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authorNiklas Cassel <cassel@kernel.org>2026-09-16 15:00:32 +0200
committerNiklas Cassel <cassel@kernel.org>2026-09-16 16:18:00 +0200
commit8d836581f9b1f57ceaa2b47654754ef1260b410b (patch)
tree1dbd4d0dfb99c2e238356cbe947e5b0be3e3a571 /arch/arm/mach-versatile/hotplug.c
downloadlinux-stable-8d836581f9b1f57ceaa2b47654754ef1260b410b.tar.gz
linux-stable-8d836581f9b1f57ceaa2b47654754ef1260b410b.zip
ata: libata-scsi: fix ata_dsm_trim_pages() kernel-docgrafted
make htmldocs fails with: Documentation/driver-api/libata:604: ./drivers/ata/libata-scsi.c:2301: ERROR: Unexpected indentation. [docutils] The Return: section of ata_dsm_trim_pages() ends its first sentence with a colon and continues with an indented bullet list. reStructuredText requires a blank line before an indented block, so docutils chokes on the list. Simply adding the missing blank line does not work either: Return: is a kernel-doc "special section", which is terminated by the first blank line, so the bullet list would end up in the Description section, detached from the sentence introducing it. Spell the two bounds out as prose instead, so that the Return: section stays self-contained. Documentation-only change. Fixes: e64e6b5dc867 ("ata: libata-scsi: scale DSM TRIM payload by MAX PAGES PER DSM COMMAND") Reported-by: Thomas Huth <thuth@redhat.com> Closes: https://lore.kernel.org/linux-ide/b0a0b8e8-cc4f-4c7b-8bc5-fee0712d405a@redhat.com/ Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Thomas Huth <thuth@redhat.com> Link: https://lore.kernel.org/r/20260916130031.29990-2-cassel@kernel.org Signed-off-by: Niklas Cassel <cassel@kernel.org>
Diffstat (limited to 'arch/arm/mach-versatile/hotplug.c')
-rw-r--r--arch/arm/mach-versatile/hotplug.c102
1 files changed, 102 insertions, 0 deletions
diff --git a/arch/arm/mach-versatile/hotplug.c b/arch/arm/mach-versatile/hotplug.c
new file mode 100644
index 000000000..5a1521755
--- /dev/null
+++ b/arch/arm/mach-versatile/hotplug.c
@@ -0,0 +1,102 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2002 ARM Ltd.
+ * All Rights Reserved
+ *
+ * This hotplug implementation is _specific_ to the situation found on
+ * ARM development platforms where there is _no_ possibility of actually
+ * taking a CPU offline, resetting it, or otherwise. Real platforms must
+ * NOT copy this code.
+ */
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/smp.h>
+
+#include <asm/smp_plat.h>
+#include <asm/cp15.h>
+
+#include "platsmp.h"
+
+static inline void versatile_immitation_enter_lowpower(unsigned int actrl_mask)
+{
+ unsigned int v;
+
+ asm volatile(
+ "mcr p15, 0, %1, c7, c5, 0\n"
+ " mcr p15, 0, %1, c7, c10, 4\n"
+ /*
+ * Turn off coherency
+ */
+ " mrc p15, 0, %0, c1, c0, 1\n"
+ " bic %0, %0, %3\n"
+ " mcr p15, 0, %0, c1, c0, 1\n"
+ " mrc p15, 0, %0, c1, c0, 0\n"
+ " bic %0, %0, %2\n"
+ " mcr p15, 0, %0, c1, c0, 0\n"
+ : "=&r" (v)
+ : "r" (0), "Ir" (CR_C), "Ir" (actrl_mask)
+ : "cc");
+}
+
+static inline void versatile_immitation_leave_lowpower(unsigned int actrl_mask)
+{
+ unsigned int v;
+
+ asm volatile(
+ "mrc p15, 0, %0, c1, c0, 0\n"
+ " orr %0, %0, %1\n"
+ " mcr p15, 0, %0, c1, c0, 0\n"
+ " mrc p15, 0, %0, c1, c0, 1\n"
+ " orr %0, %0, %2\n"
+ " mcr p15, 0, %0, c1, c0, 1\n"
+ : "=&r" (v)
+ : "Ir" (CR_C), "Ir" (actrl_mask)
+ : "cc");
+}
+
+static inline void versatile_immitation_do_lowpower(unsigned int cpu, int *spurious)
+{
+ /*
+ * there is no power-control hardware on this platform, so all
+ * we can do is put the core into WFI; this is safe as the calling
+ * code will have already disabled interrupts.
+ *
+ * This code should not be used outside Versatile platforms.
+ */
+ for (;;) {
+ wfi();
+
+ if (versatile_cpu_release == cpu_logical_map(cpu)) {
+ /*
+ * OK, proper wakeup, we're done
+ */
+ break;
+ }
+
+ /*
+ * Getting here, means that we have come out of WFI without
+ * having been woken up - this shouldn't happen
+ *
+ * Just note it happening - when we're woken, we can report
+ * its occurrence.
+ */
+ (*spurious)++;
+ }
+}
+
+/*
+ * platform-specific code to shutdown a CPU.
+ * This code supports immitation-style CPU hotplug for Versatile/Realview/
+ * Versatile Express platforms that are unable to do real CPU hotplug.
+ */
+void versatile_immitation_cpu_die(unsigned int cpu, unsigned int actrl_mask)
+{
+ int spurious = 0;
+
+ versatile_immitation_enter_lowpower(actrl_mask);
+ versatile_immitation_do_lowpower(cpu, &spurious);
+ versatile_immitation_leave_lowpower(actrl_mask);
+
+ if (spurious)
+ pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious);
+}