From: Julien Grall <julien.grall@arm.com>
To: xen-devel@lists.xen.org
Cc: andre.przywara@arm.com, Julien Grall <julien.grall@arm.com>,
sstabellini@kernel.org
Subject: [PATCH v3 6/9] xen/arm: page: Describe the layout of flags used to update page tables
Date: Mon, 2 Oct 2017 18:31:47 +0100 [thread overview]
Message-ID: <20171002173150.5404-7-julien.grall@arm.com> (raw)
In-Reply-To: <20171002173150.5404-1-julien.grall@arm.com>
Currently, the flags used to update page tables (i.e PAGE_HYPERVISOR_*)
only contains the memory attribute index. Follow-up patches will add
more information in it. So document the current layout.
At the same time introduce PAGE_AI_MASK to get the memory attribute
index easily.
Signed-off-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
---
Changes in v3:
- Add Stefano's reviewed-by
Changes in v2:
- Slightly update the commit message to specify we describe the
current layout.
- Add Andre's reviewed-by
---
xen/arch/arm/mm.c | 2 +-
xen/include/asm-arm/page.h | 7 +++++++
2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
index 39bade63f5..117f05a1d6 100644
--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -1021,7 +1021,7 @@ static int create_xen_entries(enum xenmap_operation op,
}
if ( op == RESERVE )
break;
- pte = mfn_to_xen_entry(mfn, flags);
+ pte = mfn_to_xen_entry(mfn, PAGE_AI_MASK(flags));
pte.pt.table = 1;
write_pte(entry, pte);
break;
diff --git a/xen/include/asm-arm/page.h b/xen/include/asm-arm/page.h
index 0ae1a2587b..aa3e83f5b4 100644
--- a/xen/include/asm-arm/page.h
+++ b/xen/include/asm-arm/page.h
@@ -65,6 +65,13 @@
#define MAIR0VAL (MAIRVAL & 0xffffffff)
#define MAIR1VAL (MAIRVAL >> 32)
+/*
+ * Layout of the flags used for updating the hypervisor page tables
+ *
+ * [0:2] Memory Attribute Index
+ */
+#define PAGE_AI_MASK(x) ((x) & 0x7U)
+
#define PAGE_HYPERVISOR (MT_NORMAL)
#define PAGE_HYPERVISOR_NOCACHE (MT_DEVICE_nGnRE)
#define PAGE_HYPERVISOR_WC (MT_NORMAL_NC)
--
2.11.0
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next prev parent reply other threads:[~2017-10-02 17:31 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-02 17:31 [PATCH v3 0/9] xen/arm: Memory subsystem clean-up Julien Grall
2017-10-02 17:31 ` [PATCH v3 1/9] xen/arm: page: Use ARMv8 naming to improve readability Julien Grall
2017-10-02 17:31 ` [PATCH v3 2/9] xen/arm: page: Clean-up the definition of MAIRVAL Julien Grall
2017-10-02 17:31 ` [PATCH v3 3/9] xen/arm: mm: Rename and clarify AP[1] in the stage-1 page table Julien Grall
2017-10-02 17:31 ` [PATCH v3 4/9] xen/arm: Switch to SYS_STATE_boot just after end_boot_allocator() Julien Grall
2017-10-02 17:31 ` [PATCH v3 5/9] xen/arm: mm: Rename 'ai' into 'flags' in create_xen_entries Julien Grall
2017-10-02 17:31 ` Julien Grall [this message]
2017-10-02 17:31 ` [PATCH v3 7/9] xen/arm: mm: Embed permission in the flags Julien Grall
2017-10-09 12:34 ` Julien Grall
2017-10-02 17:31 ` [PATCH v3 8/9] xen/arm: mm: Handle permission flags when adding a new mapping Julien Grall
2017-10-02 17:31 ` [PATCH v3 9/9] xen/arm: mm: Use memory flags for modify_xen_mappings rather than custom one Julien Grall
2017-10-02 18:14 ` Konrad Rzeszutek Wilk
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