On 04/08/14 16:28, Hanjun Guo wrote:
MADT contains the information for MPIDR which is essential for SMP initialization, parse the GIC cpu interface structures to get the MPIDR value and map it to cpu_logical_map(), and add enabled cpu with valid MPIDR into cpu_possible_map and cpu_present_map.
Signed-off-by: Hanjun Guo hanjun.guo@linaro.org Signed-off-by: Tomasz Nowicki tomasz.nowicki@linaro.org
arch/arm64/include/asm/acpi.h | 2 + arch/arm64/kernel/acpi.c | 129 ++++++++++++++++++++++++++++++++++++++++- arch/arm64/kernel/smp.c | 10 +++- 3 files changed, 138 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h index 6e04868..e877967 100644 --- a/arch/arm64/include/asm/acpi.h +++ b/arch/arm64/include/asm/acpi.h @@ -64,6 +64,8 @@ static inline void arch_fix_phys_package_id(int num, u32 slot) { } extern int (*acpi_suspend_lowlevel)(void); #define acpi_wakeup_address 0
+#define MAX_GIC_CPU_INTERFACE 65535
Did you get this information from GIC specification ?
IIUC you are trying to represent max number of interrupt controller entries MADT can possibly have. So, I had suggested to change the name like MAX_MADT_INTERRUPT_CONTROLLER_ENTRIES so that it is not GIC specific.
#endif /* CONFIG_ACPI */
#endif /*_ASM_ACPI_H*/ diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c index 69a315d..9e07d99 100644 --- a/arch/arm64/kernel/acpi.c +++ b/arch/arm64/kernel/acpi.c @@ -22,6 +22,9 @@ #include <linux/bootmem.h> #include <linux/smp.h>
+#include <asm/smp_plat.h> +#include <asm/cputype.h>
- int acpi_noirq; /* skip ACPI IRQ initialization */ int acpi_disabled; EXPORT_SYMBOL(acpi_disabled);
@@ -29,6 +32,8 @@ EXPORT_SYMBOL(acpi_disabled); int acpi_pci_disabled; /* skip ACPI PCI scan and IRQ initialization */ EXPORT_SYMBOL(acpi_pci_disabled);
+static int enabled_cpus; /* Processors (GICC) with enabled flag in MADT */
- /*
- __acpi_map_table() will be called before page_init(), so early_ioremap()
- or early_memremap() should be called here to for ACPI table mapping.
@@ -49,6 +54,122 @@ void __init __acpi_unmap_table(char *map, unsigned long size) early_memunmap(map, size); }
+/**
- acpi_register_gic_cpu_interface - register a gic cpu interface and
- generates a logical cpu number
- @mpidr: CPU's hardware id to register, MPIDR represented in MADT
- @enabled: this cpu is enabled or not
- Returns the logical cpu number which maps to the gic cpu interface
- */
+static int acpi_register_gic_cpu_interface(u64 mpidr, u8 enabled) +{
IMO the function name gives me a wrong idea that you are registering something with GIC. How about acpi_map_gic_cpu_interface ?
- int cpu;
- if (mpidr == INVALID_HWID) {
pr_info("Skip invalid cpu hardware ID\n");
return -EINVAL;
- }
- total_cpus++;
- if (!enabled)
return -EINVAL;
- if (enabled_cpus >= NR_CPUS) {
pr_warn("NR_CPUS limit of %d reached, Processor %d/0x%llx ignored.\n",
NR_CPUS, total_cpus, mpidr);
return -EINVAL;
- }
- /* If it is the first CPU, no need to check duplicate MPIDRs */
- if (!enabled_cpus)
goto skip_mpidr_check;
- /*
* Duplicate MPIDRs are a recipe for disaster. Scan
* all initialized entries and check for
* duplicates. If any is found just ignore the CPU.
*/
- for_each_present_cpu(cpu) {
if (cpu_logical_map(cpu) == mpidr) {
pr_err("Firmware bug, duplicate CPU MPIDR: 0x%llx in MADT\n",
mpidr);
return -EINVAL;
}
- }
+skip_mpidr_check:
- enabled_cpus++;
- /* allocate a logical cpu id for the new comer */
- if (cpu_logical_map(0) == mpidr) {
/*
* boot_cpu_init() already hold bit 0 in cpu_present_mask
* for BSP, no need to allocate again.
*/
cpu = 0;
- } else {
cpu = cpumask_next_zero(-1, cpu_present_mask);
- }
- /* map the logical cpu id to cpu MPIDR */
- cpu_logical_map(cpu) = mpidr;
- set_cpu_possible(cpu, true);
IMO it better to keep all these updates to cpumasks contained in the smp.c as I had mentioned before. I think you can refactor smp_init_cpus to achieve that.
- set_cpu_present(cpu, true);
This is totally wrong ? What would you do if the cpu failed to initialize ? I don't see that handled.
- return cpu;
+}
+static int __init +acpi_parse_gic_cpu_interface(struct acpi_subtable_header *header,
const unsigned long end)
+{
- struct acpi_madt_generic_interrupt *processor;
- processor = (struct acpi_madt_generic_interrupt *)header;
- if (BAD_MADT_ENTRY(processor, end))
return -EINVAL;
- acpi_table_print_madt_entry(header);
- acpi_register_gic_cpu_interface(processor->arm_mpidr,
processor->flags & ACPI_MADT_ENABLED);
- return 0;
+}
+/*
- Parse GIC cpu interface related entries in MADT
- returns 0 on success, < 0 on error
- */
+static int __init acpi_parse_madt_gic_cpu_interface_entries(void) +{
- int count;
- /*
* do a partial walk of MADT to determine how many CPUs
* we have including disabled CPUs, and get information
* we need for SMP init
*/
- count = acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_INTERRUPT,
acpi_parse_gic_cpu_interface, MAX_GIC_CPU_INTERFACE);
- if (!count) {
pr_err("No GIC CPU interface entries present\n");
return -ENODEV;
- } else if (count < 0) {
pr_err("Error parsing GIC CPU interface entry\n");
return count;
- }
- /* Make boot-up look pretty */
- pr_info("%d CPUs enabled, %d CPUs total\n", enabled_cpus, total_cpus);
Ideally just setup cpu_logical_map in acpi_parse_gic_cpu_interface and setup cpumasks in smp_init_cpus.
- return 0;
+}
- static int __init acpi_parse_fadt(struct acpi_table_header *table) { struct acpi_table_fadt *fadt = (struct acpi_table_fadt *)table;
@@ -99,8 +220,12 @@ int __init acpi_boot_init(void) return -ENODEV;
err = acpi_table_parse(ACPI_SIG_FADT, acpi_parse_fadt);
- if (err)
pr_err("Can't find FADT\n");
if (err) {
pr_err("Can't find FADT or error happened during parsing FADT\n");
return err;
}
err = acpi_parse_madt_gic_cpu_interface_entries();
return err; }
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index 40f38f4..8f1d37c 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -36,6 +36,7 @@ #include <linux/completion.h> #include <linux/of.h> #include <linux/irq_work.h> +#include <linux/acpi.h>
#include <asm/atomic.h> #include <asm/cacheflush.h> @@ -458,7 +459,14 @@ void __init smp_prepare_cpus(unsigned int max_cpus) if (err) continue;
set_cpu_present(cpu, true);
/*
* In ACPI mode, cpu_present_map was initialised when
* MADT table was parsed which before this function
* is called.
*/
if (acpi_disabled)
set_cpu_present(cpu, true);
This is the right place to set the cpu present based on the return value of cpu_prepare.
max_cpus--;
} }