diff options
| author | Tony Lindgren <tony@atomide.com> | 2014-09-16 13:50:01 -0700 |
|---|---|---|
| committer | Tony Luck <tony.luck@intel.com> | 2014-12-11 13:38:31 -0800 |
| commit | 027bc8b08242c59e19356b4b2c189f2d849ab660 (patch) | |
| tree | 4bd5ad81fef12692af2c9d278f14903d15ddfb60 /fs/pstore/ram.c | |
| parent | 7ae9cb81933515dc7db1aa3c47ef7653717e3090 (diff) | |
pstore-ram: Allow optional mapping with pgprot_noncached
On some ARMs the memory can be mapped pgprot_noncached() and still
be working for atomic operations. As pointed out by Colin Cross
<ccross@android.com>, in some cases you do want to use
pgprot_noncached() if the SoC supports it to see a debug printk
just before a write hanging the system.
On ARMs, the atomic operations on strongly ordered memory are
implementation defined. So let's provide an optional kernel parameter
for configuring pgprot_noncached(), and use pgprot_writecombine() by
default.
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <robherring2@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Olof Johansson <olof@lixom.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: stable@vger.kernel.org
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Diffstat (limited to 'fs/pstore/ram.c')
| -rw-r--r-- | fs/pstore/ram.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c index ec881b312700..2f389ce5023c 100644 --- a/fs/pstore/ram.c +++ b/fs/pstore/ram.c @@ -61,6 +61,11 @@ module_param(mem_size, ulong, 0400); MODULE_PARM_DESC(mem_size, "size of reserved RAM used to store oops/panic logs"); +static unsigned int mem_type; +module_param(mem_type, uint, 0600); +MODULE_PARM_DESC(mem_type, + "set to 1 to try to use unbuffered memory (default 0)"); + static int dump_oops = 1; module_param(dump_oops, int, 0600); MODULE_PARM_DESC(dump_oops, @@ -79,6 +84,7 @@ struct ramoops_context { struct persistent_ram_zone *fprz; phys_addr_t phys_addr; unsigned long size; + unsigned int memtype; size_t record_size; size_t console_size; size_t ftrace_size; @@ -366,7 +372,8 @@ static int ramoops_init_przs(struct device *dev, struct ramoops_context *cxt, size_t sz = cxt->record_size; cxt->przs[i] = persistent_ram_new(*paddr, sz, 0, - &cxt->ecc_info); + &cxt->ecc_info, + cxt->memtype); if (IS_ERR(cxt->przs[i])) { err = PTR_ERR(cxt->przs[i]); dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n", @@ -396,7 +403,7 @@ static int ramoops_init_prz(struct device *dev, struct ramoops_context *cxt, return -ENOMEM; } - *prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info); + *prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info, cxt->memtype); if (IS_ERR(*prz)) { int err = PTR_ERR(*prz); @@ -443,6 +450,7 @@ static int ramoops_probe(struct platform_device *pdev) cxt->size = pdata->mem_size; cxt->phys_addr = pdata->mem_address; + cxt->memtype = pdata->mem_type; cxt->record_size = pdata->record_size; cxt->console_size = pdata->console_size; cxt->ftrace_size = pdata->ftrace_size; @@ -572,6 +580,7 @@ static void ramoops_register_dummy(void) dummy_data->mem_size = mem_size; dummy_data->mem_address = mem_address; + dummy_data->mem_type = 0; dummy_data->record_size = record_size; dummy_data->console_size = ramoops_console_size; dummy_data->ftrace_size = ramoops_ftrace_size; |