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[Qemu-devel] [PATCH for 4.1] target/riscv: More accurate handling of `sip` CSR

Jonathan Behrens posted 1 patch 4 years, 11 months ago
Failed in applying to current master (apply log)
target/riscv/csr.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
[Qemu-devel] [PATCH for 4.1] target/riscv: More accurate handling of `sip` CSR
Posted by Jonathan Behrens 4 years, 11 months ago 
According to the spec, "All bits besides SSIP, USIP, and UEIP in the sip
register are read-only." Further, if an interrupt is not delegated to mode
x,
then "the corresponding bits in xip [...] should appear to be hardwired to
zero. This patch implements both of those requirements.

Signed-off-by: Jonathan Behrens <fintelia@gmail.com>
---
 target/riscv/csr.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 1ec1222da1..fff7d834e8 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -246,6 +246,7 @@ static const target_ulong sstatus_v1_9_mask =
SSTATUS_SIE | SSTATUS_SPIE |
 static const target_ulong sstatus_v1_10_mask = SSTATUS_SIE | SSTATUS_SPIE |
     SSTATUS_UIE | SSTATUS_UPIE | SSTATUS_SPP | SSTATUS_FS | SSTATUS_XS |
     SSTATUS_SUM | SSTATUS_MXR | SSTATUS_SD;
+static const target_ulong sip_writable_mask = SIP_SSIP | MIP_USIP |
MIP_UEIP;

 #if defined(TARGET_RISCV32)
 static const char valid_vm_1_09[16] = {
@@ -694,8 +695,10 @@ static int write_sbadaddr(CPURISCVState *env, int
csrno, target_ulong val)
 static int rmw_sip(CPURISCVState *env, int csrno, target_ulong *ret_value,
                    target_ulong new_value, target_ulong write_mask)
 {
-    return rmw_mip(env, CSR_MSTATUS, ret_value, new_value,
-                   write_mask & env->mideleg);
+    int ret = rmw_mip(env, CSR_MSTATUS, ret_value, new_value,
+                      write_mask & env->mideleg & sip_writable_mask);
+    *ret_value &= env->mideleg;
+    return ret;
 }

 /* Supervisor Protection and Translation */
-- 
2.20.1
Re: [Qemu-devel] [PATCH for 4.1] target/riscv: More accurate handling of `sip` CSR
Posted by Palmer Dabbelt 4 years, 11 months ago 
On Mon, 06 May 2019 08:52:43 PDT (-0700), fintelia@gmail.com wrote:
> According to the spec, "All bits besides SSIP, USIP, and UEIP in the sip
> register are read-only." Further, if an interrupt is not delegated to mode
> x,
> then "the corresponding bits in xip [...] should appear to be hardwired to
> zero. This patch implements both of those requirements.
>
> Signed-off-by: Jonathan Behrens <fintelia@gmail.com>
> ---
>  target/riscv/csr.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/target/riscv/csr.c b/target/riscv/csr.c
> index 1ec1222da1..fff7d834e8 100644
> --- a/target/riscv/csr.c
> +++ b/target/riscv/csr.c
> @@ -246,6 +246,7 @@ static const target_ulong sstatus_v1_9_mask =
> SSTATUS_SIE | SSTATUS_SPIE |
>  static const target_ulong sstatus_v1_10_mask = SSTATUS_SIE | SSTATUS_SPIE |
>      SSTATUS_UIE | SSTATUS_UPIE | SSTATUS_SPP | SSTATUS_FS | SSTATUS_XS |
>      SSTATUS_SUM | SSTATUS_MXR | SSTATUS_SD;
> +static const target_ulong sip_writable_mask = SIP_SSIP | MIP_USIP |
> MIP_UEIP;
>
>  #if defined(TARGET_RISCV32)
>  static const char valid_vm_1_09[16] = {
> @@ -694,8 +695,10 @@ static int write_sbadaddr(CPURISCVState *env, int
> csrno, target_ulong val)
>  static int rmw_sip(CPURISCVState *env, int csrno, target_ulong *ret_value,
>                     target_ulong new_value, target_ulong write_mask)
>  {
> -    return rmw_mip(env, CSR_MSTATUS, ret_value, new_value,
> -                   write_mask & env->mideleg);
> +    int ret = rmw_mip(env, CSR_MSTATUS, ret_value, new_value,
> +                      write_mask & env->mideleg & sip_writable_mask);
> +    *ret_value &= env->mideleg;
> +    return ret;
>  }
>
>  /* Supervisor Protection and Translation */

This patch (and your previous one) don't apply for me.  I don't see the
git-send-email tags in your messages, are you trying to do something like paste
them into gmail?  If so I think they're getting line wrapped.
Re: [Qemu-devel] [PATCH for 4.1] target/riscv: More accurate handling of `sip` CSR
Posted by Jonathan Behrens 4 years, 11 months ago 
Yes, I was pasting the output of `git format-patch`. Gmail displays
properly for me, but seems to have hard-wrapped the plaintext version of my
outgoing message to 78 characters. I've tried re-sending from a different
address where I can use `git send-email` directly, please let me know if it
works and I'll resend the other patch the same way. Sorry about this!

Jonathan


On Tue, May 7, 2019 at 1:52 PM Palmer Dabbelt <palmer@sifive.com> wrote:

> On Mon, 06 May 2019 08:52:43 PDT (-0700), fintelia@gmail.com wrote:
> > According to the spec, "All bits besides SSIP, USIP, and UEIP in the sip
> > register are read-only." Further, if an interrupt is not delegated to
> mode
> > x,
> > then "the corresponding bits in xip [...] should appear to be hardwired
> to
> > zero. This patch implements both of those requirements.
> >
> > Signed-off-by: Jonathan Behrens <fintelia@gmail.com>
> > ---
> >  target/riscv/csr.c | 7 +++++--
> >  1 file changed, 5 insertions(+), 2 deletions(-)
> >
> > diff --git a/target/riscv/csr.c b/target/riscv/csr.c
> > index 1ec1222da1..fff7d834e8 100644
> > --- a/target/riscv/csr.c
> > +++ b/target/riscv/csr.c
> > @@ -246,6 +246,7 @@ static const target_ulong sstatus_v1_9_mask =
> > SSTATUS_SIE | SSTATUS_SPIE |
> >  static const target_ulong sstatus_v1_10_mask = SSTATUS_SIE |
> SSTATUS_SPIE |
> >      SSTATUS_UIE | SSTATUS_UPIE | SSTATUS_SPP | SSTATUS_FS | SSTATUS_XS |
> >      SSTATUS_SUM | SSTATUS_MXR | SSTATUS_SD;
> > +static const target_ulong sip_writable_mask = SIP_SSIP | MIP_USIP |
> > MIP_UEIP;
> >
> >  #if defined(TARGET_RISCV32)
> >  static const char valid_vm_1_09[16] = {
> > @@ -694,8 +695,10 @@ static int write_sbadaddr(CPURISCVState *env, int
> > csrno, target_ulong val)
> >  static int rmw_sip(CPURISCVState *env, int csrno, target_ulong
> *ret_value,
> >                     target_ulong new_value, target_ulong write_mask)
> >  {
> > -    return rmw_mip(env, CSR_MSTATUS, ret_value, new_value,
> > -                   write_mask & env->mideleg);
> > +    int ret = rmw_mip(env, CSR_MSTATUS, ret_value, new_value,
> > +                      write_mask & env->mideleg & sip_writable_mask);
> > +    *ret_value &= env->mideleg;
> > +    return ret;
> >  }
> >
> >  /* Supervisor Protection and Translation */
>
> This patch (and your previous one) don't apply for me.  I don't see the
> git-send-email tags in your messages, are you trying to do something like
> paste
> them into gmail?  If so I think they're getting line wrapped.
>

Patchew 2.1-devel-0870f84

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