Commit 288321a9 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'pstore-v5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux 

Pull pstore update from Kees Cook:

 - Add mem_type property to expand support for >2 memory types (Mukesh Ojha)

* tag 'pstore-v5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  pstore: Add mem_type property DT parsing support
parents 7e4910b9 9d843e8f

Documentation/admin-guide/ramoops.rst

+3 −1
Original line number Diff line number Diff line
@@ -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

Documentation/devicetree/bindings/reserved-memory/ramoops.txt

+8 −2
Original line number Diff line number Diff line
@@ -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

fs/pstore/ram.c

+6 −1
Original line number Diff line number Diff line
@@ -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);

fs/pstore/ram_core.c

+16 −2
Original line number Diff line number Diff line
@@ -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) {