_FD (1 << 22)  /* Flush Data cache (Write only) */
> +#define CACHE_CTRL_DS (1 << 23)  /* Data cache snoop enable */
> +
> +void leon3_cache_control_int(void)
> +{
> +    uint32_t state = 0;
> +
> +    if (leon3_state.cache_control & CACHE_CTRL_IF) {
> +        /* Instruction cache state */
> +        state = leon3_state.cache_control & 0x3;

Please add a new define CACHE_CTRL_xxx to replace 0x3.

> +        if (state == CACHE_ENABLED) {
> +            state = CACHE_FROZEN;
> +            DPRINTF("Instruction cache: freeze\n");
> +        }
> +
> +        leon3_state.cache_control &= ~0x3;
> +        leon3_state.cache_control |= state;
> +    }
> +
> +    if (leon3_state.cache_control & CACHE_CTRL_DF) {
> +        /* Data cache state */
> +        state = (leon3_state.cache_control >> 2) & 0x3;
> +        if (state == CACHE_ENABLED) {
> +            state = CACHE_FROZEN;
> +            DPRINTF("Data cache: freeze\n");
> +        }
> +
> +        leon3_state.cache_control &= ~(0x3 << 2);
> +        leon3_state.cache_control |= (state << 2);
> +    }
> +}
> +
> +void leon3_cache_control_st(target_ulong addr, uint64_t val, int size)
> +{
> +    DPRINTF("cc st addr:%lu, val:0x%x, size:%d\n", (long unsigned int)addr,
> +            (unsigned int)val, size);

There's PRIx64 to print uint64_t portably, then the casts can be removed.

> +
> +    if (size != 4) {
> +        DPRINTF(" CC 32bits only\n");
> +        return;
> +    }
> +
> +    switch (addr) {
> +        case 0x00:              /* Cache control */
> +
> +            /* These values must always be read as zeros */
> +            val &= ~CACHE_CTRL_FD;
> +            val &= ~CACHE_CTRL_FI;
> +            val &= ~CACHE_CTRL_IB;
> +            val &= ~CACHE_CTRL_IP;
> +            val &= ~CACHE_CTRL_DP;
> +
> +            leon3_state.cache_control = val;
> +            break;
> +        case 0x04:              /* Instruction cache configuration */
> +        case 0x08:              /* Data cache configuration */
> +            /* Read Only */
> +            break;
> +        default:
> +            DPRINTF(" CC write unknown register 0x%04x\n", (int)addr);
> +            break;
> +    };
> +}
> +
> +uint64_t leon3_cache_control_ld(target_ulong addr, int size)
> +{
> +    uint64_t ret = 0;
> +
> +    if (size != 4) {
> +        DPRINTF(" CC 32bits only\n");
> +        return 0;
> +    }
> +
> +    switch (addr) {
> +        case 0x00:              /* Cache control */
> +            ret = leon3_state.cache_control;
> +            break;
> +        case 0x04:              /* Instruction cache configuration */
> +            ret = leon3_state.inst_cache_conf;
> +            break;
> +        case 0x08:              /* Data cache configuration */
> +            ret = leon3_state.data_cache_conf;
> +            break;
> +        default:
> +            DPRINTF(" CC read unknown register 0x%04x\n", (int)addr);
> +            break;
> +    };
> +    DPRINTF("cc ld addr:%lu, size:%d, ret:%lu\n", (long unsigned int)addr,
> +            size, (long unsigned int)ret );
> +    return ret;
> +}
> +
> +void leon3_shutdown(void)
> +{
> +    qemu_system_shutdown_request();
> +}
> +
> +static void main_cpu_reset(void *opaque)
> +{
> +    CPUState *env = opaque;

Here you can introduce a helper structure to pass PC and NPC, like
sun4u.c ResetData. Then the global state should not be needed anymore.

> +
> +    cpu_reset(env);
> +
> +    env->halted = 0;
> +    env->pc     = leon3_state.entry;
> +    env->npc    = leon3_state.entry + 4;
> +
> +    /* Initialize cache control */
> +    leon3_state.cache_control   = 0x0;
> +
> +    /* Configuration registers are read and only always keep those predefined
> +       values */
> +    leon3_state.inst_cache_conf = 0x10220000;
> +    leon3_state.data_cache_conf = 0x18220000;
> +}
> +
> +static void leon3_generic_hw_init(ram_addr_t  ram_size,
> +                                  const char *boot_device,
> +                                  const char *kernel_filename,
> +                                  const char *kernel_cmdline,
> +                                  const char *initrd_filename,
> +                                  const char *cpu_model)
> +{
> +    CPUState   *env;
> +    ram_addr_t  ram_offset, prom_offset;
> +    int         ret;
> +    char       *filename;
> +    qemu_irq   *cpu_irqs = NULL;
> +    int         bios_size;
> +    int         prom_size;
> +    int         aligned_bios_size;
> +
> +    /* Init CPU */
> +    if (!cpu_model)
> +        cpu_model = "LEON3";

Missing braces.

> +
> +    env = cpu_init(cpu_model);
> +    if (!env) {
> +        fprintf(stderr, "qemu: Unable to find Sparc CPU definition\n");
> +        exit(1);
> +    }
> +
> +    cpu_sparc_set_id(env, 0);
> +
> +    qemu_register_reset(main_cpu_reset, env);
> +
> +    /* Allocate IRQ manager */
> +    grlib_irqmp_create(0x80000200, env, &cpu_irqs, MAX_PILS);
> +
> +    /* Allocate RAM */
> +    if ((uint64_t)ram_size > (1UL << 30)) {
> +        fprintf(stderr,
> +                "qemu: Too much memory for this machine: %d, maximum 1G\n",
> +                (unsigned int)(ram_size / (1024 * 1024)));
> +        exit(1);
> +    }
> +
> +    ram_offset = qemu_ram_alloc(NULL, "leon3.ram", ram_size);
> +    cpu_register_physical_memory(0x40000000, ram_size, ram_offset | 
> IO_MEM_RAM);
> +
> +    /* Allocate BIOS */
> +    prom_size = 8 * 1024 * 1024; /* 8Mb */
> +    prom_offset = qemu_ram_alloc(NULL, "Leon3.bios", prom_size);
> +    cpu_register_physical_memory(0x00000000, prom_size,
> +                                 prom_offset | IO_MEM_ROM);
> +
> +    /* Load boot prom */
> +    if (bios_name == NULL)
> +        bios_name = PROM_FILENAME;
> +    filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, bios_name);
> +
> +    bios_size = get_image_size(filename);
> +
> +    if (bios_size > prom_size) {
> +        fprintf(stderr, "qemu: could not load prom '%s': file too big \n",
> +                filename);
> +        exit(1);
> +    }
> +
> +    if (bios_size > 0) {
> +        aligned_bios_size =
> +            (bios_size + TARGET_PAGE_SIZE - 1) & TARGET_PAGE_MASK;
> +
> +        ret = load_image_targphys(filename, 0x00000000, bios_size);
> +        if (ret < 0 || ret > prom_size) {
> +            fprintf(stderr, "qemu: could not load prom '%s'\n", filename);
> +            exit(1);
> +        }
> +    }
> +    else if (kernel_filename == NULL) {
> +        fprintf(stderr,"Can't read bios image %s\n", filename);
> +        exit(1);
> +    }
> +
> +    /* Can directly load an application. */
> +    if (kernel_filename != NULL) {
> +        long     kernel_size;
> +        uint64_t entry;
> +
> +        kernel_size = load_elf(kernel_filename, NULL, NULL, &entry, NULL, 
> NULL,
> +                               1 /* big endian */, ELF_MACHINE, 0);
> +        if (kernel_size < 0) {
> +            fprintf(stderr, "qemu: could not load kernel '%s'\n",
> +                    kernel_filename);
> +            exit(1);
> +        }
> +        if (bios_size <= 0) {
> +            /* If there is no bios/monitor, start the application.  */
> +            env->pc = entry;
> +            env->npc = entry + 4;
> +            leon3_state.entry = entry;
> +        }
> +    }
> +
> +    /* Allocate timers */
> +    grlib_gptimer_create(0x80000300, 2, CPU_CLK, cpu_irqs, 6);
> +
> +    /* Allocate uart */
> +    if (serial_hds[0])
> +        grlib_apbuart_create(0x80000100, serial_hds[0], cpu_irqs[3]);
> +}
> +
> +QEMUMachine leon3_generic_machine = {
> +    .name     = "leon3_generic",
> +    .desc     = "Leon-3 generic",
> +    .init     = leon3_generic_hw_init,
> +    .use_scsi = 0,
> +};
> +
> +static void leon3_machine_init(void)
> +{
> +    qemu_register_machine(&leon3_generic_machine);
> +}
> +
> +machine_init(leon3_machine_init);
> diff --git a/target-sparc/cpu.h b/target-sparc/cpu.h
> index 7e0d17c..6020ffd 100644
> --- a/target-sparc/cpu.h
> +++ b/target-sparc/cpu.h
> @@ -474,6 +474,16 @@ void cpu_set_cwp(CPUState *env1, int new_cwp);
>  /* sun4m.c, sun4u.c */
>  void cpu_check_irqs(CPUSPARCState *env);
>
> +/* grlib_irqmp.c */
> +void grlib_irqmp_ack(CPUSPARCState *env, int intno);
> +
> +/* leon3.c */
> +void     leon3_shutdown(void);
> +void     leon3_cache_control_st(target_ulong addr, uint64_t val, int size);
> +uint64_t leon3_cache_control_ld(target_ulong addr, int size);
> +void     leon3_cache_control_int(void);
> +
> +
>  #if defined (TARGET_SPARC64)
>
>  static inline int compare_masked(uint64_t x, uint64_t y, uint64_t mask)
> diff --git a/target-sparc/helper.c b/target-sparc/helper.c
> index e84c312..3bf990f 100644
> --- a/target-sparc/helper.c
> +++ b/target-sparc/helper.c
> @@ -1295,7 +1295,7 @@ static const sparc_def_t sparc_defs[] = {
>         .iu_version = 0xf3000000,
>         .fpu_version = 4 << 17, /* FPU version 4 (Meiko) */
>         .mmu_version = 0xf3000000,
> -        .mmu_bm = 0x00004000,
> +        .mmu_bm = 0x00000000,
>         .mmu_ctpr_mask = 0x007ffff0,
>         .mmu_cxr_mask = 0x0000003f,
>         .mmu_sfsr_mask = 0xffffffff,
> diff --git a/target-sparc/op_helper.c b/target-sparc/op_helper.c
> index be3c1e0..85df077 100644
> --- a/target-sparc/op_helper.c
> +++ b/target-sparc/op_helper.c
> @@ -1609,8 +1609,13 @@ uint64_t helper_ld_asi(target_ulong addr, int asi, int 
> size, int sign)
>
>     helper_check_align(addr, size - 1);
>     switch (asi) {
> -    case 2: /* SuperSparc MXCC registers */
> +    case 2: /* SuperSparc MXCC registers and Leon3 cache control */
>         switch (addr) {
> +        case 0x00:          /* Leon3 Cache Control */
> +        case 0x08:          /* Leon3 Instruction Cache config */
> +        case 0x0C:          /* Leon3 Date Cache config */
> +            ret = leon3_cache_control_ld(addr, size);
> +            break;
>         case 0x01c00a00: /* MXCC control register */
>             if (size == 8)
>                 ret = env->mxccregs[3];
> @@ -1838,8 +1843,14 @@ void helper_st_asi(target_ulong addr, uint64_t val, 
> int asi, int size)
>  {
>     helper_check_align(addr, size - 1);
>     switch(asi) {
> -    case 2: /* SuperSparc MXCC registers */
> +    case 2: /* SuperSparc MXCC registers and Leon3 cache control */
>         switch (addr) {
> +        case 0x00:          /* Leon3 Cache Control */
> +        case 0x08:          /* Leon3 Instruction Cache config */
> +        case 0x0C:          /* Leon3 Date Cache config */
> +            leon3_cache_control_st(addr, val, size);
> +            break;
> +
>         case 0x01c00000: /* MXCC stream data register 0 */
>             if (size == 8)
>                 env->mxccdata[0] = val;
> @@ -4081,6 +4092,13 @@ void do_interrupt(CPUState *env)
>  {
>     int cwp, intno = env->exception_index;
>
> +#if !defined(CONFIG_USER_ONLY)
> +    /* Leon3 shutdown */
> +    if (intno == 0x80 && env->version == 0xf3000000) {
> +        leon3_shutdown();
> +    }

This looks like a hack. Should a trap instruction initiate a shutdown?

> +#endif
> +
>  #ifdef DEBUG_PCALL
>     if (qemu_loglevel_mask(CPU_LOG_INT)) {
>         static int count;
> @@ -4135,6 +4153,14 @@ void do_interrupt(CPUState *env)
>     env->pc = env->tbr;
>     env->npc = env->pc + 4;
>     env->exception_index = -1;
> +
> +#if !defined(CONFIG_USER_ONLY)
> +    /* IRQ acknowledgment for Leon3 */
> +    if (env->version == 0xf3000000 && (intno & ~15) == TT_EXTINT) {
> +        grlib_irqmp_ack (env, intno);
> +        leon3_cache_control_int();
> +    }

Like this. I don't think a CPU should immediately ack any incoming interrupts.