Hi Rob, On 09/25/18 22:57, AKASHI Takahiro wrote: > Frank, > > On Fri, Sep 14, 2018 at 10:19:38AM -0700, Frank Rowand wrote: >> On 09/13/18 18:26, Frank Rowand wrote: >>> I was re-reading this while answering a later email in the thread. After reading >>> other patches in the series that were not sent to me, I have a better understanding >>> of the intent behind this patch, and some changes to my previous reply. >>> >>> The intent of the helper functions is related to properties whose values are >>> tuples of the same format as the "reg" property of the "/memory" nodes. For >>> example, the "linux,usable-memory-range" and "linux,elfcoredhr" properties of >>> the "/chosen" node. >>> >>> The patch header and the function names should be updated to reflect this intent. >>> This means most or all of my previous suggested function name changes are no longer >>> useful. >>> >>> Please add devicetree@xxxxxxxxxxxxxxx to the next version of this patch and to >>> the patches that use the functions in this patch. >>> >>> >>> On 09/07/18 12:53, Frank Rowand wrote: >>>> On 09/07/18 01:00, AKASHI Takahiro wrote: >>>>> These functions will be used later to handle kexec-specific properties >>>>> in arm64's kexec_file implementation. >>>>> >>>>> Signed-off-by: AKASHI Takahiro <takahiro.akashi@xxxxxxxxxx> >>>>> Cc: Rob Herring <robh+dt@xxxxxxxxxx> >>>>> Cc: Frank Rowand <frowand.list@xxxxxxxxx> >>>>> --- >>>>> drivers/of/fdt.c | 62 ++++++++++++++++++++++++++++++++++++++++-- >>>>> include/linux/of_fdt.h | 10 +++++-- >>>>> 2 files changed, 68 insertions(+), 4 deletions(-) >>>>> >>>>> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c >>>>> index 800ad252cf9c..dc960cea1355 100644 >>>>> --- a/drivers/of/fdt.c >>>>> +++ b/drivers/of/fdt.c >>>>> @@ -25,6 +25,7 @@ >>>>> #include <linux/debugfs.h> >>>>> #include <linux/serial_core.h> >>>>> #include <linux/sysfs.h> >>>>> +#include <linux/types.h> >>>>> >>>>> #include <asm/setup.h> /* for COMMAND_LINE_SIZE */ >>>>> #include <asm/page.h> >>>>> @@ -537,8 +538,8 @@ void *of_fdt_unflatten_tree(const unsigned long *blob, >>>>> EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree); >>>>> >>>>> /* Everything below here references initial_boot_params directly. */ >>>>> -int __initdata dt_root_addr_cells; >>>>> -int __initdata dt_root_size_cells; >>>>> +int dt_root_addr_cells; >>>>> +int dt_root_size_cells; >>>>> >>>>> void *initial_boot_params; >>>>> >>>>> @@ -1323,3 +1324,60 @@ late_initcall(of_fdt_raw_init); >>>>> #endif >>>>> >>>>> #endif /* CONFIG_OF_EARLY_FLATTREE */ >>>>> + >>> >>> Global comment: this code should not be using the variables >>> dt_root_addr_cells and dt_root_size_cells. These variables are >>> __initdata. >>> >>> The code that is using these helpers is acting upon a specific FDT >>> (copied from initial_boot_params). This code should be getting the >>> values of the root node's "#address-cells" and "#size-cells" from >>> the FDT. >> Can you confirm whether "[PATCH 3/3] scripts/dtc: ..." (see below) will be in the v4.20 pull request? >> There will be new functions available soon to return the values of >> a node's "#address-cells" and "#size-cells" from an fdt. They are >> fdt_address_cells() and fdt_size_cells(). >> >> Rob submitted the patch to add them yesterday in "[PATCH 3/3] scripts/dtc: >> Update to upstream version v1.4.7-14-gc86da84d30e4" [1] > > Will this patch go into mainline in v4.20 merge window? > >> [1] https://lkml.kernel.org/r/<20180913202828.15372-3-robh@xxxxxxxxxx> > > Unfortunately, fdt_addresses.c where fdt_address_cells() and > fdt_size_cells() are defined is NOT compiled in the kernel. > I will submit a patch. > > -Takahiro Akashi > > >> -Frank Thanks, Frank >> >> >>> >>> >>>> Please add comment: >>>> >>>> /* helper functions for arm64 kexec */ >>>> >>>> >>>>> +bool of_fdt_cells_size_fitted(u64 base, u64 size) >>>> >>>> Please rename as of_fdt_range_valid() >>> >>> I'm not entirely sure of what the caller in 12/16 is trying to ensure >>> with this function. >>> >>> (1) At the minimum (and what the implementation in of_fdt_cells_size_fitted() >>> does) is make sure that an address and size tuple are consistent with >>> the root properties "#address-cells" and "#size-cells". >>> >>> The caller in 12/16 is using this check to validate values for the >>> properties "linux,elfcorehdr" and "linux,usable-memory-range". >>> >>> (2) A more complete check _might_ be to ensure that the values also >>> specify memory that is available to the kernel. This memory is described >>> by the "reg" property of one or more "/memory" nodes. >>> >>> This second check is probably what is actually desired. >>> >>> One possible issue to note is that the binding for "linux,usable-memory-range" >>> suggests that available memory could be described by an EFI memory map. >>> I am not familiar with how or when an EFI memory map might exist instead >>> of the "/memory" nodes. >>> >>> >>>>> +{ >>>>> + /* if *_cells >= 2, cells can hold 64-bit values anyway */ >>>>> + if ((dt_root_addr_cells == 1) && (base > U32_MAX)) >>>>> + return false; >>>>> + >>>>> + if ((dt_root_size_cells == 1) && (size > U32_MAX)) >>>>> + return false; >>>> >>>> Should also check that base + size does not wrap around. >>>> >>>> >>>>> + >>>>> + return true; >>>>> +} >>>>> + >>>>> +size_t of_fdt_reg_cells_size(void) >>>> >>>> Please rename as of_fdt_root_range_size() >>> >>> Even better would be to remove this function and replace the one place >>> that it is called from with the one line of code in this function. >>> >>> -Frank >>> >>> >>>>> +{ >>>>> + return (dt_root_addr_cells + dt_root_size_cells) * sizeof(u32); >>>>> +} >>>>> + >>>>> +#define FDT_ALIGN(x, a) (((x) + (a) - 1) & ~((a) - 1)) >>>>> +#define FDT_TAGALIGN(x) (FDT_ALIGN((x), FDT_TAGSIZE)) >>>>> + >>>>> +int fdt_prop_len(const char *prop_name, int len) >>>> >>>> Please rename as fdt_len_added_prop() >>>> >>>> >>>>> +{ >>>>> + return (strlen(prop_name) + 1) + >>>>> + sizeof(struct fdt_property) + >>>>> + FDT_TAGALIGN(len); >>>>> +} >>>>> + >>>> >>>> Please add comment, something like: >>>> >>>> /* cells must be 1 or 2 */ >>>> >>>> >>>>> +static void fill_property(void *buf, u64 val64, int cells) >>>> >>>> Please rename as cpu64_to_fdt_cells() >>>> >>>> Thanks, >>>> >>>> Frank >>>> >>>>> +{ >>>>> + __be32 val32; >>>>> + >>>>> + while (cells) { >>>>> + val32 = cpu_to_fdt32((val64 >> (32 * (--cells))) & U32_MAX); >>>>> + memcpy(buf, &val32, sizeof(val32)); >>>>> + buf += sizeof(val32); >>>>> + } >>>>> +} >>>>> + >>>>> +int fdt_setprop_reg(void *fdt, int nodeoffset, const char *name, >>>>> + u64 addr, u64 size) >>>>> +{ >>>>> + char buf[sizeof(__be32) * 2 * 2]; >>>>> + /* assume dt_root_[addr|size]_cells <= 2 */ >>>>> + void *prop; >>>>> + size_t buf_size; >>>>> + >>>>> + buf_size = of_fdt_reg_cells_size(); >>>>> + prop = buf; >>>>> + >>>>> + fill_property(prop, addr, dt_root_addr_cells); >>>>> + prop += dt_root_addr_cells * sizeof(u32); >>>>> + >>>>> + fill_property(prop, size, dt_root_size_cells); >>>>> + >>>>> + return fdt_setprop(fdt, nodeoffset, name, buf, buf_size); >>>>> +} >>>>> diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h >>>>> index b9cd9ebdf9b9..9615d6142578 100644 >>>>> --- a/include/linux/of_fdt.h >>>>> +++ b/include/linux/of_fdt.h >>>>> @@ -37,8 +37,8 @@ extern void *of_fdt_unflatten_tree(const unsigned long *blob, >>>>> struct device_node **mynodes); >>>>> >>>>> /* TBD: Temporary export of fdt globals - remove when code fully merged */ >>>>> -extern int __initdata dt_root_addr_cells; >>>>> -extern int __initdata dt_root_size_cells; >>>>> +extern int dt_root_addr_cells; >>>>> +extern int dt_root_size_cells; >>>>> extern void *initial_boot_params; >>>>> >>>>> extern char __dtb_start[]; >>>>> @@ -108,5 +108,11 @@ static inline void unflatten_device_tree(void) {} >>>>> static inline void unflatten_and_copy_device_tree(void) {} >>>>> #endif /* CONFIG_OF_EARLY_FLATTREE */ >>>>> >>>>> +bool of_fdt_cells_size_fitted(u64 base, u64 size); >>>>> +size_t of_fdt_reg_cells_size(void); >>>>> +int fdt_prop_len(const char *prop_name, int len); >>>>> +int fdt_setprop_reg(void *fdt, int nodeoffset, const char *name, >>>>> + u64 addr, u64 size); >>>>> + >>>>> #endif /* __ASSEMBLY__ */ >>>>> #endif /* _LINUX_OF_FDT_H */ >>>>> >>>> >>>> >>> >>> >> > _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
