Patch "x86/platform/UV: Use new set memory block size function" has been added to the 4.14-stable tree

This is a note to let you know that I've just added the patch titled

x86/platform/UV: Use new set memory block size function

to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
x86-platform-uv-use-new-set-memory-block-size-function.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From bbbd2b51a2aa0d76b3676271e216cf3647773397 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Thu, 24 May 2018 15:17:13 -0500
Subject: x86/platform/UV: Use new set memory block size function

From: [email protected] <[email protected]>

commit bbbd2b51a2aa0d76b3676271e216cf3647773397 upstream.

Add a call to the new function to "adjust" the current fixed UV memory block size of 2GB so it can be changed to a different physical boundary. This accommodates changes in the Intel BIOS, and therefore UV BIOS, which now can align boundaries different than the previous UV standard of 2GB. It also flags any UV Global Address boundaries from BIOS that cause a change in the mem block size (boundary).

The current boundary of 2GB has been used on UV since the first system release in 2009 with Linux 2.6 and has worked fine. But the new NVDIMM persistent memory modules (PMEM), along with the Intel BIOS changes to support these modules caused the memory block size boundary to be set to a lower limit. Intel only guarantees that this minimum boundary at 64MB though the current Linux limit is 128MB.

Note that the default remains 2GB if no changes occur.

Signed-off-by Mike Travis <[email protected]>

Reviewed-by Andrew Banman <[email protected]>

Cc Andrew Morton <[email protected]>

Cc Dimitri Sivanich <[email protected]>

Cc Linus Torvalds <[email protected]>

Cc Peter Zijlstra <[email protected]>

Cc Russ Anderson <[email protected]>

Cc Thomas Gleixner <[email protected]>

Cc [email protected]

Cc [email protected]

Cc [email protected]

Cc [email protected]

Cc [email protected]

Link https://lkml.kernel.org/lkml/[email protected] open here

Signed-off-by Ingo Molnar <[email protected]>

Signed-off-by Greg Kroah-Hartman <[email protected]>

---
  arch/x86/kernel/apic/x2apic_uv_x.c |   49 ++++++++++++++++++++++++++++++++++---
  1 file changed, 46 insertions(+), 3 deletions(-)

arch/x86/kernel/apic/x2apic_uv_x.c +46 -3

@@ -26,6 +26,7 @@
  #include <linux/delay.h>
  #include <linux/crash_dump.h>
  #include <linux/reboot.h>
+#include <linux/memory.h>
 
  #include <asm/uv/uv_mmrs.h>
  #include <asm/uv/uv_hub.h>

@@ -346,6 +347,40 @@ extern int uv_hub_info_version(void)
  }
  EXPORT_SYMBOL(uv_hub_info_version);
 
+/* Default UV memory block size is 2GB */
+static unsigned long mem_block_size = (2UL << 30);
+
+static __init int adj_blksize(u32 lgre)
+{
+	unsigned long base = (unsigned long)lgre << UV_GAM_RANGE_SHFT;
+	unsigned long size;
+
+	for (size = mem_block_size; size > MIN_MEMORY_BLOCK_SIZE; size >>= 1)
+		if (IS_ALIGNED(base, size))
+			break;
+
+	if (size >= mem_block_size)
+		return 0;
+
+	mem_block_size = size;
+	return 1;
+}
+
+static __init void set_block_size(void)
+{
+	unsigned int order = ffs(mem_block_size);
+
+	if (order) {
+		/* adjust for ffs return of 1..64 */
+		set_memory_block_size_order(order - 1);
+		pr_info("UV: mem_block_size set to 0x%lx\n", mem_block_size);
+	} else {
+		/* bad or zero value, default to 1UL << 31 (2GB) */
+		pr_err("UV: mem_block_size error with 0x%lx\n", mem_block_size);
+		set_memory_block_size_order(31);
+	}
+}
+
  /* Build GAM range lookup table: */
  static __init void build_uv_gr_table(void)
  {

@@ -1144,23 +1179,30 @@ static void __init decode_gam_rng_tbl(un
  					<< UV_GAM_RANGE_SHFT);
  		int order = 0;
  		char suffix[] = " KMGTPE";
+		int flag = ' ';
 
  		while (size > 9999 && order < sizeof(suffix)) {
  			size /= 1024;
  			order++;
  		}
 
+		/* adjust max block size to current range start */
+		if (gre->type == 1 || gre->type == 2)
+			if (adj_blksize(lgre))
+				flag = '*';
+
  		if (!index) {
  			pr_info("UV: GAM Range Table...\n");
-			pr_info("UV:  # %20s %14s %5s %4s %5s %3s %2s\n", "Range", "", "Size", "Type", "NASID", "SID", "PN");
+			pr_info("UV:  # %20s %14s %6s %4s %5s %3s %2s\n", "Range", "", "Size", "Type", "NASID", "SID", "PN");
  		}
-		pr_info("UV: %2d: 0x%014lx-0x%014lx %5lu%c %3d   %04x  %02x %02x\n",
+		pr_info("UV: %2d: 0x%014lx-0x%014lx%c %5lu%c %3d   %04x  %02x %02x\n",
  			index++,
  			(unsigned long)lgre << UV_GAM_RANGE_SHFT,
  			(unsigned long)gre->limit << UV_GAM_RANGE_SHFT,
-			size, suffix[order],
+			flag, size, suffix[order],
  			gre->type, gre->nasid, gre->sockid, gre->pnode);
 
+		/* update to next range start */
  		lgre = gre->limit;
  		if (sock_min > gre->sockid)
  			sock_min = gre->sockid;

@@ -1391,6 +1433,7 @@ static void __init uv_system_init_hub(vo
 
  	build_socket_tables();
  	build_uv_gr_table();
+	set_block_size();
  	uv_init_hub_info(&hub_info);
  	uv_possible_blades = num_possible_nodes();
  	if (!_node_to_pnode)

Patches currently in stable-queue which might be from [email protected] are

queue-4.14/x86-platform-uv-add-kernel-parameter-to-set-memory-block-size.patch queue-4.14/x86-platform-uv-use-new-set-memory-block-size-function.patch

Until the original patch that adds the set_memory_block_size_order() function is added, then the following two patches should also not be applied. In fact I'm surprised it built with that function undefined.