[Xen-devel] [PATCH] ARM: GICv3: copy Dom0 GICv3 reg property from host DT

[Andre Przywara <andre.przywara@xxxxxxx>]

At the moment we re-generate the Dom0 GICv3 DT node, by creating the
"reg" property from scratch using our previously parsed and
translated(!) host addresses. However we then write the *absolute*
addresses into the new node, not considering possible "range" mappings
in any of the GIC's parent nodes. So whenever one of the parents has a
non-empty ranges property, Dom0 will wrongly translate the addresses.
Properly incorporating the ranges properties sounds tedious, so let's
just copy the first part of the reg property instead (as we do for GICv2),
since the addresses for Dom0 are identical to those from the hardware.

The mainline kernel DT for the Espressobin board with an Marvell 3720 SoC
has the GIC in such an translated bus, so this patch allows this board
to boot properly (after adding support for the SoC's UART).

Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
---
 xen/arch/arm/gic-v3.c | 29 +++++++++++------------------
 1 file changed, 11 insertions(+), 18 deletions(-)

diff --git a/xen/arch/arm/gic-v3.c b/xen/arch/arm/gic-v3.c
index a0d290b55c..6b17abd0a1 100644
--- a/xen/arch/arm/gic-v3.c
+++ b/xen/arch/arm/gic-v3.c
@@ -1147,10 +1147,9 @@ static int gicv3_make_hwdom_dt_node(const struct domain 
*d,
                                     const struct dt_device_node *gic,
                                     void *fdt)
 {
-    const void *compatible = NULL;
-    uint32_t len;
-    __be32 *new_cells, *tmp;
-    int i, res = 0;
+    const void *compatible, *hw_reg;
+    uint32_t len, new_len;
+    int res;
 
     compatible = dt_get_property(gic, "compatible", &len);
     if ( !compatible )
@@ -1173,27 +1172,21 @@ static int gicv3_make_hwdom_dt_node(const struct domain 
*d,
     if ( res )
         return res;
 
-    len = dt_cells_to_size(dt_n_addr_cells(gic) + dt_n_size_cells(gic));
+    new_len = dt_cells_to_size(dt_n_addr_cells(gic) + dt_n_size_cells(gic));
     /*
      * GIC has two memory regions: Distributor + rdist regions
      * CPU interface and virtual cpu interfaces accessesed as System registers
      * So cells are created only for Distributor and rdist regions
      */
-    len = len * (d->arch.vgic.nr_regions + 1);
-    new_cells = xzalloc_bytes(len);
-    if ( new_cells == NULL )
-        return -FDT_ERR_XEN(ENOMEM);
-
-    tmp = new_cells;
-
-    dt_set_range(&tmp, gic, d->arch.vgic.dbase, SZ_64K);
+    new_len = new_len * (d->arch.vgic.nr_regions + 1);
 
-    for ( i = 0; i < d->arch.vgic.nr_regions; i++ )
-        dt_set_range(&tmp, gic, d->arch.vgic.rdist_regions[i].base,
-                     d->arch.vgic.rdist_regions[i].size);
+    hw_reg = dt_get_property(gic, "reg", &len);
+    if ( !hw_reg )
+        return -FDT_ERR_XEN(ENOENT);
+    if ( new_len > len )
+       return -FDT_ERR_XEN(ERANGE);
 
-    res = fdt_property(fdt, "reg", new_cells, len);
-    xfree(new_cells);
+    res = fdt_property(fdt, "reg", hw_reg, new_len);
     if ( res )
         return res;
 
-- 
2.14.1


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