From e8d9d1f5485b52ec3c4d7af839e6914438f6c285 Mon Sep 17 00:00:00 2001 From: Marek Szyprowski Date: Fri, 28 Feb 2014 14:42:47 +0100 Subject: drivers: of: add initialization code for static reserved memory This patch adds support for static (defined by 'reg' property) reserved memory regions declared in device tree. Memory blocks can be reliably reserved only during early boot. This must happen before the whole memory management subsystem is initialized, because we need to ensure that the given contiguous blocks are not yet allocated by kernel. Also it must happen before kernel mappings for the whole low memory are created, to ensure that there will be no mappings (for reserved blocks). Typically, all this happens before device tree structures are unflattened, so we need to get reserved memory layout directly from fdt. Based on previous code provided by Josh Cartwright Signed-off-by: Marek Szyprowski Signed-off-by: Grant Likely --- drivers/of/fdt.c | 131 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 131 insertions(+) (limited to 'drivers/of/fdt.c') diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 758b4f8b30b7..819e11209718 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include @@ -439,6 +440,118 @@ struct boot_param_header *initial_boot_params; #ifdef CONFIG_OF_EARLY_FLATTREE +/** + * res_mem_reserve_reg() - reserve all memory described in 'reg' property + */ +static int __init __reserved_mem_reserve_reg(unsigned long node, + const char *uname) +{ + int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32); + phys_addr_t base, size; + unsigned long len; + __be32 *prop; + int nomap; + + prop = of_get_flat_dt_prop(node, "reg", &len); + if (!prop) + return -ENOENT; + + if (len && len % t_len != 0) { + pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n", + uname); + return -EINVAL; + } + + nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL; + + while (len >= t_len) { + base = dt_mem_next_cell(dt_root_addr_cells, &prop); + size = dt_mem_next_cell(dt_root_size_cells, &prop); + + if (base && size && + early_init_dt_reserve_memory_arch(base, size, nomap) == 0) + pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %ld MiB\n", + uname, &base, (unsigned long)size / SZ_1M); + else + pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %ld MiB\n", + uname, &base, (unsigned long)size / SZ_1M); + + len -= t_len; + } + return 0; +} + +/** + * __reserved_mem_check_root() - check if #size-cells, #address-cells provided + * in /reserved-memory matches the values supported by the current implementation, + * also check if ranges property has been provided + */ +static int __reserved_mem_check_root(unsigned long node) +{ + __be32 *prop; + + prop = of_get_flat_dt_prop(node, "#size-cells", NULL); + if (!prop || be32_to_cpup(prop) != dt_root_size_cells) + return -EINVAL; + + prop = of_get_flat_dt_prop(node, "#address-cells", NULL); + if (!prop || be32_to_cpup(prop) != dt_root_addr_cells) + return -EINVAL; + + prop = of_get_flat_dt_prop(node, "ranges", NULL); + if (!prop) + return -EINVAL; + return 0; +} + +/** + * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory + */ +static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname, + int depth, void *data) +{ + static int found; + const char *status; + + if (!found && depth == 1 && strcmp(uname, "reserved-memory") == 0) { + if (__reserved_mem_check_root(node) != 0) { + pr_err("Reserved memory: unsupported node format, ignoring\n"); + /* break scan */ + return 1; + } + found = 1; + /* scan next node */ + return 0; + } else if (!found) { + /* scan next node */ + return 0; + } else if (found && depth < 2) { + /* scanning of /reserved-memory has been finished */ + return 1; + } + + status = of_get_flat_dt_prop(node, "status", NULL); + if (status && strcmp(status, "okay") != 0 && strcmp(status, "ok") != 0) + return 0; + + __reserved_mem_reserve_reg(node, uname); + + /* scan next node */ + return 0; +} + +/** + * early_init_fdt_scan_reserved_mem() - create reserved memory regions + * + * This function grabs memory from early allocator for device exclusive use + * defined in device tree structures. It should be called by arch specific code + * once the early allocator (i.e. memblock) has been fully activated. + */ +void __init early_init_fdt_scan_reserved_mem(void) +{ + of_scan_flat_dt(__fdt_scan_reserved_mem, NULL); +} + /** * of_scan_flat_dt - scan flattened tree blob and call callback on each. * @it: callback function @@ -856,6 +969,16 @@ void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size) memblock_add(base, size); } +int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base, + phys_addr_t size, bool nomap) +{ + if (memblock_is_region_reserved(base, size)) + return -EBUSY; + if (nomap) + return memblock_remove(base, size); + return memblock_reserve(base, size); +} + /* * called from unflatten_device_tree() to bootstrap devicetree itself * Architectures can override this definition if memblock isn't used @@ -864,6 +987,14 @@ void * __init __weak early_init_dt_alloc_memory_arch(u64 size, u64 align) { return __va(memblock_alloc(size, align)); } +#else +int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base, + phys_addr_t size, bool nomap) +{ + pr_err("Reserved memory not supported, ignoring range 0x%llx - 0x%llx%s\n", + base, size, nomap ? " (nomap)" : ""); + return -ENOSYS; +} #endif bool __init early_init_dt_scan(void *params) -- cgit v1.2.3 From 3f0c8206644836e4f10a6b9fc47cda6a9a372f9b Mon Sep 17 00:00:00 2001 From: Marek Szyprowski Date: Fri, 28 Feb 2014 14:42:48 +0100 Subject: drivers: of: add initialization code for dynamic reserved memory This patch adds support for dynamically allocated reserved memory regions declared in device tree. Such regions are defined by 'size', 'alignment' and 'alloc-ranges' properties. Based on previous code provided by Josh Cartwright Signed-off-by: Marek Szyprowski Signed-off-by: Grant Likely --- drivers/of/fdt.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) (limited to 'drivers/of/fdt.c') diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 819e11209718..510c0d8de8a0 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include @@ -450,7 +451,7 @@ static int __init __reserved_mem_reserve_reg(unsigned long node, phys_addr_t base, size; unsigned long len; __be32 *prop; - int nomap; + int nomap, first = 1; prop = of_get_flat_dt_prop(node, "reg", &len); if (!prop) @@ -477,6 +478,10 @@ static int __init __reserved_mem_reserve_reg(unsigned long node, uname, &base, (unsigned long)size / SZ_1M); len -= t_len; + if (first) { + fdt_reserved_mem_save_node(node, uname, base, size); + first = 0; + } } return 0; } @@ -512,6 +517,7 @@ static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname, { static int found; const char *status; + int err; if (!found && depth == 1 && strcmp(uname, "reserved-memory") == 0) { if (__reserved_mem_check_root(node) != 0) { @@ -534,7 +540,9 @@ static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname, if (status && strcmp(status, "okay") != 0 && strcmp(status, "ok") != 0) return 0; - __reserved_mem_reserve_reg(node, uname); + err = __reserved_mem_reserve_reg(node, uname); + if (err == -ENOENT && of_get_flat_dt_prop(node, "size", NULL)) + fdt_reserved_mem_save_node(node, uname, 0, 0); /* scan next node */ return 0; @@ -550,6 +558,7 @@ static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname, void __init early_init_fdt_scan_reserved_mem(void) { of_scan_flat_dt(__fdt_scan_reserved_mem, NULL); + fdt_init_reserved_mem(); } /** -- cgit v1.2.3 From 2040b52768ebab6e7bd73af0dc63703269c62f17 Mon Sep 17 00:00:00 2001 From: Josh Cartwright Date: Thu, 13 Mar 2014 16:36:36 -0500 Subject: of: only scan for reserved mem when fdt present When the reserved memory patches hit -next, several legacy (non-DT) boot failures were detected and bisected down to that commit. There needs to be some sanity checking whether a DT is even present before parsing the reserved ranges. Reported-by: Kevin Hilman Signed-off-by: Josh Cartwright Tested-by: Kevin Hilman Signed-off-by: Grant Likely --- drivers/of/fdt.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/of/fdt.c') diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 510c0d8de8a0..501bc83f8cdf 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -557,6 +557,9 @@ static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname, */ void __init early_init_fdt_scan_reserved_mem(void) { + if (!initial_boot_params) + return; + of_scan_flat_dt(__fdt_scan_reserved_mem, NULL); fdt_init_reserved_mem(); } -- cgit v1.2.3