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From: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
To: Dave Young <dyoung@redhat.com>
Cc: linuxppc-dev@lists.ozlabs.org, kexec@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	Eric Biederman <ebiederm@xmission.com>
Subject: Re: [PATCH v2 2/9] kexec_file: Generalize kexec_add_buffer.
Date: Thu, 16 Jun 2016 17:39:21 -0300	[thread overview]
Message-ID: <16133071.BqvF7Se0c2@hactar> (raw)
In-Reply-To: <20160616015853.GA4103@dhcp-128-65.nay.redhat.com>

Am Donnerstag, 16 Juni 2016, 09:58:53 schrieb Dave Young:
> On 06/15/16 at 01:21pm, Thiago Jung Bauermann wrote:
> > +/**
> > + * arch_kexec_walk_mem - call func(data) on free memory regions
> > + * @image_type:	kimage.type
> > + * @top_down:	Start from the highest address?
> > + * @data:	Argument to pass to @func.
> > + * @func:	Function to call for each memory region.
> > + *
> > + * Return: The memory walk will stop when func returns a non-zero value
> > + * and that value will be returned. If all free regions are visited
> > without + * func returning non-zero, then zero will be returned.
> > + */
> > +int __weak arch_kexec_walk_mem(unsigned int image_type, bool top_down,
> > +			       void *data, int (*func)(u64, u64, void *))
> > +{
> 
> top_down is also not used?

It's unused in the default implementation, but the powerpc implementation in patch 8 uses it:

int arch_kexec_walk_mem(unsigned int type, bool top_down, void *data,
			int (*func)(u64, u64, void *))
{
	int ret = 0;
	u64 i;
	phys_addr_t mstart, mend;

	if (top_down) {
		for_each_free_mem_range_reverse(i, NUMA_NO_NODE, 0,
						&mstart, &mend, NULL) {
			ret = func(mstart, mend, data);
			if (ret)
				break;
		}
	} else {
		for_each_free_mem_range(i, NUMA_NO_NODE, 0, &mstart, &mend,
					NULL) {
			ret = func(mstart, mend, data);
			if (ret)
				break;
		}
	}

	return ret;
}

> Rethink about the argument name type should be better than image_type,
> it is obvious in the comments and the code and simpler.

Ok, renamed in the patch below.

[]'s
Thiago Jung Bauermann
IBM Linux Technology Center


    kexec_file: Generalize kexec_add_buffer.
    
    Allow architectures to specify different memory walking functions for
    kexec_add_buffer. Intel uses iomem to track reserved memory ranges,
    but PowerPC uses the memblock subsystem.
    
    Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
    Cc: Eric Biederman <ebiederm@xmission.com>
    Cc: Dave Young <dyoung@redhat.com>
    Cc: kexec@lists.infradead.org
    Cc: linux-kernel@vger.kernel.org

diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index e8acb2b43dd9..42b31f2e1d88 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -315,6 +315,8 @@ int __weak arch_kexec_apply_relocations_add(const Elf_Ehdr *ehdr,
 					Elf_Shdr *sechdrs, unsigned int relsec);
 int __weak arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
 					unsigned int relsec);
+int __weak arch_kexec_walk_mem(unsigned int type, bool top_down, void *data,
+			       int (*func)(u64, u64, void *));
 void arch_kexec_protect_crashkres(void);
 void arch_kexec_unprotect_crashkres(void);
 
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index b6eec7527e9f..989647a324f2 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -428,6 +428,29 @@ static int locate_mem_hole_callback(u64 start, u64 end, void *arg)
 	return locate_mem_hole_bottom_up(start, end, kbuf);
 }
 
+/**
+ * arch_kexec_walk_mem - call func(data) on free memory regions
+ * @type:	kimage.type
+ * @top_down:	Start from the highest address?
+ * @data:	Argument to pass to @func.
+ * @func:	Function to call for each memory region.
+ *
+ * Return: The memory walk will stop when func returns a non-zero value
+ * and that value will be returned. If all free regions are visited without
+ * func returning non-zero, then zero will be returned.
+ */
+int __weak arch_kexec_walk_mem(unsigned int type, bool top_down, void *data,
+			       int (*func)(u64, u64, void *))
+{
+	if (type == KEXEC_TYPE_CRASH)
+		return walk_iomem_res_desc(crashk_res.desc,
+					   IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
+					   crashk_res.start, crashk_res.end,
+					   data, func);
+	else
+		return walk_system_ram_res(0, ULONG_MAX, data, func);
+}
+
 /*
  * Helper function for placing a buffer in a kexec segment. This assumes
  * that kexec_mutex is held.
@@ -472,14 +495,8 @@ int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long bufsz,
 	kbuf->top_down = top_down;
 
 	/* Walk the RAM ranges and allocate a suitable range for the buffer */
-	if (image->type == KEXEC_TYPE_CRASH)
-		ret = walk_iomem_res_desc(crashk_res.desc,
-				IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
-				crashk_res.start, crashk_res.end, kbuf,
-				locate_mem_hole_callback);
-	else
-		ret = walk_system_ram_res(0, -1, kbuf,
-					  locate_mem_hole_callback);
+	ret = arch_kexec_walk_mem(image->type, top_down, kbuf,
+				   locate_mem_hole_callback);
 	if (ret != 1) {
 		/* A suitable memory range could not be found for buffer */
 		return -EADDRNOTAVAIL;

  reply	other threads:[~2016-06-16 20:39 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-06-14 14:59 [PATCH v2 0/9] kexec_file_load implementation for PowerPC Thiago Jung Bauermann
2016-06-14 14:59 ` [PATCH v2 1/9] kexec_file: Remove unused members from struct kexec_buf Thiago Jung Bauermann
2016-06-14 14:59 ` [PATCH v2 2/9] kexec_file: Generalize kexec_add_buffer Thiago Jung Bauermann
2016-06-15  7:33   ` Dave Young
2016-06-15 16:21     ` Thiago Jung Bauermann
2016-06-16  1:58       ` Dave Young
2016-06-16 20:39         ` Thiago Jung Bauermann [this message]
2016-06-17  7:35           ` Dave Young
2016-06-17 20:51             ` Thiago Jung Bauermann
2016-06-20  2:26               ` Dave Young
2016-06-20 16:01                 ` Thiago Jung Bauermann
2016-06-14 14:59 ` [PATCH v2 3/9] kexec_file: Factor out kexec_locate_mem_hole from kexec_add_buffer Thiago Jung Bauermann
2016-06-14 14:59 ` [PATCH v2 4/9] powerpc: Factor out relocation code from module_64.c to elf_util_64.c Thiago Jung Bauermann
2016-06-14 14:59 ` [PATCH v2 5/9] powerpc: Generalize elf64_apply_relocate_add Thiago Jung Bauermann
2016-06-14 14:59 ` [PATCH v2 6/9] powerpc: Add functions to read ELF files of any endianness Thiago Jung Bauermann
2016-06-14 14:59 ` [PATCH v2 7/9] powerpc: Implement kexec_file_load Thiago Jung Bauermann
2016-06-14 14:59 ` [PATCH v2 8/9] powerpc: Add support for loading ELF kernels with kexec_file_load Thiago Jung Bauermann
2016-06-14 14:59 ` [PATCH v2 9/9] powerpc: Add purgatory for kexec_file_load implementation Thiago Jung Bauermann
2016-06-16  5:48 ` [PATCH v2 0/9] kexec_file_load implementation for PowerPC Michael Ellerman
2016-06-16 19:55   ` Thiago Jung Bauermann

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