extmem.c

优龙2410linux2.6.8内核源代码

/*
 * File...........: arch/s390/mm/dcss.c
 * Author(s)......: Steven Shultz <[e-mail]>
 *                  Carsten Otte <[e-mail]>
 * Bugreports.to..: <[e-mail]>
 * thanks to Rob M van der Heij
 * - he wrote the diag64 function
 * (C) IBM Corporation 2002
 */

#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/bootmem.h>
#include <asm/page.h>
#include <asm/ebcdic.h>
#include <asm/errno.h>
#include <asm/extmem.h>
#include <asm/cpcmd.h>
#include <linux/ctype.h>

#define DCSS_DEBUG	/* Debug messages on/off */

#define DCSS_NAME "extmem"
#ifdef DCSS_DEBUG
#define PRINT_DEBUG(x...)	printk(KERN_DEBUG DCSS_NAME " debug:" x)
#else
#define PRINT_DEBUG(x...)   do {} while (0)
#endif
#define PRINT_INFO(x...)	printk(KERN_INFO DCSS_NAME " info:" x)
#define PRINT_WARN(x...)	printk(KERN_WARNING DCSS_NAME " warning:" x)
#define PRINT_ERR(x...)		printk(KERN_ERR DCSS_NAME " error:" x)


#define DCSS_LOADSHR    0x00
#define DCSS_LOADNSR    0x04
#define DCSS_PURGESEG   0x08
#define DCSS_FINDSEG    0x0c
#define DCSS_LOADNOLY   0x10
#define DCSS_SEGEXT     0x18
#define DCSS_QACTV      0x0c

struct dcss_segment {
        struct list_head list;
        char dcss_name[8];
        unsigned long start_addr;
        unsigned long end;
        atomic_t ref_count;
        int dcss_attr;
	int shared_attr;
};

static spinlock_t dcss_lock = SPIN_LOCK_UNLOCKED;
static struct list_head dcss_list = LIST_HEAD_INIT(dcss_list);
extern struct {
	unsigned long addr, size, type;
} memory_chunk[MEMORY_CHUNKS];

/*
 * Create the 8 bytes, ebcdic VM segment name from
 * an ascii name.
 */
static void inline dcss_mkname(char *name, char *dcss_name)
{
        int i;

        for (i = 0; i <= 8; i++) {
                if (name[i] == '\0')
                        break;
                dcss_name[i] = toupper(name[i]);
        };
        for (; i <= 8; i++)
                dcss_name[i] = ' ';
        ASCEBC(dcss_name, 8);
}

/*
 * Perform a function on a dcss segment.
 */
static inline int
dcss_diag (__u8 func, void *parameter,
           unsigned long *ret1, unsigned long *ret2)
{
        unsigned long rx, ry;
        int rc;

        rx = (unsigned long) parameter;
        ry = (unsigned long) func;
        __asm__ __volatile__(
#ifdef CONFIG_ARCH_S390X
                             "   sam31\n" // switch to 31 bit
                             "   diag    %0,%1,0x64\n"
                             "   sam64\n" // switch back to 64 bit
#else
                             "   diag    %0,%1,0x64\n"
#endif
                             "   ipm     %2\n"
                             "   srl     %2,28\n"
                             : "+d" (rx), "+d" (ry), "=d" (rc) : : "cc" );
        *ret1 = rx;
        *ret2 = ry;
        return rc;
}


/* use to issue "extended" dcss query */
static inline int
dcss_diag_query(char *name, int *rwattr, int *shattr, unsigned long *segstart, unsigned long *segend)
{
        int i,j,rc;
        unsigned long  rx, ry;

        typedef struct segentry {
                char thisseg[8];
        } segentry;

        struct qout64 {
                int segstart;
                int segend;
                int segcnt;
                int segrcnt;
                segentry segout[6];
        };

        struct qin64 {
                char qopcode;
                char rsrv1[3];
                char qrcode;
                char rsrv2[3];
                char qname[8];
                unsigned int qoutptr;
                short int qoutlen;
        };


        struct qin64  *qinarea;
        struct qout64 *qoutarea;

        qinarea = (struct qin64*) get_zeroed_page (GFP_DMA);
        if (!qinarea) {
                rc =-ENOMEM;
                goto out;
        }
        qoutarea = (struct qout64*) get_zeroed_page (GFP_DMA);
        if (!qoutarea) {
                rc = -ENOMEM;
                free_page ((unsigned long) qinarea);
                goto out;
        }
        memset (qinarea,0,PAGE_SIZE);
        memset (qoutarea,0,PAGE_SIZE);

        qinarea->qopcode = DCSS_QACTV; /* do a query for active
                                          segments */
        qinarea->qoutptr = (unsigned long) qoutarea;
        qinarea->qoutlen = sizeof(struct qout64);

        /* Move segment name into double word aligned
           field and pad with blanks to 8 long.
         */

        for (i = j = 0 ; i < 8; i++) {
                qinarea->qname[i] = (name[j] == '\0') ? ' ' : name[j++];
        }

        /* name already in EBCDIC */
        /* ASCEBC ((void *)&qinarea.qname, 8); */

        /* set the assembler variables */
        rx = (unsigned long) qinarea;
        ry = DCSS_SEGEXT; /* this is extended function */

        /* issue diagnose x'64' */
        __asm__ __volatile__(
#ifdef CONFIG_ARCH_S390X
                             "   sam31\n" // switch to 31 bit
                             "   diag    %0,%1,0x64\n"
                             "   sam64\n" // switch back to 64 bit
#else
                             "   diag    %0,%1,0x64\n"
#endif
                             "   ipm     %2\n"
                             "   srl     %2,28\n"
                             : "+d" (rx), "+d" (ry), "=d" (rc) : : "cc" );

        /* parse the query output area */
	*segstart=qoutarea->segstart;
	*segend=qoutarea->segend;

        if (rc > 1)
                {
                        *rwattr = 2;
                        *shattr = 2;
                        rc = 0;
                        goto free;
                }

        if (qoutarea->segcnt > 6)
                {
                        *rwattr = 3;
                        *shattr = 3;
                        rc = 0;
                        goto free;
                }

        *rwattr = 1;
        *shattr = 1;

        for (i=0; i < qoutarea->segrcnt; i++) {
                if (qoutarea->segout[i].thisseg[3] == 2 ||
                    qoutarea->segout[i].thisseg[3] == 3 ||
                    qoutarea->segout[i].thisseg[3] == 6 )
                        *rwattr = 0;
                if (qoutarea->segout[i].thisseg[3] == 1 ||
                    qoutarea->segout[i].thisseg[3] == 3 ||
                    qoutarea->segout[i].thisseg[3] == 5 )
                        *shattr = 0;
        } /* end of for statement */
        rc = 0;
 free:
        free_page ((unsigned long) qoutarea);
        free_page ((unsigned long) qinarea);
 out:
        return rc;
}

/*
 * Load a DCSS segment via the diag 0x64.
 */
int segment_load(char *name, int segtype, unsigned long *addr,
                 unsigned long *end)
{
        char dcss_name[8];
        struct list_head *l;
        struct dcss_segment *seg, *tmp;
	unsigned long dummy;
	unsigned long segstart, segend;
        int rc = 0,i;
        int rwattr, shattr;

        if (!MACHINE_IS_VM)
                return -ENOSYS;
        dcss_mkname(name, dcss_name);
	/* search for the dcss in list of currently loaded segments */
        spin_lock(&dcss_lock);
        seg = NULL;
        list_for_each(l, &dcss_list) {
                tmp = list_entry(l, struct dcss_segment, list);
                if (memcmp(tmp->dcss_name, dcss_name, 8) == 0) {
                        seg = tmp;