Re: [PATCH] kexec memory ranges dynamic allocation

["Maxim Uvarov" <muvarov@gmail.com>]

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Patch corrected. ( git_kexec_powerpc_v2.patch is attached.)

I tested it on ppc64 pasemi electra board. Both kexec -l and kexec -p works.

Maxim.



2008/10/15 Simon Horman <horms@verge.net.au>

> On Tue, Oct 14, 2008 at 07:11:19PM +0400, Maxim Uvarov wrote:
> > Hello all,
> >
> > As you all know it is not easy to count exact value of memory ranges from
> > device tree on powerpc.
> > It very depends on how dts file was written. What do you think about
> really
> > dynamic allocation buffers
> > for this buffers?
>
> Conceptually I have no objections to the change,
> though I would like to get some review from ppc people.
> (linuxppc-dev@ozlabs.org CCed)
>
> > Patch is attached.
>
> This patch doesn't seem to compile for me.
>
> # powerpc64-unknown-linux-gnu-gcc --version
> powerpc64-unknown-linux-gnu-gcc (GCC) 4.1.1
> Copyright (C) 2006 Free Software Foundation, Inc.
> This is free software; see the source for copying conditions.  There is NO
> warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
>
> #make
> [snip]
> kexec/arch/ppc64/kexec-ppc64.c:100: warning: function declaration isn't a
> prototype
> kexec/arch/ppc64/kexec-ppc64.c: In function 'realloc_memory_ranges':
> kexec/arch/ppc64/kexec-ppc64.c:107: warning: passing argument 1 of
> 'realloc' makes pointer from integer without a cast
> kexec/arch/ppc64/kexec-ppc64.c:107: error: too few arguments to function
> 'realloc'
> kexec/arch/ppc64/kexec-ppc64.c:102: warning: unused variable 'tmp'
>
> --
> Simon Horman
>  VA Linux Systems Japan K.K., Sydney, Australia Satellite Office
>  H: www.vergenet.net/~horms/ <http://www.vergenet.net/%7Ehorms/>
>   W: www.valinux.co.jp/en
>
>


-- 
Best regards,
Maxim Uvarov

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diff --git a/kexec/arch/ppc64/kexec-ppc64.c b/kexec/arch/ppc64/kexec-ppc64.c
index 069a9fc..0ad40fa 100644
--- a/kexec/arch/ppc64/kexec-ppc64.c
+++ b/kexec/arch/ppc64/kexec-ppc64.c
@@ -96,96 +96,46 @@ err1:
 
 }
 
-static int count_dyn_reconf_memory_ranges(void)
+static int realloc_memory_ranges()
 {
-	char device_tree[] = "/proc/device-tree/";
-	char fname[128];
-	char buf[32];
-	FILE *file;
-
-	strcpy(fname, device_tree);
-	strcat(fname, "ibm,dynamic-reconfiguration-memory/ibm,lmb-size");
-	if ((file = fopen(fname, "r")) == NULL) {
-		perror(fname);
-		return -1;
-	}
+	size_t memory_range_len;
 
-	if (fread(buf, 1, 8, file) < 0) {
-		perror(fname);
-		fclose(file);
-		return -1;
-	}
-
-	lmb_size = ((uint64_t *)buf)[0];
-	fclose(file);
+	max_memory_ranges++;
+	memory_range_len = sizeof(struct memory_range) * max_memory_ranges;
 
-	/* Get number of lmbs from ibm,dynamic-memory */
-	strcpy(fname, device_tree);
-	strcat(fname, "ibm,dynamic-reconfiguration-memory/ibm,dynamic-memory");
-	if ((file = fopen(fname, "r")) == NULL) {
-		perror(fname);
-		return -1;
-	}
-	/*
-	 * first 4 bytes provide number of entries(lmbs)
-	 */
-	if (fread(buf, 1, 4, file) < 0) {
-		perror(fname);
-		fclose(file);
-		return -1;
-	}
-	num_of_lmbs = ((unsigned int *)buf)[0];
-	max_memory_ranges += num_of_lmbs;
-	fclose(file);
+	memory_range = (struct memory_range *) realloc(memory_range, memory_range_len);
+	if (!memory_range)
+		goto err;
 
-	return 0;
-}
+	base_memory_range = (struct memory_range *) realloc(memory_range, memory_range_len);
+	if (!base_memory_range)
+		goto err;
 
-/*
- * Count the memory nodes under /proc/device-tree and populate the
- * max_memory_ranges variable. This variable replaces MAX_MEMORY_RANGES
- * macro used earlier.
- */
-static int count_memory_ranges(void)
-{
-	char device_tree[256] = "/proc/device-tree/";
-	struct dirent *dentry;
-	DIR *dir;
+	exclude_range = (struct memory_range *) realloc(exclude_range, memory_range_len);
+	if (!exclude_range)
+		goto err;
 
-	if ((dir = opendir(device_tree)) == NULL) {
-		perror(device_tree);
-		return -1;
-	}
+	usablemem_rgns.ranges = (struct memory_range *)
+				realloc(usablemem_rgns.ranges, memory_range_len);
+	if (!(usablemem_rgns.ranges))
+		goto err;
 
-	while ((dentry = readdir(dir)) != NULL) {
-		if (!strncmp(dentry->d_name,
-				"ibm,dynamic-reconfiguration-memory", 35)){
-			if (count_dyn_reconf_memory_ranges() != 0)
-				return -1;
-			continue;
-		}
+	return 0;
 
-		if (strncmp(dentry->d_name, "memory@", 7) &&
-			strcmp(dentry->d_name, "memory") &&
-			strncmp(dentry->d_name, "pci@", 4))
-			continue;
-		max_memory_ranges++;
-	}
-	/* need to add extra region for retained initrd */
-	if (reuse_initrd) {
-		max_memory_ranges++;
-	}
+err:
+	fprintf(stderr, "memory range structure re-allocation failure\n");
+	return -1;
+}
 
-	closedir(dir);
 
-	return 0;
-}
 static void add_base_memory_range(uint64_t start, uint64_t end)
 {
 	base_memory_range[nr_memory_ranges].start = start;
 	base_memory_range[nr_memory_ranges].end  = end;
 	base_memory_range[nr_memory_ranges].type = RANGE_RAM;
 	nr_memory_ranges++;
+	if (nr_memory_ranges >= max_memory_ranges) 
+		realloc_memory_ranges(); 
 
 	dbgprintf("%016llx-%016llx : %x\n",
 		base_memory_range[nr_memory_ranges-1].start,
@@ -300,8 +250,8 @@ static int get_base_ranges(void)
 				return -1;
 			}
 			if (nr_memory_ranges >= max_memory_ranges) {
-				fclose(file);
-				break;
+				if (realloc_memory_ranges() < 0)
+					break;
 			}
 			start = ((uint64_t *)buf)[0];
 			end = start + ((uint64_t *)buf)[1];
@@ -396,6 +346,8 @@ static int get_devtree_details(unsigned long kexec_flags)
 			exclude_range[i].start = 0x0UL;
 			exclude_range[i].end = kernel_end;
 			i++;
+			if (i >= max_memory_ranges)
+				realloc_memory_ranges();
 
 			if (kexec_flags & KEXEC_ON_CRASH) {
 				memset(fname, 0, sizeof(fname));
@@ -470,6 +422,8 @@ static int get_devtree_details(unsigned long kexec_flags)
 			exclude_range[i].start = htab_base;
 			exclude_range[i].end = htab_base + htab_size;
 			i++;
+			if (i >= max_memory_ranges)
+				realloc_memory_ranges();
 
 			/* reserve the initrd_start and end locations. */
 			if (reuse_initrd) {
@@ -545,6 +499,8 @@ static int get_devtree_details(unsigned long kexec_flags)
 			exclude_range[i].start = rtas_base;
 			exclude_range[i].end = rtas_base + rtas_size;
 			i++;
+			if (i >= max_memory_ranges)
+				realloc_memory_ranges();
 			if (kexec_flags & KEXEC_ON_CRASH)
 				add_usable_mem_rgns(rtas_base, rtas_size);
 		} /* rtas */
@@ -740,9 +696,10 @@ out:
 /* Return a list of valid memory ranges */
 int get_memory_ranges(struct memory_range **range, int *ranges,
 			unsigned long kexec_flags)
-{
-	if (count_memory_ranges())
-		return -1;
+{	
+        /* allocate memory_range dynamically */
+        max_memory_ranges = 1;
+
 	if (alloc_memory_ranges())
 		return -1;
 	if (setup_memory_ranges(kexec_flags))