[S390] add hardware capability support (ELF_HWCAP). (cf8ba7a9) · Commits · e / devices / android_kernel_fairphone_FP3

arch/s390/kernel/setup.c

+109 −0

Original line number	Diff line number	Diff line
		@@ -74,6 +74,8 @@ unsigned int console_mode = 0;
		unsigned int console_devno = -1;
		unsigned int console_irq = -1;
		unsigned long machine_flags = 0;
		unsigned long elf_hwcap = 0;
		char elf_platform[ELF_PLATFORM_SIZE];

		struct mem_chunk __initdata memory_chunk[MEMORY_CHUNKS];
		volatile int __cpu_logical_map[NR_CPUS]; /* logical cpu to cpu address */
		@@ -749,6 +751,98 @@ setup_memory(void)
		#endif
		}

		static __init unsigned int stfl(void)
		{
		asm volatile(
		" .insn s,0xb2b10000,0(0)\n" /* stfl */
		"0:\n"
		EX_TABLE(0b,0b));
		return S390_lowcore.stfl_fac_list;
		}

		static __init int stfle(unsigned long long *list, int doublewords)
		{
		typedef struct { unsigned long long _[doublewords]; } addrtype;
		register unsigned long __nr asm("0") = doublewords - 1;

		asm volatile(".insn s,0xb2b00000,%0" /* stfle */
		: "=m" ((addrtype ) list), "+d" (__nr) : : "cc");
		return __nr + 1;
		}

		/*
		* Setup hardware capabilities.
		*/
		static void __init setup_hwcaps(void)
		{
		static const int stfl_bits[6] = { 0, 2, 7, 17, 19, 21 };
		struct cpuinfo_S390 *cpuinfo = &S390_lowcore.cpu_data;
		unsigned long long facility_list_extended;
		unsigned int facility_list;
		int i;

		facility_list = stfl();
		/*
		* The store facility list bits numbers as found in the principles
		* of operation are numbered with bit 1UL<<31 as number 0 to
		* bit 1UL<<0 as number 31.
		* Bit 0: instructions named N3, "backported" to esa-mode
		* Bit 2: z/Architecture mode is active
		* Bit 7: the store-facility-list-extended facility is installed
		* Bit 17: the message-security assist is installed
		* Bit 19: the long-displacement facility is installed
		* Bit 21: the extended-immediate facility is installed
		* These get translated to:
		* HWCAP_S390_ESAN3 bit 0, HWCAP_S390_ZARCH bit 1,
		* HWCAP_S390_STFLE bit 2, HWCAP_S390_MSA bit 3,
		* HWCAP_S390_LDISP bit 4, and HWCAP_S390_EIMM bit 5.
		*/
		for (i = 0; i < 6; i++)
		if (facility_list & (1UL << (31 - stfl_bits[i])))
		elf_hwcap \|= 1UL << i;

		/*
		* Check for additional facilities with store-facility-list-extended.
		* stfle stores doublewords (8 byte) with bit 1ULL<<63 as bit 0
		* and 1ULL<<0 as bit 63. Bits 0-31 contain the same information
		* as stored by stfl, bits 32-xxx contain additional facilities.
		* How many facility words are stored depends on the number of
		* doublewords passed to the instruction. The additional facilites
		* are:
		* Bit 43: decimal floating point facility is installed
		* translated to:
		* HWCAP_S390_DFP bit 6.
		*/
		if ((elf_hwcap & (1UL << 2)) &&
		stfle(&facility_list_extended, 1) > 0) {
		if (facility_list_extended & (1ULL << (64 - 43)))
		elf_hwcap \|= 1UL << 6;
		}

		switch (cpuinfo->cpu_id.machine) {
		case 0x9672:
		#if !defined(CONFIG_64BIT)
		default: /* Use "g5" as default for 31 bit kernels. */
		#endif
		strcpy(elf_platform, "g5");
		break;
		case 0x2064:
		case 0x2066:
		#if defined(CONFIG_64BIT)
		default: /* Use "z900" as default for 64 bit kernels. */
		#endif
		strcpy(elf_platform, "z900");
		break;
		case 0x2084:
		case 0x2086:
		strcpy(elf_platform, "z990");
		break;
		case 0x2094:
		strcpy(elf_platform, "z9-109");
		break;
		}
		}

		/*
		* Setup function called from init/main.c just after the banner
		* was printed.
		@@ -804,6 +898,11 @@ setup_arch(char **cmdline_p)
		__cpu_logical_map[0] = S390_lowcore.cpu_data.cpu_addr;
		smp_setup_cpu_possible_map();

		/*
		* Setup capabilities (ELF_HWCAP & ELF_PLATFORM).
		*/
		setup_hwcaps();

		/*
		* Create kernel page tables and switch to virtual addressing.
		*/
		@@ -839,8 +938,12 @@ void print_cpu_info(struct cpuinfo_S390 *cpuinfo)

		static int show_cpuinfo(struct seq_file m, void v)
		{
		static const char *hwcap_str[7] = {
		"esan3", "zarch", "stfle", "msa", "ldisp", "eimm", "dfp"
		};
		struct cpuinfo_S390 *cpuinfo;
		unsigned long n = (unsigned long) v - 1;
		int i;

		s390_adjust_jiffies();
		preempt_disable();
		@@ -850,7 +953,13 @@ static int show_cpuinfo(struct seq_file m, void v)
		"bogomips per cpu: %lu.%02lu\n",
		num_online_cpus(), loops_per_jiffy/(500000/HZ),
		(loops_per_jiffy/(5000/HZ))%100);
		seq_puts(m, "features\t: ");
		for (i = 0; i < 7; i++)
		if (hwcap_str[i] && (elf_hwcap & (1UL << i)))
		seq_printf(m, "%s ", hwcap_str[i]);
		seq_puts(m, "\n");
		}

		if (cpu_online(n)) {
		#ifdef CONFIG_SMP
		if (smp_processor_id() == n)

include/asm-s390/elf.h

+5 −2

Original line number	Diff line number	Diff line
		@@ -188,7 +188,8 @@ static inline int dump_task_fpu(struct task_struct tsk, elf_fpregset_t fpregs)
		/* This yields a mask that user programs can use to figure out what
		instruction set this CPU supports. */

		#define ELF_HWCAP (0)
		extern unsigned long elf_hwcap;
		#define ELF_HWCAP (elf_hwcap)

		/* This yields a string that ld.so will use to load implementation
		specific libraries for optimization. This is more specific in
		@@ -197,7 +198,9 @@ static inline int dump_task_fpu(struct task_struct tsk, elf_fpregset_t fpregs)
		For the moment, we have only optimizations for the Intel generations,
		but that could change... */

		#define ELF_PLATFORM (NULL)
		#define ELF_PLATFORM_SIZE 8
		extern char elf_platform[];
		#define ELF_PLATFORM (elf_platform)

		#ifndef __s390x__
		#define SET_PERSONALITY(ex, ibcs2) set_personality((ibcs2)?PER_SVR4:PER_LINUX)

include/asm-s390/lowcore.h

+6 −4

Original line number	Diff line number	Diff line
		@@ -229,17 +229,19 @@ struct _lowcore
		__u16 subchannel_nr; /* 0x0ba */
		__u32 io_int_parm; /* 0x0bc */
		__u32 io_int_word; /* 0x0c0 */
		__u8 pad3[0xD4-0xC4]; /* 0x0c4 */
		__u8 pad3[0xc8-0xc4]; /* 0x0c4 */
		__u32 stfl_fac_list; /* 0x0c8 */
		__u8 pad4[0xd4-0xcc]; /* 0x0cc */
		__u32 extended_save_area_addr; /* 0x0d4 */
		__u32 cpu_timer_save_area[2]; /* 0x0d8 */
		__u32 clock_comp_save_area[2]; /* 0x0e0 */
		__u32 mcck_interruption_code[2]; /* 0x0e8 */
		__u8 pad4[0xf4-0xf0]; /* 0x0f0 */
		__u8 pad5[0xf4-0xf0]; /* 0x0f0 */
		__u32 external_damage_code; /* 0x0f4 */
		__u32 failing_storage_address; /* 0x0f8 */
		__u8 pad5[0x100-0xfc]; /* 0x0fc */
		__u8 pad6[0x100-0xfc]; /* 0x0fc */
		__u32 st_status_fixed_logout[4];/* 0x100 */
		__u8 pad6[0x120-0x110]; /* 0x110 */
		__u8 pad7[0x120-0x110]; /* 0x110 */
		__u32 access_regs_save_area[16];/* 0x120 */
		__u32 floating_pt_save_area[8]; /* 0x160 */
		__u32 gpregs_save_area[16]; /* 0x180 */