76 lines
2.4 KiB
Diff
76 lines
2.4 KiB
Diff
From c567f2948f57bdc03ed03403ae0234085f376b7d Mon Sep 17 00:00:00 2001
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From: Ingo Molnar <mingo@kernel.org>
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Date: Mon, 25 Mar 2024 11:47:51 +0100
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Subject: Revert "x86/mm/ident_map: Use gbpages only where full GB page should
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be mapped."
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This reverts commit d794734c9bbfe22f86686dc2909c25f5ffe1a572.
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While the original change tries to fix a bug, it also unintentionally broke
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existing systems, see the regressions reported at:
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https://lore.kernel.org/all/3a1b9909-45ac-4f97-ad68-d16ef1ce99db@pavinjoseph.com/
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Since d794734c9bbf was also marked for -stable, let's back it out before
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causing more damage.
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Note that due to another upstream change the revert was not 100% automatic:
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0a845e0f6348 mm/treewide: replace pud_large() with pud_leaf()
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Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Cc: <stable@vger.kernel.org>
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Cc: Russ Anderson <rja@hpe.com>
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Cc: Steve Wahl <steve.wahl@hpe.com>
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Cc: Dave Hansen <dave.hansen@linux.intel.com>
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Link: https://lore.kernel.org/all/3a1b9909-45ac-4f97-ad68-d16ef1ce99db@pavinjoseph.com/
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Fixes: d794734c9bbf ("x86/mm/ident_map: Use gbpages only where full GB page should be mapped.")
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---
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arch/x86/mm/ident_map.c | 23 +++++------------------
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1 file changed, 5 insertions(+), 18 deletions(-)
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diff --git a/arch/x86/mm/ident_map.c b/arch/x86/mm/ident_map.c
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index a204a332c71fc5..968d7005f4a724 100644
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--- a/arch/x86/mm/ident_map.c
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+++ b/arch/x86/mm/ident_map.c
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@@ -26,31 +26,18 @@ static int ident_pud_init(struct x86_mapping_info *info, pud_t *pud_page,
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for (; addr < end; addr = next) {
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pud_t *pud = pud_page + pud_index(addr);
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pmd_t *pmd;
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- bool use_gbpage;
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next = (addr & PUD_MASK) + PUD_SIZE;
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if (next > end)
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next = end;
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- /* if this is already a gbpage, this portion is already mapped */
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- if (pud_large(*pud))
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- continue;
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-
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- /* Is using a gbpage allowed? */
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- use_gbpage = info->direct_gbpages;
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-
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- /* Don't use gbpage if it maps more than the requested region. */
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- /* at the begining: */
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- use_gbpage &= ((addr & ~PUD_MASK) == 0);
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- /* ... or at the end: */
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- use_gbpage &= ((next & ~PUD_MASK) == 0);
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-
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- /* Never overwrite existing mappings */
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- use_gbpage &= !pud_present(*pud);
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-
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- if (use_gbpage) {
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+ if (info->direct_gbpages) {
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pud_t pudval;
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+ if (pud_present(*pud))
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+ continue;
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+
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+ addr &= PUD_MASK;
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pudval = __pud((addr - info->offset) | info->page_flag);
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set_pud(pud, pudval);
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continue;
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--
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cgit 1.2.3-korg
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