Re: [Qemu-devel] [PATCH 19/24] target-arm: Implement AArch64 TTBR*

[Peter Crosthwaite]

On Wed, Jan 22, 2014 at 6:12 AM, Peter Maydell <address@hidden> wrote:
> Implement the AArch64 TTBR* registers. For v7 these were already 64 bits
> to handle LPAE, but implemented as two separate uint32_t fields.
> Combine them into a single uint64_t which can be used for all purposes.
> Since this requires touching every use, take the opportunity to rename
> the field to the architectural name.
>
> Signed-off-by: Peter Maydell <address@hidden>
> ---
>  hw/arm/pxa2xx.c     |  2 +-
>  target-arm/cpu.h    |  6 ++--
>  target-arm/helper.c | 95 
> +++++++++++++++++------------------------------------
>  3 files changed, 33 insertions(+), 70 deletions(-)
>
> diff --git a/hw/arm/pxa2xx.c b/hw/arm/pxa2xx.c
> index 02b7016..b6465d6 100644
> --- a/hw/arm/pxa2xx.c
> +++ b/hw/arm/pxa2xx.c
> @@ -279,7 +279,7 @@ static int pxa2xx_pwrmode_write(CPUARMState *env, const 
> ARMCPRegInfo *ri,
>              ARM_CPU_MODE_SVC | CPSR_A | CPSR_F | CPSR_I;
>          s->cpu->env.cp15.c1_sys = 0;
>          s->cpu->env.cp15.c1_coproc = 0;
> -        s->cpu->env.cp15.c2_base0 = 0;
> +        s->cpu->env.cp15.ttbr0_el1 = 0;
>          s->cpu->env.cp15.c3 = 0;
>          s->pm_regs[PSSR >> 2] |= 0x8; /* Set STS */
>          s->pm_regs[RCSR >> 2] |= 0x8; /* Set GPR */
> diff --git a/target-arm/cpu.h b/target-arm/cpu.h
> index 6f4d174..7138882 100644
> --- a/target-arm/cpu.h
> +++ b/target-arm/cpu.h
> @@ -173,10 +173,8 @@ typedef struct CPUARMState {
>          uint32_t c1_coproc; /* Coprocessor access register.  */
>          uint32_t c1_xscaleauxcr; /* XScale auxiliary control register.  */
>          uint32_t c1_scr; /* secure config register.  */
> -        uint32_t c2_base0; /* MMU translation table base 0.  */
> -        uint32_t c2_base0_hi; /* MMU translation table base 0, high 32 bits 
> */
> -        uint32_t c2_base1; /* MMU translation table base 0.  */
> -        uint32_t c2_base1_hi; /* MMU translation table base 1, high 32 bits 
> */
> +        uint64_t ttbr0_el1; /* MMU translation table base 0. */
> +        uint32_t ttbr1_el1; /* MMU translation table base 1. */
>          uint64_t c2_control; /* MMU translation table base control.  */
>          uint32_t c2_mask; /* MMU translation table base selection mask.  */
>          uint32_t c2_base_mask; /* MMU translation table base 0 mask. */
> diff --git a/target-arm/helper.c b/target-arm/helper.c
> index e2ae159..1f1dec1 100644
> --- a/target-arm/helper.c
> +++ b/target-arm/helper.c
> @@ -1288,6 +1288,18 @@ static int vmsa_tcr_el1_write(CPUARMState *env, const 
> ARMCPRegInfo *ri,
>      return 0;
>  }
>
> +static int vmsa_ttbr_write(CPUARMState *env, const ARMCPRegInfo *ri,
> +                             uint64_t value)
> +{
> +    /* 64 bit accesses to the TTBRs can change the ASID and so we
> +     * must flush the TLB.
> +     */
> +    if ((ri->state == ARM_CP_STATE_AA64) || (ri->type & ARM_CP_64BIT)) {
> +        tlb_flush(env, 1);
> +    }

With the level of complexity this if has reached, is it better to just
check for this ASID change rather than make this overly conservative
flush?

Regards,
Peter

> +    return raw_write(env, ri, value);
> +}
> +
>  static const ARMCPRegInfo vmsa_cp_reginfo[] = {
>      { .name = "DFSR", .cp = 15, .crn = 5, .crm = 0, .opc1 = 0, .opc2 = 0,
>        .access = PL1_RW,
> @@ -1295,12 +1307,14 @@ static const ARMCPRegInfo vmsa_cp_reginfo[] = {
>      { .name = "IFSR", .cp = 15, .crn = 5, .crm = 0, .opc1 = 0, .opc2 = 1,
>        .access = PL1_RW,
>        .fieldoffset = offsetof(CPUARMState, cp15.c5_insn), .resetvalue = 0, },
> -    { .name = "TTBR0", .cp = 15, .crn = 2, .crm = 0, .opc1 = 0, .opc2 = 0,
> -      .access = PL1_RW,
> -      .fieldoffset = offsetof(CPUARMState, cp15.c2_base0), .resetvalue = 0, 
> },
> -    { .name = "TTBR1", .cp = 15, .crn = 2, .crm = 0, .opc1 = 0, .opc2 = 1,
> -      .access = PL1_RW,
> -      .fieldoffset = offsetof(CPUARMState, cp15.c2_base1), .resetvalue = 0, 
> },
> +    { .name = "TTBR0_EL1", .state = ARM_CP_STATE_BOTH,
> +      .opc0 = 3, .crn = 2, .crm = 0, .opc1 = 0, .opc2 = 0,
> +      .access = PL1_RW, .fieldoffset = offsetof(CPUARMState, cp15.ttbr0_el1),
> +      .writefn = vmsa_ttbr_write, .resetvalue = 0 },
> +    { .name = "TTBR1_EL1", .state = ARM_CP_STATE_BOTH,
> +      .opc0 = 3, .crn = 2, .crm = 0, .opc1 = 0, .opc2 = 1,
> +      .access = PL1_RW, .fieldoffset = offsetof(CPUARMState, cp15.ttbr1_el1),
> +      .writefn = vmsa_ttbr_write, .resetvalue = 0 },
>      { .name = "TCR_EL1", .state = ARM_CP_STATE_AA64,
>        .opc0 = 3, .crn = 2, .crm = 0, .opc1 = 0, .opc2 = 2,
>        .access = PL1_RW, .writefn = vmsa_tcr_el1_write,
> @@ -1525,56 +1539,6 @@ static void par64_reset(CPUARMState *env, const 
> ARMCPRegInfo *ri)
>      env->cp15.c7_par = 0;
>  }
>
> -static int ttbr064_read(CPUARMState *env, const ARMCPRegInfo *ri,
> -                        uint64_t *value)
> -{
> -    *value = ((uint64_t)env->cp15.c2_base0_hi << 32) | env->cp15.c2_base0;
> -    return 0;
> -}
> -
> -static int ttbr064_raw_write(CPUARMState *env, const ARMCPRegInfo *ri,
> -                             uint64_t value)
> -{
> -    env->cp15.c2_base0_hi = value >> 32;
> -    env->cp15.c2_base0 = value;
> -    return 0;
> -}
> -
> -static int ttbr064_write(CPUARMState *env, const ARMCPRegInfo *ri,
> -                         uint64_t value)
> -{
> -    /* Writes to the 64 bit format TTBRs may change the ASID */
> -    tlb_flush(env, 1);
> -    return ttbr064_raw_write(env, ri, value);
> -}
> -
> -static void ttbr064_reset(CPUARMState *env, const ARMCPRegInfo *ri)
> -{
> -    env->cp15.c2_base0_hi = 0;
> -    env->cp15.c2_base0 = 0;
> -}
> -
> -static int ttbr164_read(CPUARMState *env, const ARMCPRegInfo *ri,
> -                        uint64_t *value)
> -{
> -    *value = ((uint64_t)env->cp15.c2_base1_hi << 32) | env->cp15.c2_base1;
> -    return 0;
> -}
> -
> -static int ttbr164_write(CPUARMState *env, const ARMCPRegInfo *ri,
> -                         uint64_t value)
> -{
> -    env->cp15.c2_base1_hi = value >> 32;
> -    env->cp15.c2_base1 = value;
> -    return 0;
> -}
> -
> -static void ttbr164_reset(CPUARMState *env, const ARMCPRegInfo *ri)
> -{
> -    env->cp15.c2_base1_hi = 0;
> -    env->cp15.c2_base1 = 0;
> -}
> -
>  static const ARMCPRegInfo lpae_cp_reginfo[] = {
>      /* NOP AMAIR0/1: the override is because these clash with the rather
>       * broadly specified TLB_LOCKDOWN entry in the generic cp_reginfo.
> @@ -1596,12 +1560,13 @@ static const ARMCPRegInfo lpae_cp_reginfo[] = {
>        .access = PL1_RW, .type = ARM_CP_64BIT,
>        .readfn = par64_read, .writefn = par64_write, .resetfn = par64_reset },
>      { .name = "TTBR0", .cp = 15, .crm = 2, .opc1 = 0,
> -      .access = PL1_RW, .type = ARM_CP_64BIT, .readfn = ttbr064_read,
> -      .writefn = ttbr064_write, .raw_writefn = ttbr064_raw_write,
> -      .resetfn = ttbr064_reset },
> +      .access = PL1_RW, .type = ARM_CP_64BIT | ARM_CP_NO_MIGRATE,
> +      .fieldoffset = offsetof(CPUARMState, cp15.ttbr0_el1),
> +      .writefn = vmsa_ttbr_write, .resetfn = arm_cp_reset_ignore },
>      { .name = "TTBR1", .cp = 15, .crm = 2, .opc1 = 1,
> -      .access = PL1_RW, .type = ARM_CP_64BIT, .readfn = ttbr164_read,
> -      .writefn = ttbr164_write, .resetfn = ttbr164_reset },
> +      .access = PL1_RW, .type = ARM_CP_64BIT | ARM_CP_NO_MIGRATE,
> +      .fieldoffset = offsetof(CPUARMState, cp15.ttbr1_el1),
> +      .writefn = vmsa_ttbr_write, .resetfn = arm_cp_reset_ignore },
>      REGINFO_SENTINEL
>  };
>
> @@ -3024,9 +2989,9 @@ static uint32_t get_level1_table_address(CPUARMState 
> *env, uint32_t address)
>      uint32_t table;
>
>      if (address & env->cp15.c2_mask)
> -        table = env->cp15.c2_base1 & 0xffffc000;
> +        table = env->cp15.ttbr1_el1 & 0xffffc000;
>      else
> -        table = env->cp15.c2_base0 & env->cp15.c2_base_mask;
> +        table = env->cp15.ttbr0_el1 & env->cp15.c2_base_mask;
>
>      table |= (address >> 18) & 0x3ffc;
>      return table;
> @@ -3299,11 +3264,11 @@ static int get_phys_addr_lpae(CPUARMState *env, 
> uint32_t address,
>       * we will always flush the TLB any time the ASID is changed).
>       */
>      if (ttbr_select == 0) {
> -        ttbr = ((uint64_t)env->cp15.c2_base0_hi << 32) | env->cp15.c2_base0;
> +        ttbr = env->cp15.ttbr0_el1;
>          epd = extract32(env->cp15.c2_control, 7, 1);
>          tsz = t0sz;
>      } else {
> -        ttbr = ((uint64_t)env->cp15.c2_base1_hi << 32) | env->cp15.c2_base1;
> +        ttbr = env->cp15.ttbr1_el1;
>          epd = extract32(env->cp15.c2_control, 23, 1);
>          tsz = t1sz;
>      }
> --
> 1.8.5
>
>