[PATCH][V3] powerpc: add support for dynamic reconfiguration memory in kexec/kdump kernels
Chandru
chandru at in.ibm.com
Sat Aug 30 00:28:16 EST 2008
kdump kernel needs to use only those memory regions that it is allowed to use
(crashkernel, rtas, tce ..etc ). Each of these regions have their own sizes
and are currently added under 'linux,usable-memory' property under each
memory@ node of the device tree. ibm,dynamic-memory property of
ibm,dynamic-reconfiguration-memory node (on power6) now stores in it the
representation for most of the logical memory blocks with the size of each
memory block being a constant (lmb_size). If one or more or part of the above
mentioned regions lie under one of the lmb from ibm,dynamic-memory property,
there is a need to identify those regions within the given lmb. Following
patch recognizes a new property 'linux,drconf-usable-memory' property added by
kexec-tools. Each entry in this property is of the form 'a counter' followed
by those many (base, size) duple for the above mentioned regions.
Signed-off-by: Chandru Siddalingappa <chandru at in.ibm.com>
---
Patch was tested on a power6 box. Could you pls add this patch to powerpc git
tree ? . Thanks,
arch/powerpc/kernel/prom.c | 40 +++++++++++++++--
arch/powerpc/mm/numa.c | 79 +++++++++++++++++++++++++++--------
2 files changed, 96 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 2008-08-14 08:23:25.000000000 +0530
+++ powerpc/arch/powerpc/kernel/prom.c 2008-08-14 14:35:24.000000000 +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;
+ cell_t *dm, *ls, *usm;
unsigned long l, n, flags;
u64 base, size, lmb_size;
+ unsigned int is_kexec_kdump = 0, rngs;
ls = (cell_t *)of_get_flat_dt_prop(node, "ibm,lmb-size", &l);
if (ls == NULL || l < dt_root_size_cells * sizeof(cell_t))
@@ -905,6 +906,12 @@ static int __init early_init_dt_scan_drc
if (l < (n * (dt_root_addr_cells + 4) + 1) * sizeof(cell_t))
return 0;
+ /* check if this is a kexec/kdump kernel. */
+ usm = (cell_t *)of_get_flat_dt_prop(node, "linux,drconf-usable-memory",
+ &l);
+ if (usm != NULL)
+ is_kexec_kdump = 1;
+
for (; n != 0; --n) {
base = dt_mem_next_cell(dt_root_addr_cells, &dm);
flags = dm[3];
@@ -915,13 +922,34 @@ static int __init early_init_dt_scan_drc
if ((flags & 0x80) || !(flags & 0x8))
continue;
size = lmb_size;
- if (iommu_is_off) {
- if (base >= 0x80000000ul)
+ rngs = 1;
+ if (is_kexec_kdump) {
+ /*
+ * For each lmb in ibm,dynamic-memory, a corresponding
+ * entry in linux,drconf-usable-memory property contains
+ * a counter 'p' followed by 'p' (base, size) duple.
+ * Now read the counter from
+ * linux,drconf-usable-memory property
+ */
+ rngs = dt_mem_next_cell(dt_root_size_cells, &usm);
+ if (!rngs) /* there are no (base, size) duple */
continue;
- if ((base + size) > 0x80000000ul)
- size = 0x80000000ul - base;
}
- lmb_add(base, size);
+ do {
+ if (is_kexec_kdump) {
+ base = dt_mem_next_cell(dt_root_addr_cells,
+ &usm);
+ size = dt_mem_next_cell(dt_root_size_cells,
+ &usm);
+ }
+ if (iommu_is_off) {
+ if (base >= 0x80000000ul)
+ continue;
+ if ((base + size) > 0x80000000ul)
+ size = 0x80000000ul - base;
+ }
+ lmb_add(base, size);
+ } while (--rngs);
}
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 2008-08-14 08:23:25.000000000 +0530
+++ powerpc/arch/powerpc/mm/numa.c 2008-08-14 14:35:42.000000000 +0530
@@ -150,6 +150,21 @@ static const int *of_get_associativity(s
return of_get_property(dev, "ibm,associativity", NULL);
}
+/*
+ * Returns the property linux,drconf-usable-memory if
+ * it exists (the property exists only in kexec/kdump kernels,
+ * added by kexec-tools)
+ */
+static const u32 *of_get_usable_memory(struct device_node *memory)
+{
+ const u32 *prop;
+ u32 len;
+ prop = of_get_property(memory, "linux,drconf-usable-memory", &len);
+ if (!prop || len < sizeof(unsigned int))
+ return 0;
+ return prop;
+}
+
/* Returns nid in the range [0..MAX_NUMNODES-1], or -1 if no useful numa
* info is found.
*/
@@ -487,14 +502,29 @@ static unsigned long __init numa_enforce
}
/*
+ * Reads the counter for a given entry in
+ * linux,drconf-usable-memory property
+ */
+static inline int __init read_usm_ranges(const u32 **usm)
+{
+ /*
+ * For each lmb in ibm,dynamic-memory a corresponding
+ * entry in linux,drconf-usable-memory property contains
+ * a counter followed by that many (base, size) duple.
+ * read the counter from linux,drconf-usable-memory
+ */
+ return read_n_cells(n_mem_size_cells, usm);
+}
+
+/*
* Extract NUMA information from the ibm,dynamic-reconfiguration-memory
* node. This assumes n_mem_{addr,size}_cells have been set.
*/
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, ranges, is_kexec_kdump = 0;
+ unsigned long lmb_size, base, size, sz;
int nid;
struct assoc_arrays aa;
@@ -510,6 +540,11 @@ static void __init parse_drconf_memory(s
if (rc)
return;
+ /* check if this is a kexec/kdump kernel */
+ usm = of_get_usable_memory(memory);
+ if (usm != NULL)
+ is_kexec_kdump = 1;
+
for (; n != 0; --n) {
struct of_drconf_cell drmem;
@@ -521,21 +556,31 @@ static void __init parse_drconf_memory(s
|| !(drmem.flags & DRCONF_MEM_ASSIGNED))
continue;
- nid = of_drconf_to_nid_single(&drmem, &aa);
-
- fake_numa_create_new_node(
- ((drmem.base_addr + lmb_size) >> PAGE_SHIFT),
+ base = drmem.base_addr;
+ size = lmb_size;
+ ranges = 1;
+
+ if (is_kexec_kdump) {
+ ranges = read_usm_ranges(&usm);
+ if (!ranges) /* there are no (base, size) duple */
+ continue;
+ }
+ do {
+ if (is_kexec_kdump) {
+ base = read_n_cells(n_mem_addr_cells, &usm);
+ size = read_n_cells(n_mem_size_cells, &usm);
+ }
+ nid = of_drconf_to_nid_single(&drmem, &aa);
+ fake_numa_create_new_node(
+ ((base + size) >> PAGE_SHIFT),
&nid);
-
- node_set_online(nid);
-
- size = numa_enforce_memory_limit(drmem.base_addr, lmb_size);
- if (!size)
- continue;
-
- add_active_range(nid, drmem.base_addr >> PAGE_SHIFT,
- (drmem.base_addr >> PAGE_SHIFT)
- + (size >> PAGE_SHIFT));
+ 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);
}
}
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