x86/kexec: Remove walk_iomem_res() call with GART type

There is no longer any driver inserting a "GART" region in the
kernel since

  707d4eef ("Revert "[PATCH] Insert GART region into resource map"").

Remove the call to walk_iomem_res() with "GART" type, its
callback function, and GART-specific variables set by the
callback.
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Young <dyoung@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Chun-Yi <joeyli.kernel@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Lee, Chun-Yi <joeyli.kernel@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Minfei Huang <mnfhuang@gmail.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Takao Indoh <indou.takao@jp.fujitsu.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: kexec@lists.infradead.org
Cc: linux-arch@vger.kernel.org
Cc: linux-mm <linux-mm@kvack.org>
Link: http://lkml.kernel.org/r/1453841853-11383-16-git-send-email-bp@alien8.deSigned-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/kernel/crash.c

@@ -57,10 +57,9 @@ struct crash_elf_data {
 	struct kimage *image;
 	/*
 	 * Total number of ram ranges we have after various adjustments for
-	 * GART, crash reserved region etc.
+	 * crash reserved region, etc.
 	 */
 	unsigned int max_nr_ranges;
-	unsigned long gart_start, gart_end;
 
 	/* Pointer to elf header */
 	void *ehdr;
@@ -201,17 +200,6 @@ static int get_nr_ram_ranges_callback(u64 start, u64 end, void *arg)
 	return 0;
 }
 
-static int get_gart_ranges_callback(u64 start, u64 end, void *arg)
-{
-	struct crash_elf_data *ced = arg;
-
-	ced->gart_start = start;
-	ced->gart_end = end;
-
-	/* Not expecting more than 1 gart aperture */
-	return 1;
-}
-
 
 /* Gather all the required information to prepare elf headers for ram regions */
 static void fill_up_crash_elf_data(struct crash_elf_data *ced,
@@ -226,22 +214,6 @@ static void fill_up_crash_elf_data(struct crash_elf_data *ced,
 
 	ced->max_nr_ranges = nr_ranges;
 
-	/*
-	 * We don't create ELF headers for GART aperture as an attempt
-	 * to dump this memory in second kernel leads to hang/crash.
-	 * If gart aperture is present, one needs to exclude that region
-	 * and that could lead to need of extra phdr.
-	 */
-	walk_iomem_res("GART", IORESOURCE_MEM, 0, -1,
-				ced, get_gart_ranges_callback);
-
-	/*
-	 * If we have gart region, excluding that could potentially split
-	 * a memory range, resulting in extra header. Account for  that.
-	 */
-	if (ced->gart_end)
-		ced->max_nr_ranges++;
-
 	/* Exclusion of crash region could split memory ranges */
 	ced->max_nr_ranges++;
 
@@ -350,13 +322,6 @@ static int elf_header_exclude_ranges(struct crash_elf_data *ced,
 			return ret;
 	}
 
-	/* Exclude GART region */
-	if (ced->gart_end) {
-		ret = exclude_mem_range(cmem, ced->gart_start, ced->gart_end);
-		if (ret)
-			return ret;
-	}
-
 	return ret;
 }