diff options
| -rw-r--r-- | arch/arm/include/asm/smp_plat.h | 18 | ||||
| -rw-r--r-- | arch/arm/include/asm/suspend.h | 5 | ||||
| -rw-r--r-- | arch/arm/kernel/asm-offsets.c | 6 | ||||
| -rw-r--r-- | arch/arm/kernel/setup.c | 67 | ||||
| -rw-r--r-- | arch/arm/kernel/sleep.S | 97 | ||||
| -rw-r--r-- | arch/arm/kernel/suspend.c | 20 |
6 files changed, 195 insertions, 18 deletions
diff --git a/arch/arm/include/asm/smp_plat.h b/arch/arm/include/asm/smp_plat.h index 1c7b6f8101ae..6e63f29f41b7 100644 --- a/arch/arm/include/asm/smp_plat.h +++ b/arch/arm/include/asm/smp_plat.h @@ -70,4 +70,22 @@ static inline int get_logical_index(u32 mpidr) return -EINVAL; } +/* + * NOTE ! Assembly code relies on the following + * structure memory layout in order to carry out load + * multiple from its base address. For more + * information check arch/arm/kernel/sleep.S + */ +struct mpidr_hash { + u32 mask; /* used by sleep.S */ + u32 shift_aff[3]; /* used by sleep.S */ + u32 bits; +}; + +extern struct mpidr_hash mpidr_hash; + +static inline u32 mpidr_hash_size(void) +{ + return 1 << mpidr_hash.bits; +} #endif diff --git a/arch/arm/include/asm/suspend.h b/arch/arm/include/asm/suspend.h index 1c0a551ae375..cd20029bcd94 100644 --- a/arch/arm/include/asm/suspend.h +++ b/arch/arm/include/asm/suspend.h @@ -1,6 +1,11 @@ #ifndef __ASM_ARM_SUSPEND_H #define __ASM_ARM_SUSPEND_H +struct sleep_save_sp { + u32 *save_ptr_stash; + u32 save_ptr_stash_phys; +}; + extern void cpu_resume(void); extern int cpu_suspend(unsigned long, int (*)(unsigned long)); diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c index ee68cce6b48e..ded041711beb 100644 --- a/arch/arm/kernel/asm-offsets.c +++ b/arch/arm/kernel/asm-offsets.c @@ -23,6 +23,7 @@ #include <asm/thread_info.h> #include <asm/memory.h> #include <asm/procinfo.h> +#include <asm/suspend.h> #include <asm/hardware/cache-l2x0.h> #include <linux/kbuild.h> @@ -145,6 +146,11 @@ int main(void) #ifdef MULTI_CACHE DEFINE(CACHE_FLUSH_KERN_ALL, offsetof(struct cpu_cache_fns, flush_kern_all)); #endif +#ifdef CONFIG_ARM_CPU_SUSPEND + DEFINE(SLEEP_SAVE_SP_SZ, sizeof(struct sleep_save_sp)); + DEFINE(SLEEP_SAVE_SP_PHYS, offsetof(struct sleep_save_sp, save_ptr_stash_phys)); + DEFINE(SLEEP_SAVE_SP_VIRT, offsetof(struct sleep_save_sp, save_ptr_stash)); +#endif BLANK(); DEFINE(DMA_BIDIRECTIONAL, DMA_BIDIRECTIONAL); DEFINE(DMA_TO_DEVICE, DMA_TO_DEVICE); diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c index ca34224f891f..9048513cbe0d 100644 --- a/arch/arm/kernel/setup.c +++ b/arch/arm/kernel/setup.c @@ -478,6 +478,72 @@ void __init smp_setup_processor_id(void) printk(KERN_INFO "Booting Linux on physical CPU 0x%x\n", mpidr); } +struct mpidr_hash mpidr_hash; +#ifdef CONFIG_SMP +/** + * smp_build_mpidr_hash - Pre-compute shifts required at each affinity + * level in order to build a linear index from an + * MPIDR value. Resulting algorithm is a collision + * free hash carried out through shifting and ORing + */ +static void __init smp_build_mpidr_hash(void) +{ + u32 i, affinity; + u32 fs[3], bits[3], ls, mask = 0; + /* + * Pre-scan the list of MPIDRS and filter out bits that do + * not contribute to affinity levels, ie they never toggle. + */ + for_each_possible_cpu(i) + mask |= (cpu_logical_map(i) ^ cpu_logical_map(0)); + pr_debug("mask of set bits 0x%x\n", mask); + /* + * Find and stash the last and first bit set at all affinity levels to + * check how many bits are required to represent them. + */ + for (i = 0; i < 3; i++) { + affinity = MPIDR_AFFINITY_LEVEL(mask, i); + /* + * Find the MSB bit and LSB bits position + * to determine how many bits are required + * to express the affinity level. + */ + ls = fls(affinity); + fs[i] = affinity ? ffs(affinity) - 1 : 0; + bits[i] = ls - fs[i]; + } + /* + * An index can be created from the MPIDR by isolating the + * significant bits at each affinity level and by shifting + * them in order to compress the 24 bits values space to a + * compressed set of values. This is equivalent to hashing + * the MPIDR through shifting and ORing. It is a collision free + * hash though not minimal since some levels might contain a number + * of CPUs that is not an exact power of 2 and their bit + * representation might contain holes, eg MPIDR[7:0] = {0x2, 0x80}. + */ + mpidr_hash.shift_aff[0] = fs[0]; + mpidr_hash.shift_aff[1] = MPIDR_LEVEL_BITS + fs[1] - bits[0]; + mpidr_hash.shift_aff[2] = 2*MPIDR_LEVEL_BITS + fs[2] - + (bits[1] + bits[0]); + mpidr_hash.mask = mask; + mpidr_hash.bits = bits[2] + bits[1] + bits[0]; + pr_debug("MPIDR hash: aff0[%u] aff1[%u] aff2[%u] mask[0x%x] bits[%u]\n", + mpidr_hash.shift_aff[0], + mpidr_hash.shift_aff[1], + mpidr_hash.shift_aff[2], + mpidr_hash.mask, + mpidr_hash.bits); + /* + * 4x is an arbitrary value used to warn on a hash table much bigger + * than expected on most systems. + */ + if (mpidr_hash_size() > 4 * num_possible_cpus()) + pr_warn("Large number of MPIDR hash buckets detected\n"); + sync_cache_w(&mpidr_hash); +} +#endif + static void __init setup_processor(void) { struct proc_info_list *list; @@ -825,6 +891,7 @@ void __init setup_arch(char **cmdline_p) smp_set_ops(mdesc->smp); } smp_init_cpus(); + smp_build_mpidr_hash(); } #endif diff --git a/arch/arm/kernel/sleep.S b/arch/arm/kernel/sleep.S index 987dcf33415c..db1536b8b30b 100644 --- a/arch/arm/kernel/sleep.S +++ b/arch/arm/kernel/sleep.S @@ -7,6 +7,49 @@ .text /* + * Implementation of MPIDR hash algorithm through shifting + * and OR'ing. + * + * @dst: register containing hash result + * @rs0: register containing affinity level 0 bit shift + * @rs1: register containing affinity level 1 bit shift + * @rs2: register containing affinity level 2 bit shift + * @mpidr: register containing MPIDR value + * @mask: register containing MPIDR mask + * + * Pseudo C-code: + * + *u32 dst; + * + *compute_mpidr_hash(u32 rs0, u32 rs1, u32 rs2, u32 mpidr, u32 mask) { + * u32 aff0, aff1, aff2; + * u32 mpidr_masked = mpidr & mask; + * aff0 = mpidr_masked & 0xff; + * aff1 = mpidr_masked & 0xff00; + * aff2 = mpidr_masked & 0xff0000; + * dst = (aff0 >> rs0 | aff1 >> rs1 | aff2 >> rs2); + *} + * Input registers: rs0, rs1, rs2, mpidr, mask + * Output register: dst + * Note: input and output registers must be disjoint register sets + (eg: a macro instance with mpidr = r1 and dst = r1 is invalid) + */ + .macro compute_mpidr_hash dst, rs0, rs1, rs2, mpidr, mask + and \mpidr, \mpidr, \mask @ mask out MPIDR bits + and \dst, \mpidr, #0xff @ mask=aff0 + ARM( mov \dst, \dst, lsr \rs0 ) @ dst=aff0>>rs0 + THUMB( lsr \dst, \dst, \rs0 ) + and \mask, \mpidr, #0xff00 @ mask = aff1 + ARM( orr \dst, \dst, \mask, lsr \rs1 ) @ dst|=(aff1>>rs1) + THUMB( lsr \mask, \mask, \rs1 ) + THUMB( orr \dst, \dst, \mask ) + and \mask, \mpidr, #0xff0000 @ mask = aff2 + ARM( orr \dst, \dst, \mask, lsr \rs2 ) @ dst|=(aff2>>rs2) + THUMB( lsr \mask, \mask, \rs2 ) + THUMB( orr \dst, \dst, \mask ) + .endm + +/* * Save CPU state for a suspend. This saves the CPU general purpose * registers, and allocates space on the kernel stack to save the CPU * specific registers and some other data for resume. @@ -29,12 +72,18 @@ ENTRY(__cpu_suspend) mov r1, r4 @ size of save block mov r2, r5 @ virtual SP ldr r3, =sleep_save_sp -#ifdef CONFIG_SMP - ALT_SMP(mrc p15, 0, lr, c0, c0, 5) - ALT_UP(mov lr, #0) - and lr, lr, #15 + ldr r3, [r3, #SLEEP_SAVE_SP_VIRT] + ALT_SMP(mrc p15, 0, r9, c0, c0, 5) + ALT_UP_B(1f) + ldr r8, =mpidr_hash + /* + * This ldmia relies on the memory layout of the mpidr_hash + * struct mpidr_hash. + */ + ldmia r8, {r4-r7} @ r4 = mpidr mask (r5,r6,r7) = l[0,1,2] shifts + compute_mpidr_hash lr, r5, r6, r7, r9, r4 add r3, r3, lr, lsl #2 -#endif +1: bl __cpu_suspend_save adr lr, BSYM(cpu_suspend_abort) ldmfd sp!, {r0, pc} @ call suspend fn @@ -81,15 +130,23 @@ ENDPROC(cpu_resume_after_mmu) .data .align ENTRY(cpu_resume) -#ifdef CONFIG_SMP - adr r0, sleep_save_sp - ALT_SMP(mrc p15, 0, r1, c0, c0, 5) - ALT_UP(mov r1, #0) - and r1, r1, #15 - ldr r0, [r0, r1, lsl #2] @ stack phys addr -#else - ldr r0, sleep_save_sp @ stack phys addr -#endif + mov r1, #0 + ALT_SMP(mrc p15, 0, r0, c0, c0, 5) + ALT_UP_B(1f) + adr r2, mpidr_hash_ptr + ldr r3, [r2] + add r2, r2, r3 @ r2 = struct mpidr_hash phys address + /* + * This ldmia relies on the memory layout of the mpidr_hash + * struct mpidr_hash. + */ + ldmia r2, { r3-r6 } @ r3 = mpidr mask (r4,r5,r6) = l[0,1,2] shifts + compute_mpidr_hash r1, r4, r5, r6, r0, r3 +1: + adr r0, _sleep_save_sp + ldr r0, [r0, #SLEEP_SAVE_SP_PHYS] + ldr r0, [r0, r1, lsl #2] + setmode PSR_I_BIT | PSR_F_BIT | SVC_MODE, r1 @ set SVC, irqs off @ load phys pgd, stack, resume fn ARM( ldmia r0!, {r1, sp, pc} ) @@ -98,7 +155,11 @@ THUMB( mov sp, r2 ) THUMB( bx r3 ) ENDPROC(cpu_resume) -sleep_save_sp: - .rept CONFIG_NR_CPUS - .long 0 @ preserve stack phys ptr here - .endr + .align 2 +mpidr_hash_ptr: + .long mpidr_hash - . @ mpidr_hash struct offset + + .type sleep_save_sp, #object +ENTRY(sleep_save_sp) +_sleep_save_sp: + .space SLEEP_SAVE_SP_SZ @ struct sleep_save_sp diff --git a/arch/arm/kernel/suspend.c b/arch/arm/kernel/suspend.c index 38a50676213b..41cf3cbf756d 100644 --- a/arch/arm/kernel/suspend.c +++ b/arch/arm/kernel/suspend.c @@ -1,9 +1,12 @@ #include <linux/init.h> +#include <linux/slab.h> +#include <asm/cacheflush.h> #include <asm/idmap.h> #include <asm/pgalloc.h> #include <asm/pgtable.h> #include <asm/memory.h> +#include <asm/smp_plat.h> #include <asm/suspend.h> #include <asm/tlbflush.h> @@ -82,3 +85,20 @@ void __cpu_suspend_save(u32 *ptr, u32 ptrsz, u32 sp, u32 *save_ptr) outer_clean_range(virt_to_phys(save_ptr), virt_to_phys(save_ptr) + sizeof(*save_ptr)); } + +extern struct sleep_save_sp sleep_save_sp; + +static int cpu_suspend_alloc_sp(void) +{ + void *ctx_ptr; + /* ctx_ptr is an array of physical addresses */ + ctx_ptr = kcalloc(mpidr_hash_size(), sizeof(u32), GFP_KERNEL); + + if (WARN_ON(!ctx_ptr)) + return -ENOMEM; + sleep_save_sp.save_ptr_stash = ctx_ptr; + sleep_save_sp.save_ptr_stash_phys = virt_to_phys(ctx_ptr); + sync_cache_w(&sleep_save_sp); + return 0; +} +early_initcall(cpu_suspend_alloc_sp); |