[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH 6/7] xen/arm: Dissociate logical and hardware CPU ID
On 09/09/2013 02:38 PM, Ian Campbell wrote: > t gOn Fri, 2013-08-30 at 14:30 +0100, Julien Grall wrote: >> Introduce cpu_logical_map to associate a logical CPU ID to an hardware CPU >> ID. >> This map will be filled during Xen boot via the device tree. Each CPU node >> contains a "reg" property which contains the hardware ID (ie MPIDR[0:23]). >> >> Also move /cpus parsing later so we can use the dt_* API. >> >> Signed-off-by: Julien Grall <julien.grall@xxxxxxxxxx> >> --- >> xen/arch/arm/setup.c | 109 >> ++++++++++++++++++++++++++++++++++++++- >> xen/arch/arm/smpboot.c | 4 ++ >> xen/common/device_tree.c | 48 ----------------- >> xen/include/asm-arm/processor.h | 4 ++ >> 4 files changed, 116 insertions(+), 49 deletions(-) >> >> diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c >> index 137a65e..fabad91 100644 >> --- a/xen/arch/arm/setup.c >> +++ b/xen/arch/arm/setup.c >> @@ -496,6 +496,111 @@ void __init setup_cache(void) >> cacheline_bytes = 1U << (4 + (ccsid & 0x7)); >> } >> >> +/* Parse the device tree and build the logical map array containing >> + * MPIDR values related to logical cpus >> + * Code base on Linux arch/arm/kernel/devtree.c >> + */ >> +static void __init init_cpus_maps(void) >> +{ >> + register_t mpidr; >> + struct dt_device_node *cpus = dt_find_node_by_path("/cpus"); >> + struct dt_device_node *cpu; >> + unsigned int i, j; >> + unsigned int cpuidx = 1; >> + u32 tmp_map[NR_CPUS] = { [0 ... NR_CPUS - 1] = MPIDR_INVALID }; > > This is potentially a fair bit of data on the stack? If yes then it > could be static init data? Rigth. I will move to init data. > >> + bool_t bootcpu_valid = 0; >> + >> + mpidr = READ_SYSREG(MPIDR_EL1) & MPIDR_HWID_MASK; > > boot_cpu_mpidr would have saved me wondering why the current CPU was so > special. boot_cpu_mpidr is filled a bit after. I will move init_cpus_map later. >> + >> + if ( !cpus ) >> + { >> + printk(XENLOG_WARNING "WARNING: Can't find /cpus in the device >> tree.\n" >> + "Using only 1 CPU\n"); >> + return; >> + } >> + >> + for_each_child_node( cpus, cpu ) >> + { >> + u32 hwid; >> + >> + if ( !dt_device_type_is_equal(cpu, "cpu") ) >> + continue; >> + >> + if ( !dt_property_read_u32(cpu, "reg", &hwid) ) >> + { >> + printk(XENLOG_WARNING "cpu node `%s`: missing reg property\n", >> + dt_node_full_name(cpu)); >> + continue; >> + } >> + >> + /* >> + * 8 MSBs must be set to 0 in the DT since the reg property >> + * defines the MPIDR[23:0] >> + */ >> + if ( hwid & ~MPIDR_HWID_MASK ) >> + { >> + printk(XENLOG_WARNING "cpu node `%s`: invalid hwid value >> (0x%x)\n", >> + dt_node_full_name(cpu), hwid); >> + continue; >> + } >> + >> + /* >> + * Duplicate MPIDRs are a recipe for disaster. Scan all initialized >> + * entries and check for duplicates. If any found just skip the >> node. >> + * temp values values are initialized to MPIDR_INVALID to avoid >> + * matching valid MPIDR[23:0] values. >> + */ >> + for ( j = 0; j < cpuidx; j++ ) >> + { >> + if ( tmp_map[j] == hwid ) >> + { >> + printk(XENLOG_WARNING "cpu node `%s`: duplicate /cpu reg >> properties in the DT\n", >> + dt_node_full_name(cpu)); >> + continue; >> + } >> + } >> + >> + /* >> + * Build a stashed array of MPIDR values. Numbering scheme requires >> + * that if detected the boot CPU must be assigned logical id 0. >> Other >> + * CPUs get sequential indexes starting from 1. If a CPU node >> + * with a reg property matching the boot CPU MPIDR is detected, >> + * this is recorded and so that the logical map build from DT is >> + * validated and can be used to set the map. >> + */ >> + if ( hwid == mpidr ) >> + { >> + i = 0; >> + bootcpu_valid = 1; >> + } >> + else >> + i = cpuidx++; >> + >> + if ( cpuidx > NR_CPUS ) >> + { >> + printk(XENLOG_WARNING "DT /cpu %u node greater than max cores >> %u, capping them\n", >> + cpuidx, NR_CPUS); >> + cpuidx = NR_CPUS; >> + break; >> + } >> + >> + tmp_map[i] = hwid; >> + } >> + >> + if ( !bootcpu_valid ) >> + { >> + printk(XENLOG_WARNING "DT missing boot CPU MPIDR[23:0]\n" >> + "Using only 1 CPU\n"); >> + return; >> + } >> + >> + for ( i = 0; i < cpuidx; i++ ) >> + { >> + cpumask_set_cpu(i, &cpu_possible_map); >> + cpu_logical_map(i) = tmp_map[i]; > > For i == 0 this happens in smp_clear_cpu_maps too. You may as well start > from 1. Ok. >> + } >> +} >> + >> /* C entry point for boot CPU */ >> void __init start_xen(unsigned long boot_phys_offset, >> unsigned long fdt_paddr, >> @@ -515,7 +620,6 @@ void __init start_xen(unsigned long boot_phys_offset, >> + (fdt_paddr & ((1 << SECOND_SHIFT) - 1)); >> fdt_size = device_tree_early_init(device_tree_flattened); >> >> - cpus = smp_get_max_cpus(); >> cmdline_parse(device_tree_bootargs(device_tree_flattened)); >> >> setup_pagetables(boot_phys_offset, get_xen_paddr()); >> @@ -528,6 +632,9 @@ void __init start_xen(unsigned long boot_phys_offset, >> dt_uart_init(); >> console_init_preirq(); >> >> + init_cpus_maps(); >> + cpus = smp_get_max_cpus(); > > It seems like anything which was previously using this should by now be > using some sort of for_each_foo() helper over the apropriate bitmasks? Yes. I will send a patch for that. >> + >> system_state = SYS_STATE_boot; >> >> processor_id(); >> diff --git a/xen/arch/arm/smpboot.c b/xen/arch/arm/smpboot.c >> index b6aea63..c0d25de 100644 >> --- a/xen/arch/arm/smpboot.c >> +++ b/xen/arch/arm/smpboot.c >> @@ -39,6 +39,9 @@ EXPORT_SYMBOL(cpu_possible_map); >> >> struct cpuinfo_arm cpu_data[NR_CPUS]; >> >> +/* CPU logical map: map xen cpuid to an MPIDR */ >> +u32 __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = MPIDR_INVALID }; >> + >> /* Fake one node for now. See also include/asm-arm/numa.h */ >> nodemask_t __read_mostly node_online_map = { { [0] = 1UL } }; >> >> @@ -82,6 +85,7 @@ smp_clear_cpu_maps (void) >> cpumask_clear(&cpu_online_map); >> cpumask_set_cpu(0, &cpu_online_map); >> cpumask_set_cpu(0, &cpu_possible_map); >> + cpu_logical_map(0) = READ_SYSREG(MPIDR_EL1) & MPIDR_HWID_MASK; >> } >> >> int __init >> diff --git a/xen/common/device_tree.c b/xen/common/device_tree.c >> index 5620b23..cc519af 100644 >> --- a/xen/common/device_tree.c >> +++ b/xen/common/device_tree.c >> @@ -118,18 +118,6 @@ static bool_t __init device_tree_node_matches(const >> void *fdt, int node, >> && (name[match_len] == '@' || name[match_len] == '\0'); >> } >> >> -static bool_t __init device_tree_type_matches(const void *fdt, int node, >> - const char *match) >> -{ >> - const void *prop; >> - >> - prop = fdt_getprop(fdt, node, "device_type", NULL); >> - if ( prop == NULL ) >> - return 0; >> - >> - return !dt_node_cmp(prop, match); >> -} >> - >> static bool_t __init device_tree_node_compatible(const void *fdt, int node, >> const char *match) >> { >> @@ -348,40 +336,6 @@ static void __init process_memory_node(const void *fdt, >> int node, >> } >> } >> >> -static void __init process_cpu_node(const void *fdt, int node, >> - const char *name, >> - u32 address_cells, u32 size_cells) >> -{ >> - const struct fdt_property *prop; >> - u32 cpuid; >> - int len; >> - >> - prop = fdt_get_property(fdt, node, "reg", &len); >> - if ( !prop ) >> - { >> - early_printk("fdt: node `%s': missing `reg' property\n", name); >> - return; >> - } >> - >> - if ( len < sizeof (cpuid) ) >> - { >> - dt_printk("fdt: node `%s': `reg` property length is too short\n", >> - name); >> - return; >> - } >> - >> - cpuid = dt_read_number((const __be32 *)prop->data, 1); >> - >> - /* TODO: handle non-contiguous CPU ID */ >> - if ( cpuid >= NR_CPUS ) >> - { >> - dt_printk("fdt: node `%s': reg(0x%x) >= NR_CPUS(%d)\n", >> - name, cpuid, NR_CPUS); >> - return; >> - } >> - cpumask_set_cpu(cpuid, &cpu_possible_map); >> -} >> - >> static void __init process_multiboot_node(const void *fdt, int node, >> const char *name, >> u32 address_cells, u32 size_cells) >> @@ -435,8 +389,6 @@ static int __init early_scan_node(const void *fdt, >> { >> if ( device_tree_node_matches(fdt, node, "memory") ) >> process_memory_node(fdt, node, name, address_cells, size_cells); >> - else if ( device_tree_type_matches(fdt, node, "cpu") ) >> - process_cpu_node(fdt, node, name, address_cells, size_cells); >> else if ( device_tree_node_compatible(fdt, node, "xen,multiboot-module" >> ) ) >> process_multiboot_node(fdt, node, name, address_cells, size_cells); >> >> diff --git a/xen/include/asm-arm/processor.h >> b/xen/include/asm-arm/processor.h >> index b884354..5bc7259 100644 >> --- a/xen/include/asm-arm/processor.h >> +++ b/xen/include/asm-arm/processor.h >> @@ -13,6 +13,7 @@ >> #define MPIDR_AFF0_SHIFT (0) >> #define MPIDR_AFF0_MASK (0xff << MPIDR_AFF0_SHIFT) >> #define MPIDR_HWID_MASK 0xffffff >> +#define MPIDR_INVALID (~MPIDR_HWID_MASK) >> >> /* TTBCR Translation Table Base Control Register */ >> #define TTBCR_EAE 0x80000000 >> @@ -234,6 +235,9 @@ extern void identify_cpu(struct cpuinfo_arm *); >> extern struct cpuinfo_arm cpu_data[]; >> #define current_cpu_data cpu_data[smp_processor_id()] >> >> +extern u32 __cpu_logical_map[]; >> +#define cpu_logical_map(cpu) __cpu_logical_map[cpu] >> + >> union hsr { >> uint32_t bits; >> struct { > > -- Julien Grall _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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