[PATCH/RFC 5/6]: phyp dump: register the dump area
Linas Vepstas
linas at austin.ibm.com
Thu Nov 22 09:43:08 EST 2007
Set up the actual dump header, register it with the hypervisor.
Signed-off-by: Manish Ahuja <mahuja at us.ibm.com>
Signed-off-by: Linas Vepstas <linas at austin.ibm.com>
------
arch/powerpc/platforms/pseries/phyp_dump.c | 169 +++++++++++++++++++++++++++--
1 file changed, 163 insertions(+), 6 deletions(-)
Index: linux-2.6.24-rc3-git1/arch/powerpc/platforms/pseries/phyp_dump.c
===================================================================
--- linux-2.6.24-rc3-git1.orig/arch/powerpc/platforms/pseries/phyp_dump.c 2007-11-21 15:55:37.000000000 -0600
+++ linux-2.6.24-rc3-git1/arch/powerpc/platforms/pseries/phyp_dump.c 2007-11-21 16:06:52.000000000 -0600
@@ -30,6 +30,134 @@ struct phyp_dump *phyp_dump_info = &phyp
static int ibm_configure_kernel_dump;
/* ------------------------------------------------- */
+/* RTAS interfaces to declare the dump regions */
+
+struct dump_section {
+ u32 dump_flags;
+ u16 source_type;
+ u16 error_flags;
+ u64 source_address;
+ u64 source_length;
+ u64 length_copied;
+ u64 destination_address;
+};
+
+struct phyp_dump_header {
+ u32 version;
+ u16 num_of_sections;
+ u16 status;
+
+ u32 first_offset_section;
+ u32 dump_disk_section;
+ u64 block_num_dd;
+ u64 num_of_blocks_dd;
+ u32 offset_dd;
+ u32 maxtime_to_auto;
+ /* No dump disk path string used */
+
+ struct dump_section cpu_data;
+ struct dump_section hpte_data;
+ struct dump_section kernel_data;
+};
+
+/* The dump header *must be* in low memory, so .bss it */
+static struct phyp_dump_header phdr;
+
+#define NUM_DUMP_SECTIONS 3
+#define DUMP_HEADER_VERSION 0x1
+#define DUMP_REQUEST_FLAG 0x1
+#define DUMP_SOURCE_CPU 0x0001
+#define DUMP_SOURCE_HPTE 0x0002
+#define DUMP_SOURCE_RMO 0x0011
+
+/**
+ * init_dump_header() - initialize the header declaring a dump
+ * Returns: length of dump save area.
+ *
+ * When the hypervisor saves crashed state, it needs to put
+ * it somewhere. The dump header tells the hypervisor where
+ * the data can be saved.
+ */
+static unsigned long init_dump_header(struct phyp_dump_header *ph)
+{
+ struct device_node *rtas;
+ const unsigned int *sizes;
+ int len;
+ unsigned long cpu_state_size = 0;
+ unsigned long hpte_region_size = 0;
+ unsigned long addr_offset = 0;
+
+ /* Get the required dump region sizes */
+ rtas = of_find_node_by_path("/rtas");
+ sizes = of_get_property(rtas, "ibm,configure-kernel-dump-sizes", &len);
+ if (!sizes || len < 20)
+ return 0;
+
+ if (sizes[0] == 1)
+ cpu_state_size = *((unsigned long *) &sizes[1]);
+
+ if (sizes[3] == 2)
+ hpte_region_size = *((unsigned long *) &sizes[4]);
+
+ /* Set up the dump header */
+ ph->version = DUMP_HEADER_VERSION;
+ ph->num_of_sections = NUM_DUMP_SECTIONS;
+ ph->status = 0;
+
+ ph->first_offset_section =
+ (u32) &(((struct phyp_dump_header *) 0)->cpu_data);
+ ph->dump_disk_section = 0;
+ ph->block_num_dd = 0;
+ ph->num_of_blocks_dd = 0;
+ ph->offset_dd = 0;
+
+ ph->maxtime_to_auto = 0; /* disabled */
+
+ /* The first two sections are mandatory */
+ ph->cpu_data.dump_flags = DUMP_REQUEST_FLAG;
+ ph->cpu_data.source_type = DUMP_SOURCE_CPU;
+ ph->cpu_data.source_address = 0;
+ ph->cpu_data.source_length = cpu_state_size;
+ ph->cpu_data.destination_address = addr_offset;
+ addr_offset += cpu_state_size;
+
+ ph->hpte_data.dump_flags = DUMP_REQUEST_FLAG;
+ ph->hpte_data.source_type = DUMP_SOURCE_HPTE;
+ ph->hpte_data.source_address = 0;
+ ph->hpte_data.source_length = hpte_region_size;
+ ph->hpte_data.destination_address = addr_offset;
+ addr_offset += hpte_region_size;
+
+ /* This section describes the low kernel region */
+ ph->kernel_data.dump_flags = DUMP_REQUEST_FLAG;
+ ph->kernel_data.source_type = DUMP_SOURCE_RMO;
+ ph->kernel_data.source_address = PHYP_DUMP_RMR_START;
+ ph->kernel_data.source_length = PHYP_DUMP_RMR_END;
+ ph->kernel_data.destination_address = addr_offset;
+ addr_offset += ph->kernel_data.source_length;
+
+ return addr_offset;
+}
+
+static void register_dump_area(struct phyp_dump_header *ph, unsigned long addr)
+{
+ int rc;
+ ph->cpu_data.destination_address += addr;
+ ph->hpte_data.destination_address += addr;
+ ph->kernel_data.destination_address += addr;
+
+ do {
+ rc = rtas_call(ibm_configure_kernel_dump, 3, 1, NULL,
+ 1, ph, sizeof(struct phyp_dump_header));
+ } while (rtas_busy_delay(rc));
+
+ if (rc)
+ {
+ printk (KERN_ERR "phyp-dump: unexpected error (%d) on register\n", rc);
+ }
+}
+
+/* ------------------------------------------------- */
/**
* release_memory_range -- release memory previously lmb_reserved
* @start_pfn: starting physical frame number
@@ -125,7 +253,11 @@ static void release_all (void)
static int __init phyp_dump_setup(void)
{
struct device_node *rtas;
- const int *dump_header;
+ const struct phyp_dump_header *dump_header;
+ unsigned long dump_area_start;
+ unsigned long dump_area_length;
+ unsigned long free_area_length;
+ unsigned long start_pfn, nr_pages;
int header_len = 0;
int rc;
@@ -140,22 +272,47 @@ static int __init phyp_dump_setup(void)
return -ENOSYS;
}
- /* Is there dump data waiting for us? */
+ /* Is there dump data waiting for us? If there isn't,
+ * then register a new dump area, and release all of
+ * the rest of the reserved ram.
+ *
+ * The /rtas/ibm,kernel-dump rtas node is present only
+ * if there is dump data waiting for us.
+ */
rtas = of_find_node_by_path("/rtas");
dump_header = of_get_property(rtas, "ibm,kernel-dump", &header_len);
+
+ dump_area_length = init_dump_header (&phdr);
+ free_area_length = phyp_dump_info->init_reserve_size - dump_area_length;
+ dump_area_start = phyp_dump_info->init_reserve_start + free_area_length;
+ dump_area_start = dump_area_start & PAGE_MASK; /* align down */
+ free_area_length = dump_area_start - phyp_dump_info->init_reserve_start;
+
if (dump_header == NULL) {
- release_all();
- return 0;
+ register_dump_area (&phdr, dump_area_start);
+ goto release_mem;
}
+ /* Don't allow user to release the 256MB scratch area */
+ phyp_dump_info->init_reserve_size = free_area_length;
+
/* Should we create a dump_subsys, analogous to s390/ipl.c ? */
rc = subsys_create_file(&kernel_subsys, &rr);
if (rc) {
printk (KERN_ERR "phyp-dump: unable to create sysfs file (%d)\n", rc);
- release_all();
- return 0;
+ goto release_mem;
}
+ /* ToDo: re-register the dump area, for next time. */
+
+ return 0;
+
+release_mem:
+ /* release everything except the top 256 MB scratch area */
+ start_pfn = PFN_DOWN(phyp_dump_info->init_reserve_start);
+ nr_pages = PFN_DOWN(free_area_length);
+ release_memory_range(start_pfn, nr_pages);
+
return 0;
}
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