summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--Documentation/admin-guide/ramoops.rst4
-rw-r--r--Documentation/devicetree/bindings/reserved-memory/ramoops.txt10
-rw-r--r--fs/pstore/ram.c7
-rw-r--r--fs/pstore/ram_core.c18
4 files changed, 33 insertions, 6 deletions
diff --git a/Documentation/admin-guide/ramoops.rst b/Documentation/admin-guide/ramoops.rst
index b0a1ae7df13b..8f107d8c9261 100644
--- a/Documentation/admin-guide/ramoops.rst
+++ b/Documentation/admin-guide/ramoops.rst
@@ -3,7 +3,7 @@ Ramoops oops/panic logger
Sergiu Iordache <sergiu@chromium.org>
-Updated: 17 November 2011
+Updated: 10 Feb 2021
Introduction
------------
@@ -30,6 +30,8 @@ mapping to pgprot_writecombine. Setting ``mem_type=1`` attempts to use
depends on atomic operations. At least on ARM, pgprot_noncached causes the
memory to be mapped strongly ordered, and atomic operations on strongly ordered
memory are implementation defined, and won't work on many ARMs such as omaps.
+Setting ``mem_type=2`` attempts to treat the memory region as normal memory,
+which enables full cache on it. This can improve the performance.
The memory area is divided into ``record_size`` chunks (also rounded down to
power of two) and each kmesg dump writes a ``record_size`` chunk of
diff --git a/Documentation/devicetree/bindings/reserved-memory/ramoops.txt b/Documentation/devicetree/bindings/reserved-memory/ramoops.txt
index b7886fea368c..b571ef6dab0f 100644
--- a/Documentation/devicetree/bindings/reserved-memory/ramoops.txt
+++ b/Documentation/devicetree/bindings/reserved-memory/ramoops.txt
@@ -42,8 +42,14 @@ Optional properties:
- pmsg-size: size in bytes of log buffer reserved for userspace messages
(defaults to 0: disabled)
-- unbuffered: if present, use unbuffered mappings to map the reserved region
- (defaults to buffered mappings)
+- mem-type: if present, sets the type of mapping is to be used to map the
+ reserved region. mem-type: 0 = write-combined (default), 1 = unbuffered,
+ 2 = cached.
+
+- unbuffered: deprecated, use mem_type instead. If present, and mem_type is
+ not specified, it is equivalent to mem_type = 1 and uses unbuffered mappings
+ to map the reserved region (defaults to buffered mappings mem_type = 0). If
+ both are specified -- "mem_type" overrides "unbuffered".
- max-reason: if present, sets maximum type of kmsg dump reasons to store
(defaults to 2: log Oopses and Panics). This can be set to INT_MAX to
diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index ca6d8a867285..fefe3d391d3a 100644
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -56,7 +56,7 @@ MODULE_PARM_DESC(mem_size,
static unsigned int mem_type;
module_param(mem_type, uint, 0400);
MODULE_PARM_DESC(mem_type,
- "set to 1 to try to use unbuffered memory (default 0)");
+ "memory type: 0=write-combined (default), 1=unbuffered, 2=cached");
static int ramoops_max_reason = -1;
module_param_named(max_reason, ramoops_max_reason, int, 0400);
@@ -648,6 +648,10 @@ static int ramoops_parse_dt(struct platform_device *pdev,
pdata->mem_size = resource_size(res);
pdata->mem_address = res->start;
+ /*
+ * Setting "unbuffered" is deprecated and will be ignored if
+ * "mem_type" is also specified.
+ */
pdata->mem_type = of_property_read_bool(of_node, "unbuffered");
/*
* Setting "no-dump-oops" is deprecated and will be ignored if
@@ -666,6 +670,7 @@ static int ramoops_parse_dt(struct platform_device *pdev,
field = value; \
}
+ parse_u32("mem-type", pdata->record_size, pdata->mem_type);
parse_u32("record-size", pdata->record_size, 0);
parse_u32("console-size", pdata->console_size, 0);
parse_u32("ftrace-size", pdata->ftrace_size, 0);
diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c
index fff363bfd484..fe5305028c6e 100644
--- a/fs/pstore/ram_core.c
+++ b/fs/pstore/ram_core.c
@@ -396,6 +396,10 @@ void persistent_ram_zap(struct persistent_ram_zone *prz)
persistent_ram_update_header_ecc(prz);
}
+#define MEM_TYPE_WCOMBINE 0
+#define MEM_TYPE_NONCACHED 1
+#define MEM_TYPE_NORMAL 2
+
static void *persistent_ram_vmap(phys_addr_t start, size_t size,
unsigned int memtype)
{
@@ -409,10 +413,20 @@ static void *persistent_ram_vmap(phys_addr_t start, size_t size,
page_start = start - offset_in_page(start);
page_count = DIV_ROUND_UP(size + offset_in_page(start), PAGE_SIZE);
- if (memtype)
+ switch (memtype) {
+ case MEM_TYPE_NORMAL:
+ prot = PAGE_KERNEL;
+ break;
+ case MEM_TYPE_NONCACHED:
prot = pgprot_noncached(PAGE_KERNEL);
- else
+ break;
+ case MEM_TYPE_WCOMBINE:
prot = pgprot_writecombine(PAGE_KERNEL);
+ break;
+ default:
+ pr_err("invalid mem_type=%d\n", memtype);
+ return NULL;
+ }
pages = kmalloc_array(page_count, sizeof(struct page *), GFP_KERNEL);
if (!pages) {