diff mbox series

[v2,04/14] efi: Avoid hard-coding the various PAT constants

Message ID aad022471c81db163ed7b4780f926898c2ff9065.1670948141.git.demi@invisiblethingslab.com (mailing list archive)
State Superseded
Headers show
Series Make PAT handling less brittle | expand

Commit Message

Demi Marie Obenour Dec. 13, 2022, 10:26 p.m. UTC 
This makes the code much easier to understand, and avoids problems if
Xen's PAT ever changes in the future.

Reviewed-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
---
 xen/common/efi/boot.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

Comments

Jan Beulich Dec. 14, 2022, 9:40 a.m. UTC | #1 
On 13.12.2022 23:26, Demi Marie Obenour wrote:
> This makes the code much easier to understand, and avoids problems if
> Xen's PAT ever changes in the future.
> 
> Reviewed-by: Jan Beulich <jbeulich@suse.com>
> Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>

Nit (quoting docs/process/sending-patches.doc):

In general tags are added in chronological order. So a `Reviewed-by:` tag
should be added **after** the `Signed-off-by:` tag, as the review happened
after the patch was written.

Otherwise it looks like this patch could go in right away, if only it was
clear that it's independent of the earlier three (it looks as if it is).

Jan
diff mbox series

Patch

diff --git a/xen/common/efi/boot.c b/xen/common/efi/boot.c
index d521b47bc6d9513ca6e65c3170abb94881a71910..e1248d63e7f99d598a6b1df04e34ed34ed0b6910 100644
--- a/xen/common/efi/boot.c
+++ b/xen/common/efi/boot.c
@@ -1748,23 +1748,23 @@  void __init efi_init_memory(void)
         emfn = PFN_UP(desc->PhysicalStart + len);
 
         if ( desc->Attribute & EFI_MEMORY_WB )
-            /* nothing */;
+            prot |= _PAGE_WB;
         else if ( desc->Attribute & EFI_MEMORY_WT )
-            prot |= _PAGE_PWT | MAP_SMALL_PAGES;
+            prot |= _PAGE_WT | MAP_SMALL_PAGES;
         else if ( desc->Attribute & EFI_MEMORY_WC )
-            prot |= _PAGE_PAT | MAP_SMALL_PAGES;
+            prot |= _PAGE_WC | MAP_SMALL_PAGES;
         else if ( desc->Attribute & (EFI_MEMORY_UC | EFI_MEMORY_UCE) )
-            prot |= _PAGE_PWT | _PAGE_PCD | MAP_SMALL_PAGES;
+            prot |= _PAGE_UC | MAP_SMALL_PAGES;
         else if ( efi_bs_revision >= EFI_REVISION(2, 5) &&
                   (desc->Attribute & EFI_MEMORY_WP) )
-            prot |= _PAGE_PAT | _PAGE_PWT | MAP_SMALL_PAGES;
+            prot |= _PAGE_WP | MAP_SMALL_PAGES;
         else
         {
             printk(XENLOG_ERR "Unknown cachability for MFNs %#lx-%#lx%s\n",
                    smfn, emfn - 1, efi_map_uc ? ", assuming UC" : "");
             if ( !efi_map_uc )
                 continue;
-            prot |= _PAGE_PWT | _PAGE_PCD | MAP_SMALL_PAGES;
+            prot |= _PAGE_UC | MAP_SMALL_PAGES;
         }
 
         if ( desc->Attribute & (efi_bs_revision < EFI_REVISION(2, 5)