Re: [kvm-unit-tests PATCH v2 07/16] arm/arm64: ITS: Set the LPI config and pending tables

[Andrew Jones]

On Fri, Jan 10, 2020 at 03:54:03PM +0100, Eric Auger wrote:
> Allocate the LPI configuration and per re-distributor pending table.
> Set redistributor's PROPBASER and PENDBASER. The LPIs are enabled
> by default in the config table.
> 
> Also introduce a helper routine that allows to set the pending table
> bit for a given LPI.
> 
> Signed-off-by: Eric Auger <address@hidden>
> 
> ---
> 
> v1 -> v2:
> - remove memory attributes
> ---
>  lib/arm/asm/gic-v3-its.h |  3 ++
>  lib/arm/asm/gic-v3.h     | 12 ++++++++
>  lib/arm/gic-v3-its.c     | 60 ++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 75 insertions(+)
> 
> diff --git a/lib/arm/asm/gic-v3-its.h b/lib/arm/asm/gic-v3-its.h
> index 5a4dfe9..2f8b8f1 100644
> --- a/lib/arm/asm/gic-v3-its.h
> +++ b/lib/arm/asm/gic-v3-its.h
> @@ -90,6 +90,9 @@ extern void its_init(void);
>  extern int its_parse_baser(int i, struct its_baser *baser);
>  extern void its_setup_baser(int i, struct its_baser *baser);
>  extern struct its_baser *its_lookup_baser(int type);
> +extern void set_lpi_config(int n, u8 val);
> +extern u8 get_lpi_config(int n);
> +extern void set_pending_table_bit(int rdist, int n, bool set);

Please prefix with 'its' or at least swap the 'lpi' and verb. E.g.
lpi_set_config, its_set_pending_table_bit.


>  
>  #endif /* !__ASSEMBLY__ */
>  #endif /* _ASMARM_GIC_V3_ITS_H_ */
> diff --git a/lib/arm/asm/gic-v3.h b/lib/arm/asm/gic-v3.h
> index ffb2e26..90a7304 100644
> --- a/lib/arm/asm/gic-v3.h
> +++ b/lib/arm/asm/gic-v3.h
> @@ -48,6 +48,16 @@
>  #define MPIDR_TO_SGI_AFFINITY(cluster_id, level) \
>       (MPIDR_AFFINITY_LEVEL(cluster_id, level) << ICC_SGI1R_AFFINITY_## level 
> ## _SHIFT)
>  
> +#define GICR_PROPBASER_IDBITS_MASK                      (0x1f)
> +
> +#define GICR_PENDBASER_PTZ                              BIT_ULL(62)
> +
> +#define LPI_PROP_GROUP1              (1 << 1)
> +#define LPI_PROP_ENABLED     (1 << 0)
> +#define LPI_PROP_DEFAULT_PRIO   0xa0
> +#define LPI_PROP_DEFAULT     (LPI_PROP_DEFAULT_PRIO | LPI_PROP_GROUP1 | \
> +                              LPI_PROP_ENABLED)
> +
>  #include <asm/arch_gicv3.h>
>  
>  #ifndef __ASSEMBLY__
> @@ -64,6 +74,8 @@ struct gicv3_data {
>       void *dist_base;
>       void *redist_bases[GICV3_NR_REDISTS];
>       void *redist_base[NR_CPUS];
> +     void *lpi_prop;
> +     void *lpi_pend[NR_CPUS];
>       unsigned int irq_nr;
>  };
>  extern struct gicv3_data gicv3_data;
> diff --git a/lib/arm/gic-v3-its.c b/lib/arm/gic-v3-its.c
> index 79946c3..6c97569 100644
> --- a/lib/arm/gic-v3-its.c
> +++ b/lib/arm/gic-v3-its.c
> @@ -117,3 +117,63 @@ void its_setup_baser(int i, struct its_baser *baser)
>       writeq(val, gicv3_its_base() + GITS_BASER + i * 8);
>  }
>  
> +inline void set_lpi_config(int n, u8 value)
> +{
> +     u8 *entry = (u8 *)(gicv3_data.lpi_prop + (n - 8192));
> +     *entry = value;
> +}
> +
> +inline u8 get_lpi_config(int n)
> +{
> +     u8 *entry = (u8 *)(gicv3_data.lpi_prop + (n - 8192));
> +     return *entry;
> +}

Probably don't need the 'inline', but ok.

> +
> +/* alloc_lpi_tables: Allocate LPI config and pending tables */
> +void alloc_lpi_tables(void);
> +void alloc_lpi_tables(void)

Why not add this to the header (renamed to lpi_alloc_tables)? Or should
this function be static?

> +{
> +     unsigned long n = SZ_64K >> PAGE_SHIFT;
> +     unsigned long order = fls(n);
> +     u64 prop_val;
> +     int cpu;
> +
> +     gicv3_data.lpi_prop = (void *)virt_to_phys(alloc_pages(order));
> +
> +     /* ID bits = 13, ie. up to 14b LPI INTID */
> +     prop_val = (u64)gicv3_data.lpi_prop | 13;
> +
> +     /*
> +      * Allocate pending tables for each redistributor
> +      * and set PROPBASER and PENDBASER
> +      */
> +     for_each_present_cpu(cpu) {
> +             u64 pend_val;
> +             void *ptr;
> +
> +             ptr = gicv3_data.redist_base[cpu];
> +
> +             writeq(prop_val, ptr + GICR_PROPBASER);
> +
> +             gicv3_data.lpi_pend[cpu] =
> +                     (void *)virt_to_phys(alloc_pages(order));

nit: I think these line brakes on = or worse than going over 80 chars.
And, you don't need to worry about 80 chars anyway. See the README, we
allow 120.

> +
> +             pend_val = (u64)gicv3_data.lpi_pend[cpu];
> +
> +             writeq(pend_val, ptr + GICR_PENDBASER);
> +     }
> +}
> +
> +void set_pending_table_bit(int rdist, int n, bool set)
> +{
> +     u8 *ptr = phys_to_virt((phys_addr_t)gicv3_data.lpi_pend[rdist]);
> +     u8 mask = 1 << (n % 8), byte;
> +
> +     ptr += (n / 8);
> +     byte = *ptr;
> +     if (set)
> +             byte |=  mask;
> +     else
> +             byte &= ~mask;
> +     *ptr = byte;
> +}
> -- 
> 2.20.1
> 

Thanks,
drew