[coreboot-gerrit] [XS] Change in coreboot[main]: soc/intel/xeon_sp/ebg/soc_xhci: Check if BAR is reachable

[Matt DeVillier (Code Review)]

Matt DeVillier has submitted this change. ( https://review.coreboot.org/c/coreboot/+/85809?usp=email )

Change subject: soc/intel/xeon_sp/ebg/soc_xhci: Check if BAR is reachable
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soc/intel/xeon_sp/ebg/soc_xhci: Check if BAR is reachable

On x86_32 the xHCI BAR isn't reachable as it's mapped in high MMIO.
Currently this is not a problem since the code is unused.

Add a check and return NULL instead of cutting of the higher bits
and thus do not return an invalid pointer. On x86_64 it's working
when the extended page-tables are installed.

Change-Id: I00496ad476c33e0984d7cb0019f27154302edda5
Signed-off-by: Patrick Rudolph 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/85809
Tested-by: build bot (Jenkins) 
Reviewed-by: Shuo Liu 
---
M src/soc/intel/xeon_sp/ebg/soc_xhci.c
1 file changed, 7 insertions(+), 0 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Shuo Liu: Looks good to me, approved

diff --git a/src/soc/intel/xeon_sp/ebg/soc_xhci.c b/src/soc/intel/xeon_sp/ebg/soc_xhci.c
index f8aa37b..f7b1320 100644
--- a/src/soc/intel/xeon_sp/ebg/soc_xhci.c
+++ b/src/soc/intel/xeon_sp/ebg/soc_xhci.c
@@ -17,6 +17,13 @@
    	printk(BIOS_ERR, "XHCI BAR is not found\n");
    	return NULL;
    }
+
+#if ENV_X86_32
+	assert(res->base < 0x100000000ULL);
+	if (res->base >= 0x100000000ULL)
+		return NULL;
+#endif
+
    return (void *)(uintptr_t)res->base;
 }