powerpc: add support for folded p4d page tables

Implement primitives necessary for the 4th level folding, add walks of p4d
level where appropriate and replace 5level-fixup.h with pgtable-nop4d.h.

[rppt@linux.ibm.com: powerpc/xmon: drop unused pgdir varialble in show_pte() function]
  Link: http://lkml.kernel.org/r/20200519181454.GI1059226@linux.ibm.com
[rppt@linux.ibm.com; build fix]
  Link: http://lkml.kernel.org/r/20200423141845.GI13521@linux.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Christophe Leroy <christophe.leroy@c-s.fr> # 8xx and 83xx
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: James Morse <james.morse@arm.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Julien Thierry <julien.thierry.kdev@gmail.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200414153455.21744-9-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 19 insertions, 13 deletions

diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c
index aa12cd4078b3..d605ed0bb2e7 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_radix.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c
@@ -499,13 +499,14 @@ void kvmppc_free_pgtable_radix(struct kvm *kvm, pgd_t *pgd, unsigned int lpid)
 	unsigned long ig;
 
 	for (ig = 0; ig < PTRS_PER_PGD; ++ig, ++pgd) {
+		p4d_t *p4d = p4d_offset(pgd, 0);
 		pud_t *pud;
 
-		if (!pgd_present(*pgd))
+		if (!p4d_present(*p4d))
 			continue;
-		pud = pud_offset(pgd, 0);
+		pud = pud_offset(p4d, 0);
 		kvmppc_unmap_free_pud(kvm, pud, lpid);
-		pgd_clear(pgd);
+		p4d_clear(p4d);
 	}
 }
 
@@ -566,6 +567,7 @@ int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte,
 		      unsigned long *rmapp, struct rmap_nested **n_rmap)
 {
 	pgd_t *pgd;
+	p4d_t *p4d;
 	pud_t *pud, *new_pud = NULL;
 	pmd_t *pmd, *new_pmd = NULL;
 	pte_t *ptep, *new_ptep = NULL;
@@ -573,9 +575,11 @@ int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte,
 
 	/* Traverse the guest's 2nd-level tree, allocate new levels needed */
 	pgd = pgtable + pgd_index(gpa);
+	p4d = p4d_offset(pgd, gpa);
+
 	pud = NULL;
-	if (pgd_present(*pgd))
-		pud = pud_offset(pgd, gpa);
+	if (p4d_present(*p4d))
+		pud = pud_offset(p4d, gpa);
 	else
 		new_pud = pud_alloc_one(kvm->mm, gpa);
 
@@ -596,13 +600,13 @@ int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte,
 
 	/* Now traverse again under the lock and change the tree */
 	ret = -ENOMEM;
-	if (pgd_none(*pgd)) {
+	if (p4d_none(*p4d)) {
 		if (!new_pud)
 			goto out_unlock;
-		pgd_populate(kvm->mm, pgd, new_pud);
+		p4d_populate(kvm->mm, p4d, new_pud);
 		new_pud = NULL;
 	}
-	pud = pud_offset(pgd, gpa);
+	pud = pud_offset(p4d, gpa);
 	if (pud_is_leaf(*pud)) {
 		unsigned long hgpa = gpa & PUD_MASK;
 
@@ -1220,7 +1224,8 @@ static ssize_t debugfs_radix_read(struct file *file, char __user *buf,
 	unsigned long gpa;
 	pgd_t *pgt;
 	struct kvm_nested_guest *nested;
-	pgd_t pgd, *pgdp;
+	pgd_t *pgdp;
+	p4d_t p4d, *p4dp;
 	pud_t pud, *pudp;
 	pmd_t pmd, *pmdp;
 	pte_t *ptep;
@@ -1293,13 +1298,14 @@ static ssize_t debugfs_radix_read(struct file *file, char __user *buf,
 		}
 
 		pgdp = pgt + pgd_index(gpa);
-		pgd = READ_ONCE(*pgdp);
-		if (!(pgd_val(pgd) & _PAGE_PRESENT)) {
-			gpa = (gpa & PGDIR_MASK) + PGDIR_SIZE;
+		p4dp = p4d_offset(pgdp, gpa);
+		p4d = READ_ONCE(*p4dp);
+		if (!(p4d_val(p4d) & _PAGE_PRESENT)) {
+			gpa = (gpa & P4D_MASK) + P4D_SIZE;
 			continue;
 		}
 
-		pudp = pud_offset(&pgd, gpa);
+		pudp = pud_offset(&p4d, gpa);
 		pud = READ_ONCE(*pudp);
 		if (!(pud_val(pud) & _PAGE_PRESENT)) {
 			gpa = (gpa & PUD_MASK) + PUD_SIZE;