• David S. Miller's avatar
    [SPARC64]: Get SUN4V SMP working. · 72aff53f
    David S. Miller authored
    
    The sibling cpu bringup is extremely fragile.  We can only
    perform the most basic calls until we take over the trap
    table from the firmware/hypervisor on the new cpu.
    
    This means no accesses to %g4, %g5, %g6 since those can't be
    TLB translated without our trap handlers.
    
    In order to achieve this:
    
    1) Change sun4v_init_mondo_queues() so that it can operate in
       several modes.
    
       It can allocate the queues, or install them in the current
       processor, or both.
    
       The boot cpu does both in it's call early on.
    
       Later, the boot cpu allocates the sibling cpu queue, starts
       the sibling cpu, then the sibling cpu loads them in.
    
    2) init_cur_cpu_trap() is changed to take the current_thread_info()
       as an argument instead of reading %g6 directly on the current
       cpu.
    
    3) Create a trampoline stack for the sibling cpus.  We do our basic
       kernel calls using this stack, which is locked into the kernel
       image, then go to our proper thread stack after taking over the
       trap table.
    
    4) While we are in this delicate startup state, we put 0xdeadbeef
       into %g4/%g5/%g6 in order to catch accidental accesses.
    
    5) On the final prom_set_trap_table*() call, we put &init_thread_union
       into %g6.  This is a hack to make prom_world(0) work.  All that
       wants to do is restore the %asi register using
       get_thread_current_ds().
    
    Longer term we should just do the OBP calls to set the trap table by
    hand just like we do for everything else.  This would avoid that silly
    prom_world(0) issue, then we can remove the init_thread_union hack.
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    72aff53f
cpudata.h 6.54 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	multiplier;
	unsigned int	counter;
	unsigned int	idle_volume;
	unsigned long	clock_tick;	/* %tick's per second */
	unsigned long	udelay_val;

	/* 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;
	unsigned int	__pad3;
	unsigned int	__pad4;
} 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		__pad1[2];

/* Dcache line 8: Unused, needed to keep trap_block a power-of-2 in size.  */
	unsigned long		__pad2[4];
} __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);

#ifdef CONFIG_SMP
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;
#endif

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_BLOCK_SZ_SHIFT		8

#include <asm/scratchpad.h>

#ifdef CONFIG_SMP

#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;

#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)		\
	__GET_CPUID(TMP)			\
	sethi	%hi(__irq_work), DEST;		\
	sllx	TMP, 6, TMP;			\
	or	DEST, %lo(__irq_work), DEST;	\
	add	DEST, TMP, 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)	\
	ldub	[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;

#define TRAP_LOAD_IRQ_WORK(DEST, TMP)		\
	sethi	%hi(__irq_work), DEST;		\
	or	DEST, %lo(__irq_work), 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 */