scsi: add AMD PCscsi driver

This is a driver for an AMD PCscsi (am53c974) SCSI card.  It can be
used together with DOS or old operating systems such as Windows NT 3.1,
Windows 3.1 or Windows 98.

Cc: Hervé Poussineau <hpoussin@reactos.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/src/Kconfig b/src/Kconfig
index bc343ee..6de3e71 100644
--- a/src/Kconfig
+++ b/src/Kconfig
@@ -119,6 +119,12 @@
         default y
         help
             Support boot from virtio-scsi storage.
+    config ESP_SCSI
+        depends on DRIVES && !COREBOOT
+        bool "AMD PCscsi controllers"
+        default y
+        help
+            Support boot from AMD PCscsi storage.
     config LSI_SCSI
         depends on DRIVES && !COREBOOT
         bool "lsi53c895a scsi controllers"
diff --git a/src/block.c b/src/block.c
index 1c200cc..243428e 100644
--- a/src/block.c
+++ b/src/block.c
@@ -335,6 +335,7 @@
     case DTYPE_UAS:
     case DTYPE_VIRTIO_SCSI:
     case DTYPE_LSI_SCSI:
+    case DTYPE_ESP_SCSI:
         return process_scsi_op(op);
     default:
         op->count = 0;
diff --git a/src/blockcmd.c b/src/blockcmd.c
index 4365650..97c72a6 100644
--- a/src/blockcmd.c
+++ b/src/blockcmd.c
@@ -15,6 +15,7 @@
 #include "usb-uas.h" // usb_cmd_data
 #include "virtio-scsi.h" // virtio_scsi_cmd_data
 #include "lsi-scsi.h" // lsi_scsi_cmd_data
+#include "esp-scsi.h" // esp_scsi_cmd_data
 #include "boot.h" // boot_add_hd
 
 // Route command to low-level handler.
@@ -35,6 +36,8 @@
         return virtio_scsi_cmd_data(op, cdbcmd, blocksize);
     case DTYPE_LSI_SCSI:
         return lsi_scsi_cmd_data(op, cdbcmd, blocksize);
+    case DTYPE_ESP_SCSI:
+        return esp_scsi_cmd_data(op, cdbcmd, blocksize);
     default:
         op->count = 0;
         return DISK_RET_EPARAM;
diff --git a/src/disk.h b/src/disk.h
index 2b2511f..3d07372 100644
--- a/src/disk.h
+++ b/src/disk.h
@@ -234,6 +234,7 @@
 #define DTYPE_USB          0x0a
 #define DTYPE_UAS          0x0b
 #define DTYPE_LSI_SCSI     0x0c
+#define DTYPE_ESP_SCSI     0x0d
 
 #define MAXDESCSIZE 80
 
diff --git a/src/esp-scsi.c b/src/esp-scsi.c
new file mode 100644
index 0000000..b795012
--- /dev/null
+++ b/src/esp-scsi.c
@@ -0,0 +1,231 @@
+// AMD PCscsi boot support.
+//
+// Copyright (C) 2012 Red Hat Inc.
+//
+// Authors:
+//  Paolo Bonzini <pbonzini@redhat.com>
+//
+// based on lsi-scsi.c which is written by:
+//  Gerd Hoffman <kraxel@redhat.com>
+//
+// This file may be distributed under the terms of the GNU LGPLv3 license.
+
+#include "util.h" // dprintf
+#include "pci.h" // foreachpci
+#include "config.h" // CONFIG_*
+#include "biosvar.h" // GET_GLOBAL
+#include "pci_ids.h" // PCI_DEVICE_ID
+#include "pci_regs.h" // PCI_VENDOR_ID
+#include "boot.h" // bootprio_find_scsi_device
+#include "blockcmd.h" // scsi_init_drive
+#include "disk.h"
+
+#define ESP_TCLO      0x00
+#define ESP_TCMID     0x04
+#define ESP_FIFO      0x08
+#define ESP_CMD       0x0c
+#define ESP_WBUSID    0x10
+#define ESP_TCHI      0x38
+
+#define ESP_RSTAT     0x10
+#define ESP_RINTR     0x14
+#define ESP_RFLAGS    0x1c
+
+#define ESP_DMA_CMD   0x40
+#define ESP_DMA_STC   0x44
+#define ESP_DMA_SPA   0x48
+#define ESP_DMA_WBC   0x4c
+#define ESP_DMA_WAC   0x50
+#define ESP_DMA_STAT  0x54
+#define ESP_DMA_SMDLA 0x58
+#define ESP_DMA_WMAC  0x58c
+
+#define ESP_CMD_DMA      0x80
+#define ESP_CMD_RESET    0x02
+#define ESP_CMD_TI       0x10
+#define ESP_CMD_ICCS     0x11
+#define ESP_CMD_SELATN   0x42
+
+#define ESP_STAT_DI      0x01
+#define ESP_STAT_CD      0x02
+#define ESP_STAT_MSG     0x04
+#define ESP_STAT_TC      0x10
+
+#define ESP_INTR_DC      0x20
+
+struct esp_lun_s {
+    struct drive_s drive;
+    struct pci_device *pci;
+    u32 iobase;
+    u8 target;
+    u8 lun;
+};
+
+static void
+esp_scsi_dma(u32 iobase, u32 buf, u32 len, int read)
+{
+    outb(len         & 0xff, iobase + ESP_TCLO);
+    outb((len >> 8)  & 0xff, iobase + ESP_TCMID);
+    outb((len >> 16) & 0xff, iobase + ESP_TCHI);
+    outl(buf,                iobase + ESP_DMA_SPA);
+    outl(len,                iobase + ESP_DMA_STC);
+    outb(read ? 0x83 : 0x03, iobase + ESP_DMA_CMD);
+}
+
+static int
+esp_scsi_cmd(struct esp_lun_s *llun, struct disk_op_s *op,
+             u8 *cdbcmd, u16 target, u16 lun, u16 blocksize)
+{
+    u32 iobase = GET_GLOBAL(llun->iobase);
+    int i, state;
+    u8 status;
+
+    outb(target, iobase + ESP_WBUSID);
+
+    /*
+     * We need to pass the LUN at the beginning of the command, and the FIFO
+     * is only 16 bytes, so we cannot support 16-byte CDBs.  The alternative
+     * would be to use DMA for the 17-byte command too, which is quite
+     * overkill.
+     */
+    outb(lun, iobase + ESP_FIFO);
+    cdbcmd[1] &= 0x1f;
+    cdbcmd[1] |= lun << 5;
+    for (i = 0; i < 12; i++)
+        outb(cdbcmd[i], iobase + ESP_FIFO);
+    outb(ESP_CMD_SELATN, iobase + ESP_CMD);
+
+    for (state = 0;;) {
+        u8 stat = inb(iobase + ESP_RSTAT);
+
+        /* Detect disconnected device.  */
+        if (state == 0 && (inb(iobase + ESP_RINTR) & ESP_INTR_DC)) {
+            return DISK_RET_ENOTREADY;
+        }
+
+        /* HBA reads command, clears CD, sets TC -> do DMA if needed.  */
+        if (state == 0 && (stat & ESP_STAT_TC)) {
+            state++;
+            if (op->count && blocksize) {
+                /* Data phase.  */
+                u32 count = (u32)op->count * blocksize;
+                esp_scsi_dma(iobase, (u32)op->buf_fl, count,
+                             cdb_is_read(cdbcmd, blocksize));
+                outb(ESP_CMD_TI | ESP_CMD_DMA, iobase + ESP_CMD);
+                continue;
+            }
+        }
+
+	/* At end of DMA TC is set again -> complete command.  */
+        if (state == 1 && (stat & ESP_STAT_TC)) {
+            state++;
+            outb(ESP_CMD_ICCS, iobase + ESP_CMD);
+            continue;
+        }
+
+	/* Finally read data from the message in phase.  */
+        if (state == 2 && (stat & ESP_STAT_MSG)) {
+            state++;
+            status = inb(iobase + ESP_FIFO);
+            inb(iobase + ESP_FIFO);
+            break;
+        }
+        usleep(5);
+    }
+
+    if (status == 0) {
+        return DISK_RET_SUCCESS;
+    }
+
+    return DISK_RET_EBADTRACK;
+}
+
+int
+esp_scsi_cmd_data(struct disk_op_s *op, void *cdbcmd, u16 blocksize)
+{
+    if (!CONFIG_ESP_SCSI)
+        return DISK_RET_EBADTRACK;
+
+    struct esp_lun_s *llun =
+        container_of(op->drive_g, struct esp_lun_s, drive);
+
+    return esp_scsi_cmd(llun, op, cdbcmd,
+                        GET_GLOBAL(llun->target), GET_GLOBAL(llun->lun),
+                        blocksize);
+}
+
+static int
+esp_scsi_add_lun(struct pci_device *pci, u32 iobase, u8 target, u8 lun)
+{
+    struct esp_lun_s *llun = malloc_fseg(sizeof(*llun));
+    if (!llun) {
+        warn_noalloc();
+        return -1;
+    }
+    memset(llun, 0, sizeof(*llun));
+    llun->drive.type = DTYPE_ESP_SCSI;
+    llun->drive.cntl_id = pci->bdf;
+    llun->pci = pci;
+    llun->target = target;
+    llun->lun = lun;
+    llun->iobase = iobase;
+
+    char *name = znprintf(16, "esp %02x:%02x.%x %d:%d",
+                          pci_bdf_to_bus(pci->bdf), pci_bdf_to_dev(pci->bdf),
+                          pci_bdf_to_fn(pci->bdf), target, lun);
+    int prio = bootprio_find_scsi_device(pci, target, lun);
+    int ret = scsi_init_drive(&llun->drive, name, prio);
+    free(name);
+    if (ret)
+        goto fail;
+    return 0;
+
+fail:
+    free(llun);
+    return -1;
+}
+
+static void
+esp_scsi_scan_target(struct pci_device *pci, u32 iobase, u8 target)
+{
+    esp_scsi_add_lun(pci, iobase, target, 0);
+}
+
+static void
+init_esp_scsi(struct pci_device *pci)
+{
+    u16 bdf = pci->bdf;
+    u32 iobase = pci_config_readl(pci->bdf, PCI_BASE_ADDRESS_0)
+        & PCI_BASE_ADDRESS_IO_MASK;
+
+    dprintf(1, "found esp at %02x:%02x.%x, io @ %x\n",
+            pci_bdf_to_bus(bdf), pci_bdf_to_dev(bdf),
+            pci_bdf_to_fn(bdf), iobase);
+
+    // reset
+    outb(ESP_CMD_RESET, iobase + ESP_CMD);
+
+    int i;
+    for (i = 0; i <= 7; i++)
+        esp_scsi_scan_target(pci, iobase, i);
+
+    return;
+}
+
+void
+esp_scsi_setup(void)
+{
+    ASSERT32FLAT();
+    if (!CONFIG_ESP_SCSI)
+        return;
+
+    dprintf(3, "init esp\n");
+
+    struct pci_device *pci;
+    foreachpci(pci) {
+        if (pci->vendor != PCI_VENDOR_ID_AMD
+            || pci->device != PCI_DEVICE_ID_AMD_SCSI)
+            continue;
+        init_esp_scsi(pci);
+    }
+}
diff --git a/src/esp-scsi.h b/src/esp-scsi.h
new file mode 100644
index 0000000..dc555f3
--- /dev/null
+++ b/src/esp-scsi.h
@@ -0,0 +1,8 @@
+#ifndef __ESP_SCSI_H
+#define __ESP_SCSI_H
+
+struct disk_op_s;
+int esp_scsi_cmd_data(struct disk_op_s *op, void *cdbcmd, u16 blocksize);
+void esp_scsi_setup(void);
+
+#endif /* __ESP_SCSI_H */
diff --git a/src/post.c b/src/post.c
index 0f31b4c..924b311 100644
--- a/src/post.c
+++ b/src/post.c
@@ -28,6 +28,7 @@
 #include "virtio-blk.h" // virtio_blk_setup
 #include "virtio-scsi.h" // virtio_scsi_setup
 #include "lsi-scsi.h" // lsi_scsi_setup
+#include "esp-scsi.h" // esp_scsi_setup
 
 
 /****************************************************************
@@ -196,6 +197,7 @@
     virtio_blk_setup();
     virtio_scsi_setup();
     lsi_scsi_setup();
+    esp_scsi_setup();
 }
 
 // Begin the boot process by invoking an int0x19 in 16bit mode.