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| author | Mukesh Ojha <mojha@codeaurora.org> | 2021-03-23 00:12:17 +0530 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2021-03-31 10:06:23 -0700 |
| commit | 9d843e8fafc7c0b15d8f511d146c0c3d7c816634 (patch) | |
| tree | aa50c176998930654d9764bdfb5c60af2f416d55 /fs/pstore | |
| parent | a38fd8748464831584a19438cbb3082b5a2dab15 (diff) | |
| download | lwn-9d843e8fafc7c0b15d8f511d146c0c3d7c816634.tar.gz lwn-9d843e8fafc7c0b15d8f511d146c0c3d7c816634.zip | |
pstore: Add mem_type property DT parsing support
There could be a scenario where we define some region
in normal memory and use them store to logs which is later
retrieved by bootloader during warm reset.
In this scenario, we wanted to treat this memory as normal
cacheable memory instead of default behaviour which
is an overhead. Making it cacheable could improve
performance.
This commit gives control to change mem_type from Device
tree, and also documents the value for normal memory.
Signed-off-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/1616438537-13719-1-git-send-email-mojha@codeaurora.org
Diffstat (limited to 'fs/pstore')
| -rw-r--r-- | fs/pstore/ram.c | 7 | ||||
| -rw-r--r-- | fs/pstore/ram_core.c | 18 |
2 files changed, 22 insertions, 3 deletions
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) { |