[PATCH 1/2] MIPS: KDUMP: skip walking indirection page for crashkernels

[PATCH 1/2] MIPS: KDUMP: skip walking indirection page for crashkernels

[Prem Mallappa]

KDUMP: skip indirection page, as crashkernel has already copied to destination

Signed-off-by: Prem Mallappa <pmallappa@caviumnetworks.com>
---
 arch/mips/kernel/relocate_kernel.S | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/mips/kernel/relocate_kernel.S b/arch/mips/kernel/relocate_kernel.S
index 43d2d78..2778a41 100644
--- a/arch/mips/kernel/relocate_kernel.S
+++ b/arch/mips/kernel/relocate_kernel.S
@@ -26,6 +26,11 @@ process_entry:
 	PTR_L		s2, (s0)
 	PTR_ADD		s0, s0, SZREG
 
+	/* In case of kdump/crash kernel, indirection page is not populated
+	* as the kernel is directly copied to reserved location
+	*/
+	beq             s2, zero, done
+
 	/* destination page */
 	and		s3, s2, 0x1
 	beq		s3, zero, 1f
-- 
1.8.4

[PATCH 2/2] MIPS: KEXEC: Fixes Random crashes while loading crashkernel

[Prem Mallappa]

MIPS: KEXEC: Fixes Random crashes while loading crashkernel

Rearranging code so that crashk_res gets updated.
- crashk_res is updated after mips_parse_crashkernel(),
   after resource_init(), which is after arch_mem_init().
- The reserved memory is actually treated as Usable memory,
   Unless we load the crash kernel, everything works.

Signed-off-by: Prem Mallappa <pmallappa@caviumnetworks.com>
---
 arch/mips/kernel/setup.c | 99 +++++++++++++++++++++++-------------------------
 1 file changed, 48 insertions(+), 51 deletions(-)

diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index c7f9051..e98a256 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -552,6 +552,52 @@ static void __init arch_mem_addpart(phys_t mem, phys_t end, int type)
 	add_memory_region(mem, size, type);
 }
 
+#ifdef CONFIG_KEXEC
+static inline unsigned long long get_total_mem(void)
+{
+	unsigned long long total;
+
+	total = max_pfn - min_low_pfn;
+	return total << PAGE_SHIFT;
+}
+
+static void __init mips_parse_crashkernel(void)
+{
+	unsigned long long total_mem;
+	unsigned long long crash_size, crash_base;
+	int ret;
+
+	total_mem = get_total_mem();
+	ret = parse_crashkernel(boot_command_line, total_mem,
+				&crash_size, &crash_base);
+	if (ret != 0 || crash_size <= 0)
+		return;
+
+	crashk_res.start = crash_base;
+	crashk_res.end	 = crash_base + crash_size - 1;
+}
+
+static void __init request_crashkernel(struct resource *res)
+{
+	int ret;
+
+	ret = request_resource(res, &crashk_res);
+	if (!ret)
+		pr_info("Reserving %ldMB of memory at %ldMB for crashkernel\n",
+			(unsigned long)((crashk_res.end -
+					 crashk_res.start + 1) >> 20),
+			(unsigned long)(crashk_res.start  >> 20));
+}
+#else /* !defined(CONFIG_KEXEC)		*/
+static void __init mips_parse_crashkernel(void)
+{
+}
+
+static void __init request_crashkernel(struct resource *res)
+{
+}
+#endif /* !defined(CONFIG_KEXEC)  */
+
 static void __init arch_mem_init(char **cmdline_p)
 {
 	extern void plat_mem_setup(void);
@@ -609,6 +655,8 @@ static void __init arch_mem_init(char **cmdline_p)
 	}
 #endif
 #ifdef CONFIG_KEXEC
+	mips_parse_crashkernel();
+
 	if (crashk_res.start != crashk_res.end)
 		reserve_bootmem(crashk_res.start,
 				crashk_res.end - crashk_res.start + 1,
@@ -620,52 +668,6 @@ static void __init arch_mem_init(char **cmdline_p)
 	paging_init();
 }
 
-#ifdef CONFIG_KEXEC
-static inline unsigned long long get_total_mem(void)
-{
-	unsigned long long total;
-
-	total = max_pfn - min_low_pfn;
-	return total << PAGE_SHIFT;
-}
-
-static void __init mips_parse_crashkernel(void)
-{
-	unsigned long long total_mem;
-	unsigned long long crash_size, crash_base;
-	int ret;
-
-	total_mem = get_total_mem();
-	ret = parse_crashkernel(boot_command_line, total_mem,
-				&crash_size, &crash_base);
-	if (ret != 0 || crash_size <= 0)
-		return;
-
-	crashk_res.start = crash_base;
-	crashk_res.end	 = crash_base + crash_size - 1;
-}
-
-static void __init request_crashkernel(struct resource *res)
-{
-	int ret;
-
-	ret = request_resource(res, &crashk_res);
-	if (!ret)
-		pr_info("Reserving %ldMB of memory at %ldMB for crashkernel\n",
-			(unsigned long)((crashk_res.end -
-				crashk_res.start + 1) >> 20),
-			(unsigned long)(crashk_res.start  >> 20));
-}
-#else /* !defined(CONFIG_KEXEC)	 */
-static void __init mips_parse_crashkernel(void)
-{
-}
-
-static void __init request_crashkernel(struct resource *res)
-{
-}
-#endif /* !defined(CONFIG_KEXEC)  */
-
 static void __init resource_init(void)
 {
 	int i;
@@ -678,11 +680,6 @@ static void __init resource_init(void)
 	data_resource.start = __pa_symbol(&_etext);
 	data_resource.end = __pa_symbol(&_edata) - 1;
 
-	/*
-	 * Request address space for all standard RAM.
-	 */
-	mips_parse_crashkernel();
-
 	for (i = 0; i < boot_mem_map.nr_map; i++) {
 		struct resource *res;
 		unsigned long start, end;
-- 
1.8.4

Re: [PATCH 2/2] MIPS: KEXEC: Fixes Random crashes while loading crashkernel

[John Crispin]

On 30/08/13 12:05, Prem Mallappa wrote:
> MIPS: KEXEC: Fixes Random crashes while loading crashkernel
>
> Rearranging code so that crashk_res gets updated.
> - crashk_res is updated after mips_parse_crashkernel(),
>     after resource_init(), which is after arch_mem_init().
> - The reserved memory is actually treated as Usable memory,
>     Unless we load the crash kernel, everything works.
>
> Signed-off-by: Prem Mallappa<pmallappa@caviumnetworks.com>
> ---
>   arch/mips/kernel/setup.c | 99 +++++++++++++++++++++++-------------------------
>   1 file changed, 48 insertions(+), 51 deletions(-)
>
> diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
> index c7f9051..e98a256 100644
> --- a/arch/mips/kernel/setup.c
> +++ b/arch/mips/kernel/setup.c

<snip>

> +static void __init request_crashkernel(struct resource *res)
> +{
> +	int ret;
> +
> +	ret = request_resource(res,&crashk_res);
> +	if (!ret)
> +		pr_info("Reserving %ldMB of memory at %ldMB for crashkernel\n",
> +			(unsigned long)((crashk_res.end -
> +					 crashk_res.start + 1)>>  20),
> +			(unsigned long)(crashk_res.start>>  20));
> +}
> +#else /* !defined(CONFIG_KEXEC)		*/
> +static void __init mips_parse_crashkernel(void)
> +{
> +}
> +

Hi,

the function is not used and causes the following error.

arch/mips/kernel/setup.c:592:20: error: 'mips_parse_crashkernel' defined 
but not used [-Werror=unused-function]
cc1: all warnings being treated as errors

make[2]: *** [arch/mips/kernel/setup.o] Error 1
make[1]: *** [arch/mips/kernel] Error 2

	John






> +static void __init request_crashkernel(struct resource *res)
> +{
> +}
> +#endif /* !defined(CONFIG_KEXEC)  */
> +
>   static void __init arch_mem_init(char **cmdline_p)
>   {
>   	extern void plat_mem_setup(void);
> @@ -609,6 +655,8 @@ static void __init arch_mem_init(char **cmdline_p)
>   	}
>   #endif
>   #ifdef CONFIG_KEXEC
> +	mips_parse_crashkernel();
> +
>   	if (crashk_res.start != crashk_res.end)
>   		reserve_bootmem(crashk_res.start,
>   				crashk_res.end - crashk_res.start + 1,
> @@ -620,52 +668,6 @@ static void __init arch_mem_init(char **cmdline_p)
>   	paging_init();
>   }
>
> -#ifdef CONFIG_KEXEC
> -static inline unsigned long long get_total_mem(void)
> -{
> -	unsigned long long total;
> -
> -	total = max_pfn - min_low_pfn;
> -	return total<<  PAGE_SHIFT;
> -}
> -
> -static void __init mips_parse_crashkernel(void)
> -{
> -	unsigned long long total_mem;
> -	unsigned long long crash_size, crash_base;
> -	int ret;
> -
> -	total_mem = get_total_mem();
> -	ret = parse_crashkernel(boot_command_line, total_mem,
> -				&crash_size,&crash_base);
> -	if (ret != 0 || crash_size<= 0)
> -		return;
> -
> -	crashk_res.start = crash_base;
> -	crashk_res.end	 = crash_base + crash_size - 1;
> -}
> -
> -static void __init request_crashkernel(struct resource *res)
> -{
> -	int ret;
> -
> -	ret = request_resource(res,&crashk_res);
> -	if (!ret)
> -		pr_info("Reserving %ldMB of memory at %ldMB for crashkernel\n",
> -			(unsigned long)((crashk_res.end -
> -				crashk_res.start + 1)>>  20),
> -			(unsigned long)(crashk_res.start>>  20));
> -}
> -#else /* !defined(CONFIG_KEXEC)	 */
> -static void __init mips_parse_crashkernel(void)
> -{
> -}
> -
> -static void __init request_crashkernel(struct resource *res)
> -{
> -}
> -#endif /* !defined(CONFIG_KEXEC)  */
> -
>   static void __init resource_init(void)
>   {
>   	int i;
> @@ -678,11 +680,6 @@ static void __init resource_init(void)
>   	data_resource.start = __pa_symbol(&_etext);
>   	data_resource.end = __pa_symbol(&_edata) - 1;
>
> -	/*
> -	 * Request address space for all standard RAM.
> -	 */
> -	mips_parse_crashkernel();
> -
>   	for (i = 0; i<  boot_mem_map.nr_map; i++) {
>   		struct resource *res;
>   		unsigned long start, end;