[PATCH 3/3] of/fdt: Rework early_init_dt_scan_memory() to call directly
Frank Rowand
frowand.list at gmail.com
Thu Nov 25 03:58:58 AEDT 2021
On 11/18/21 1:12 PM, Rob Herring wrote:
> Use of the of_scan_flat_dt() function predates libfdt and is discouraged
> as libfdt provides a nicer set of APIs. Rework
> early_init_dt_scan_memory() to be called directly and use libfdt.
>
> Cc: John Crispin <john at phrozen.org>
> Cc: Thomas Bogendoerfer <tsbogend at alpha.franken.de>
> Cc: Michael Ellerman <mpe at ellerman.id.au>
> Cc: Benjamin Herrenschmidt <benh at kernel.crashing.org>
> Cc: Paul Mackerras <paulus at samba.org>
> Cc: Frank Rowand <frowand.list at gmail.com>
> Cc: linux-mips at vger.kernel.org
> Cc: linuxppc-dev at lists.ozlabs.org
> Signed-off-by: Rob Herring <robh at kernel.org>
> ---
> arch/mips/ralink/of.c | 16 ++-------
> arch/powerpc/kernel/prom.c | 16 ++++-----
> drivers/of/fdt.c | 68 ++++++++++++++++++++------------------
> include/linux/of_fdt.h | 3 +-
> 4 files changed, 47 insertions(+), 56 deletions(-)
>
> diff --git a/arch/mips/ralink/of.c b/arch/mips/ralink/of.c
> index 0135376c5de5..e1d79523343a 100644
> --- a/arch/mips/ralink/of.c
> +++ b/arch/mips/ralink/of.c
> @@ -53,17 +53,6 @@ void __init device_tree_init(void)
> unflatten_and_copy_device_tree();
> }
>
> -static int memory_dtb;
> -
> -static int __init early_init_dt_find_memory(unsigned long node,
> - const char *uname, int depth, void *data)
> -{
> - if (depth == 1 && !strcmp(uname, "memory at 0"))
> - memory_dtb = 1;
> -
> - return 0;
> -}
> -
> void __init plat_mem_setup(void)
> {
> void *dtb;
> @@ -77,9 +66,8 @@ void __init plat_mem_setup(void)
> dtb = get_fdt();
> __dt_setup_arch(dtb);
>
> - of_scan_flat_dt(early_init_dt_find_memory, NULL);
> - if (memory_dtb)
> - of_scan_flat_dt(early_init_dt_scan_memory, NULL);
> + if (!early_init_dt_scan_memory())
> + return;
> else if (soc_info.mem_detect)
The previous chunk is now:
if (XXX)
return;
instead of:
if (XXX)
YYY();
so "else if (soc_info.mem_detect)" should be:
if (soc_info.mem_detect)
> soc_info.mem_detect();
> else if (soc_info.mem_size)
> diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
> index 6e1a106f02eb..63762a3b75e8 100644
> --- a/arch/powerpc/kernel/prom.c
> +++ b/arch/powerpc/kernel/prom.c
> @@ -532,19 +532,19 @@ static int __init early_init_drmem_lmb(struct drmem_lmb *lmb,
> }
> #endif /* CONFIG_PPC_PSERIES */
>
> -static int __init early_init_dt_scan_memory_ppc(unsigned long node,
> - const char *uname,
> - int depth, void *data)
> +static int __init early_init_dt_scan_memory_ppc(void)
> {
> #ifdef CONFIG_PPC_PSERIES
> - if (depth == 1 &&
> - strcmp(uname, "ibm,dynamic-reconfiguration-memory") == 0) {
> + const void *fdt = initial_boot_params;
> + int node = fdt_path_offset(fdt, "/ibm,dynamic-reconfiguration-memory");
> +
> + if (node > 0) {
> walk_drmem_lmbs_early(node, NULL, early_init_drmem_lmb);
> return 0;
> }
> #endif
>
> - return early_init_dt_scan_memory(node, uname, depth, data);
> + return early_init_dt_scan_memory();
> }
>
> /*
> @@ -749,7 +749,7 @@ void __init early_init_devtree(void *params)
>
> /* Scan memory nodes and rebuild MEMBLOCKs */
> early_init_dt_scan_root();
> - of_scan_flat_dt(early_init_dt_scan_memory_ppc, NULL);
> + early_init_dt_scan_memory_ppc();
>
> parse_early_param();
>
> @@ -858,7 +858,7 @@ void __init early_get_first_memblock_info(void *params, phys_addr_t *size)
> */
> add_mem_to_memblock = 0;
> early_init_dt_scan_root();
> - of_scan_flat_dt(early_init_dt_scan_memory_ppc, NULL);
> + early_init_dt_scan_memory_ppc();
> add_mem_to_memblock = 1;
>
> if (size)
> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
> index 5e216555fe4f..a799117886f4 100644
> --- a/drivers/of/fdt.c
> +++ b/drivers/of/fdt.c
> @@ -1078,49 +1078,53 @@ u64 __init dt_mem_next_cell(int s, const __be32 **cellp)
> /*
> * early_init_dt_scan_memory - Look for and parse memory nodes
> */
> -int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
> - int depth, void *data)
> +int __init early_init_dt_scan_memory(void)
> {
> - const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
> - const __be32 *reg, *endp;
> - int l;
> - bool hotpluggable;
> + int node;
> + const void *fdt = initial_boot_params;
>
> - /* We are scanning "memory" nodes only */
> - if (type == NULL || strcmp(type, "memory") != 0)
> - return 0;
> + fdt_for_each_subnode(node, fdt, 0) {
> + const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
> + const __be32 *reg, *endp;
> + int l;
> + bool hotpluggable;
>
> - reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
> - if (reg == NULL)
> - reg = of_get_flat_dt_prop(node, "reg", &l);
> - if (reg == NULL)
> - return 0;
> + /* We are scanning "memory" nodes only */
> + if (type == NULL || strcmp(type, "memory") != 0)
> + continue;
>
> - endp = reg + (l / sizeof(__be32));
> - hotpluggable = of_get_flat_dt_prop(node, "hotpluggable", NULL);
> + reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
> + if (reg == NULL)
> + reg = of_get_flat_dt_prop(node, "reg", &l);
> + if (reg == NULL)
> + return 0;
Should be "continue" instead of "return 0"?
>
> - pr_debug("memory scan node %s, reg size %d,\n", uname, l);
> + endp = reg + (l / sizeof(__be32));
> + hotpluggable = of_get_flat_dt_prop(node, "hotpluggable", NULL);
>
> - while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
> - u64 base, size;
> + pr_debug("memory scan node %s, reg size %d,\n",
> + fdt_get_name(fdt, node, NULL), l);
Second line of pr_debug() should be indented one more space.
>
> - base = dt_mem_next_cell(dt_root_addr_cells, ®);
> - size = dt_mem_next_cell(dt_root_size_cells, ®);
> + while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
> + u64 base, size;
>
> - if (size == 0)
> - continue;
> - pr_debug(" - %llx, %llx\n", base, size);
> + base = dt_mem_next_cell(dt_root_addr_cells, ®);
> + size = dt_mem_next_cell(dt_root_size_cells, ®);
>
> - early_init_dt_add_memory_arch(base, size);
> + if (size == 0)
> + continue;
> + pr_debug(" - %llx, %llx\n", base, size);
>
> - if (!hotpluggable)
> - continue;
> + early_init_dt_add_memory_arch(base, size);
>
> - if (memblock_mark_hotplug(base, size))
> - pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n",
> - base, base + size);
> - }
> + if (!hotpluggable)
> + continue;
>
> + if (memblock_mark_hotplug(base, size))
> + pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n",
> + base, base + size);
> + }
> + }
> return 0;
> }
>
> @@ -1271,7 +1275,7 @@ void __init early_init_dt_scan_nodes(void)
> pr_warn("No chosen node found, continuing without\n");
>
> /* Setup memory, calling early_init_dt_add_memory_arch */
> - of_scan_flat_dt(early_init_dt_scan_memory, NULL);
> + early_init_dt_scan_memory();
>
> /* Handle linux,usable-memory-range property */
> memblock_cap_memory_range(cap_mem_addr, cap_mem_size);
> diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h
> index df3d31926c3c..914739f3c192 100644
> --- a/include/linux/of_fdt.h
> +++ b/include/linux/of_fdt.h
> @@ -59,8 +59,7 @@ extern unsigned long of_get_flat_dt_root(void);
> extern uint32_t of_get_flat_dt_phandle(unsigned long node);
>
> extern int early_init_dt_scan_chosen(char *cmdline);
> -extern int early_init_dt_scan_memory(unsigned long node, const char *uname,
> - int depth, void *data);
> +extern int early_init_dt_scan_memory(void);
> extern int early_init_dt_scan_chosen_stdout(void);
> extern void early_init_fdt_scan_reserved_mem(void);
> extern void early_init_fdt_reserve_self(void);
>
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