Subject: Re: [PATCH 1/4][V2] powerpc : add support for linux, usable-memory properties for drconf memory

From: Benjamin Herrenschmidt <[email-masked]>
Date: Tue, 22 Jul 2008 19:12:06 +1000

On Tue, 2008-07-22 at 14:31 +0530, Chandru wrote:
> Scan for linux,usable-memory properties in case of dynamic reconfiguration 
> memory . Support for kexec/kdump.
> 
> Signed-off-by: Chandru Siddalingappa <[email-masked]>
> ---
> 
> Patch applies on powerpc tree. Patch was reviewed by Nathan Fontenot, Stephen 
> Rothwell, Michael Neuling.  

Any reason why there's no acks there then ? I don't have an objection to
the patch per-se and I was planning to review it this week too, but if
you had positive reviews and you addressed whatever comments the people
had, there should be Acked-by: lines in your patch (ie, don't invent
them, only put them there if you actually got that from the reviewers).

Cheers,
Ben.

>  arch/powerpc/kernel/prom.c |   40 +++++++++++++++++++++++------
>  arch/powerpc/mm/numa.c     |   48 ++++++++++++++++++++++++-----------
>  2 files changed, 65 insertions(+), 23 deletions(-)
> 
> diff -Naurp powerpc-orig/arch/powerpc/kernel/prom.c 
> powerpc/arch/powerpc/kernel/prom.c
> --- powerpc-orig/arch/powerpc/kernel/prom.c	2008-07-22 14:11:53.000000000 
> +0530
> +++ powerpc/arch/powerpc/kernel/prom.c	2008-07-22 14:12:17.000000000 +0530
> @@ -888,9 +888,10 @@ static u64 __init dt_mem_next_cell(int s
>   */
>  static int __init early_init_dt_scan_drconf_memory(unsigned long node)
>  {
> -	cell_t *dm, *ls;
> -	unsigned long l, n, flags;
> +	cell_t *dm, *ls, *usm;
> +	unsigned long l, n, flags, ranges;
>  	u64 base, size, lmb_size;
> +	char buf[32];
>  
>  	ls = (cell_t *)of_get_flat_dt_prop(node, "ibm,lmb-size", &l);
>  	if (ls == NULL || l < dt_root_size_cells * sizeof(cell_t))
> @@ -914,14 +915,37 @@ static int __init early_init_dt_scan_drc
>  		   or if the block is not assigned to this partition (0x8) */
>  		if ((flags & 0x80) || !(flags & 0x8))
>  			continue;
> -		size = lmb_size;
> -		if (iommu_is_off) {
> +		if (iommu_is_off)
>  			if (base >= 0x80000000ul)
>  				continue;
> -			if ((base + size) > 0x80000000ul)
> -				size = 0x80000000ul - base;
> -		}
> -		lmb_add(base, size);
> +		size = lmb_size;
> +
> +		/*
> +		 * Append 'n' to 'linux,usable-memory' to get special
> +		 * properties passed in by tools like kexec-tools. Relevant
> +		 * only if this is a kexec/kdump kernel.
> +		 */
> +		sprintf(buf, "linux,usable-memory%d", (int)n);
> +		usm = of_get_flat_dt_prop(node, buf, &l);
> +		ranges = 1;
> +		if (usm != NULL)
> +			ranges = (l >> 2)/(dt_root_addr_cells
> +						+ dt_root_size_cells);
> +		do {
> +			if (usm != NULL) {
> +				base = dt_mem_next_cell(dt_root_addr_cells,
> +							 &usm);
> +				size = dt_mem_next_cell(dt_root_size_cells,
> +							 &usm);
> +				if (size == 0)
> +					break;
> +			}
> +			if (iommu_is_off)
> +				if ((base + size) > 0x80000000ul)
> +					size = 0x80000000ul - base;
> +
> +			lmb_add(base, size);
> +		} while (--ranges);
>  	}
>  	lmb_dump_all();
>  	return 0;
> diff -Naurp powerpc-orig/arch/powerpc/mm/numa.c powerpc/arch/powerpc/mm/numa.c
> --- powerpc-orig/arch/powerpc/mm/numa.c	2008-07-22 14:11:53.000000000 +0530
> +++ powerpc/arch/powerpc/mm/numa.c	2008-07-22 14:12:17.000000000 +0530
> @@ -493,11 +493,13 @@ static unsigned long __init numa_enforce
>   */
>  static void __init parse_drconf_memory(struct device_node *memory)
>  {
> -	const u32 *dm;
> -	unsigned int n, rc;
> -	unsigned long lmb_size, size;
> +	const u32 *dm, *usm;
> +	unsigned int n, rc, len, ranges;
> +	unsigned long lmb_size, size, sz;
>  	int nid;
>  	struct assoc_arrays aa;
> +	char buf[32];
> +	u64 base;
>  
>  	n = of_get_drconf_memory(memory, &dm);
>  	if (!n)
> @@ -524,19 +526,35 @@ static void __init parse_drconf_memory(s
>  
>  		nid = of_drconf_to_nid_single(&drmem, &aa);
>  
> -		fake_numa_create_new_node(
> -				((drmem.base_addr + lmb_size) >> PAGE_SHIFT),
> -					   &nid);
> -
> -		node_set_online(nid);
> -
> -		size = numa_enforce_memory_limit(drmem.base_addr, lmb_size);
> -		if (!size)
> -			continue;
> +		/*
> +		 * Append 'n' to 'linux,usable-memory' to get special
> +		 * properties passed in by tools like kexec-tools. Relevant
> +		 * only if this is a kexec/kdump kernel.
> +		 */
> +		sprintf(buf, "linux,usable-memory%d", (int)n);
> +		usm = of_get_property(memory, buf, &len);
> +		ranges = 1;
> +		if (usm != NULL)
> +			ranges = (len >> 2) /
> +					 (n_mem_addr_cells + n_mem_size_cells);
> +
> +		base = drmem.base_addr;
> +		size = lmb_size;
> +		do {
> +			if (usm != NULL) {
> +				base = read_n_cells(n_mem_addr_cells, &usm);
> +				size = read_n_cells(n_mem_size_cells, &usm);
> +			}
>  
> -		add_active_range(nid, drmem.base_addr >> PAGE_SHIFT,
> -				 (drmem.base_addr >> PAGE_SHIFT)
> -				 + (size >> PAGE_SHIFT));
> +			fake_numa_create_new_node(((base + size) >> PAGE_SHIFT),
> +							 &nid);
> +			node_set_online(nid);
> +			sz = numa_enforce_memory_limit(base, size);
> +			if (sz)
> +				add_active_range(nid, base >> PAGE_SHIFT,
> +						 (base >> PAGE_SHIFT)
> +						+ (sz >> PAGE_SHIFT));
> +		} while (--ranges);
>  	}
>  }