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authorZeng Chi <zengchi@kylinos.cn>2026-09-21 18:24:42 +0800
committerSean Christopherson <seanjc@google.com>2026-09-22 08:36:16 -0700
commit119e9db233ad0f4cbd4cfb9f9385a7bca378b37d (patch)
tree660d50d4139cb750fbde1ae3432452c20726c99d /arch/powerpc/sysdev/6xx-suspend.S
downloadlinux-stable-119e9db233ad0f4cbd4cfb9f9385a7bca378b37d.tar.gz
linux-stable-119e9db233ad0f4cbd4cfb9f9385a7bca378b37d.zip
KVM: Don't pre-reserve xarray entries when storing empty/NULL attributesgrafted
Skip the xarray reservation loop when clearing all memory attributes, as storing NULL only erases the entry and never needs to allocate, so no reservation (and no cleanup of a failed one) is required in that case. Suggested-by: Sean Christopherson <seanjc@google.com> Cc: David Ballesteros <davimaba.v@proton.me> Signed-off-by: Zeng Chi <zengchi@kylinos.cn> Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com [sean: split to separate patch] Signed-off-by: Sean Christopherson <seanjc@google.com>
Diffstat (limited to 'arch/powerpc/sysdev/6xx-suspend.S')
-rw-r--r--arch/powerpc/sysdev/6xx-suspend.S48
1 files changed, 48 insertions, 0 deletions
diff --git a/arch/powerpc/sysdev/6xx-suspend.S b/arch/powerpc/sysdev/6xx-suspend.S
new file mode 100644
index 000000000..e882524ff
--- /dev/null
+++ b/arch/powerpc/sysdev/6xx-suspend.S
@@ -0,0 +1,48 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Enter and leave sleep state on chips with 6xx-style HID0
+ * power management bits, which don't leave sleep state via reset.
+ *
+ * Author: Scott Wood <scottwood@freescale.com>
+ *
+ * Copyright (c) 2006-2007 Freescale Semiconductor, Inc.
+ */
+
+#include <asm/ppc_asm.h>
+#include <asm/reg.h>
+#include <asm/thread_info.h>
+#include <asm/asm-offsets.h>
+
+_GLOBAL(mpc6xx_enter_standby)
+ mflr r4
+
+ mfspr r5, SPRN_HID0
+ rlwinm r5, r5, 0, ~(HID0_DOZE | HID0_NAP)
+ oris r5, r5, HID0_SLEEP@h
+ mtspr SPRN_HID0, r5
+ isync
+
+ lis r5, ret_from_standby@h
+ ori r5, r5, ret_from_standby@l
+ mtlr r5
+
+ lwz r6, TI_LOCAL_FLAGS(r2)
+ ori r6, r6, _TLF_SLEEPING
+ stw r6, TI_LOCAL_FLAGS(r2)
+
+ mfmsr r5
+ ori r5, r5, MSR_EE
+ oris r5, r5, MSR_POW@h
+ sync
+ mtmsr r5
+ isync
+
+1: b 1b
+
+ret_from_standby:
+ mfspr r5, SPRN_HID0
+ rlwinm r5, r5, 0, ~HID0_SLEEP
+ mtspr SPRN_HID0, r5
+
+ mtlr r4
+ blr