diff options
| -rw-r--r-- | Documentation/admin-guide/ramoops.rst | 4 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/reserved-memory/ramoops.txt | 10 | ||||
| -rw-r--r-- | fs/pstore/ram.c | 7 | ||||
| -rw-r--r-- | fs/pstore/ram_core.c | 18 |
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) { |