[PATCH V3 2/8] powerpc/memory: Parse new memory property to register blocks.
Nathan Fontenot
nfont at linux.vnet.ibm.com
Thu Aug 11 02:26:32 AEST 2016
On 08/01/2016 08:24 PM, Michael Bringmann wrote:
> powerpc/memory: Add parallel routines to parse the new property
> "ibm,dynamic-memory-v2" property when it is present, and then to
> register the relevant memory blocks with the operating system.
> This property format is intended to provide a more compact
> representation of memory when communicating with the front end
> processor, especially when describing vast amounts of RAM.
>
> Signed-off-by: Michael Bringmann <mwb at linux.vnet.ibm.com>
> ---
It's generally a good idea to include a short description of what
changed in the patch between patch versions. This helps reviewers
avoid digging through the patch and trying to find updates.
> diff --git a/arch/powerpc/include/asm/prom.h b/arch/powerpc/include/asm/prom.h
> index 7f436ba..b9a1534 100644
> --- a/arch/powerpc/include/asm/prom.h
> +++ b/arch/powerpc/include/asm/prom.h
> @@ -69,6 +69,8 @@ struct boot_param_header {
> * OF address retreival & translation
> */
>
> +extern int n_mem_addr_cells;
> +
> /* Parse the ibm,dma-window property of an OF node into the busno, phys and
> * size parameters.
> */
> @@ -81,8 +83,9 @@ extern void of_instantiate_rtc(void);
> extern int of_get_ibm_chip_id(struct device_node *np);
>
> /* The of_drconf_cell struct defines the layout of the LMB array
> - * specified in the device tree property
> - * ibm,dynamic-reconfiguration-memory/ibm,dynamic-memory
> + * specified in the device tree properties,
> + * ibm,dynamic-reconfiguration-memory/ibm,dynamic-memory
> + * ibm,dynamic-reconfiguration-memory/ibm,dynamic-memory-v2
> */
> struct of_drconf_cell {
> u64 base_addr;
> @@ -92,9 +95,32 @@ struct of_drconf_cell {
> u32 flags;
> };
>
> -#define DRCONF_MEM_ASSIGNED 0x00000008
> -#define DRCONF_MEM_AI_INVALID 0x00000040
> -#define DRCONF_MEM_RESERVED 0x00000080
> +#define DRCONF_MEM_ASSIGNED 0x00000008
> +#define DRCONF_MEM_AI_INVALID 0x00000040
> +#define DRCONF_MEM_RESERVED 0x00000080
> +
> +struct of_drconf_cell_v2 {
> + u32 num_seq_lmbs;
> + u64 base_addr;
> + u32 drc_index;
> + u32 aa_index;
> + u32 flags;
> +} __attribute__((packed));
> +
> +
> +static inline int dyn_mem_v2_len(int entries)
> +{
> + int drconf_v2_cells = (n_mem_addr_cells + 4);
> + int drconf_v2_cells_len = (drconf_v2_cells * sizeof(unsigned int));
> + return (((entries) * drconf_v2_cells_len) +
> + (1 * sizeof(unsigned int)));
> +}
> +
> +extern void read_drconf_cell_v2(struct of_drconf_cell_v2 *drmem,
> + const __be32 **cellp);
> +extern void read_one_drc_info(int **info, char **drc_type, char **drc_name,
> + unsigned long int *fdi_p, unsigned long int *nsl_p,
> + unsigned long int *si_p, unsigned long int *ldi_p);
>
These two functions, read_drconf_cell_v2 and read_one_drc_info, are defined
in this patch but are not used. I think it makes more sense to introduce
new functionality in the patch that uses that functionality.
> /*
> * There are two methods for telling firmware what our capabilities are.
> diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
> index 669a15e..ad294ce 100644
> --- a/arch/powerpc/mm/numa.c
> +++ b/arch/powerpc/mm/numa.c
> @@ -57,8 +57,10 @@
> EXPORT_SYMBOL(node_data);
>
> static int min_common_depth;
> -static int n_mem_addr_cells, n_mem_size_cells;
> +int n_mem_addr_cells;
> +static int n_mem_size_cells;
> static int form1_affinity;
> +EXPORT_SYMBOL(n_mem_addr_cells);
>
> #define MAX_DISTANCE_REF_POINTS 4
> static int distance_ref_points_depth;
> @@ -405,6 +405,24 @@ static void read_drconf_cell(struct of_drconf_cell *drmem, const __be32 **cellp)
>
> *cellp = cp + 4;
> }
> +
> + /*
> + * Retrieve and validate the ibm,dynamic-memory property of the device tree.
> + * Read the next memory block set entry from the ibm,dynamic-memory-v2 property
> + * and return the information in the provided of_drconf_cell_v2 structure.
> + */
> +void read_drconf_cell_v2(struct of_drconf_cell_v2 *drmem, const __be32 **cellp)
> +{
> + const __be32 *cp = (const __be32 *)*cellp;
> + drmem->num_seq_lmbs = be32_to_cpu(*cp++);
> + drmem->base_addr = read_n_cells(n_mem_addr_cells, &cp);
> + drmem->drc_index = be32_to_cpu(*cp++);
> + drmem->aa_index = be32_to_cpu(*cp++);
> + drmem->flags = be32_to_cpu(*cp++);
> +
> + *cellp = cp;
> +}
> +EXPORT_SYMBOL(read_drconf_cell_v2);
>
> /*
> * Retrieve and validate the ibm,dynamic-memory property of the device tree.
> diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
> index 946e34f..b6f8ae5 100644
> --- a/arch/powerpc/kernel/prom.c
> +++ b/arch/powerpc/kernel/prom.c
> @@ -441,12 +442,12 @@ static int __init early_init_dt_scan_chosen_ppc(unsigned long node,
>
> #ifdef CONFIG_PPC_PSERIES
> /*
> - * Interpret the ibm,dynamic-memory property in the
> - * /ibm,dynamic-reconfiguration-memory node.
> + * Interpret the ibm,dynamic-memory property/ibm,dynamic-memory-v2
> + * in the /ibm,dynamic-reconfiguration-memory node.
> * This contains a list of memory blocks along with NUMA affinity
> * information.
> */
> -static int __init early_init_dt_scan_drconf_memory(unsigned long node)
> +static int __init early_init_dt_scan_drconf_memory_v1(unsigned long node)
> {
> const __be32 *dm, *ls, *usm;
> int l;
> @@ -516,6 +517,73 @@ static int __init early_init_dt_scan_drconf_memory(unsigned long node)
> memblock_dump_all();
> return 0;
> }
> +
> +static int __init early_init_dt_scan_drconf_memory_v2(unsigned long node)
> +{
> + const __be32 *dm, *ls;
> + int l;
> + unsigned long num_sets;
> + u64 size, base, memblock_size;
> +
> + ls = of_get_flat_dt_prop(node, "ibm,lmb-size", &l);
> + if (ls == NULL || l < dt_root_size_cells * sizeof(__be32))
> + return 0;
> + memblock_size = dt_mem_next_cell(dt_root_size_cells, &ls);
We do the same thing in early_init_dt_scan_drconf_memory_v1 to retrieve
the memblock_size, perhaps it makes sense to break this out into a
helper routine.
> +
> + dm = of_get_flat_dt_prop(node, "ibm,dynamic-memory-v2", &l);
> + if (dm == NULL || l < sizeof(__be32))
> + return 0;
> +
> + num_sets = of_read_number(dm++, 1);
> + if (l < (num_sets * (dt_root_addr_cells + 4) + 1) * sizeof(__be32))
Perhaps a comment here to help understand the calculation without having
to look up the format of the dynamic-mnemory-v2 device tree format.
-Nathan
> + return 0;
> +
> + if (n_mem_addr_cells == 0)
> + n_mem_addr_cells = dt_root_addr_cells;
> +
> + for (; num_sets != 0; --num_sets) {
> + struct of_drconf_cell_v2 drmem;
> + unsigned long nsl;
> +
> + read_drconf_cell_v2(&drmem, &dm);
> + base = drmem.base_addr;
> + nsl = drmem.num_seq_lmbs;
> + size = memblock_size;
> +
> + /* SKip this block if the reserved bit is set in flags
> + * or if the block is not assigned to this partition
> + */
> + if ((drmem.flags & DRCONF_MEM_RESERVED) ||
> + !(drmem.flags & DRCONF_MEM_ASSIGNED))
> + continue;
> +
> + for (; nsl != 0; nsl--) {
> + size = memblock_size;
> +
> + if (iommu_is_off) {
> + if (base >= 0x80000000ul)
> + continue;
> + if ((base + size) > 0x80000000ul)
> + size = 0x80000000ul - base;
> + }
> + memblock_add(base, size);
> +
> + base += size;
> + }
> + }
> +
> + memblock_dump_all();
> + return 0;
> +}
> +
> +static int __init early_init_dt_scan_drconf_memory(unsigned long node)
> +{
> + if (firmware_has_feature(FW_FEATURE_DYN_MEM_V2))
Will this check still work?
I believe the goal is to convert the dynamic-memory-v2 property
back to the current dynamic-memory property update and manage memory
with that. This allows us to not have to worry about kexec during
parse of the -v2 property. On a kexec boot though, will this test for
FW_FEATURE_DYN_MEM_V2 succeed even though we would have a -v1
version of the property. Perhaps the test should be for the
existence of the -v2 property.
-Nathan
> + return early_init_dt_scan_drconf_memory_v2(node);
> + else
> + return early_init_dt_scan_drconf_memory_v1(node);
> +}
> +
> #else
> #define early_init_dt_scan_drconf_memory(node) 0
> #endif /* CONFIG_PPC_PSERIES */
>
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