Re: [Qemu-arm] [Qemu-devel] [kvm-unit-tests PATCH v5 09/11] arm/arm64: add initial gicv3 support

[Andrew Jones]

On Fri, Nov 11, 2016 at 04:31:36PM +0000, Andre Przywara wrote:
> Hi,
> 
> On 10/11/16 17:21, Andrew Jones wrote:
> > Signed-off-by: Andrew Jones <address@hidden>
> > 
> > ---
> > v5: use modern register names [Andre]
> > v4:
> >  - only take defines from kernel we need now [Andre]
> >  - simplify enable by not caring if we reinit the distributor [drew]
> > v2:
> >  - configure irqs as NS GRP1
> > ---
> >  lib/arm/asm/arch_gicv3.h   | 42 +++++++++++++++++++++
> >  lib/arm/asm/gic-v3.h       | 94 
> > ++++++++++++++++++++++++++++++++++++++++++++++
> >  lib/arm/asm/gic.h          |  6 ++-
> >  lib/arm/gic.c              | 65 ++++++++++++++++++++++++++++++++
> >  lib/arm64/asm/arch_gicv3.h | 44 ++++++++++++++++++++++
> >  lib/arm64/asm/gic-v3.h     |  1 +
> >  lib/arm64/asm/sysreg.h     | 44 ++++++++++++++++++++++
> >  7 files changed, 294 insertions(+), 2 deletions(-)
> >  create mode 100644 lib/arm/asm/arch_gicv3.h
> >  create mode 100644 lib/arm/asm/gic-v3.h
> >  create mode 100644 lib/arm64/asm/arch_gicv3.h
> >  create mode 100644 lib/arm64/asm/gic-v3.h
> >  create mode 100644 lib/arm64/asm/sysreg.h
> > 
> > diff --git a/lib/arm/asm/arch_gicv3.h b/lib/arm/asm/arch_gicv3.h
> > new file mode 100644
> > index 000000000000..81a1e5f6c29c
> > --- /dev/null
> > +++ b/lib/arm/asm/arch_gicv3.h
> > @@ -0,0 +1,42 @@
> > +/*
> > + * All ripped off from arch/arm/include/asm/arch_gicv3.h
> > + *
> > + * Copyright (C) 2016, Red Hat Inc, Andrew Jones <address@hidden>
> > + *
> > + * This work is licensed under the terms of the GNU LGPL, version 2.
> > + */
> > +#ifndef _ASMARM_ARCH_GICV3_H_
> > +#define _ASMARM_ARCH_GICV3_H_
> > +
> > +#ifndef __ASSEMBLY__
> > +#include <libcflat.h>
> > +#include <asm/barrier.h>
> > +#include <asm/io.h>
> > +
> > +#define __stringify xstr
> > +
> > +#define __ACCESS_CP15(CRn, Op1, CRm, Op2)  p15, Op1, %0, CRn, CRm, Op2
> > +
> > +#define ICC_PMR                            __ACCESS_CP15(c4, 0, c6, 0)
> > +#define ICC_IGRPEN1                        __ACCESS_CP15(c12, 0, c12, 7)
> > +
> > +static inline void gicv3_write_pmr(u32 val)
> > +{
> > +   asm volatile("mcr " __stringify(ICC_PMR) : : "r" (val));
> > +}
> > +
> > +static inline void gicv3_write_grpen1(u32 val)
> > +{
> > +   asm volatile("mcr " __stringify(ICC_IGRPEN1) : : "r" (val));
> > +   isb();
> > +}
> > +
> > +static inline u64 gicv3_read_typer(const volatile void __iomem *addr)
> 
> It may be worth to add that this is for GICR_TYPER (or GITS_TYPER),
> because GICD_TYPER is 32-bit only.
> Or to make the naming generic (because the code actually is), along the
> lines of read_64bit_reg or the like?

Hmm, the fact that these two consecutive mmio addresses allow me to
read and combine them into one address isn't a general property, but
rather one of this particular register. So I think we want typer in
the name. I'm not sure how to improve on the name, since it's useful
for both GICR_ and GITS_. I'll just add a comment above it.

> 
> > +{
> > +   u64 val = readl(addr);
> > +   val |= (u64)readl(addr + 4) << 32;
> > +   return val;
> > +}
> > +
> > +#endif /* !__ASSEMBLY__ */
> > +#endif /* _ASMARM_ARCH_GICV3_H_ */
> > diff --git a/lib/arm/asm/gic-v3.h b/lib/arm/asm/gic-v3.h
> > new file mode 100644
> > index 000000000000..e0f303d82508
> > --- /dev/null
> > +++ b/lib/arm/asm/gic-v3.h
> > @@ -0,0 +1,94 @@
> > +/*
> > + * All GIC* defines are lifted from include/linux/irqchip/arm-gic-v3.h
> > + *
> > + * Copyright (C) 2016, Red Hat Inc, Andrew Jones <address@hidden>
> > + *
> > + * This work is licensed under the terms of the GNU LGPL, version 2.
> > + */
> > +#ifndef _ASMARM_GIC_V3_H_
> > +#define _ASMARM_GIC_V3_H_
> > +
> > +#ifndef _ASMARM_GIC_H_
> > +#error Do not directly include <asm/gic-v3.h>. Include <asm/gic.h>
> > +#endif
> > +
> > +#define GICD_CTLR_RWP                      (1U << 31)
> > +#define GICD_CTLR_ARE_NS           (1U << 4)
> > +#define GICD_CTLR_ENABLE_G1A               (1U << 1)
> > +#define GICD_CTLR_ENABLE_G1                (1U << 0)
> 
> +1 to Alex for adding a comment noting the non-secure view here.

Will do.

> 
> > +
> > +/* Re-Distributor registers, offsets from RD_base */
> > +#define GICR_TYPER                 0x0008
> > +
> > +#define GICR_TYPER_LAST                    (1U << 4)
> > +
> > +/* Re-Distributor registers, offsets from SGI_base */
> > +#define GICR_IGROUPR0                      GICD_IGROUPR
> > +#define GICR_ISENABLER0                    GICD_ISENABLER
> > +#define GICR_IPRIORITYR0           GICD_IPRIORITYR
> > +
> > +#include <asm/arch_gicv3.h>
> > +
> > +#ifndef __ASSEMBLY__
> > +#include <asm/setup.h>
> > +#include <asm/smp.h>
> > +#include <asm/processor.h>
> > +#include <asm/io.h>
> > +
> > +struct gicv3_data {
> > +   void *dist_base;
> > +   void *redist_base[NR_CPUS];
> > +   unsigned int irq_nr;
> > +};
> > +extern struct gicv3_data gicv3_data;
> > +
> > +#define gicv3_dist_base()          (gicv3_data.dist_base)
> > +#define gicv3_redist_base()                
> > (gicv3_data.redist_base[smp_processor_id()])
> > +#define gicv3_sgi_base()           
> > (gicv3_data.redist_base[smp_processor_id()] + SZ_64K)
> > +
> > +extern int gicv3_init(void);
> > +extern void gicv3_enable_defaults(void);
> > +extern void gicv3_set_redist_base(void);
> > +
> > +static inline void gicv3_do_wait_for_rwp(void *base)
> > +{
> > +   int count = 100000;     /* 1s */
> > +
> > +   while (readl(base + GICD_CTLR) & GICD_CTLR_RWP) {
> > +           if (!--count) {
> > +                   printf("GICv3: RWP timeout!\n");
> > +                   abort();
> > +           }
> > +           cpu_relax();
> > +           udelay(10);
> > +   };
> > +}
> > +
> > +static inline void gicv3_dist_wait_for_rwp(void)
> > +{
> > +   gicv3_do_wait_for_rwp(gicv3_dist_base());
> > +}
> > +
> > +static inline void gicv3_redist_wait_for_rwp(void)
> 
> Careful here. RWP is bit 3 in GICR_CTLR, while UWP (with a slightly
> different semantic) is bit 31. I guess it's bit 3 you are after, so this
> has to be taken into account.

When I stole this from the kernel I noticed that GICD_CTLR_RWP wasn't
mapped the same as GICR_CTLR_RWP, but GICR_CTLR_UWP looked "stronger"
to me, so I figured that was a subtle, but by design decision. I
could make our version less subtle by renaming to _uwp, and also adding
a comment that we abuse the gicr-uwp==gicd-rwp mapping. Maybe that's
something the kernel would like to do too, assuming I'm correct to do it
here...

> 
> > +{
> > +   gicv3_do_wait_for_rwp(gicv3_redist_base());
> > +}
> > +
> > +static inline u32 mpidr_compress(u64 mpidr)
> > +{
> > +   u64 compressed = mpidr & MPIDR_HWID_BITMASK;
> > +
> > +   compressed = (((compressed >> 32) & 0xff) << 24) | compressed;
> > +   return compressed;
> > +}
> > +
> > +static inline u64 mpidr_uncompress(u32 compressed)
> > +{
> > +   u64 mpidr = ((u64)compressed >> 24) << 32;
> > +
> > +   mpidr |= compressed & MPIDR_HWID_BITMASK;
> > +   return mpidr;
> > +}
> > +
> > +#endif /* !__ASSEMBLY__ */
> > +#endif /* _ASMARM_GIC_V3_H_ */
> > diff --git a/lib/arm/asm/gic.h b/lib/arm/asm/gic.h
> > index a16645708c35..981518620d18 100644
> > --- a/lib/arm/asm/gic.h
> > +++ b/lib/arm/asm/gic.h
> > @@ -6,10 +6,9 @@
> >  #ifndef _ASMARM_GIC_H_
> >  #define _ASMARM_GIC_H_
> >  
> > -#include <asm/gic-v2.h>
> > -
> >  #define GICD_CTLR                  0x0000
> >  #define GICD_TYPER                 0x0004
> > +#define GICD_IGROUPR                       0x0080
> >  #define GICD_ISENABLER                     0x0100
> >  #define GICD_IPRIORITYR                    0x0400
> >  #define GICD_SGIR                  0x0f00
> > @@ -26,6 +25,9 @@
> >  #define GICC_INT_PRI_THRESHOLD             0xf0
> >  #define GICC_INT_SPURIOUS          0x3ff
> >  
> > +#include <asm/gic-v2.h>
> > +#include <asm/gic-v3.h>
> > +
> >  #ifndef __ASSEMBLY__
> >  
> >  /*
> > diff --git a/lib/arm/gic.c b/lib/arm/gic.c
> > index d655105e058b..d929d3f0fa05 100644
> > --- a/lib/arm/gic.c
> > +++ b/lib/arm/gic.c
> > @@ -8,9 +8,11 @@
> >  #include <asm/io.h>
> >  
> >  struct gicv2_data gicv2_data;
> > +struct gicv3_data gicv3_data;
> >  
> >  /*
> >   * Documentation/devicetree/bindings/interrupt-controller/arm,gic.txt
> > + * Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.txt
> >   */
> >  static bool
> >  gic_get_dt_bases(const char *compatible, void **base1, void **base2)
> > @@ -48,10 +50,18 @@ int gicv2_init(void)
> >                     &gicv2_data.dist_base, &gicv2_data.cpu_base);
> >  }
> >  
> > +int gicv3_init(void)
> > +{
> > +   return gic_get_dt_bases("arm,gic-v3", &gicv3_data.dist_base,
> > +                   &gicv3_data.redist_base[0]);
> > +}
> > +
> >  int gic_init(void)
> >  {
> >     if (gicv2_init())
> >             return 2;
> > +   else if (gicv3_init())
> > +           return 3;
> >     return 0;
> >  }
> >  
> > @@ -74,3 +84,58 @@ void gicv2_enable_defaults(void)
> >     writel(GICC_INT_PRI_THRESHOLD, cpu_base + GICC_PMR);
> >     writel(GICC_ENABLE, cpu_base + GICC_CTLR);
> >  }
> > +
> > +void gicv3_set_redist_base(void)
> > +{
> > +   u32 aff = mpidr_compress(get_mpidr());
> > +   void *ptr = gicv3_data.redist_base[0];
> > +   u64 typer;
> > +
> > +   do {
> > +           typer = gicv3_read_typer(ptr + GICR_TYPER);
> > +           if ((typer >> 32) == aff) {
> > +                   gicv3_redist_base() = ptr;
> > +                   return;
> > +           }
> > +           ptr += SZ_64K * 2; /* skip RD_base and SGI_base */
> 
> For a GICv4 the stride is four 64K pages instead of 2.
> I guess we don't need to bother atm, but maybe worth a comment or even a
> TODO?

Will fix for v6 by adding a stride parameter to this function

> 
> > +   } while (!(typer & GICR_TYPER_LAST));
> > +   assert(0);
> > +}
> > +
> > +void gicv3_enable_defaults(void)
> > +{
> > +   void *dist = gicv3_dist_base();
> > +   void *sgi_base;
> > +   unsigned int i;
> > +
> > +   gicv3_data.irq_nr = GICD_TYPER_IRQS(readl(dist + GICD_TYPER));
> > +   if (gicv3_data.irq_nr > 1020)
> > +           gicv3_data.irq_nr = 1020;
> > +
> > +   writel(0, dist + GICD_CTLR);
> > +   gicv3_dist_wait_for_rwp();
> > +
> > +   writel(GICD_CTLR_ARE_NS | GICD_CTLR_ENABLE_G1A | GICD_CTLR_ENABLE_G1,
> > +          dist + GICD_CTLR);
> > +   gicv3_dist_wait_for_rwp();
> > +
> > +   for (i = 0; i < gicv3_data.irq_nr; i += 4)
> > +           writel(~0, dist + GICD_IGROUPR + i);
> > +   gicv3_dist_wait_for_rwp();
> 
> I don't think we need this. The spec says that IGROUPR accesses are not
> tracked by this bit.

Indeed, will drop.

> 
> > +
> > +   if (!gicv3_redist_base())
> > +           gicv3_set_redist_base();
> > +   sgi_base = gicv3_sgi_base();
> > +
> > +   writel(~0, sgi_base + GICR_IGROUPR0);
> > +
> > +   for (i = 0; i < 16; i += 4)
> > +           writel(GICD_INT_DEF_PRI_X4, sgi_base + GICR_IPRIORITYR0 + i);
> > +
> > +   writel(GICD_INT_EN_SET_SGI, sgi_base + GICR_ISENABLER0);
> > +
> > +   gicv3_redist_wait_for_rwp();
> 
> I think we don't need this either, only for clear enable. That applies
> to both RWP (= bit 3) and UWP (= bit 31).

Seems to work without it, will drop.

Thanks,
drew

> 
> Cheers,
> Andre.
> 
> > +
> > +   gicv3_write_pmr(GICC_INT_PRI_THRESHOLD);
> > +   gicv3_write_grpen1(1);
> > +}
> > diff --git a/lib/arm64/asm/arch_gicv3.h b/lib/arm64/asm/arch_gicv3.h
> > new file mode 100644
> > index 000000000000..6d353567f56a
> > --- /dev/null
> > +++ b/lib/arm64/asm/arch_gicv3.h
> > @@ -0,0 +1,44 @@
> > +/*
> > + * All ripped off from arch/arm64/include/asm/arch_gicv3.h
> > + *
> > + * Copyright (C) 2016, Red Hat Inc, Andrew Jones <address@hidden>
> > + *
> > + * This work is licensed under the terms of the GNU LGPL, version 2.
> > + */
> > +#ifndef _ASMARM64_ARCH_GICV3_H_
> > +#define _ASMARM64_ARCH_GICV3_H_
> > +
> > +#include <asm/sysreg.h>
> > +
> > +#define ICC_PMR_EL1                        sys_reg(3, 0, 4, 6, 0)
> > +#define ICC_GRPEN1_EL1                     sys_reg(3, 0, 12, 12, 7)
> > +
> > +#ifndef __ASSEMBLY__
> > +
> > +#include <libcflat.h>
> > +#include <asm/barrier.h>
> > +
> > +#define __stringify xstr
> > +
> > +/*
> > + * Low-level accessors
> > + *
> > + * These system registers are 32 bits, but we make sure that the compiler
> > + * sets the GP register's most significant bits to 0 with an explicit cast.
> > + */
> > +
> > +static inline void gicv3_write_pmr(u32 val)
> > +{
> > +   asm volatile("msr_s " __stringify(ICC_PMR_EL1) ", %0" : : "r" 
> > ((u64)val));
> > +}
> > +
> > +static inline void gicv3_write_grpen1(u32 val)
> > +{
> > +   asm volatile("msr_s " __stringify(ICC_GRPEN1_EL1) ", %0" : : "r" 
> > ((u64)val));
> > +   isb();
> > +}
> > +
> > +#define gicv3_read_typer(c)                readq(c)
> > +
> > +#endif /* __ASSEMBLY__ */
> > +#endif /* _ASMARM64_ARCH_GICV3_H_ */
> > diff --git a/lib/arm64/asm/gic-v3.h b/lib/arm64/asm/gic-v3.h
> > new file mode 100644
> > index 000000000000..8ee5d4d9c181
> > --- /dev/null
> > +++ b/lib/arm64/asm/gic-v3.h
> > @@ -0,0 +1 @@
> > +#include "../../arm/asm/gic-v3.h"
> > diff --git a/lib/arm64/asm/sysreg.h b/lib/arm64/asm/sysreg.h
> > new file mode 100644
> > index 000000000000..544a46cb8cc5
> > --- /dev/null
> > +++ b/lib/arm64/asm/sysreg.h
> > @@ -0,0 +1,44 @@
> > +/*
> > + * Ripped off from arch/arm64/include/asm/sysreg.h
> > + *
> > + * Copyright (C) 2016, Red Hat Inc, Andrew Jones <address@hidden>
> > + *
> > + * This work is licensed under the terms of the GNU LGPL, version 2.
> > + */
> > +#ifndef _ASMARM64_SYSREG_H_
> > +#define _ASMARM64_SYSREG_H_
> > +
> > +#define sys_reg(op0, op1, crn, crm, op2) \
> > +   ((((op0)&3)<<19)|((op1)<<16)|((crn)<<12)|((crm)<<8)|((op2)<<5))
> > +
> > +#ifdef __ASSEMBLY__
> > +   .irp    
> > num,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30
> > +   .equ    .L__reg_num_x\num, \num
> > +   .endr
> > +   .equ    .L__reg_num_xzr, 31
> > +
> > +   .macro  mrs_s, rt, sreg
> > +   .inst   0xd5200000|(\sreg)|(.L__reg_num_\rt)
> > +   .endm
> > +
> > +   .macro  msr_s, sreg, rt
> > +   .inst   0xd5000000|(\sreg)|(.L__reg_num_\rt)
> > +   .endm
> > +#else
> > +asm(
> > +"  .irp    
> > num,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30\n"
> > +"  .equ    .L__reg_num_x\\num, \\num\n"
> > +"  .endr\n"
> > +"  .equ    .L__reg_num_xzr, 31\n"
> > +"\n"
> > +"  .macro  mrs_s, rt, sreg\n"
> > +"  .inst   0xd5200000|(\\sreg)|(.L__reg_num_\\rt)\n"
> > +"  .endm\n"
> > +"\n"
> > +"  .macro  msr_s, sreg, rt\n"
> > +"  .inst   0xd5000000|(\\sreg)|(.L__reg_num_\\rt)\n"
> > +"  .endm\n"
> > +);
> > +#endif
> > +
> > +#endif /* _ASMARM64_SYSREG_H_ */
> > 
>