@@ -31,6 +31,7 @@
#include <linux/hugetlb.h>
#include <linux/acpi_iort.h>
#include <linux/kmemleak.h>
+#include <linux/pstore_ram.h>
#include <asm/boot.h>
#include <asm/fixmap.h>
@@ -100,6 +101,93 @@ phys_addr_t __ro_after_init arm64_dma_phys_limit;
#define ARM64_MEMSTART_ALIGN (1UL << ARM64_MEMSTART_SHIFT)
#endif
+#define RAMOOPS_ADDR_HIGH_MAX (PHYS_MASK + 1)
+
+/* Location of the reserved area for the dynamic ramoops */
+struct resource dyn_ramoops_res = {
+ .name = "ramoops",
+ .start = 0,
+ .end = 0,
+ .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
+ .desc = IORES_DESC_NONE,
+};
+EXPORT_SYMBOL(dyn_ramoops_res);
+
+static int __init parse_dynamic_ramoops(char *cmdline, unsigned long long *size)
+{
+ const char *name = "dyn_ramoops_size=";
+ char *p = NULL;
+ char *q = NULL;
+ char *tmp;
+
+ if (!cmdline)
+ return -ENOENT;
+
+ /* Check for "dyn_ramoops_size" and use the later if there are more */
+ p = strstr(cmdline, name);
+ while (p) {
+ q = p;
+ p = strchr(p, ' ');
+ if (!p)
+ break;
+
+ p = strstr(p + 1, name);
+ }
+
+ if (!q) {
+ pr_err("ramoops: No entry found for %s\n", name);
+ return -ENOENT;
+ }
+
+ p = q + strlen(name);
+ *size = memparse(p, &tmp);
+ if (p == tmp) {
+ pr_err("ramoops: memory value expected\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int __init parse_dyn_ramoops_size_dummy(char *arg)
+{
+ return 0;
+}
+early_param("dyn_ramoops_size", parse_dyn_ramoops_size_dummy);
+
+/*
+ * reserve_dynamic_ramoops() - reserves memory for dynamic ramoops
+ *
+ * This enable dynamic reserve memory support for ramoops through
+ * command line.
+ */
+static void __init reserve_dynamic_ramoops(void)
+{
+ char *cmdline = boot_command_line;
+ unsigned long long ramoops_base;
+ unsigned long long ramoops_size;
+
+ if (!IS_ENABLED(CONFIG_PSTORE_RAM))
+ return;
+
+ if (parse_dynamic_ramoops(cmdline, &ramoops_size))
+ return;
+
+ ramoops_base = memblock_phys_alloc_range(ramoops_size, SMP_CACHE_BYTES,
+ 0, RAMOOPS_ADDR_HIGH_MAX);
+ if (!ramoops_base) {
+ pr_err("cannot allocate ramoops dynamic memory (size:0x%llx).\n",
+ ramoops_size);
+ return;
+ }
+
+ kmemleak_ignore_phys(ramoops_base);
+
+ dyn_ramoops_res.start = ramoops_base;
+ dyn_ramoops_res.end = ramoops_base + ramoops_size - 1;
+ insert_resource(&iomem_resource, &dyn_ramoops_res);
+}
+
static int __init reserve_crashkernel_low(unsigned long long low_size)
{
unsigned long long low_base;
@@ -481,6 +569,12 @@ void __init bootmem_init(void)
*/
reserve_crashkernel();
+ /*
+ * Reserving ramoops region resource dynamically in case it is
+ * requested from command line.
+ */
+ reserve_dynamic_ramoops();
+
memblock_dump_all();
}
@@ -10,6 +10,8 @@
#include <linux/pstore.h>
+extern struct resource dyn_ramoops_res;
+
struct persistent_ram_ecc_info {
int block_size;
int ecc_size;
The reserved memory region for ramoops is assumed to be at a fixed and known location when read from the devicetree. This may not be required for something like Qualcomm's minidump which is interested in knowing addresses of ramoops region but it does not put hard requirement of address being fixed as most of it's SoC does not support warm reset and does not use pstorefs at all instead it has firmware way of collecting ramoops region if it gets to know the address and register it with apss minidump table which is sitting in shared memory region in DDR and firmware will have access to these table during reset and collects it on crash of SoC. So, add the support of reserving ramoops region to be dynamically allocated early during boot if it is request through command line via 'dyn_ramoops_size=' and fill up reserved resource structure and export the structure, so that it can be read by ramoops driver. Signed-off-by: Mukesh Ojha <quic_mojha@quicinc.com> --- arch/arm64/mm/init.c | 94 ++++++++++++++++++++++++++++++++++++++++++++++ include/linux/pstore_ram.h | 2 + 2 files changed, 96 insertions(+)