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From: alison.schofield@intel.com
To: Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>,
	Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	x86@kernel.org
Cc: Alison Schofield <alison.schofield@intel.com>,
	"H. Peter Anvin" <hpa@zytor.com>,
	"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
	Kai Huang <kai.huang@intel.com>,
	linux-kernel@vger.kernel.org
Subject: [PATCH v2 2/2] x86/pconfig: Remove unused MKTME pconfig code
Date: Mon,  6 May 2024 21:24:22 -0700
Message-Id: <4ddff30d466785b4adb1400f0518783012835141.1715054189.git.alison.schofield@intel.com>
In-Reply-To: <cover.1715054189.git.alison.schofield@intel.com>
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From: Alison Schofield <alison.schofield@intel.com>

Code supporting Intel PCONFIG targets was an early piece of enabling
for MKTME (Multi-Key Total Memory Encryption).

Since MKTME feature enablement did not follow into the kernel, remove
the unused PCONFIG code.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Kai Huang <kai.huang@intel.com>
---
 arch/x86/include/asm/intel_pconfig.h | 65 ---------------------
 arch/x86/kernel/cpu/Makefile         |  2 +-
 arch/x86/kernel/cpu/intel_pconfig.c  | 84 ----------------------------
 3 files changed, 1 insertion(+), 150 deletions(-)
 delete mode 100644 arch/x86/include/asm/intel_pconfig.h
 delete mode 100644 arch/x86/kernel/cpu/intel_pconfig.c

diff --git a/arch/x86/include/asm/intel_pconfig.h b/arch/x86/include/asm/intel_pconfig.h
deleted file mode 100644
index 994638ef171b..000000000000
--- a/arch/x86/include/asm/intel_pconfig.h
+++ /dev/null
@@ -1,65 +0,0 @@
-#ifndef	_ASM_X86_INTEL_PCONFIG_H
-#define	_ASM_X86_INTEL_PCONFIG_H
-
-#include <asm/asm.h>
-#include <asm/processor.h>
-
-enum pconfig_target {
-	INVALID_TARGET	= 0,
-	MKTME_TARGET	= 1,
-	PCONFIG_TARGET_NR
-};
-
-int pconfig_target_supported(enum pconfig_target target);
-
-enum pconfig_leaf {
-	MKTME_KEY_PROGRAM	= 0,
-	PCONFIG_LEAF_INVALID,
-};
-
-#define PCONFIG ".byte 0x0f, 0x01, 0xc5"
-
-/* Defines and structure for MKTME_KEY_PROGRAM of PCONFIG instruction */
-
-/* mktme_key_program::keyid_ctrl COMMAND, bits [7:0] */
-#define MKTME_KEYID_SET_KEY_DIRECT	0
-#define MKTME_KEYID_SET_KEY_RANDOM	1
-#define MKTME_KEYID_CLEAR_KEY		2
-#define MKTME_KEYID_NO_ENCRYPT		3
-
-/* mktme_key_program::keyid_ctrl ENC_ALG, bits [23:8] */
-#define MKTME_AES_XTS_128	(1 << 8)
-
-/* Return codes from the PCONFIG MKTME_KEY_PROGRAM */
-#define MKTME_PROG_SUCCESS	0
-#define MKTME_INVALID_PROG_CMD	1
-#define MKTME_ENTROPY_ERROR	2
-#define MKTME_INVALID_KEYID	3
-#define MKTME_INVALID_ENC_ALG	4
-#define MKTME_DEVICE_BUSY	5
-
-/* Hardware requires the structure to be 256 byte aligned. Otherwise #GP(0). */
-struct mktme_key_program {
-	u16 keyid;
-	u32 keyid_ctrl;
-	u8 __rsvd[58];
-	u8 key_field_1[64];
-	u8 key_field_2[64];
-} __packed __aligned(256);
-
-static inline int mktme_key_program(struct mktme_key_program *key_program)
-{
-	unsigned long rax = MKTME_KEY_PROGRAM;
-
-	if (!pconfig_target_supported(MKTME_TARGET))
-		return -ENXIO;
-
-	asm volatile(PCONFIG
-		: "=a" (rax), "=b" (key_program)
-		: "0" (rax), "1" (key_program)
-		: "memory", "cc");
-
-	return rax;
-}
-
-#endif	/* _ASM_X86_INTEL_PCONFIG_H */
diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index eb4dbcdf41f1..ecd78a61da2e 100644
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -34,7 +34,7 @@ obj-$(CONFIG_PROC_FS)			+= proc.o
 
 obj-$(CONFIG_IA32_FEAT_CTL)		+= feat_ctl.o
 ifdef CONFIG_CPU_SUP_INTEL
-obj-y					+= intel.o intel_pconfig.o tsx.o
+obj-y					+= intel.o tsx.o
 obj-$(CONFIG_PM)			+= intel_epb.o
 endif
 obj-$(CONFIG_CPU_SUP_AMD)		+= amd.o
diff --git a/arch/x86/kernel/cpu/intel_pconfig.c b/arch/x86/kernel/cpu/intel_pconfig.c
deleted file mode 100644
index 5be2b1790282..000000000000
--- a/arch/x86/kernel/cpu/intel_pconfig.c
+++ /dev/null
@@ -1,84 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Intel PCONFIG instruction support.
- *
- * Copyright (C) 2017 Intel Corporation
- *
- * Author:
- *	Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
- */
-#include <linux/bug.h>
-#include <linux/limits.h>
-
-#include <asm/cpufeature.h>
-#include <asm/intel_pconfig.h>
-
-#define	PCONFIG_CPUID			0x1b
-
-#define PCONFIG_CPUID_SUBLEAF_MASK	((1 << 12) - 1)
-
-/* Subleaf type (EAX) for PCONFIG CPUID leaf (0x1B) */
-enum {
-	PCONFIG_CPUID_SUBLEAF_INVALID	= 0,
-	PCONFIG_CPUID_SUBLEAF_TARGETID	= 1,
-};
-
-/* Bitmask of supported targets */
-static u64 targets_supported __read_mostly;
-
-int pconfig_target_supported(enum pconfig_target target)
-{
-	/*
-	 * We would need to re-think the implementation once we get > 64
-	 * PCONFIG targets. Spec allows up to 2^32 targets.
-	 */
-	BUILD_BUG_ON(PCONFIG_TARGET_NR >= 64);
-
-	if (WARN_ON_ONCE(target >= 64))
-		return 0;
-	return targets_supported & (1ULL << target);
-}
-
-static int __init intel_pconfig_init(void)
-{
-	int subleaf;
-
-	if (!boot_cpu_has(X86_FEATURE_PCONFIG))
-		return 0;
-
-	/*
-	 * Scan subleafs of PCONFIG CPUID leaf.
-	 *
-	 * Subleafs of the same type need not to be consecutive.
-	 *
-	 * Stop on the first invalid subleaf type. All subleafs after the first
-	 * invalid are invalid too.
-	 */
-	for (subleaf = 0; subleaf < INT_MAX; subleaf++) {
-		struct cpuid_regs regs;
-
-		cpuid_count(PCONFIG_CPUID, subleaf,
-				&regs.eax, &regs.ebx, &regs.ecx, &regs.edx);
-
-		switch (regs.eax & PCONFIG_CPUID_SUBLEAF_MASK) {
-		case PCONFIG_CPUID_SUBLEAF_INVALID:
-			/* Stop on the first invalid subleaf */
-			goto out;
-		case PCONFIG_CPUID_SUBLEAF_TARGETID:
-			/* Mark supported PCONFIG targets */
-			if (regs.ebx < 64)
-				targets_supported |= (1ULL << regs.ebx);
-			if (regs.ecx < 64)
-				targets_supported |= (1ULL << regs.ecx);
-			if (regs.edx < 64)
-				targets_supported |= (1ULL << regs.edx);
-			break;
-		default:
-			/* Unknown CPUID.PCONFIG subleaf: ignore */
-			break;
-		}
-	}
-out:
-	return 0;
-}
-arch_initcall(intel_pconfig_init);
-- 
2.37.3