Re: [kvm-unit-tests PATCH v3 06/14] arm/arm64: gicv3: Set the LPI config and pending tables

[Zenghui Yu]

Hi Eric,

On 2020/1/28 18:34, 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>
>
> ---
>
> v2 -> v3:
> - Move the helpers in lib/arm/gic-v3.c and prefix them with "gicv3_"
>    and add _lpi prefix too
>
> v1 -> v2:
> - remove memory attributes
> ---
>   lib/arm/asm/gic-v3.h | 16 +++++++++++
>   lib/arm/gic-v3.c     | 64 ++++++++++++++++++++++++++++++++++++++++++++
>   2 files changed, 80 insertions(+)
>
> diff --git a/lib/arm/asm/gic-v3.h b/lib/arm/asm/gic-v3.h
> index ffb2e26..ec2a6f0 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)

This is not being used.  You can use it when calculating prop_val
or just drop it.

> +
> +#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;
> @@ -80,6 +92,10 @@ extern void gicv3_write_eoir(u32 irqstat);
>   extern void gicv3_ipi_send_single(int irq, int cpu);
>   extern void gicv3_ipi_send_mask(int irq, const cpumask_t *dest);
>   extern void gicv3_set_redist_base(size_t stride);
> +extern void gicv3_lpi_set_config(int n, u8 val);
> +extern u8 gicv3_lpi_get_config(int n);
> +extern void gicv3_lpi_set_pending_table_bit(int rdist, int n, bool set);
> +extern void gicv3_lpi_alloc_tables(void);
>   
>   static inline void gicv3_do_wait_for_rwp(void *base)
>   {
> diff --git a/lib/arm/gic-v3.c b/lib/arm/gic-v3.c
> index feecb5e..c33f883 100644
> --- a/lib/arm/gic-v3.c
> +++ b/lib/arm/gic-v3.c
> @@ -5,6 +5,7 @@
>    */
>   #include <asm/gic.h>
>   #include <asm/io.h>
> +#include <alloc_page.h>
>   
>   void gicv3_set_redist_base(size_t stride)
>   {
> @@ -147,3 +148,66 @@ void gicv3_ipi_send_single(int irq, int cpu)
>         cpumask_set_cpu(cpu, &dest);
>         gicv3_ipi_send_mask(irq, &dest);
>   }
> +
> +#if defined(__aarch64__)
> +/* alloc_lpi_tables: Allocate LPI config and pending tables */
> +void gicv3_lpi_alloc_tables(void)
> +{
> +       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));
> +
> +               pend_val = (u64)gicv3_data.lpi_pend[cpu];
> +
> +               writeq(pend_val, ptr + GICR_PENDBASER);
> +       }
> +}
> +
> +void gicv3_lpi_set_config(int n, u8 value)
> +{
> +       u8 *entry = (u8 *)(gicv3_data.lpi_prop + (n - 8192));

But this is actually the *physical* address, shouldn't it be
converted by phys_to_virt() before reading/writing something?
Like what you've done for the 'lpi_pend[rdist]' before writing
pending bit.  Or I'm missing some points here?

> +
> +       *entry = value;
> +}
> +
> +u8 gicv3_lpi_get_config(int n)
> +{
> +       u8 *entry = (u8 *)(gicv3_data.lpi_prop + (n - 8192));

The same as above.


Thanks,
Zenghui

> +
> +       return *entry;
> +}
> +
> +void gicv3_lpi_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;
> +}
> +#endif /* __aarch64__ */