From: gregory.clement@free-electrons•com (Gregory CLEMENT)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 2/6] ARM: mvebu: start using the CPU reset driver
Date: Thu, 27 Mar 2014 16:58:54 +0100 [thread overview]
Message-ID: <53344ABE.70501@free-electrons.com> (raw)
In-Reply-To: <1395927485-11842-3-git-send-email-thomas.petazzoni@free-electrons.com>
On 27/03/2014 14:38, Thomas Petazzoni wrote:
> This commit changes the PMSU driver to no longer map itself the CPU
> reset registers, and instead call into the CPU reset driver to
> deassert the secondary CPUs for SMP booting.
>
> In order to provide Device Tree backward compatibility, the CPU reset
> driver is extended to not only support its official compatible strings
> "marvell,armada-370-cpu-reset" and "marvell,armada-xp-cpu-reset", but
> to also look at the PMSU compatible string
> "marvell,armada-370-xp-pmsu" to find the CPU reset registers
> address. This allows old Device Tree to work correctly with newer
> kernel versions. Therefore, the CPU reset driver implements the
> following logic:
>
> * If one of the normal compatible strings
> "marvell,armada-<chip>-cpu-reset" is found, then we map its first
> memory resource as the CPU reset registers.
>
> * Otherwise, if none of the normal compatible strings have been
> found, we look for the "marvell,armada-370-xp-pmsu" compatible
> string, and we map the second memory as the CPU reset registers.
>
> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons•com>
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons•com>
> ---
> arch/arm/mach-mvebu/cpu-reset.c | 56 ++++++++++++++++++++++++++++-------------
> arch/arm/mach-mvebu/pmsu.c | 20 +++++++--------
> 2 files changed, 48 insertions(+), 28 deletions(-)
>
> diff --git a/arch/arm/mach-mvebu/cpu-reset.c b/arch/arm/mach-mvebu/cpu-reset.c
> index 2819887..e3821b1 100644
> --- a/arch/arm/mach-mvebu/cpu-reset.c
> +++ b/arch/arm/mach-mvebu/cpu-reset.c
> @@ -46,43 +46,63 @@ int mvebu_cpu_reset_deassert(int cpu)
> return 0;
> }
>
> -static int __init mvebu_cpu_reset_init(void)
> +static int mvebu_cpu_reset_map(struct device_node *np, int res_idx)
> {
> - struct device_node *np;
> - const struct of_device_id *match;
> struct resource res;
> - int ret = 0;
>
> - np = of_find_matching_node_and_match(NULL, of_cpu_reset_table,
> - &match);
> - if (!np)
> - return 0;
> -
> - if (of_address_to_resource(np, 0, &res)) {
> + if (of_address_to_resource(np, res_idx, &res)) {
> pr_err("unable to get resource\n");
> - ret = -ENOENT;
> - goto out;
> + return -ENOENT;
> }
>
> if (!request_mem_region(res.start, resource_size(&res),
> np->full_name)) {
> pr_err("unable to request region\n");
> - ret = -EBUSY;
> - goto out;
> + return -EBUSY;
> }
>
> cpu_reset_base = ioremap(res.start, resource_size(&res));
> if (!cpu_reset_base) {
> pr_err("unable to map registers\n");
> release_mem_region(res.start, resource_size(&res));
> - ret = -ENOMEM;
> - goto out;
> + return -ENOMEM;
> }
>
> - ncpus = (int) match->data;
> + return 0;
> +}
>
> -out:
> +int __init mvebu_cpu_reset_init(void)
> +{
> + struct device_node *np;
> + const struct of_device_id *match;
> + int res_idx;
> + int ret;
> +
> + np = of_find_matching_node_and_match(NULL, of_cpu_reset_table,
> + &match);
> + if (np) {
> + res_idx = 0;
> + ncpus = (int) match->data;
> + } else {
> + /*
> + * This code is kept for backward compatibility with
> + * old Device Trees.
> + */
> + np = of_find_compatible_node(NULL, NULL, "marvell,armada-370-xp-pmsu");
> + if (np) {
> + pr_warn(FW_WARN "deprecated pmsu binding\n");
> + res_idx = 1;
> + ncpus = ARMADA_XP_MAX_CPUS;
> + }
> + }
> +
> + /* No reset node found */
> + if (!np)
> + return 0;
> +
> + ret = mvebu_cpu_reset_map(np, res_idx);
> of_node_put(np);
> +
> return ret;
> }
>
> diff --git a/arch/arm/mach-mvebu/pmsu.c b/arch/arm/mach-mvebu/pmsu.c
> index d71ef53..1807639 100644
> --- a/arch/arm/mach-mvebu/pmsu.c
> +++ b/arch/arm/mach-mvebu/pmsu.c
> @@ -21,14 +21,14 @@
> #include <linux/of_address.h>
> #include <linux/io.h>
> #include <linux/smp.h>
> +#include <linux/resource.h>
> #include <asm/smp_plat.h>
> +#include "common.h"
> #include "pmsu.h"
>
> static void __iomem *pmsu_mp_base;
> -static void __iomem *pmsu_reset_base;
>
> #define PMSU_BOOT_ADDR_REDIRECT_OFFSET(cpu) ((cpu * 0x100) + 0x24)
> -#define PMSU_RESET_CTL_OFFSET(cpu) (cpu * 0x8)
>
> static struct of_device_id of_pmsu_table[] = {
> {.compatible = "marvell,armada-370-xp-pmsu"},
> @@ -38,11 +38,11 @@ static struct of_device_id of_pmsu_table[] = {
> #ifdef CONFIG_SMP
> int armada_xp_boot_cpu(unsigned int cpu_id, void *boot_addr)
> {
> - int reg, hw_cpu;
> + int hw_cpu, ret;
>
> - if (!pmsu_mp_base || !pmsu_reset_base) {
> + if (!pmsu_mp_base) {
> pr_warn("Can't boot CPU. PMSU is uninitialized\n");
> - return 1;
> + return -ENODEV;
> }
>
> hw_cpu = cpu_logical_map(cpu_id);
> @@ -50,10 +50,11 @@ int armada_xp_boot_cpu(unsigned int cpu_id, void *boot_addr)
> writel(virt_to_phys(boot_addr), pmsu_mp_base +
> PMSU_BOOT_ADDR_REDIRECT_OFFSET(hw_cpu));
>
> - /* Release CPU from reset by clearing reset bit*/
> - reg = readl(pmsu_reset_base + PMSU_RESET_CTL_OFFSET(hw_cpu));
> - reg &= (~0x1);
> - writel(reg, pmsu_reset_base + PMSU_RESET_CTL_OFFSET(hw_cpu));
> + ret = mvebu_cpu_reset_deassert(hw_cpu);
> + if (ret) {
> + pr_warn("unable to boot CPU: %d\n", ret);
> + return ret;
> + }
>
> return 0;
> }
> @@ -67,7 +68,6 @@ static int __init armada_370_xp_pmsu_init(void)
> if (np) {
> pr_info("Initializing Power Management Service Unit\n");
> pmsu_mp_base = of_iomap(np, 0);
> - pmsu_reset_base = of_iomap(np, 1);
> of_node_put(np);
> }
>
>
--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
next prev parent reply other threads:[~2014-03-27 15:58 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-27 13:37 [PATCH 0/6] ARM: mvebu: prepare PMSU code for cpuidle and Armada 375/38x SMP Thomas Petazzoni
2014-03-27 13:38 ` [PATCH 1/6] ARM: mvebu: introduce CPU reset code Thomas Petazzoni
2014-03-27 14:00 ` Gregory CLEMENT
2014-03-27 14:19 ` Thomas Petazzoni
2014-03-27 15:58 ` Gregory CLEMENT
2014-03-27 14:12 ` Sebastian Hesselbarth
2014-03-27 14:21 ` Thomas Petazzoni
2014-03-27 13:38 ` [PATCH 2/6] ARM: mvebu: start using the CPU reset driver Thomas Petazzoni
2014-03-27 15:58 ` Gregory CLEMENT [this message]
2014-03-27 13:38 ` [PATCH 3/6] ARM: mvebu: improve PMSU driver to request its resource Thomas Petazzoni
2014-03-27 15:59 ` Gregory CLEMENT
2014-03-27 13:38 ` [PATCH 4/6] ARM: mvebu: extend the PMSU registers Thomas Petazzoni
2014-03-27 13:38 ` [PATCH 5/6] ARM: mvebu: switch to the new PMSU binding in Armada 370/XP Device Tree Thomas Petazzoni
2014-03-27 13:38 ` [PATCH 6/6] ARM: mvebu: use a separate function to set the boot address of CPUs Thomas Petazzoni
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