--- /dev/null
+From: Chandru <chandru@in.ibm.com>
+Date: Sat, 30 Aug 2008 00:28:16 +1000
+Subject: [PATCH] powerpc: Add support for dynamic reconfiguration memory in kexec/kdump kernels
+References: bnc#431492
+X-Git-Commit: cf00085d8045cddd80a8aabad97de96fa8131793 Mon Sep 17 00:00:00 2001
+
+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@xxx node of the device tree.
+
+The 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.
+
+This makes the kernel recognize a new 'linux,drconf-usable-memory'
+property added by kexec-tools. Each entry in this property is of the
+form of a count followed by that many (base, size) pairs for the above
+mentioned regions. The number of cells in the count value is given by
+the #size-cells property of the root node.
+
+Signed-off-by: Chandru Siddalingappa <chandru@in.ibm.com>
+Signed-off-by: Paul Mackerras <paulus@samba.org>
+Acked-by: Bernhard Walle <bwalle@suse.de>
+
+---
+ arch/powerpc/kernel/prom.c | 40 +++++++++++++++++++---
+ arch/powerpc/mm/numa.c | 79 +++++++++++++++++++++++++++++++++++----------
+ 2 files changed, 96 insertions(+), 23 deletions(-)
+
+--- a/arch/powerpc/kernel/prom.c
++++ b/arch/powerpc/kernel/prom.c
+@@ -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;
+--- a/arch/powerpc/mm/numa.c
++++ b/arch/powerpc/mm/numa.c
+@@ -192,6 +192,21 @@ 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.
+ */
+@@ -529,14 +544,29 @@ 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;
+
+@@ -552,6 +582,11 @@ 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;
+
+@@ -563,21 +598,31 @@ 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);
+ }
+ }
+
projects / people / pmueller / ipfire-2.x.git / blobdiff