[RFC PATCH 06/10] MIPS: Octeon: Initialize and fixup device tree.
Grant Likely
grant.likely at secretlab.ca
Thu Feb 24 04:41:20 EST 2011
On Tue, Feb 22, 2011 at 12:57:50PM -0800, David Daney wrote:
> Signed-off-by: David Daney <ddaney at caviumnetworks.com>
> ---
> arch/mips/Kconfig | 2 +
> arch/mips/cavium-octeon/octeon-platform.c | 280 +++++++++++++++++++++++++++++
> arch/mips/cavium-octeon/setup.c | 17 ++
> 3 files changed, 299 insertions(+), 0 deletions(-)
I've got an odd feeling of foreboding about this patch. It makes me
nervous, but I can't articulate why yet. Gut-wise I'd rather see the
device tree pruned/fixed up before it gets unflattened, or for the
kernel to have a separate .dtb linked in for each legacy platform. I
need to think about this some more....
I've made some comments below anyway.
>
> diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
> index 4baf7f2..a8fc970 100644
> --- a/arch/mips/Kconfig
> +++ b/arch/mips/Kconfig
> @@ -699,6 +699,7 @@ config CAVIUM_OCTEON_SIMULATOR
> select SYS_SUPPORTS_HIGHMEM
> select SYS_SUPPORTS_HOTPLUG_CPU
> select SYS_HAS_CPU_CAVIUM_OCTEON
> + select OF_DYNAMIC
> help
> The Octeon simulator is software performance model of the Cavium
> Octeon Processor. It supports simulating Octeon processors on x86
> @@ -715,6 +716,7 @@ config CAVIUM_OCTEON_REFERENCE_BOARD
> select SYS_SUPPORTS_HOTPLUG_CPU
> select SYS_HAS_EARLY_PRINTK
> select SYS_HAS_CPU_CAVIUM_OCTEON
> + select OF_DYNAMIC
> select SWAP_IO_SPACE
> select HW_HAS_PCI
> select ARCH_SUPPORTS_MSI
> diff --git a/arch/mips/cavium-octeon/octeon-platform.c b/arch/mips/cavium-octeon/octeon-platform.c
> index cecaf62..428de0d 100644
> --- a/arch/mips/cavium-octeon/octeon-platform.c
> +++ b/arch/mips/cavium-octeon/octeon-platform.c
> @@ -13,10 +13,14 @@
> #include <linux/usb.h>
> #include <linux/dma-mapping.h>
> #include <linux/module.h>
> +#include <linux/slab.h>
> #include <linux/platform_device.h>
> +#include <linux/of_platform.h>
>
> #include <asm/octeon/octeon.h>
> #include <asm/octeon/cvmx-rnm-defs.h>
> +#include <asm/octeon/cvmx-helper.h>
> +#include <asm/octeon/cvmx-helper-board.h>
>
> static struct octeon_cf_data octeon_cf_data;
>
> @@ -440,6 +444,282 @@ device_initcall(octeon_ohci_device_init);
>
> #endif /* CONFIG_USB */
>
> +static struct of_device_id __initdata octeon_ids[] = {
> + { .type = "soc", },
> + { .compatible = "simple-bus", },
> + {},
> +};
> +
> +static int __init set_phy_addr_prop(struct device_node *n, int phy)
> +{
> + u32 *vp;
> + struct property *old_p;
> + struct property *p = kzalloc(sizeof(struct device_node) + sizeof(u32), GFP_KERNEL);
> + if (!p)
> + return -ENOMEM;
> + /* The value will immediatly follow the node in memory. */
> + vp = (u32 *)(&p[1]);
This is unsafe (I was on the losing end of an argument when I tried to
do exactly the same thing). If you want to allocate 2 things with one
appended to the other, then you need to define a structure
with the two element in it and allocate the size of that structure.
> + p->name = "reg";
> + p->length = sizeof(u32);
> + p->value = vp;
> +
> + *vp = cpu_to_be32((u32)phy);
phy is already an integer. Why the cast?
> +
> + old_p = of_find_property(n, "reg", NULL);
> + if (old_p)
> + prom_remove_property(n, old_p);
> + return prom_add_property(n, p);
Would it not be more efficient to change the value in the existing reg
property instead of doing this allocation song-and-dance?
> +}
> +
> +static int __init set_mac_addr_prop(struct device_node *n, u64 mac)
> +{
> + u8 *vp;
> + struct property *old_p;
> + struct property *p = kzalloc(sizeof(struct device_node) + 6, GFP_KERNEL);
> + if (!p)
> + return -ENOMEM;
> + /* The value will immediatly follow the node in memory. */
> + vp = (u8 *)(&p[1]);
> + p->name = "local-mac-address";
> + p->length = 6;
> + p->value = vp;
> +
> + vp[0] = (mac >> 40) & 0xff;
> + vp[1] = (mac >> 32) & 0xff;
> + vp[2] = (mac >> 24) & 0xff;
> + vp[3] = (mac >> 16) & 0xff;
> + vp[4] = (mac >> 8) & 0xff;
> + vp[5] = mac & 0xff;
> +
> + old_p = of_find_property(n, "local-mac-address", NULL);
> + if (old_p)
> + prom_remove_property(n, old_p);
> + return prom_add_property(n, p);
Same comments apply to this function.
> +}
> +
> +static struct device_node * __init octeon_of_get_child(const struct device_node *parent,
> + int reg_val)
> +{
> + struct device_node *node = NULL;
> + int size;
> + const __be32 *addr;
> +
> + for (;;) {
> + node = of_get_next_child(parent, node);
Use for_each_child_of_node() here.
> + if (!node)
> + break;
> + addr = of_get_property(node, "reg", &size);
> + if (addr && (be32_to_cpu(*addr) == reg_val))
be32_to_cpup(addr)
> + break;
> + }
> + return node;
> +}
> +
> +int __init octeon_prune_device_tree(void)
> +{
> + int i, p, max_port;
> + const char *node_path;
> + char name_buffer[20];
> + struct device_node *aliases;
> + struct device_node *pip;
> + struct device_node *iface;
> + struct device_node *eth;
> + struct device_node *node;
> +
> + aliases = of_find_node_by_path("/aliases");
> + if (!aliases) {
> + pr_err("Error: No /aliases node in device tree.");
> + return -EINVAL;
> + }
> +
> + if (OCTEON_IS_MODEL(OCTEON_CN52XX) || OCTEON_IS_MODEL(OCTEON_CN63XX))
> + max_port = 2;
> + else if (OCTEON_IS_MODEL(OCTEON_CN56XX))
> + max_port = 1;
> + else
> + max_port = 0;
> +
> + for (i = 0; i < 2; i++) {
> + struct device_node *mgmt;
> + snprintf(name_buffer, sizeof(name_buffer),
> + "ethernet-mgmt%d", i);
> + node_path = of_get_property(aliases, name_buffer, NULL);
> + if (node_path) {
> + mgmt = of_find_node_by_path(node_path);
of_find_node_by_path() needs to be fixed to also accept alias values
so that a string that starts with a '/' is a full path, but no leading
'/' means start with an alias. This code will lose a level of
indentation if you can make that change to the common code.
> + if (!mgmt)
> + continue;
> + if (i >= max_port) {
> + pr_notice("Deleting mgmt%d\n", i);
> + node = of_parse_phandle(mgmt, "phy-handle", 0);
> + if (node) {
> + of_detach_node(node);
> + of_node_put(node);
> + }
> + of_node_put(node);
> +
> + of_detach_node(mgmt);
> + of_node_put(mgmt);
> + }
> + of_node_put(mgmt);
> + }
> + }
> +
> + node_path = of_get_property(aliases, "pip", NULL);
> + if (node_path && (pip = of_find_node_by_path(node_path))) {
> + for (i = 0; i < 4; i++) {
> + cvmx_helper_interface_enumerate(i);
> + iface = octeon_of_get_child(pip, i);
> + if (!iface)
> + continue;
> + for (p = 0; p < 4; p++) {
> + eth = octeon_of_get_child(iface, p);
> + if (!eth)
> + continue;
> + node = of_parse_phandle(eth, "phy-handle", 0);
> + if (p < cvmx_helper_ports_on_interface(i)) {
> + int phy = cvmx_helper_board_get_mii_address(16 * i + p);
> + if (node && phy < 0) {
> + struct property *p = of_find_property(eth, "phy-handle", NULL);
> + of_detach_node(node);
> + of_node_put(node);
> + prom_remove_property(eth, p);
> + }
There is a lot of nesting here; could this be refactored?
> + } else {
> + pr_notice("Deleting Ethernet %x:%x\n", i, p);
> + if (node) {
> + of_detach_node(node);
> + of_node_put(node);
> + }
> + of_detach_node(eth);
> + of_node_put(eth);
> + }
> + of_node_put(node);
> + of_node_put(eth);
> + }
> + of_node_put(iface);
> + }
> + of_node_put(pip);
> + }
> +
> + /* I2C */
> + if (OCTEON_IS_MODEL(OCTEON_CN52XX) ||
> + OCTEON_IS_MODEL(OCTEON_CN63XX) ||
> + OCTEON_IS_MODEL(OCTEON_CN56XX))
> + max_port = 2;
> + else
> + max_port = 1;
> +
> + for (i = 0; i < 2; i++) {
> + struct device_node *i2c;
> + snprintf(name_buffer, sizeof(name_buffer),
> + "i2c%d", i);
> + node_path = of_get_property(aliases, name_buffer, NULL);
> + if (node_path) {
> + i2c = of_find_node_by_path(node_path);
> + if (!i2c)
> + continue;
> + if (i >= max_port) {
> + pr_notice("Deleting i2c%d\n", i);
> +
> + of_detach_node(i2c);
> + of_node_put(i2c);
> + }
> + of_node_put(i2c);
> + }
> + }
> +
> + of_node_put(aliases);
> + return 0;
> +}
> +
> +int __init octeon_fix_device_tree(void)
> +{
> + int i, p;
> + int rv;
> + const char *node_path;
> + char name_buffer[20];
> + u64 mac_addr_base;
> + struct device_node *aliases;
> + struct device_node *pip;
> + struct device_node *iface;
> + struct device_node *eth;
> + struct device_node *node;
> +
> + /*
> + * Edit the device tree to reflect known board
> + * configurations.
> + */
> + mac_addr_base =
> + ((octeon_bootinfo->mac_addr_base[0] & 0xffull)) << 40 |
> + ((octeon_bootinfo->mac_addr_base[1] & 0xffull)) << 32 |
> + ((octeon_bootinfo->mac_addr_base[2] & 0xffull)) << 24 |
> + ((octeon_bootinfo->mac_addr_base[3] & 0xffull)) << 16 |
> + ((octeon_bootinfo->mac_addr_base[4] & 0xffull)) << 8 |
> + (octeon_bootinfo->mac_addr_base[5] & 0xffull);
> +
> + aliases = of_find_node_by_path("/aliases");
> + if (!aliases) {
> + pr_err("Error: No /aliases node in device tree.");
> + return -EINVAL;
> + }
> +
> + for (i = 0; i < 2; i++) {
> + struct device_node *mgmt;
> + snprintf(name_buffer, sizeof(name_buffer),
> + "ethernet-mgmt%d", i);
> + node_path = of_get_property(aliases, name_buffer, NULL);
> + if (node_path) {
Ditto here to comment above.
> + mgmt = of_find_node_by_path(node_path);
> + if (!mgmt)
> + continue;
> + /* Set the ethernet address */
> + rv = set_mac_addr_prop(mgmt, mac_addr_base);
> + if (rv)
> + goto err;
> + mac_addr_base++;
> +
> + of_node_put(mgmt);
> + }
> + }
> +
> + node_path = of_get_property(aliases, "pip", NULL);
> + if (node_path && (pip = of_find_node_by_path(node_path))) {
> + for (i = 0; i < 4; i++) {
> + iface = octeon_of_get_child(pip, i);
> + if (!iface)
> + continue;
> + for (p = 0; p < 4; p++) {
> + int phy = cvmx_helper_board_get_mii_address(16 * i + p);
> + eth = octeon_of_get_child(iface, p);
> + if (!eth)
> + continue;
> + node = of_parse_phandle(eth, "phy-handle", 0);
> + rv = set_mac_addr_prop(eth, mac_addr_base);
> + mac_addr_base++;
> + if (node && phy >= 0)
> + set_phy_addr_prop(node, cvmx_helper_board_get_mii_address(16 * i + p));
> + of_node_put(node);
> + of_node_put(eth);
> + }
> + of_node_put(iface);
> + }
> + of_node_put(pip);
> + }
> +
> + of_node_put(aliases);
> + return 0;
> +err:
> + return rv;
> +}
> +arch_initcall(octeon_fix_device_tree);
Calling this from an initcall really makes me nervous. I'm worried
about ordering issues. Why can this code not be part of the prune
routine above?
> +
> +static int __init octeon_publish_devices(void)
> +{
> + return of_platform_bus_probe(NULL, octeon_ids, NULL);
> +}
> +device_initcall(octeon_publish_devices);
> +
> +
> MODULE_AUTHOR("David Daney <ddaney at caviumnetworks.com>");
> MODULE_LICENSE("GPL");
> MODULE_DESCRIPTION("Platform driver for Octeon SOC");
> diff --git a/arch/mips/cavium-octeon/setup.c b/arch/mips/cavium-octeon/setup.c
> index ab1a106..818f66d5 100644
> --- a/arch/mips/cavium-octeon/setup.c
> +++ b/arch/mips/cavium-octeon/setup.c
> @@ -20,6 +20,7 @@
> #include <linux/platform_device.h>
> #include <linux/serial_core.h>
> #include <linux/serial_8250.h>
> +#include <linux/of_fdt.h>
> #ifdef CONFIG_BLK_DEV_INITRD
> #include <linux/initrd.h>
> #endif
> @@ -797,3 +798,19 @@ void prom_free_prom_memory(void)
> }
> #endif
> }
> +
> +int octeon_prune_device_tree(void);
> +
> +extern const char __dtb_octeon_3xxx_begin;
> +extern const char __dtb_octeon_3xxx_end;
> +void __init device_tree_init(void)
> +{
> + int dt_size = &__dtb_octeon_3xxx_end - &__dtb_octeon_3xxx_begin;
> + /* Copy the default tree from init memory. */
> + initial_boot_params = early_init_dt_alloc_memory_arch(dt_size, 8);
> + if (initial_boot_params == NULL)
> + panic("Could not allocate initial_boot_params\n");
> + memcpy(initial_boot_params, &__dtb_octeon_3xxx_begin, dt_size);
> + unflatten_device_tree();
> + octeon_prune_device_tree();
> +}
> --
> 1.7.2.3
>
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