Merge branch 'is_kdump_kernel'

Amir Vadai says:

====================
Make is_kdump_kernel() accessible from modules

I'm re-spinning this patchset. At the begining it was suggested to use a
different name for the parameter, but at the end [3] the resolution was to
leave it as it is in this patch.

Drivers need to know if running from kdump kernel in order to change their
memory profile - since kdump environment is limited by available memory.
Currently there are drivers that are using reset_devices as suggested in [2].
In [2] it was suggested to use reset_devices, but the context was, to enable
driver to know when the hardware device is needed to be reset, and not if this
is a kdump environment. We think that is_kdump_kernel() is better suited to
select between different memory profiles.

The first patch in this patchset exports a needed symbol in order to make
is_kdump_kernel() accessible from the drivers. The rest of the patches change
from reset_devices to is_kdump_kernel() in 2 networking drivers.

The idea of this patchset was suggested by Vivek Goyal.

Tested (only build) and applied on top of commit 8fc54f6: ("net: use
reciprocal_scale() helper")

[1] - ea1c1af: ("net/mlx4_en: Reduce memory consumption on kdump kernel")
[2] - https://lkml.org/lkml/2011/1/27/341
[3] - http://www.spinics.net/lists/netdev/msg291492.html
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c

@@ -21,6 +21,7 @@
 #include <linux/if_vlan.h>
 #include <linux/interrupt.h>
 #include <linux/ip.h>
+#include <linux/crash_dump.h>
 #include <net/tcp.h>
 #include <net/ipv6.h>
 #include <net/ip6_checksum.h>
@@ -64,7 +65,7 @@ static int bnx2x_calc_num_queues(struct bnx2x *bp)
 	int nq = bnx2x_num_queues ? : netif_get_num_default_rss_queues();
 
 	/* Reduce memory usage in kdump environment by using only one queue */
-	if (reset_devices)
+	if (is_kdump_kernel())
 		nq = 1;
 
 	nq = clamp(nq, 1, BNX2X_MAX_QUEUES(bp));

drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c

@@ -41,6 +41,7 @@
 #include <linux/ethtool.h>
 #include <linux/mii.h>
 #include <linux/if_vlan.h>
+#include <linux/crash_dump.h>
 #include <net/ip.h>
 #include <net/ipv6.h>
 #include <net/tcp.h>
@@ -11956,7 +11957,7 @@ static int bnx2x_init_bp(struct bnx2x *bp)
 	bp->disable_tpa = disable_tpa;
 	bp->disable_tpa |= IS_MF_STORAGE_SD(bp) || IS_MF_FCOE_AFEX(bp);
 	/* Reduce memory usage in kdump environment by disabling TPA */
-	bp->disable_tpa |= reset_devices;
+	bp->disable_tpa |= is_kdump_kernel();
 
 	/* Set TPA flags */
 	if (bp->disable_tpa) {

include/linux/mlx4/device.h

@@ -38,6 +38,7 @@
 #include <linux/completion.h>
 #include <linux/radix-tree.h>
 #include <linux/cpu_rmap.h>
+#include <linux/crash_dump.h>
 
 #include <linux/atomic.h>
 
@@ -1275,7 +1276,7 @@ int mlx4_mr_rereg_mem_write(struct mlx4_dev *dev, struct mlx4_mr *mr,
 /* Returns true if running in low memory profile (kdump kernel) */
 static inline bool mlx4_low_memory_profile(void)
 {
-	return reset_devices;
+	return is_kdump_kernel();
 }
 
 #endif /* MLX4_DEVICE_H */

kernel/crash_dump.c

@@ -18,6 +18,7 @@ unsigned long saved_max_pfn;
  * it under CONFIG_CRASH_DUMP and not CONFIG_PROC_VMCORE.
  */
 unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX;
+EXPORT_SYMBOL_GPL(elfcorehdr_addr);
 
 /*
  * stores the size of elf header of crash image