• David S. Miller's avatar
    [SPARC64]: Eliminate NR_CPUS limitations. · 22adb358
    David S. Miller authored
    
    Cheetah systems can have cpuids as large as 1023, although physical
    systems don't have that many cpus.
    
    Only three limitations existed in the kernel preventing arbitrary
    NR_CPUS values:
    
    1) dcache dirty cpu state stored in page->flags on
       D-cache aliasing platforms.  With some build time
       calculations and some build-time BUG checks on
       page->flags layout, this one was easily solved.
    
    2) The cheetah XCALL delivery code could only handle
       a cpumask with up to 32 cpus set.  Some simple looping
       logic clears that up too.
    
    3) thread_info->cpu was a u8, easily changed to a u16.
    
    There are a few spots in the kernel that still put NR_CPUS
    sized arrays on the kernel stack, but that's not a sparc64
    specific problem.
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    22adb358
cpudata.h 7.05 KB
/* cpudata.h: Per-cpu parameters.
 *
 * Copyright (C) 2003, 2005, 2006 David S. Miller (davem@davemloft.net)
 */

#ifndef _SPARC64_CPUDATA_H
#define _SPARC64_CPUDATA_H

#include <asm/hypervisor.h>
#include <asm/asi.h>

#ifndef __ASSEMBLY__

#include <linux/percpu.h>
#include <linux/threads.h>

typedef struct {
	/* Dcache line 1 */
	unsigned int	__softirq_pending; /* must be 1st, see rtrap.S */
	unsigned int	__pad0;
	unsigned long	clock_tick;	/* %tick's per second */
	unsigned long	udelay_val;
	unsigned int	__pad1;
	unsigned int	__pad2;

	/* Dcache line 2, rarely used */
	unsigned int	dcache_size;
	unsigned int	dcache_line_size;
	unsigned int	icache_size;
	unsigned int	icache_line_size;
	unsigned int	ecache_size;
	unsigned int	ecache_line_size;
	int		core_id;
	unsigned int	__pad3;
} cpuinfo_sparc;

DECLARE_PER_CPU(cpuinfo_sparc, __cpu_data);
#define cpu_data(__cpu)		per_cpu(__cpu_data, (__cpu))
#define local_cpu_data()	__get_cpu_var(__cpu_data)

/* Trap handling code needs to get at a few critical values upon
 * trap entry and to process TSB misses.  These cannot be in the
 * per_cpu() area as we really need to lock them into the TLB and
 * thus make them part of the main kernel image.  As a result we
 * try to make this as small as possible.
 *
 * This is padded out and aligned to 64-bytes to avoid false sharing
 * on SMP.
 */

/* If you modify the size of this structure, please update
 * TRAP_BLOCK_SZ_SHIFT below.
 */
struct thread_info;
struct trap_per_cpu {
/* D-cache line 1: Basic thread information, cpu and device mondo queues */
	struct thread_info	*thread;
	unsigned long		pgd_paddr;
	unsigned long		cpu_mondo_pa;
	unsigned long		dev_mondo_pa;

/* D-cache line 2: Error Mondo Queue and kernel buffer pointers */
	unsigned long		resum_mondo_pa;
	unsigned long		resum_kernel_buf_pa;
	unsigned long		nonresum_mondo_pa;
	unsigned long		nonresum_kernel_buf_pa;

/* Dcache lines 3, 4, 5, and 6: Hypervisor Fault Status */
	struct hv_fault_status	fault_info;

/* Dcache line 7: Physical addresses of CPU send mondo block and CPU list.  */
	unsigned long		cpu_mondo_block_pa;
	unsigned long		cpu_list_pa;
	unsigned long		tsb_huge;
	unsigned long		tsb_huge_temp;

/* Dcache line 8: IRQ work list, and keep trap_block a power-of-2 in size.  */
	unsigned int		irq_worklist;
	unsigned int		cpu_mondo_qmask;
	unsigned int		dev_mondo_qmask;
	unsigned int		resum_qmask;
	unsigned int		nonresum_qmask;
	unsigned int		__pad2[3];
} __attribute__((aligned(64)));
extern struct trap_per_cpu trap_block[NR_CPUS];
extern void init_cur_cpu_trap(struct thread_info *);
extern void setup_tba(void);
extern int ncpus_probed;

extern unsigned long real_hard_smp_processor_id(void);

struct cpuid_patch_entry {
	unsigned int	addr;
	unsigned int	cheetah_safari[4];
	unsigned int	cheetah_jbus[4];
	unsigned int	starfire[4];
	unsigned int	sun4v[4];
};
extern struct cpuid_patch_entry __cpuid_patch, __cpuid_patch_end;

struct sun4v_1insn_patch_entry {
	unsigned int	addr;
	unsigned int	insn;
};
extern struct sun4v_1insn_patch_entry __sun4v_1insn_patch,
	__sun4v_1insn_patch_end;

struct sun4v_2insn_patch_entry {
	unsigned int	addr;
	unsigned int	insns[2];
};
extern struct sun4v_2insn_patch_entry __sun4v_2insn_patch,
	__sun4v_2insn_patch_end;

#endif /* !(__ASSEMBLY__) */

#define TRAP_PER_CPU_THREAD		0x00
#define TRAP_PER_CPU_PGD_PADDR		0x08
#define TRAP_PER_CPU_CPU_MONDO_PA	0x10
#define TRAP_PER_CPU_DEV_MONDO_PA	0x18
#define TRAP_PER_CPU_RESUM_MONDO_PA	0x20
#define TRAP_PER_CPU_RESUM_KBUF_PA	0x28
#define TRAP_PER_CPU_NONRESUM_MONDO_PA	0x30
#define TRAP_PER_CPU_NONRESUM_KBUF_PA	0x38
#define TRAP_PER_CPU_FAULT_INFO		0x40
#define TRAP_PER_CPU_CPU_MONDO_BLOCK_PA	0xc0
#define TRAP_PER_CPU_CPU_LIST_PA	0xc8
#define TRAP_PER_CPU_TSB_HUGE		0xd0
#define TRAP_PER_CPU_TSB_HUGE_TEMP	0xd8
#define TRAP_PER_CPU_IRQ_WORKLIST	0xe0
#define TRAP_PER_CPU_CPU_MONDO_QMASK	0xe4
#define TRAP_PER_CPU_DEV_MONDO_QMASK	0xe8
#define TRAP_PER_CPU_RESUM_QMASK	0xec
#define TRAP_PER_CPU_NONRESUM_QMASK	0xf0

#define TRAP_BLOCK_SZ_SHIFT		8

#include <asm/scratchpad.h>

#define __GET_CPUID(REG)				\
	/* Spitfire implementation (default). */	\
661:	ldxa		[%g0] ASI_UPA_CONFIG, REG;	\
	srlx		REG, 17, REG;			\
	 and		REG, 0x1f, REG;			\
	nop;						\
	.section	.cpuid_patch, "ax";		\
	/* Instruction location. */			\
	.word		661b;				\
	/* Cheetah Safari implementation. */		\
	ldxa		[%g0] ASI_SAFARI_CONFIG, REG;	\
	srlx		REG, 17, REG;			\
	and		REG, 0x3ff, REG;		\
	nop;						\
	/* Cheetah JBUS implementation. */		\
	ldxa		[%g0] ASI_JBUS_CONFIG, REG;	\
	srlx		REG, 17, REG;			\
	and		REG, 0x1f, REG;			\
	nop;						\
	/* Starfire implementation. */			\
	sethi		%hi(0x1fff40000d0 >> 9), REG;	\
	sllx		REG, 9, REG;			\
	or		REG, 0xd0, REG;			\
	lduwa		[REG] ASI_PHYS_BYPASS_EC_E, REG;\
	/* sun4v implementation. */			\
	mov		SCRATCHPAD_CPUID, REG;		\
	ldxa		[REG] ASI_SCRATCHPAD, REG;	\
	nop;						\
	nop;						\
	.previous;

#ifdef CONFIG_SMP

#define TRAP_LOAD_TRAP_BLOCK(DEST, TMP)		\
	__GET_CPUID(TMP)			\
	sethi	%hi(trap_block), DEST;		\
	sllx	TMP, TRAP_BLOCK_SZ_SHIFT, TMP;	\
	or	DEST, %lo(trap_block), DEST;	\
	add	DEST, TMP, DEST;		\

/* Clobbers TMP, current address space PGD phys address into DEST.  */
#define TRAP_LOAD_PGD_PHYS(DEST, TMP)		\
	TRAP_LOAD_TRAP_BLOCK(DEST, TMP)		\
	ldx	[DEST + TRAP_PER_CPU_PGD_PADDR], DEST;

/* Clobbers TMP, loads local processor's IRQ work area into DEST.  */
#define TRAP_LOAD_IRQ_WORK(DEST, TMP)		\
	TRAP_LOAD_TRAP_BLOCK(DEST, TMP)		\
	add	DEST, TRAP_PER_CPU_IRQ_WORKLIST, DEST;

/* Clobbers TMP, loads DEST with current thread info pointer.  */
#define TRAP_LOAD_THREAD_REG(DEST, TMP)		\
	TRAP_LOAD_TRAP_BLOCK(DEST, TMP)		\
	ldx	[DEST + TRAP_PER_CPU_THREAD], DEST;

/* Given the current thread info pointer in THR, load the per-cpu
 * area base of the current processor into DEST.  REG1, REG2, and REG3 are
 * clobbered.
 *
 * You absolutely cannot use DEST as a temporary in this code.  The
 * reason is that traps can happen during execution, and return from
 * trap will load the fully resolved DEST per-cpu base.  This can corrupt
 * the calculations done by the macro mid-stream.
 */
#define LOAD_PER_CPU_BASE(DEST, THR, REG1, REG2, REG3)	\
	lduh	[THR + TI_CPU], REG1;			\
	sethi	%hi(__per_cpu_shift), REG3;		\
	sethi	%hi(__per_cpu_base), REG2;		\
	ldx	[REG3 + %lo(__per_cpu_shift)], REG3;	\
	ldx	[REG2 + %lo(__per_cpu_base)], REG2;	\
	sllx	REG1, REG3, REG3;			\
	add	REG3, REG2, DEST;

#else

#define TRAP_LOAD_TRAP_BLOCK(DEST, TMP)		\
	sethi	%hi(trap_block), DEST;		\
	or	DEST, %lo(trap_block), DEST;	\

/* Uniprocessor versions, we know the cpuid is zero.  */
#define TRAP_LOAD_PGD_PHYS(DEST, TMP)		\
	TRAP_LOAD_TRAP_BLOCK(DEST, TMP)		\
	ldx	[DEST + TRAP_PER_CPU_PGD_PADDR], DEST;

/* Clobbers TMP, loads local processor's IRQ work area into DEST.  */
#define TRAP_LOAD_IRQ_WORK(DEST, TMP)		\
	TRAP_LOAD_TRAP_BLOCK(DEST, TMP)		\
	add	DEST, TRAP_PER_CPU_IRQ_WORKLIST, DEST;

#define TRAP_LOAD_THREAD_REG(DEST, TMP)		\
	TRAP_LOAD_TRAP_BLOCK(DEST, TMP)		\
	ldx	[DEST + TRAP_PER_CPU_THREAD], DEST;

/* No per-cpu areas on uniprocessor, so no need to load DEST.  */
#define LOAD_PER_CPU_BASE(DEST, THR, REG1, REG2, REG3)

#endif /* !(CONFIG_SMP) */

#endif /* _SPARC64_CPUDATA_H */