Re: [Xen-devel] [PATCH v4 16/17] xen/arm: ITS: Generate ITS node for Dom0

[Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>]

On Fri, 10 Jul 2015, vijay.kilari@xxxxxxxxx wrote:
> From: Vijaya Kumar K <Vijaya.Kumar@xxxxxxxxxxxxxxxxxx>
> 
> Parse host dt and generate ITS node for Dom0.
> ITS node resides inside GIC node so when GIC node
> is encountered look for ITS node.
> 
> Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@xxxxxxxxxxxxxxxxxx>
> ---
> v4: - Generate only one ITS node for Dom0
>     - Replace msi-parent references to single its phandle
> ---
>  xen/arch/arm/domain_build.c   |   78 
> +++++++++++++++++++++++++++++++++++++++++
>  xen/arch/arm/gic-v3-its.c     |   57 ++++++++++++++++++++++++++++++
>  xen/include/asm-arm/gic-its.h |    2 ++
>  3 files changed, 137 insertions(+)
> 
> diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
> index e9cb8a9..5c62437 100644
> --- a/xen/arch/arm/domain_build.c
> +++ b/xen/arch/arm/domain_build.c
> @@ -20,6 +20,7 @@
>  #include <asm/cpufeature.h>
>  
>  #include <asm/gic.h>
> +#include <asm/gic-its.h>
>  #include <xen/irq.h>
>  #include "kernel.h"
>  
> @@ -61,6 +62,9 @@ custom_param("dom0_mem", parse_dom0_mem);
>   */
>  #define DOM0_FDT_EXTRA_SIZE (128 + sizeof(struct fdt_reserve_entry))
>  
> +#ifdef CONFIG_ARM_64
> +static fdt32_t its_phandle;
> +#endif
>  struct vcpu *__init alloc_dom0_vcpu0(struct domain *dom0)
>  {
>      if ( opt_dom0_max_vcpus == 0 )
> @@ -468,6 +472,18 @@ static int write_properties(struct domain *d, struct 
> kernel_info *kinfo,
>              continue;
>          }
>  
> +#ifdef CONFIG_ARM_64
> +        /*
> +         * Replace all msi-parent phandle references to single ITS node
> +         * generated for Dom0
> +         */
> +        if ( dt_property_name_is_equal(prop, "msi-parent") )
> +        {
> +            fdt_property(kinfo->fdt, prop->name, (void *)&its_phandle,
> +                         sizeof(its_phandle));
> +            continue;
> +        }
> +#endif
>          res = fdt_property(kinfo->fdt, prop->name, prop_data, prop_len);
>  
>          xfree(new_data);
> @@ -803,6 +819,38 @@ static int make_cpus_node(const struct domain *d, void 
> *fdt,
>      return res;
>  }
>  
> +#ifdef CONFIG_ARM_64
> +static int make_its_node(const struct domain *d, void *fdt,
> +                         const struct dt_device_node *node)
> +{
> +    int res = 0;
> +
> +    DPRINT("Create GIC ITS node\n");
> +
> +    res = its_make_dt_node(d, node, fdt);
> +    if ( res )
> +        return res;
> +
> +    /*
> +     * The value of the property "phandle" in the property "interrupts"
> +     * to know on which interrupt controller the interrupt is wired.
> +     */
> +    if ( node->phandle )
> +    {
> +        DPRINT("  Set phandle = 0x%x\n", node->phandle);
> +        res = fdt_property_cell(fdt, "phandle", node->phandle);
> +        if ( res )
> +            return res;
> +    }
> +
> +    its_phandle = cpu_to_fdt32(node->phandle);
> +
> +    res = fdt_end_node(fdt);
> +
> +    return res;
> +}
> +#endif
> +
>  static int make_gic_node(const struct domain *d, void *fdt,
>                           const struct dt_device_node *node)
>  {
> @@ -1119,6 +1167,14 @@ static int handle_node(struct domain *d, struct 
> kernel_info *kinfo,
>          DT_MATCH_TIMER,
>          { /* sentinel */ },
>      };
> +#ifdef CONFIG_ARM_64
> +    static const struct dt_device_match gits_matches[] __initconst =
> +    {
> +        DT_MATCH_GIC_ITS,
> +        { /* sentinel */ },
> +    };
> +    struct dt_device_node *gic_child;
> +#endif
>      struct dt_device_node *child;
>      int res;
>      const char *name;
> @@ -1143,7 +1199,29 @@ static int handle_node(struct domain *d, struct 
> kernel_info *kinfo,
>      /* Replace these nodes with our own. Note that the original may be
>       * used_by DOMID_XEN so this check comes first. */
>      if ( device_get_class(node) == DEVICE_GIC )
> +    {
> +#ifdef CONFIG_ARM_64
> +        if ( !make_gic_node(d, kinfo->fdt, node) )
> +        {
> +            res = 0;
> +            dt_for_each_child_node(node, gic_child)
> +            {
> +                if ( gic_child != NULL )
> +                {
> +                    if ( dt_match_node(gits_matches, gic_child) )
> +                    {
> +                        res = make_its_node(d, kinfo->fdt, gic_child);
> +                        break;
> +                    }
> +                }
> +            }
> +            return res;
> +        }
> +        return 0;
> +#else
>          return make_gic_node(d, kinfo->fdt, node);
> +#endif

All these #ifdefs are a bit ugly. Couldn't we just build this code
always, even on arm32, relying on dt_match_node not to match in that
case?


> +    }
>      if ( dt_match_node(timer_matches, node) )
>          return make_timer_node(d, kinfo->fdt, node);
>  
> diff --git a/xen/arch/arm/gic-v3-its.c b/xen/arch/arm/gic-v3-its.c
> index b159b0b..4193624 100644
> --- a/xen/arch/arm/gic-v3-its.c
> +++ b/xen/arch/arm/gic-v3-its.c
> @@ -27,6 +27,8 @@
>  #include <xen/sched.h>
>  #include <xen/errno.h>
>  #include <xen/delay.h>
> +#include <xen/device_tree.h>
> +#include <xen/libfdt/libfdt.h>
>  #include <xen/list.h>
>  #include <xen/sizes.h>
>  #include <xen/vmap.h>
> @@ -1227,6 +1229,61 @@ static void its_cpu_init_collection(void)
>      spin_unlock(&its_lock);
>  }
>  
> +int its_make_dt_node(const struct domain *d,
> +                     const struct dt_device_node *node, void *fdt)
> +{
> +    struct its_node *its;
> +    const struct dt_device_node *gic;
> +    const void *compatible = NULL;
> +    u32 len;
> +    __be32 *new_cells, *tmp;
> +    int res = 0;
> +
> +    /* Will pass only first ITS node info */
> +    /* TODO: Handle multi node */
> +    its = list_first_entry(&its_nodes, struct its_node, entry);
> +    if ( !its )
> +    {
> +        dprintk(XENLOG_ERR, "ITS node not found\n");
> +        return -FDT_ERR_XEN(ENOENT);
> +    }
> +
> +    gic = its->dt_node;
> +
> +    compatible = dt_get_property(gic, "compatible", &len);
> +    if ( !compatible )
> +    {
> +        dprintk(XENLOG_ERR, "Can't find compatible property for the its 
> node\n");
> +        return -FDT_ERR_XEN(ENOENT);
> +    }
> +
> +    res = fdt_begin_node(fdt, "gic-its");
> +    if ( res )
> +        return res;
> +
> +    res = fdt_property(fdt, "compatible", compatible, len);
> +    if ( res )
> +        return res;
> +
> +    res = fdt_property(fdt, "msi-controller", NULL, 0);
> +    if ( res )
> +        return res;
> +
> +    len = dt_cells_to_size(dt_n_addr_cells(node) + dt_n_size_cells(node));
> +
> +    new_cells = xzalloc_bytes(len);
> +    if ( new_cells == NULL )
> +        return -FDT_ERR_XEN(ENOMEM);
> +    tmp = new_cells;
> +
> +    dt_set_range(&tmp, node, its->phys_base, its->phys_size);
> +
> +    res = fdt_property(fdt, "reg", new_cells, len);
> +    xfree(new_cells);
> +
> +    return res;
> +}
> +
>  static int its_force_quiescent(void __iomem *base)
>  {
>      u32 count = 1000000;   /* 1s */
> diff --git a/xen/include/asm-arm/gic-its.h b/xen/include/asm-arm/gic-its.h
> index cbe7596..1bb9825 100644
> --- a/xen/include/asm-arm/gic-its.h
> +++ b/xen/include/asm-arm/gic-its.h
> @@ -258,6 +258,8 @@ struct gic_its_info {
>  u32 its_get_id_bits(void);
>  u32 its_get_dev_bits(void);
>  u32 its_get_nr_events(void);
> +int its_make_dt_node(const struct domain *d,
> +                     const struct dt_device_node *node, void *fdt);
>  int its_lpi_init(u32 id_bits);
>  int its_init(struct rdist_prop *rdists);
>  int its_cpu_init(void);
> -- 
> 1.7.9.5
> 

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