[PATCH v4 01/14] ARM: Add page table and page defines needed by KVM

Christoffer Dall
2012-11-10T15:42:20Z

KVM uses the stage-2 page tables and the Hyp page table format,
so we define the fields and page protection flags needed by KVM.

The nomenclature is this:
- page_hyp: PL2 code/data mappings
- page_hyp_device: PL2 device mappings (vgic access)
- page_s2: Stage-2 code/data page mappings
- page_s2_device: Stage-2 device mappings (vgic access)

Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Christoffer Dall <c.dall@virtualopensystems.com>
---
arch/arm/include/asm/pgtable-3level.h | 18 ++++++++++++++++++
arch/arm/include/asm/pgtable.h | 7 +++++++
arch/arm/mm/mmu.c | 25 +++++++++++++++++++++++++
3 files changed, 50 insertions(+)

diff --git a/arch/arm/include/asm/pgtable-3level.h b/arch/arm/include/asm/pgtable-3level.h
index b249035..eaba5a4 100644
--- a/arch/arm/include/asm/pgtable-3level.h
+++ b/arch/arm/include/asm/pgtable-3level.h
@@ -102,11 +102,29 @@
*/
#define L_PGD_SWAPPER (_AT(pgdval_t, 1) << 55) /* swapper_pg_dir entry */

+/*
+ * 2nd stage PTE definitions for LPAE.
+ */
+#define L_PTE_S2_MT_UNCACHED (_AT(pteval_t, 0x5) << 2) /* MemAttr[3:0] */
+#define L_PTE_S2_MT_WRITETHROUGH (_AT(pteval_t, 0xa) << 2) /* MemAttr[3:0] */
+#define L_PTE_S2_MT_WRITEBACK (_AT(pteval_t, 0xf) << 2) /* MemAttr[3:0] */
+#define L_PTE_S2_RDONLY (_AT(pteval_t, 1) << 6) /* HAP[1] */
+#define L_PTE_S2_RDWR (_AT(pteval_t, 2) << 6) /* HAP[2:1] */
+
+/*
+ * Hyp-mode PL2 PTE definitions for LPAE.
+ */
+#define L_PTE_HYP L_PTE_USER
+
#ifndef __ASSEMBLY__

#define pud_none(pud) (!pud_val(pud))
#define pud_bad(pud) (!(pud_val(pud) & 2))
#define pud_present(pud) (pud_val(pud))
+#define pmd_table(pmd) ((pmd_val(pmd) & PMD_TYPE_MASK) == \
+ PMD_TYPE_TABLE)
+#define pmd_sect(pmd) ((pmd_val(pmd) & PMD_TYPE_MASK) == \
+ PMD_TYPE_SECT)

#define pud_clear(pudp) \
do { \
diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h
index 08c1231..dfb3918 100644
--- a/arch/arm/include/asm/pgtable.h
+++ b/arch/arm/include/asm/pgtable.h
@@ -70,6 +70,9 @@ extern void __pgd_error(const char *file, int line, pgd_t);

extern pgprot_t pgprot_user;
extern pgprot_t pgprot_kernel;
+extern pgprot_t pgprot_hyp_device;
+extern pgprot_t pgprot_s2;
+extern pgprot_t pgprot_s2_device;

#define _MOD_PROT(p, b) __pgprot(pgprot_val(p) | (b))

@@ -82,6 +85,10 @@ extern pgprot_t pgprot_kernel;
#define PAGE_READONLY_EXEC _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY)
#define PAGE_KERNEL _MOD_PROT(pgprot_kernel, L_PTE_XN)
#define PAGE_KERNEL_EXEC pgprot_kernel
+#define PAGE_HYP _MOD_PROT(pgprot_kernel, L_PTE_HYP)
+#define PAGE_HYP_DEVICE _MOD_PROT(pgprot_hyp_device, L_PTE_HYP)
+#define PAGE_S2 _MOD_PROT(pgprot_s2, L_PTE_S2_RDONLY)
+#define PAGE_S2_DEVICE _MOD_PROT(pgprot_s2_device, L_PTE_USER | L_PTE_S2_RDONLY)

#define __PAGE_NONE __pgprot(_L_PTE_DEFAULT | L_PTE_RDONLY | L_PTE_XN)
#define __PAGE_SHARED __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_XN)
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 941dfb9..087d949 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -57,43 +57,61 @@ static unsigned int cachepolicy __initdata = CPOLICY_WRITEBACK;
static unsigned int ecc_mask __initdata = 0;
pgprot_t pgprot_user;
pgprot_t pgprot_kernel;
+pgprot_t pgprot_hyp_device;
+pgprot_t pgprot_s2;
+pgprot_t pgprot_s2_device;

EXPORT_SYMBOL(pgprot_user);
EXPORT_SYMBOL(pgprot_kernel);
+EXPORT_SYMBOL(pgprot_hyp_device);
+EXPORT_SYMBOL(pgprot_s2);
+EXPORT_SYMBOL(pgprot_s2_device);

struct cachepolicy {
const char policy[16];
unsigned int cr_mask;
pmdval_t pmd;
pteval_t pte;
+ pteval_t pte_s2;
};

+#ifdef CONFIG_ARM_LPAE
+#define s2_policy(policy) policy
+#else
+#define s2_policy(policy) 0
+#endif
+
static struct cachepolicy cache_policies[] __initdata = {
{
.policy = "uncached",
.cr_mask = CR_W|CR_C,
.pmd = PMD_SECT_UNCACHED,
.pte = L_PTE_MT_UNCACHED,
+ .pte_s2 = s2_policy(L_PTE_S2_MT_UNCACHED),
}, {
.policy = "buffered",
.cr_mask = CR_C,
.pmd = PMD_SECT_BUFFERED,
.pte = L_PTE_MT_BUFFERABLE,
+ .pte_s2 = s2_policy(L_PTE_S2_MT_UNCACHED),
}, {
.policy = "writethrough",
.cr_mask = 0,
.pmd = PMD_SECT_WT,
.pte = L_PTE_MT_WRITETHROUGH,
+ .pte_s2 = s2_policy(L_PTE_S2_MT_WRITETHROUGH),
}, {
.policy = "writeback",
.cr_mask = 0,
.pmd = PMD_SECT_WB,
.pte = L_PTE_MT_WRITEBACK,
+ .pte_s2 = s2_policy(L_PTE_S2_MT_WRITEBACK),
}, {
.policy = "writealloc",
.cr_mask = 0,
.pmd = PMD_SECT_WBWA,
.pte = L_PTE_MT_WRITEALLOC,
+ .pte_s2 = s2_policy(L_PTE_S2_MT_WRITEBACK),
}
};

@@ -310,6 +328,7 @@ static void __init build_mem_type_table(void)
struct cachepolicy *cp;
unsigned int cr = get_cr();
pteval_t user_pgprot, kern_pgprot, vecs_pgprot;
+ pteval_t hyp_device_pgprot, s2_pgprot, s2_device_pgprot;
int cpu_arch = cpu_architecture();
int i;

@@ -421,6 +440,8 @@ static void __init build_mem_type_table(void)
*/
cp = &cache_policies[cachepolicy];
vecs_pgprot = kern_pgprot = user_pgprot = cp->pte;
+ s2_pgprot = cp->pte_s2;
+ hyp_device_pgprot = s2_device_pgprot = mem_types[MT_DEVICE].prot_pte;

/*
* ARMv6 and above have extended page tables.
@@ -444,6 +465,7 @@ static void __init build_mem_type_table(void)
user_pgprot |= L_PTE_SHARED;
kern_pgprot |= L_PTE_SHARED;
vecs_pgprot |= L_PTE_SHARED;
+ s2_pgprot |= L_PTE_SHARED;
mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_S;
mem_types[MT_DEVICE_WC].prot_pte |= L_PTE_SHARED;
mem_types[MT_DEVICE_CACHED].prot_sect |= PMD_SECT_S;
@@ -498,6 +520,9 @@ static void __init build_mem_type_table(void)
pgprot_user = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG | user_pgprot);
pgprot_kernel = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG |
L_PTE_DIRTY | kern_pgprot);
+ pgprot_s2 = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG | s2_pgprot);
+ pgprot_s2_device = __pgprot(s2_device_pgprot);
+ pgprot_hyp_device = __pgprot(hyp_device_pgprot);

mem_types[MT_LOW_VECTORS].prot_l1 |= ecc_mask;
mem_types[MT_HIGH_VECTORS].prot_l1 |= ecc_mask;