Collect all page_base_address bits for pte-further addresses

Submitted by StDenis, Tom on July 18, 2019, 4:29 p.m.

Details

Message ID 20190718162848.29246-1-tom.stdenis@amd.com
State New
Headers show
Series "Collect all page_base_address bits for pte-further addresses" ( rev: 1 ) in AMD X.Org drivers

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Commit Message

StDenis, Tom July 18, 2019, 4:29 p.m.
The specification says to treat a PTE with the F bit set "like a PDE"
which means that all but the lower 6 bits are part of the page base
address.  Indeed, in the wild a comment came back indicating that
we were stripping off bits needed to properly fetch the next
PTE.

Signed-off-by: Tom St Denis <tom.stdenis@amd.com>
---
 src/lib/read_vram.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

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diff --git a/src/lib/read_vram.c b/src/lib/read_vram.c
index cba8f6b..209ca84 100644
--- a/src/lib/read_vram.c
+++ b/src/lib/read_vram.c
@@ -654,7 +654,7 @@  pte_further:
 
 			// decode PTE values
 pde_is_pte:
-			pte_fields.page_base_addr = pte_entry & 0xFFFFFFFFF000ULL;
+			pte_fields.page_base_addr = pte_entry & 0xFFFFFFFFFFC0ULL; // all but bottom 6 bits are PBA
 			pte_fields.fragment       = (pte_entry >> 7)  & 0x1F;
 			pte_fields.system         = (pte_entry >> 1) & 1;
 			pte_fields.valid          = pte_entry & 1;