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author | 2015-08-28 09:58:54 +0800 | |
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committer | 2015-09-01 12:44:00 +0800 | |
commit | e44e3482bdb4d0ebde2d8b41830ac2cdb07948fb (patch) | |
tree | 66b09f592c55df2878107a468a91d21506104d3f /qemu/pc-bios/s390-ccw/virtio.c | |
parent | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (diff) |
Add qemu 2.4.0
Change-Id: Ic99cbad4b61f8b127b7dc74d04576c0bcbaaf4f5
Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>
Diffstat (limited to 'qemu/pc-bios/s390-ccw/virtio.c')
-rw-r--r-- | qemu/pc-bios/s390-ccw/virtio.c | 434 |
1 files changed, 434 insertions, 0 deletions
diff --git a/qemu/pc-bios/s390-ccw/virtio.c b/qemu/pc-bios/s390-ccw/virtio.c new file mode 100644 index 000000000..57ff1b07e --- /dev/null +++ b/qemu/pc-bios/s390-ccw/virtio.c @@ -0,0 +1,434 @@ +/* + * Virtio driver bits + * + * Copyright (c) 2013 Alexander Graf <agraf@suse.de> + * + * This work is licensed under the terms of the GNU GPL, version 2 or (at + * your option) any later version. See the COPYING file in the top-level + * directory. + */ + +#include "s390-ccw.h" +#include "virtio.h" + +static struct vring block; + +static char chsc_page[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE))); + +static long kvm_hypercall(unsigned long nr, unsigned long param1, + unsigned long param2) +{ + register ulong r_nr asm("1") = nr; + register ulong r_param1 asm("2") = param1; + register ulong r_param2 asm("3") = param2; + register long retval asm("2"); + + asm volatile ("diag 2,4,0x500" + : "=d" (retval) + : "d" (r_nr), "0" (r_param1), "r"(r_param2) + : "memory", "cc"); + + return retval; +} + +static void virtio_notify(struct subchannel_id schid) +{ + kvm_hypercall(KVM_S390_VIRTIO_CCW_NOTIFY, *(u32 *)&schid, 0); +} + +/*********************************************** + * Virtio functions * + ***********************************************/ + +static int drain_irqs(struct subchannel_id schid) +{ + struct irb irb = {}; + int r = 0; + + while (1) { + /* FIXME: make use of TPI, for that enable subchannel and isc */ + if (tsch(schid, &irb)) { + /* Might want to differentiate error codes later on. */ + if (irb.scsw.cstat) { + r = -EIO; + } else if (irb.scsw.dstat != 0xc) { + r = -EIO; + } + return r; + } + } +} + +static int run_ccw(struct subchannel_id schid, int cmd, void *ptr, int len) +{ + struct ccw1 ccw = {}; + struct cmd_orb orb = {}; + struct schib schib; + int r; + + /* start command processing */ + stsch_err(schid, &schib); + schib.scsw.ctrl = SCSW_FCTL_START_FUNC; + msch(schid, &schib); + + /* start subchannel command */ + orb.fmt = 1; + orb.cpa = (u32)(long)&ccw; + orb.lpm = 0x80; + + ccw.cmd_code = cmd; + ccw.cda = (long)ptr; + ccw.count = len; + + r = ssch(schid, &orb); + /* + * XXX Wait until device is done processing the CCW. For now we can + * assume that a simple tsch will have finished the CCW processing, + * but the architecture allows for asynchronous operation + */ + if (!r) { + r = drain_irqs(schid); + } + return r; +} + +static void virtio_set_status(struct subchannel_id schid, + unsigned long dev_addr) +{ + unsigned char status = dev_addr; + if (run_ccw(schid, CCW_CMD_WRITE_STATUS, &status, sizeof(status))) { + virtio_panic("Could not write status to host!\n"); + } +} + +static void virtio_reset(struct subchannel_id schid) +{ + run_ccw(schid, CCW_CMD_VDEV_RESET, NULL, 0); +} + +static void vring_init(struct vring *vr, unsigned int num, void *p, + unsigned long align) +{ + debug_print_addr("init p", p); + vr->num = num; + vr->desc = p; + vr->avail = p + num*sizeof(struct vring_desc); + vr->used = (void *)(((unsigned long)&vr->avail->ring[num] + align-1) + & ~(align - 1)); + + /* Zero out all relevant field */ + vr->avail->flags = 0; + vr->avail->idx = 0; + + /* We're running with interrupts off anyways, so don't bother */ + vr->used->flags = VRING_USED_F_NO_NOTIFY; + vr->used->idx = 0; + vr->used_idx = 0; + vr->next_idx = 0; + + debug_print_addr("init vr", vr); +} + +static void vring_notify(struct subchannel_id schid) +{ + virtio_notify(schid); +} + +static void vring_send_buf(struct vring *vr, void *p, int len, int flags) +{ + /* For follow-up chains we need to keep the first entry point */ + if (!(flags & VRING_HIDDEN_IS_CHAIN)) { + vr->avail->ring[vr->avail->idx % vr->num] = vr->next_idx; + } + + vr->desc[vr->next_idx].addr = (ulong)p; + vr->desc[vr->next_idx].len = len; + vr->desc[vr->next_idx].flags = flags & ~VRING_HIDDEN_IS_CHAIN; + vr->desc[vr->next_idx].next = vr->next_idx; + vr->desc[vr->next_idx].next++; + vr->next_idx++; + + /* Chains only have a single ID */ + if (!(flags & VRING_DESC_F_NEXT)) { + vr->avail->idx++; + } +} + +static u64 get_clock(void) +{ + u64 r; + + asm volatile("stck %0" : "=Q" (r) : : "cc"); + return r; +} + +static ulong get_second(void) +{ + return (get_clock() >> 12) / 1000000; +} + +/* + * Wait for the host to reply. + * + * timeout is in seconds if > 0. + * + * Returns 0 on success, 1 on timeout. + */ +static int vring_wait_reply(struct vring *vr, int timeout) +{ + ulong target_second = get_second() + timeout; + struct subchannel_id schid = vr->schid; + int r = 0; + + /* Wait until the used index has moved. */ + while (vr->used->idx == vr->used_idx) { + vring_notify(schid); + if (timeout && (get_second() >= target_second)) { + r = 1; + break; + } + yield(); + } + + vr->used_idx = vr->used->idx; + vr->next_idx = 0; + vr->desc[0].len = 0; + vr->desc[0].flags = 0; + + return r; +} + +/*********************************************** + * Virtio block * + ***********************************************/ + +int virtio_read_many(ulong sector, void *load_addr, int sec_num) +{ + struct virtio_blk_outhdr out_hdr; + u8 status; + int r; + + /* Tell the host we want to read */ + out_hdr.type = VIRTIO_BLK_T_IN; + out_hdr.ioprio = 99; + out_hdr.sector = virtio_sector_adjust(sector); + + vring_send_buf(&block, &out_hdr, sizeof(out_hdr), VRING_DESC_F_NEXT); + + /* This is where we want to receive data */ + vring_send_buf(&block, load_addr, virtio_get_block_size() * sec_num, + VRING_DESC_F_WRITE | VRING_HIDDEN_IS_CHAIN | + VRING_DESC_F_NEXT); + + /* status field */ + vring_send_buf(&block, &status, sizeof(u8), VRING_DESC_F_WRITE | + VRING_HIDDEN_IS_CHAIN); + + /* Now we can tell the host to read */ + vring_wait_reply(&block, 0); + + r = drain_irqs(block.schid); + if (r) { + /* Well, whatever status is supposed to contain... */ + status = 1; + } + return status; +} + +unsigned long virtio_load_direct(ulong rec_list1, ulong rec_list2, + ulong subchan_id, void *load_addr) +{ + u8 status; + int sec = rec_list1; + int sec_num = ((rec_list2 >> 32) & 0xffff) + 1; + int sec_len = rec_list2 >> 48; + ulong addr = (ulong)load_addr; + + if (sec_len != virtio_get_block_size()) { + return -1; + } + + sclp_print("."); + status = virtio_read_many(sec, (void *)addr, sec_num); + if (status) { + virtio_panic("I/O Error"); + } + addr += sec_num * virtio_get_block_size(); + + return addr; +} + +int virtio_read(ulong sector, void *load_addr) +{ + return virtio_read_many(sector, load_addr, 1); +} + +static VirtioBlkConfig blk_cfg = {}; +static bool guessed_disk_nature; + +bool virtio_guessed_disk_nature(void) +{ + return guessed_disk_nature; +} + +void virtio_assume_scsi(void) +{ + guessed_disk_nature = true; + blk_cfg.blk_size = 512; + blk_cfg.physical_block_exp = 0; +} + +void virtio_assume_eckd(void) +{ + guessed_disk_nature = true; + blk_cfg.blk_size = 4096; + blk_cfg.physical_block_exp = 0; + + /* this must be here to calculate code segment position */ + blk_cfg.geometry.heads = 15; + blk_cfg.geometry.sectors = 12; +} + +bool virtio_disk_is_scsi(void) +{ + if (guessed_disk_nature) { + return (virtio_get_block_size() == 512); + } + return (blk_cfg.geometry.heads == 255) + && (blk_cfg.geometry.sectors == 63) + && (virtio_get_block_size() == 512); +} + +/* + * Other supported value pairs, if any, would need to be added here. + * Note: head count is always 15. + */ +static inline u8 virtio_eckd_sectors_for_block_size(int size) +{ + switch (size) { + case 512: + return 49; + case 1024: + return 33; + case 2048: + return 21; + case 4096: + return 12; + } + return 0; +} + +bool virtio_disk_is_eckd(void) +{ + const int block_size = virtio_get_block_size(); + + if (guessed_disk_nature) { + return (block_size == 4096); + } + return (blk_cfg.geometry.heads == 15) + && (blk_cfg.geometry.sectors == + virtio_eckd_sectors_for_block_size(block_size)); +} + +bool virtio_ipl_disk_is_valid(void) +{ + return virtio_disk_is_scsi() || virtio_disk_is_eckd(); +} + +int virtio_get_block_size(void) +{ + return blk_cfg.blk_size << blk_cfg.physical_block_exp; +} + +uint8_t virtio_get_heads(void) +{ + return blk_cfg.geometry.heads; +} + +uint8_t virtio_get_sectors(void) +{ + return blk_cfg.geometry.sectors; +} + +uint64_t virtio_get_blocks(void) +{ + return blk_cfg.capacity / + (virtio_get_block_size() / VIRTIO_SECTOR_SIZE); +} + +void virtio_setup_block(struct subchannel_id schid) +{ + struct vq_info_block info; + struct vq_config_block config = {}; + + blk_cfg.blk_size = 0; /* mark "illegal" - setup started... */ + guessed_disk_nature = false; + + virtio_reset(schid); + + /* + * Skipping CCW_CMD_READ_FEAT. We're not doing anything fancy, and + * we'll just stop dead anyway if anything does not work like we + * expect it. + */ + + config.index = 0; + if (run_ccw(schid, CCW_CMD_READ_VQ_CONF, &config, sizeof(config))) { + virtio_panic("Could not get block device VQ configuration\n"); + } + if (run_ccw(schid, CCW_CMD_READ_CONF, &blk_cfg, sizeof(blk_cfg))) { + virtio_panic("Could not get block device configuration\n"); + } + vring_init(&block, config.num, ring_area, + KVM_S390_VIRTIO_RING_ALIGN); + + info.queue = (unsigned long long) ring_area; + info.align = KVM_S390_VIRTIO_RING_ALIGN; + info.index = 0; + info.num = config.num; + block.schid = schid; + + if (!run_ccw(schid, CCW_CMD_SET_VQ, &info, sizeof(info))) { + virtio_set_status(schid, VIRTIO_CONFIG_S_DRIVER_OK); + } + + if (!virtio_ipl_disk_is_valid()) { + /* make sure all getters but blocksize return 0 for invalid IPL disk */ + memset(&blk_cfg, 0, sizeof(blk_cfg)); + virtio_assume_scsi(); + } +} + +bool virtio_is_blk(struct subchannel_id schid) +{ + int r; + struct senseid senseid = {}; + + /* run sense id command */ + r = run_ccw(schid, CCW_CMD_SENSE_ID, &senseid, sizeof(senseid)); + if (r) { + return false; + } + if ((senseid.cu_type != 0x3832) || (senseid.cu_model != VIRTIO_ID_BLOCK)) { + return false; + } + + return true; +} + +int enable_mss_facility(void) +{ + int ret; + struct chsc_area_sda *sda_area = (struct chsc_area_sda *) chsc_page; + + memset(sda_area, 0, PAGE_SIZE); + sda_area->request.length = 0x0400; + sda_area->request.code = 0x0031; + sda_area->operation_code = 0x2; + + ret = chsc(sda_area); + if ((ret == 0) && (sda_area->response.code == 0x0001)) { + return 0; + } + return -EIO; +} |