Linux KVM/arm64 development list
 help / color / mirror / Atom feed
From: James Morse <james.morse@arm.com>
To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu
Cc: Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>, Marc Zyngier <maz@kernel.org>
Subject: [RFC PATCH 5/7] arm64: mm: Add pgprot_pbha() to allow drivers to request PBHA values
Date: Fri, 15 Oct 2021 16:14:14 +0000	[thread overview]
Message-ID: <20211015161416.2196-6-james.morse@arm.com> (raw)
In-Reply-To: <20211015161416.2196-1-james.morse@arm.com>

Add a pgprot_pbha() helper that modifies a pgprot_t to include a pbha
value. The value is checked against those that were listed as only
affecting performance.

Signed-off-by: James Morse <james.morse@arm.com>
---
 arch/arm64/include/asm/pgtable-hwdef.h |  1 +
 arch/arm64/include/asm/pgtable.h       | 12 ++++++++++++
 arch/arm64/kernel/cpufeature.c         |  1 +
 3 files changed, 14 insertions(+)

diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h
index 3d41242c52b0..bef11fb9a255 100644
--- a/arch/arm64/include/asm/pgtable-hwdef.h
+++ b/arch/arm64/include/asm/pgtable-hwdef.h
@@ -154,6 +154,7 @@
 #define PTE_CONT		(_AT(pteval_t, 1) << 52)	/* Contiguous range */
 #define PTE_PXN			(_AT(pteval_t, 1) << 53)	/* Privileged XN */
 #define PTE_UXN			(_AT(pteval_t, 1) << 54)	/* User XN */
+#define PTE_PBHA_MASK		(_AT(pteval_t, 0xf) << 59)	/* Page Base Hardware Attributes */
 
 #define PTE_ADDR_LOW		(((_AT(pteval_t, 1) << (48 - PAGE_SHIFT)) - 1) << PAGE_SHIFT)
 #ifdef CONFIG_ARM64_PA_BITS_52
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index dfa76afa0ccf..3bc242db2c3c 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -518,6 +518,18 @@ static inline pmd_t pmd_mkdevmap(pmd_t pmd)
 	__pgprot_modify(prot, PTE_ATTRINDX_MASK, \
 			PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)
 
+
+extern unsigned long arm64_pbha_perf_only_values;
+static inline unsigned long __pbha_check_perf_only(unsigned long pbha_val)
+{
+	if (test_bit(pbha_val, &arm64_pbha_perf_only_values))
+		return FIELD_PREP(PTE_PBHA_MASK, pbha_val);
+	return 0;
+}
+
+#define pgprot_pbha(prot, pbha_val) \
+	__pgprot_modify(prot, PTE_PBHA_MASK, __pbha_check_perf_only(pbha_val))
+
 #define __HAVE_PHYS_MEM_ACCESS_PROT
 struct file;
 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 548c6f96a878..88f0f805b938 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -112,6 +112,7 @@ bool arm64_use_ng_mappings = false;
 EXPORT_SYMBOL(arm64_use_ng_mappings);
 
 unsigned long __ro_after_init arm64_pbha_perf_only_values;
+EXPORT_SYMBOL(arm64_pbha_perf_only_values);
 
 /*
  * Permit PER_LINUX32 and execve() of 32-bit binaries even if not all CPUs
-- 
2.30.2

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

  parent reply	other threads:[~2021-10-15 16:15 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-15 16:14 [RFC PATCH 0/7] arm64: mm: Prototype to allow drivers to request PBHA values James Morse
2021-10-15 16:14 ` [RFC PATCH 1/7] KVM: arm64: Detect and enable PBHA for stage2 James Morse
2021-10-16 13:27   ` Marc Zyngier
2021-10-18 17:26     ` James Morse
2021-10-15 16:14 ` [RFC PATCH 2/7] dt-bindings: Rename the description of cpu nodes cpu.yaml James Morse
2021-10-15 16:14 ` [RFC PATCH 3/7] dt-bindings: arm: Add binding for Page Based Hardware Attributes James Morse
2021-10-15 16:14 ` [RFC PATCH 4/7] arm64: cpufeature: Enable PBHA bits for stage1 James Morse
2021-10-16 13:50   ` Marc Zyngier
2021-10-18 17:26     ` James Morse
2021-10-15 16:14 ` James Morse [this message]
2021-10-15 16:14 ` [RFC PATCH 6/7] KVM: arm64: Configure PBHA bits for stage2 James Morse
2021-10-16 13:46   ` Marc Zyngier
2021-10-15 16:14 ` [RFC PATCH 7/7] Documentation: arm64: Describe the support and expectations for PBHA James Morse
2021-10-16 13:54 ` [RFC PATCH 0/7] arm64: mm: Prototype to allow drivers to request PBHA values Marc Zyngier

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20211015161416.2196-6-james.morse@arm.com \
    --to=james.morse@arm.com \
    --cc=catalin.marinas@arm.com \
    --cc=kvmarm@lists.cs.columbia.edu \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=maz@kernel.org \
    --cc=will@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox