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

[Simon Horman]

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? 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) &&
>