x86/resctrl: Rename and move rdt files to a separate directory

New generation of AMD processors add support for RDT (or QOS) features.
Together, these features will be called RESCTRL. With more than one
vendors supporting these features, it seems more appropriate to rename
these files.

Create a new directory with the name 'resctrl' and move all the
intel_rdt files to the new directory. This way all the resctrl related
code resides inside one directory.

 [ bp: Add SPDX identifier to the Makefile ]

Suggested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: "Chang S. Bae" <chang.seok.bae@intel.com>
Cc: David Miller <davem@davemloft.net>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Dmitry Safonov <dima@arista.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: <linux-doc@vger.kernel.org>
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Pu Wen <puwen@hygon.cn>
Cc: <qianyue.zj@alibaba-inc.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Cc: Rian Hunter <rian@alum.mit.edu>
Cc: Sherry Hurwitz <sherry.hurwitz@amd.com>
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Lendacky <Thomas.Lendacky@amd.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: <xiaochen.shen@intel.com>
Link: https://lkml.kernel.org/r/20181121202811.4492-2-babu.moger@amd.com

1 files changed, 93 insertions, 0 deletions

diff --git a/arch/x86/include/asm/resctrl_sched.h b/arch/x86/include/asm/resctrl_sched.h
new file mode 100644
index 000000000000..9acb06b6f81e
--- /dev/null
+++ b/arch/x86/include/asm/resctrl_sched.h
@@ -0,0 +1,93 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_INTEL_RDT_SCHED_H
+#define _ASM_X86_INTEL_RDT_SCHED_H
+
+#ifdef CONFIG_INTEL_RDT
+
+#include <linux/sched.h>
+#include <linux/jump_label.h>
+
+#define IA32_PQR_ASSOC	0x0c8f
+
+/**
+ * struct intel_pqr_state - State cache for the PQR MSR
+ * @cur_rmid:		The cached Resource Monitoring ID
+ * @cur_closid:	The cached Class Of Service ID
+ * @default_rmid:	The user assigned Resource Monitoring ID
+ * @default_closid:	The user assigned cached Class Of Service ID
+ *
+ * The upper 32 bits of IA32_PQR_ASSOC contain closid and the
+ * lower 10 bits rmid. The update to IA32_PQR_ASSOC always
+ * contains both parts, so we need to cache them. This also
+ * stores the user configured per cpu CLOSID and RMID.
+ *
+ * The cache also helps to avoid pointless updates if the value does
+ * not change.
+ */
+struct intel_pqr_state {
+	u32			cur_rmid;
+	u32			cur_closid;
+	u32			default_rmid;
+	u32			default_closid;
+};
+
+DECLARE_PER_CPU(struct intel_pqr_state, pqr_state);
+
+DECLARE_STATIC_KEY_FALSE(rdt_enable_key);
+DECLARE_STATIC_KEY_FALSE(rdt_alloc_enable_key);
+DECLARE_STATIC_KEY_FALSE(rdt_mon_enable_key);
+
+/*
+ * __intel_rdt_sched_in() - Writes the task's CLOSid/RMID to IA32_PQR_MSR
+ *
+ * Following considerations are made so that this has minimal impact
+ * on scheduler hot path:
+ * - This will stay as no-op unless we are running on an Intel SKU
+ *   which supports resource control or monitoring and we enable by
+ *   mounting the resctrl file system.
+ * - Caches the per cpu CLOSid/RMID values and does the MSR write only
+ *   when a task with a different CLOSid/RMID is scheduled in.
+ * - We allocate RMIDs/CLOSids globally in order to keep this as
+ *   simple as possible.
+ * Must be called with preemption disabled.
+ */
+static void __intel_rdt_sched_in(void)
+{
+	struct intel_pqr_state *state = this_cpu_ptr(&pqr_state);
+	u32 closid = state->default_closid;
+	u32 rmid = state->default_rmid;
+
+	/*
+	 * If this task has a closid/rmid assigned, use it.
+	 * Else use the closid/rmid assigned to this cpu.
+	 */
+	if (static_branch_likely(&rdt_alloc_enable_key)) {
+		if (current->closid)
+			closid = current->closid;
+	}
+
+	if (static_branch_likely(&rdt_mon_enable_key)) {
+		if (current->rmid)
+			rmid = current->rmid;
+	}
+
+	if (closid != state->cur_closid || rmid != state->cur_rmid) {
+		state->cur_closid = closid;
+		state->cur_rmid = rmid;
+		wrmsr(IA32_PQR_ASSOC, rmid, closid);
+	}
+}
+
+static inline void intel_rdt_sched_in(void)
+{
+	if (static_branch_likely(&rdt_enable_key))
+		__intel_rdt_sched_in();
+}
+
+#else
+
+static inline void intel_rdt_sched_in(void) {}
+
+#endif /* CONFIG_INTEL_RDT */
+
+#endif /* _ASM_X86_INTEL_RDT_SCHED_H */