[PATCH v3 02/23] x86/numa: Add 'nohmat' option

Dan Williams
2020-08-01T03:41:33Z

Disable parsing of the HMAT for debug, to workaround broken platform
instances, or cases where it is otherwise not wanted.

Cc: x86@kernel.org
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
arch/x86/mm/numa.c | 2 ++
drivers/acpi/numa/hmat.c | 8 +++++++-
include/acpi/acpi_numa.h | 8 ++++++++
3 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
index 87c52822cc44..f3805bbaa784 100644
--- a/arch/x86/mm/numa.c
+++ b/arch/x86/mm/numa.c
@@ -41,6 +41,8 @@ static __init int numa_setup(char *opt)
return numa_emu_cmdline(opt + 5);
if (!strncmp(opt, "noacpi", 6))
disable_srat();
+ if (!strncmp(opt, "nohmat", 6))
+ disable_hmat();
return 0;
}
early_param("numa", numa_setup);
diff --git a/drivers/acpi/numa/hmat.c b/drivers/acpi/numa/hmat.c
index 2c32cfb72370..a12e36a12618 100644
--- a/drivers/acpi/numa/hmat.c
+++ b/drivers/acpi/numa/hmat.c
@@ -26,6 +26,12 @@
#include <linux/sysfs.h>

static u8 hmat_revision;
+static int hmat_disable __initdata;
+
+void __init disable_hmat(void)
+{
+ hmat_disable = 1;
+}

static LIST_HEAD(targets);
static LIST_HEAD(initiators);
@@ -814,7 +820,7 @@ static __init int hmat_init(void)
enum acpi_hmat_type i;
acpi_status status;

- if (srat_disabled())
+ if (srat_disabled() || hmat_disable)
return 0;

status = acpi_get_table(ACPI_SIG_SRAT, 0, &tbl);
diff --git a/include/acpi/acpi_numa.h b/include/acpi/acpi_numa.h
index 8784183b2204..0e9302285f14 100644
--- a/include/acpi/acpi_numa.h
+++ b/include/acpi/acpi_numa.h
@@ -27,4 +27,12 @@ static inline void disable_srat(void)
{
}
#endif /* CONFIG_ACPI_NUMA */
+
+#ifdef CONFIG_ACPI_HMAT
+extern void disable_hmat(void);
+#else /* CONFIG_ACPI_HMAT */
+static inline void disable_hmat(void)
+{
+}
+#endif /* CONFIG_ACPI_HMAT */
#endif /* __ACP_NUMA_H */