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author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-11-11 07:32:21 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-11-11 07:32:21 (GMT) |
commit | 05ad391dbc2bd27b8d868cf9c3ec1b68a2126a16 (patch) | |
tree | abfc59028a00a15428ab8b14abe8a9e99f69a9a3 /arch/arm64/kernel/smp_spin_table.c | |
parent | 8b5baa460b69c27389353eeff0dbe51dc695da60 (diff) | |
parent | 67317c2689567c24d18e0dd43ab6d409fd42dc6e (diff) | |
download | linux-fsl-qoriq-05ad391dbc2bd27b8d868cf9c3ec1b68a2126a16.tar.xz |
Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-aarch64
Pull ARM64 update from Catalin Marinas:
"Main features:
- Ticket-based spinlock implementation and lockless lockref support
- Big endian support
- CPU hotplug support, currently for PSCI (Power State Coordination
Interface) capable firmware
- Virtual address space extended to 42-bit in the 64K page
configuration (maximum VA space with 2 levels of page tables)
- Compat (AArch32) kuser helpers updated to ARMv8 (make use of
load-acquire/store-release instructions)
- Code cleanup, defconfig update and minor fixes"
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-aarch64: (43 commits)
ARM64: /proc/interrupts: display IPIs of online CPUs only
arm64: locks: Remove CONFIG_GENERIC_LOCKBREAK
arm64: KVM: vgic: byteswap GICv2 access on world switch if BE
arm64: KVM: initialize HYP mode following the kernel endianness
arm64: compat: Clear the IT state independent of the 32-bit ARM or Thumb-2 mode
arm64: Use 42-bit address space with 64K pages
arm64: module: ensure instruction is little-endian before manipulation
arm64: defconfig: Enable CONFIG_PREEMPT by default
arm64: fix access to preempt_count from assembly code
arm64: move enabling of GIC before CPUs are set online
arm64: use generic RW_DATA_SECTION macro in linker script
arm64: Slightly improve the warning on CPU0 enable-method
ARM64: simplify cpu_read_bootcpu_ops using OF/DT helper
ARM64: DT: define ARM64 specific arch_match_cpu_phys_id
arm64: allow ioremap_cache() to use existing RAM mappings
arm64: update 32-bit kuser helpers to ARMv8
arm64: perf: fix event number mask
arm64: kconfig: allow CPU_BIG_ENDIAN to be selected
arm64: Fix the endianness of arch_spinlock_t
arm64: big-endian: write CPU holding pen address as LE
...
Diffstat (limited to 'arch/arm64/kernel/smp_spin_table.c')
-rw-r--r-- | arch/arm64/kernel/smp_spin_table.c | 97 |
1 files changed, 91 insertions, 6 deletions
diff --git a/arch/arm64/kernel/smp_spin_table.c b/arch/arm64/kernel/smp_spin_table.c index 7c35fa6..44c2280 100644 --- a/arch/arm64/kernel/smp_spin_table.c +++ b/arch/arm64/kernel/smp_spin_table.c @@ -16,15 +16,39 @@ * along with this program. If not, see <http://www.gnu.org/licenses/>. */ +#include <linux/delay.h> #include <linux/init.h> #include <linux/of.h> #include <linux/smp.h> #include <asm/cacheflush.h> +#include <asm/cpu_ops.h> +#include <asm/cputype.h> +#include <asm/smp_plat.h> + +extern void secondary_holding_pen(void); +volatile unsigned long secondary_holding_pen_release = INVALID_HWID; static phys_addr_t cpu_release_addr[NR_CPUS]; +static DEFINE_RAW_SPINLOCK(boot_lock); + +/* + * Write secondary_holding_pen_release in a way that is guaranteed to be + * visible to all observers, irrespective of whether they're taking part + * in coherency or not. This is necessary for the hotplug code to work + * reliably. + */ +static void write_pen_release(u64 val) +{ + void *start = (void *)&secondary_holding_pen_release; + unsigned long size = sizeof(secondary_holding_pen_release); -static int __init smp_spin_table_init_cpu(struct device_node *dn, int cpu) + secondary_holding_pen_release = val; + __flush_dcache_area(start, size); +} + + +static int smp_spin_table_cpu_init(struct device_node *dn, unsigned int cpu) { /* * Determine the address from which the CPU is polling. @@ -40,7 +64,7 @@ static int __init smp_spin_table_init_cpu(struct device_node *dn, int cpu) return 0; } -static int __init smp_spin_table_prepare_cpu(int cpu) +static int smp_spin_table_cpu_prepare(unsigned int cpu) { void **release_addr; @@ -48,7 +72,16 @@ static int __init smp_spin_table_prepare_cpu(int cpu) return -ENODEV; release_addr = __va(cpu_release_addr[cpu]); - release_addr[0] = (void *)__pa(secondary_holding_pen); + + /* + * We write the release address as LE regardless of the native + * endianess of the kernel. Therefore, any boot-loaders that + * read this address need to convert this address to the + * boot-loader's endianess before jumping. This is mandated by + * the boot protocol. + */ + release_addr[0] = (void *) cpu_to_le64(__pa(secondary_holding_pen)); + __flush_dcache_area(release_addr, sizeof(release_addr[0])); /* @@ -59,8 +92,60 @@ static int __init smp_spin_table_prepare_cpu(int cpu) return 0; } -const struct smp_enable_ops smp_spin_table_ops __initconst = { +static int smp_spin_table_cpu_boot(unsigned int cpu) +{ + unsigned long timeout; + + /* + * Set synchronisation state between this boot processor + * and the secondary one + */ + raw_spin_lock(&boot_lock); + + /* + * Update the pen release flag. + */ + write_pen_release(cpu_logical_map(cpu)); + + /* + * Send an event, causing the secondaries to read pen_release. + */ + sev(); + + timeout = jiffies + (1 * HZ); + while (time_before(jiffies, timeout)) { + if (secondary_holding_pen_release == INVALID_HWID) + break; + udelay(10); + } + + /* + * Now the secondary core is starting up let it run its + * calibrations, then wait for it to finish + */ + raw_spin_unlock(&boot_lock); + + return secondary_holding_pen_release != INVALID_HWID ? -ENOSYS : 0; +} + +void smp_spin_table_cpu_postboot(void) +{ + /* + * Let the primary processor know we're out of the pen. + */ + write_pen_release(INVALID_HWID); + + /* + * Synchronise with the boot thread. + */ + raw_spin_lock(&boot_lock); + raw_spin_unlock(&boot_lock); +} + +const struct cpu_operations smp_spin_table_ops = { .name = "spin-table", - .init_cpu = smp_spin_table_init_cpu, - .prepare_cpu = smp_spin_table_prepare_cpu, + .cpu_init = smp_spin_table_cpu_init, + .cpu_prepare = smp_spin_table_cpu_prepare, + .cpu_boot = smp_spin_table_cpu_boot, + .cpu_postboot = smp_spin_table_cpu_postboot, }; |