[026/181] x86/numa: cleanup configuration dependent command-line options

Commit Message

Andrew Morton Oct. 13, 2020, 11:48 p.m. UTC

From: Dan Williams <[e-mail]>
Subject: x86/numa: cleanup configuration dependent command-line options

Patch series "device-dax: Support sub-dividing soft-reserved ranges", v5.

The device-dax facility allows an address range to be directly mapped
through a chardev, or optionally hotplugged to the core kernel page
allocator as System-RAM.  It is the mechanism for converting persistent
memory (pmem) to be used as another volatile memory pool i.e.  the current
Memory Tiering hot topic on linux-mm.

In the case of pmem the nvdimm-namespace-label mechanism can sub-divide
it, but that labeling mechanism is not available / applicable to
soft-reserved ("EFI specific purpose") memory [3].  This series provides a
sysfs-mechanism for the daxctl utility to enable provisioning of
volatile-soft-reserved memory ranges.

The motivations for this facility are:

1/ Allow performance differentiated memory ranges to be split between
   kernel-managed and directly-accessed use cases.

2/ Allow physical memory to be provisioned along performance relevant
   address boundaries. For example, divide a memory-side cache [4] along
   cache-color boundaries.

3/ Parcel out soft-reserved memory to VMs using device-dax as a security
   / permissions boundary [5]. Specifically I have seen people (ab)using
   memmap=nn!ss (mark System-RAM as Persistent Memory) just to get the
   device-dax interface on custom address ranges. A follow-on for the VM
   use case is to teach device-dax to dynamically allocate 'struct page' at
   runtime to reduce the duplication of 'struct page' space in both the
   guest and the host kernel for the same physical pages.

[2]: http://lore.kernel.org/r/[e-mail]
[3]: http://lore.kernel.org/r/[e-mail]
[4]: http://lore.kernel.org/r/[e-mail]
[5]: http://lore.kernel.org/r/[e-mail]


This patch (of 23):

In preparation for adding a new numa= option clean up the existing ones to
avoid ifdefs in numa_setup(), and provide feedback when the option is
numa=fake= option is invalid due to kernel config.  The same does not need
to be done for numa=noacpi, since the capability is already hard disabled
at compile-time.

Link: https://lkml.kernel.org/r/[e-mail]
Link: https://lkml.kernel.org/r/[e-mail]
Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Dan Williams <[e-mail]>
Suggested-by: Rafael J. Wysocki <[e-mail]>
Cc: Andy Lutomirski <[e-mail]>
Cc: Ard Biesheuvel <[e-mail]>
Cc: Benjamin Herrenschmidt <[e-mail]>
Cc: Ben Skeggs <[e-mail]>
Cc: Borislav Petkov <[e-mail]>
Cc: Brice Goglin <[e-mail]>
Cc: Catalin Marinas <[e-mail]>
Cc: Daniel Vetter <[e-mail]>
Cc: Dave Hansen <[e-mail]>
Cc: Dave Jiang <[e-mail]>
Cc: David Airlie <[e-mail]>
Cc: David Hildenbrand <[e-mail]>
Cc: Greg Kroah-Hartman <[e-mail]>
Cc: "H. Peter Anvin" <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Ira Weiny <[e-mail]>
Cc: Jason Gunthorpe <[e-mail]>
Cc: Jeff Moyer <[e-mail]>
Cc: Jia He <[e-mail]>
Cc: Joao Martins <[e-mail]>
Cc: Jonathan Cameron <[e-mail]>
Cc: Michael Ellerman <[e-mail]>
Cc: Mike Rapoport <[e-mail]>
Cc: Paul Mackerras <[e-mail]>
Cc: Pavel Tatashin <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Rafael J. Wysocki <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Cc: Tom Lendacky <[e-mail]>
Cc: Vishal Verma <[e-mail]>
Cc: Wei Yang <[e-mail]>
Cc: Will Deacon <[e-mail]>
Cc: Ard Biesheuvel <[e-mail]>
Cc: Bjorn Helgaas <[e-mail]>
Cc: Boris Ostrovsky <[e-mail]>
Cc: Hulk Robot <[e-mail]>
Cc: Jason Yan <[e-mail]>
Cc: "Jérôme Glisse" <[e-mail]>
Cc: Juergen Gross <[e-mail]>
Cc: kernel test robot <[e-mail]>
Cc: Randy Dunlap <[e-mail]>
Cc: Stefano Stabellini <[e-mail]>
Cc: Vivek Goyal <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
---

 arch/x86/include/asm/numa.h  |    8 +++++++-
 arch/x86/mm/numa.c           |    8 ++------
 arch/x86/mm/numa_emulation.c |    3 ++-
 arch/x86/xen/enlighten_pv.c  |    2 +-
 drivers/acpi/numa/srat.c     |    9 +++++++--
 include/acpi/acpi_numa.h     |    6 +++++-
 6 files changed, 24 insertions(+), 12 deletions(-)

Patch

--- a/arch/x86/include/asm/numa.h~x86-numa-cleanup-configuration-dependent-command-line-options
+++ a/arch/x86/include/asm/numa.h
@@ -3,6 +3,7 @@ 
 #define _ASM_X86_NUMA_H
 
 #include <linux/nodemask.h>
+#include <linux/errno.h>
 
 #include <asm/topology.h>
 #include <asm/apicdef.h>
@@ -77,7 +78,12 @@  void debug_cpumask_set_cpu(int cpu, int
 #ifdef CONFIG_NUMA_EMU
 #define FAKE_NODE_MIN_SIZE	((u64)32 << 20)
 #define FAKE_NODE_MIN_HASH_MASK	(~(FAKE_NODE_MIN_SIZE - 1UL))
-void numa_emu_cmdline(char *);
+int numa_emu_cmdline(char *str);
+#else /* CONFIG_NUMA_EMU */
+static inline int numa_emu_cmdline(char *str)
+{
+	return -EINVAL;
+}
 #endif /* CONFIG_NUMA_EMU */
 
 #endif	/* _ASM_X86_NUMA_H */
--- a/arch/x86/mm/numa.c~x86-numa-cleanup-configuration-dependent-command-line-options
+++ a/arch/x86/mm/numa.c
@@ -37,14 +37,10 @@  static __init int numa_setup(char *opt)
 		return -EINVAL;
 	if (!strncmp(opt, "off", 3))
 		numa_off = 1;
-#ifdef CONFIG_NUMA_EMU
 	if (!strncmp(opt, "fake=", 5))
-		numa_emu_cmdline(opt + 5);
-#endif
-#ifdef CONFIG_ACPI_NUMA
+		return numa_emu_cmdline(opt + 5);
 	if (!strncmp(opt, "noacpi", 6))
-		acpi_numa = -1;
-#endif
+		disable_srat();
 	return 0;
 }
 early_param("numa", numa_setup);
--- a/arch/x86/mm/numa_emulation.c~x86-numa-cleanup-configuration-dependent-command-line-options
+++ a/arch/x86/mm/numa_emulation.c
@@ -13,9 +13,10 @@ 
 static int emu_nid_to_phys[MAX_NUMNODES];
 static char *emu_cmdline __initdata;
 
-void __init numa_emu_cmdline(char *str)
+int __init numa_emu_cmdline(char *str)
 {
 	emu_cmdline = str;
+	return 0;
 }
 
 static int __init emu_find_memblk_by_nid(int nid, const struct numa_meminfo *mi)
--- a/arch/x86/xen/enlighten_pv.c~x86-numa-cleanup-configuration-dependent-command-line-options
+++ a/arch/x86/xen/enlighten_pv.c
@@ -1300,7 +1300,7 @@  asmlinkage __visible void __init xen_sta
 	 * any NUMA information the kernel tries to get from ACPI will
 	 * be meaningless.  Prevent it from trying.
 	 */
-	acpi_numa = -1;
+	disable_srat();
 #endif
 	WARN_ON(xen_cpuhp_setup(xen_cpu_up_prepare_pv, xen_cpu_dead_pv));
 
--- a/drivers/acpi/numa/srat.c~x86-numa-cleanup-configuration-dependent-command-line-options
+++ a/drivers/acpi/numa/srat.c
@@ -27,7 +27,12 @@  static int node_to_pxm_map[MAX_NUMNODES]
 			= { [0 ... MAX_NUMNODES - 1] = PXM_INVAL };
 
 unsigned char acpi_srat_revision __initdata;
-int acpi_numa __initdata;
+static int acpi_numa __initdata;
+
+void __init disable_srat(void)
+{
+	acpi_numa = -1;
+}
 
 int pxm_to_node(int pxm)
 {
@@ -163,7 +168,7 @@  static int __init slit_valid(struct acpi
 void __init bad_srat(void)
 {
 	pr_err("SRAT: SRAT not used.\n");
-	acpi_numa = -1;
+	disable_srat();
 }
 
 int __init srat_disabled(void)
--- a/include/acpi/acpi_numa.h~x86-numa-cleanup-configuration-dependent-command-line-options
+++ a/include/acpi/acpi_numa.h
@@ -17,10 +17,14 @@  extern int pxm_to_node(int);
 extern int node_to_pxm(int);
 extern int acpi_map_pxm_to_node(int);
 extern unsigned char acpi_srat_revision;
-extern int acpi_numa __initdata;
+extern void disable_srat(void);
 
 extern void bad_srat(void);
 extern int srat_disabled(void);
 
+#else				/* CONFIG_ACPI_NUMA */
+static inline void disable_srat(void)
+{
+}
 #endif				/* CONFIG_ACPI_NUMA */
 #endif				/* __ACP_NUMA_H */