On Thu, Jul 28, 2016 at 3:50 PM, Kees Cook <keescook@xxxxxxxxxxxx> wrote: > On Thu, Jul 28, 2016 at 1:25 PM, Rob Herring <robh@xxxxxxxxxx> wrote: >> This reverts commit 35da60941e44dbf57868e67686dd24cc1a33125a. >> --- >> WTF! >> >> I don't recall acking this nor have my comments (Arnd's really) been >> addressed[1]. This should not have been merged yet. > > The conversation seemed to me to describe an alternative that could be > moved to, but that it was going to need more work. In the meantime, > these are the DT bindings used in real devices already. It seemed > clear to me that reducing the delta now and improving the > implementation in the future was the right thing to do in this case. I > didn't think your comments were a hard NAK, but rather a "we should do > this in the future", and I added it as a TODO for the pstore tree. > > Is a revert really justified here? This doesn't break anything (quite > the opposite, actually). Yes. Bindings are an ABI, so they can't evolve other than get additional properties. I'm keen to have this in too because I know there are lots of users (extract a DT from a Calxeda system ;)). It's not really that far off (drop memory-region and define the location in /reserved-memory) I think. So send a follow-up for 4.8 and then it doesn't need a revert. Rob > > -Kees > >> >> Rob >> >> [1] https://lkml.org/lkml/2016/6/21/969 >> >> Documentation/devicetree/bindings/misc/ramoops.txt | 48 ----------- >> Documentation/ramoops.txt | 6 +- >> fs/pstore/ram.c | 95 +--------------------- >> 3 files changed, 4 insertions(+), 145 deletions(-) >> delete mode 100644 Documentation/devicetree/bindings/misc/ramoops.txt >> >> diff --git a/Documentation/devicetree/bindings/misc/ramoops.txt b/Documentation/devicetree/bindings/misc/ramoops.txt >> deleted file mode 100644 >> index cd02cec..0000000 >> --- a/Documentation/devicetree/bindings/misc/ramoops.txt >> +++ /dev/null >> @@ -1,48 +0,0 @@ >> -Ramoops oops/panic logger >> -========================= >> - >> -ramoops provides persistent RAM storage for oops and panics, so they can be >> -recovered after a reboot. It is a backend to pstore, so this node is named >> -"ramoops" after the backend, rather than "pstore" which is the subsystem. >> - >> -Parts of this storage may be set aside for other persistent log buffers, such >> -as kernel log messages, or for optional ECC error-correction data. The total >> -size of these optional buffers must fit in the reserved region. >> - >> -Any remaining space will be used for a circular buffer of oops and panic >> -records. These records have a configurable size, with a size of 0 indicating >> -that they should be disabled. >> - >> -At least one of "record-size", "console-size", "ftrace-size", or "pmsg-size" >> -must be set non-zero, but are otherwise optional as listed below. >> - >> - >> -Required properties: >> - >> -- compatible: must be "ramoops" >> - >> -- memory-region: phandle to a region of memory that is preserved between >> - reboots >> - >> - >> -Optional properties: >> - >> -- ecc-size: enables ECC support and specifies ECC buffer size in bytes >> - (defaults to 0: no ECC) >> - >> -- record-size: maximum size in bytes of each dump done on oops/panic >> - (defaults to 0: disabled) >> - >> -- console-size: size in bytes of log buffer reserved for kernel messages >> - (defaults to 0: disabled) >> - >> -- ftrace-size: size in bytes of log buffer reserved for function tracing and >> - profiling (defaults to 0: disabled) >> - >> -- 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) >> - >> -- no-dump-oops: if present, only dump panics (defaults to panics and oops) >> diff --git a/Documentation/ramoops.txt b/Documentation/ramoops.txt >> index 9264bca..5d86756 100644 >> --- a/Documentation/ramoops.txt >> +++ b/Documentation/ramoops.txt >> @@ -45,7 +45,7 @@ corrupt, but usually it is restorable. >> >> 2. Setting the parameters >> >> -Setting the ramoops parameters can be done in 3 different manners: >> +Setting the ramoops parameters can be done in 2 different manners: >> 1. Use the module parameters (which have the names of the variables described >> as before). >> For quick debugging, you can also reserve parts of memory during boot >> @@ -54,9 +54,7 @@ Setting the ramoops parameters can be done in 3 different manners: >> kernel to use only the first 128 MB of memory, and place ECC-protected ramoops >> region at 128 MB boundary: >> "mem=128M ramoops.mem_address=0x8000000 ramoops.ecc=1" >> - 2. Use Device Tree bindings, as described in >> - Documentation/device-tree/bindings/misc/ramoops.txt. >> - 3. Use a platform device and set the platform data. The parameters can then >> + 2. Use a platform device and set the platform data. The parameters can then >> be set through that platform data. An example of doing that is: >> >> #include <linux/pstore_ram.h> >> diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c >> index 47516a7..d9668c2 100644 >> --- a/fs/pstore/ram.c >> +++ b/fs/pstore/ram.c >> @@ -34,8 +34,6 @@ >> #include <linux/slab.h> >> #include <linux/compiler.h> >> #include <linux/pstore_ram.h> >> -#include <linux/of.h> >> -#include <linux/of_address.h> >> >> #define RAMOOPS_KERNMSG_HDR "====" >> #define MIN_MEM_SIZE 4096UL >> @@ -460,98 +458,15 @@ static int ramoops_init_prz(struct device *dev, struct ramoops_context *cxt, >> return 0; >> } >> >> -static int ramoops_parse_dt_size(struct platform_device *pdev, >> - const char *propname, u32 *value) >> -{ >> - u32 val32 = 0; >> - int ret; >> - >> - ret = of_property_read_u32(pdev->dev.of_node, propname, &val32); >> - if (ret < 0 && ret != -EINVAL) { >> - dev_err(&pdev->dev, "failed to parse property %s: %d\n", >> - propname, ret); >> - return ret; >> - } >> - >> - if (val32 > INT_MAX) { >> - dev_err(&pdev->dev, "%s %u > INT_MAX\n", propname, val32); >> - return -EOVERFLOW; >> - } >> - >> - *value = val32; >> - return 0; >> -} >> - >> -static int ramoops_parse_dt(struct platform_device *pdev, >> - struct ramoops_platform_data *pdata) >> -{ >> - struct device_node *of_node = pdev->dev.of_node; >> - struct device_node *mem_region; >> - struct resource res; >> - u32 value; >> - int ret; >> - >> - dev_dbg(&pdev->dev, "using Device Tree\n"); >> - >> - mem_region = of_parse_phandle(of_node, "memory-region", 0); >> - if (!mem_region) { >> - dev_err(&pdev->dev, "no memory-region phandle\n"); >> - return -ENODEV; >> - } >> - >> - ret = of_address_to_resource(mem_region, 0, &res); >> - of_node_put(mem_region); >> - if (ret) { >> - dev_err(&pdev->dev, >> - "failed to translate memory-region to resource: %d\n", >> - ret); >> - return ret; >> - } >> - >> - pdata->mem_size = resource_size(&res); >> - pdata->mem_address = res.start; >> - pdata->mem_type = of_property_read_bool(of_node, "unbuffered"); >> - pdata->dump_oops = !of_property_read_bool(of_node, "no-dump-oops"); >> - >> -#define parse_size(name, field) { \ >> - ret = ramoops_parse_dt_size(pdev, name, &value); \ >> - if (ret < 0) \ >> - return ret; \ >> - field = value; \ >> - } >> - >> - parse_size("record-size", pdata->record_size); >> - parse_size("console-size", pdata->console_size); >> - parse_size("ftrace-size", pdata->ftrace_size); >> - parse_size("pmsg-size", pdata->pmsg_size); >> - parse_size("ecc-size", pdata->ecc_info.ecc_size); >> - >> -#undef parse_size >> - >> - return 0; >> -} >> - >> static int ramoops_probe(struct platform_device *pdev) >> { >> struct device *dev = &pdev->dev; >> - struct ramoops_platform_data *pdata = dev->platform_data; >> + struct ramoops_platform_data *pdata = pdev->dev.platform_data; >> struct ramoops_context *cxt = &oops_cxt; >> size_t dump_mem_sz; >> phys_addr_t paddr; >> int err = -EINVAL; >> >> - if (dev_of_node(dev) && !pdata) { >> - pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); >> - if (!pdata) { >> - err = -ENOMEM; >> - goto fail_out; >> - } >> - >> - err = ramoops_parse_dt(pdev, pdata); >> - if (err < 0) >> - goto fail_out; >> - } >> - >> /* Only a single ramoops area allowed at a time, so fail extra >> * probes. >> */ >> @@ -681,17 +596,11 @@ static int ramoops_remove(struct platform_device *pdev) >> return 0; >> } >> >> -static const struct of_device_id dt_match[] = { >> - { .compatible = "ramoops" }, >> - {} >> -}; >> - >> static struct platform_driver ramoops_driver = { >> .probe = ramoops_probe, >> .remove = ramoops_remove, >> .driver = { >> - .name = "ramoops", >> - .of_match_table = dt_match, >> + .name = "ramoops", >> }, >> }; >> >> -- >> 2.9.2 >> > > > > -- > Kees Cook > Chrome OS & Brillo Security -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
