[PATCH v3 02/11] x86/kexec: Add extra pointers to transition page table PGD, PUD, PMD and PTE

[Daniel Kiper <daniel.kiper-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>]

Some implementations (e.g. Xen PVOPS) could not use part of identity page table
to construct transition page table. It means that they require separate PUDs,
PMDs and PTEs for virtual and physical (identity) mapping. To satisfy that
requirement add extra pointer to PGD, PUD, PMD and PTE and align existing code.

Signed-off-by: Daniel Kiper <daniel.kiper-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
---
 arch/x86/include/asm/kexec.h       |   10 +++++++---
 arch/x86/kernel/machine_kexec_64.c |   12 ++++++------
 2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h
index 6080d26..cedd204 100644
--- a/arch/x86/include/asm/kexec.h
+++ b/arch/x86/include/asm/kexec.h
@@ -157,9 +157,13 @@ struct kimage_arch {
 };
 #else
 struct kimage_arch {
-	pud_t *pud;
-	pmd_t *pmd;
-	pte_t *pte;
+	pgd_t *pgd;
+	pud_t *pud0;
+	pud_t *pud1;
+	pmd_t *pmd0;
+	pmd_t *pmd1;
+	pte_t *pte0;
+	pte_t *pte1;
 };
 #endif
 
diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c
index b3ea9db..976e54b 100644
--- a/arch/x86/kernel/machine_kexec_64.c
+++ b/arch/x86/kernel/machine_kexec_64.c
@@ -137,9 +137,9 @@ out:
 
 static void free_transition_pgtable(struct kimage *image)
 {
-	free_page((unsigned long)image->arch.pud);
-	free_page((unsigned long)image->arch.pmd);
-	free_page((unsigned long)image->arch.pte);
+	free_page((unsigned long)image->arch.pud0);
+	free_page((unsigned long)image->arch.pmd0);
+	free_page((unsigned long)image->arch.pte0);
 }
 
 static int init_transition_pgtable(struct kimage *image, pgd_t *pgd)
@@ -157,7 +157,7 @@ static int init_transition_pgtable(struct kimage *image, pgd_t *pgd)
 		pud = (pud_t *)get_zeroed_page(GFP_KERNEL);
 		if (!pud)
 			goto err;
-		image->arch.pud = pud;
+		image->arch.pud0 = pud;
 		set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE));
 	}
 	pud = pud_offset(pgd, vaddr);
@@ -165,7 +165,7 @@ static int init_transition_pgtable(struct kimage *image, pgd_t *pgd)
 		pmd = (pmd_t *)get_zeroed_page(GFP_KERNEL);
 		if (!pmd)
 			goto err;
-		image->arch.pmd = pmd;
+		image->arch.pmd0 = pmd;
 		set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE));
 	}
 	pmd = pmd_offset(pud, vaddr);
@@ -173,7 +173,7 @@ static int init_transition_pgtable(struct kimage *image, pgd_t *pgd)
 		pte = (pte_t *)get_zeroed_page(GFP_KERNEL);
 		if (!pte)
 			goto err;
-		image->arch.pte = pte;
+		image->arch.pte0 = pte;
 		set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE));
 	}
 	pte = pte_offset_kernel(pmd, vaddr);
-- 
1.5.6.5