[PATCH] kexec/ppc64: Handle reserved memory ranges exported by OPAL firmware.

[Mahesh Jagannath Salgaonkar]

On 05/11/2014 05:21 AM, Simon Horman wrote:
> On Sun, Feb 09, 2014 at 10:25:45PM +0530, Mahesh J Salgaonkar wrote:
>> From: Mahesh Salgaonkar <mahesh at linux.vnet.ibm.com>
>>
>> OPAL based system exports reserved memory ranges through /proc/device-tree
>> for the regions that are reserved by OPAL firmware. Traverse
>> /proc/device-tree/reserved-ranges and add them to exclude_ranges[] and
>> reserve them.
>>
>> Signed-off-by: Mahesh Salgaonkar <mahesh at linux.vnet.ibm.com>
> 
> I apologise that this seems to have slipped through the cracks.
> Manesh, is this patch still needed?

Yup. We need this also.

 If so, is it possible for
> someone on the power side of things to review it?
> 
>> ---
>>  kexec/arch/ppc64/kexec-ppc64.c |   44 ++++++++++++++++++++++++++++++++++++++++
>>  1 file changed, 44 insertions(+)
>>
>> diff --git a/kexec/arch/ppc64/kexec-ppc64.c b/kexec/arch/ppc64/kexec-ppc64.c
>> index 5956836..6e79f52 100644
>> --- a/kexec/arch/ppc64/kexec-ppc64.c
>> +++ b/kexec/arch/ppc64/kexec-ppc64.c
>> @@ -31,6 +31,7 @@
>>  #include "../../kexec.h"
>>  #include "../../kexec-syscall.h"
>>  #include "kexec-ppc64.h"
>> +#include "../../fs2dt.h"
>>  #include "crashdump-ppc64.h"
>>  #include <arch/options.h>
>>  
>> @@ -314,6 +315,47 @@ static int sort_ranges(void)
>>  	return 0;
>>  }
>>  
>> +void scan_reserved_ranges(unsigned long kexec_flags, int *range_index)
>> +{
>> +	char fname[256], buf[16];
>> +	FILE *file;
>> +	int i = *range_index;
>> +
>> +	strcpy(fname, "/proc/device-tree/reserved-ranges");
>> +
>> +	file = fopen(fname, "r");
>> +	if (file == NULL) {
>> +		if (errno != ENOENT) {
>> +			perror(fname);
>> +			return;
>> +		}
>> +		errno = 0;
>> +		/* File not present. Non PowerKVM system. */
>> +		return;
>> +	}
>> +
>> +	/*
>> +	 * Each reserved range is an (address,size) pair, 2 cells each,
>> +	 * totalling 4 cells per range.
>> +	 */
>> +	while (fread(buf, sizeof(uint64_t) * 2, 1, file) == 1) {
>> +		uint64_t base, size;
>> +
>> +		base = be64_to_cpu(((uint64_t *)buf)[0]);
>> +		size = be64_to_cpu(((uint64_t *)buf)[1]);
>> +
>> +		exclude_range[i].start = base;
>> +		exclude_range[i].end = base + size;
>> +		i++;
>> +		if (i >= max_memory_ranges)
>> +			realloc_memory_ranges();
>> +
>> +		reserve(base, size);
>> +	}
>> +	fclose(file);
>> +	*range_index = i;
>> +}
>> +
>>  /* Get devtree details and create exclude_range array
>>   * Also create usablemem_ranges for KEXEC_ON_CRASH
>>   */
>> @@ -339,6 +381,8 @@ static int get_devtree_details(unsigned long kexec_flags)
>>  		return -1;
>>  	}
>>  
>> +	scan_reserved_ranges(kexec_flags, &i);
>> +
>>  	while ((dentry = readdir(dir)) != NULL) {
>>  		if (strncmp(dentry->d_name, "chosen", 6) &&
>>  			strncmp(dentry->d_name, "memory@", 7) &&
>>
>