From: Mate Kukri <k...@mkukri.xyz>

It is based on existing SeaBIOS code, so the license is LGPLv3.

Tested as a coreboot paload on the following targets:
- QEMU Q35 with emulated NVMe disk
- ASUS H610M-K with Intel 660p NVME disk

Signed-off-by: Mate Kukri <k...@mkukri.xyz>
---
 Makefile.am                     |   2 +-
 grub-core/Makefile.core.def     |   6 +
 grub-core/commands/nativedisk.c |   1 +
 grub-core/disk/nvme.c           | 861 ++++++++++++++++++++++++++++++++
 include/grub/disk.h             |   1 +
 include/grub/nvme.h             | 225 +++++++++
 6 files changed, 1095 insertions(+), 1 deletion(-)
 create mode 100644 grub-core/disk/nvme.c
 create mode 100644 include/grub/nvme.h

diff --git a/Makefile.am b/Makefile.am
index 43635d5ff..2c86dbbf6 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -434,7 +434,7 @@ if COND_i386_coreboot
 FS_PAYLOAD_MODULES ?= $(shell cat grub-core/fs.lst)
 default_payload.elf: grub-mkstandalone grub-mkimage FORCE
        test -f $@ && rm $@ || true
-       pkgdatadir=. ./grub-mkstandalone --grub-mkimage=./grub-mkimage -O 
i386-coreboot -o $@ --modules='ahci pata ehci uhci ohci usb_keyboard usbms 
part_msdos ext2 fat at_keyboard part_gpt usbserial_usbdebug cbfs' 
--install-modules='ls linux search configfile normal cbtime cbls memrw iorw 
minicmd lsmmap lspci halt reboot hexdump pcidump regexp setpci lsacpi chain 
test serial multiboot cbmemc linux16 gzio echo help syslinuxcfg xnu 
$(FS_PAYLOAD_MODULES) password_pbkdf2 $(EXTRA_PAYLOAD_MODULES)' --fonts= 
--themes= --locales= -d grub-core/ /boot/grub/grub.cfg=$(srcdir)/coreboot.cfg
+       pkgdatadir=. ./grub-mkstandalone --grub-mkimage=./grub-mkimage -O 
i386-coreboot -o $@ --modules='ahci pata nvme ehci uhci ohci usb_keyboard usbms 
part_msdos ext2 fat at_keyboard part_gpt usbserial_usbdebug cbfs' 
--install-modules='ls linux search configfile normal cbtime cbls memrw iorw 
minicmd lsmmap lspci halt reboot hexdump pcidump regexp setpci lsacpi chain 
test serial multiboot cbmemc linux16 gzio echo help syslinuxcfg xnu 
$(FS_PAYLOAD_MODULES) password_pbkdf2 $(EXTRA_PAYLOAD_MODULES)' --fonts= 
--themes= --locales= -d grub-core/ /boot/grub/grub.cfg=$(srcdir)/coreboot.cfg
 endif
 
 endif
diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
index 063ef5dd7..7b4cf972a 100644
--- a/grub-core/Makefile.core.def
+++ b/grub-core/Makefile.core.def
@@ -2606,3 +2606,9 @@ module = {
   enable = efi;
   depends = part_gpt;
 };
+
+module = {
+  name = nvme;
+  common = disk/nvme.c;
+  enable = pci;
+};
diff --git a/grub-core/commands/nativedisk.c b/grub-core/commands/nativedisk.c
index 580c8d3b0..a2c766fbd 100644
--- a/grub-core/commands/nativedisk.c
+++ b/grub-core/commands/nativedisk.c
@@ -78,6 +78,7 @@ get_uuid (const char *name, char **uuid, int getnative)
     case GRUB_DISK_DEVICE_ATA_ID:
     case GRUB_DISK_DEVICE_SCSI_ID:
     case GRUB_DISK_DEVICE_XEN:
+    case GRUB_DISK_DEVICE_NVME_ID:
       if (getnative)
        break;
       /* FALLTHROUGH */
diff --git a/grub-core/disk/nvme.c b/grub-core/disk/nvme.c
new file mode 100644
index 000000000..b6a886464
--- /dev/null
+++ b/grub-core/disk/nvme.c
@@ -0,0 +1,861 @@
+/* nvme.c - NVMe support. */
+/*
+ * Based on SeaBIOS NVMe driver, ported to GRUB2 by Mate Kukri
+ *
+ * Copyright 2017 Amazon.com, Inc. or its affiliates.
+ * Copyright 2024 Mate Kukri <k...@mkukri.xyz>
+ *
+ * This file may be distributed under the terms of the GNU LGPLv3 license.
+ */
+
+#include <grub/disk.h>
+#include <grub/dl.h>
+#include <grub/nvme.h>
+#include <grub/pci.h>
+#include <grub/time.h>
+
+GRUB_MOD_LICENSE ("GPLv3");    /* LGPLv3 is GPLv3 compatible */
+
+static grub_uint32_t grub_nvme_ctrlcnt;
+static grub_uint32_t grub_nvme_nscnt;
+
+static struct grub_nvme_namespace *grub_nvme_namespaces;
+
+/* Page aligned "dma bounce buffer" of size GRUB_NVME_PAGE_SIZE */
+static void *nvme_dma_buffer;
+
+static void *
+zalloc_page_aligned (grub_uint32_t size)
+{
+  void *res = grub_memalign (GRUB_NVME_PAGE_SIZE, size);
+  if (res)
+    grub_memset (res, 0, size);
+  return res;
+}
+
+static void
+nvme_init_queue_common (struct grub_nvme_ctrl *ctrl,
+                       struct grub_nvme_queue *q, grub_uint16_t q_idx,
+                       grub_uint16_t length)
+{
+  grub_memset (q, 0, sizeof (*q));
+  q->dbl =
+    (grub_uint32_t *) ((char *) ctrl->reg + 0x1000 +
+                      q_idx * ctrl->doorbell_stride);
+  grub_dprintf ("nvme", " q %p q_idx %u dbl %p\n", q, q_idx, q->dbl);
+  q->mask = length - 1;
+}
+
+static int
+nvme_init_sq (struct grub_nvme_ctrl *ctrl, struct grub_nvme_sq *sq,
+             grub_uint16_t q_idx, grub_uint16_t length,
+             struct grub_nvme_cq *cq)
+{
+  nvme_init_queue_common (ctrl, &sq->common, q_idx, length);
+  sq->sqe = zalloc_page_aligned (sizeof (*sq->sqe) * length);
+
+  if (!sq->sqe)
+    {
+      return -1;
+    }
+
+  grub_dprintf ("nvme", "sq %p q_idx %u sqe %p\n", sq, q_idx, sq->sqe);
+  sq->cq = cq;
+  sq->head = 0;
+  sq->tail = 0;
+
+  return 0;
+}
+
+static int
+nvme_init_cq (struct grub_nvme_ctrl *ctrl, struct grub_nvme_cq *cq,
+             grub_uint16_t q_idx, grub_uint16_t length)
+{
+  nvme_init_queue_common (ctrl, &cq->common, q_idx, length);
+  cq->cqe = zalloc_page_aligned (sizeof (*cq->cqe) * length);
+  if (!cq->cqe)
+    {
+      return -1;
+    }
+
+  cq->head = 0;
+
+  /* All CQE phase bits are initialized to zero. This means initially we wait
+     for the host controller to set these to 1. */
+  cq->phase = 1;
+
+  return 0;
+}
+
+static int
+nvme_poll_cq (struct grub_nvme_cq *cq)
+{
+  grub_uint32_t dw3 = *(volatile grub_uint32_t *) &cq->cqe[cq->head].dword[3];
+  return (!!(dw3 & GRUB_NVME_CQE_DW3_P) == cq->phase);
+}
+
+static int
+nvme_is_cqe_success (const struct grub_nvme_cqe *cqe)
+{
+  return ((cqe->status >> 1) & 0xFF) == 0;
+}
+
+static struct grub_nvme_cqe
+nvme_error_cqe (void)
+{
+  struct grub_nvme_cqe r;
+
+  /* 0xFF is a vendor specific status code != success. Should be okay for
+     indicating failure. */
+  grub_memset (&r, 0xFF, sizeof (r));
+  return r;
+}
+
+static struct grub_nvme_cqe
+nvme_consume_cqe (struct grub_nvme_sq *sq)
+{
+  struct grub_nvme_cq *cq = sq->cq;
+
+  if (!nvme_poll_cq (cq))
+    {
+      /* Cannot consume a completion queue entry, if there is none ready. */
+      return nvme_error_cqe ();
+    }
+
+  struct grub_nvme_cqe *cqe = &cq->cqe[cq->head];
+  grub_uint16_t cq_next_head = (cq->head + 1) & cq->common.mask;
+  grub_dprintf ("nvme", "cq %p head %u -> %u\n", cq, cq->head, cq_next_head);
+  if (cq_next_head < cq->head)
+    {
+      grub_dprintf ("nvme", "cq %p wrap\n", cq);
+      cq->phase = ~cq->phase;
+    }
+  cq->head = cq_next_head;
+
+  /* Update the submission queue head. */
+  if (cqe->sq_head != sq->head)
+    {
+      sq->head = cqe->sq_head;
+      grub_dprintf ("nvme", "sq %p advanced to %u\n", sq, cqe->sq_head);
+    }
+
+  /* Tell the controller that we consumed the completion. */
+  *(volatile grub_uint32_t *) cq->common.dbl = cq->head;
+
+  return *cqe;
+}
+
+static struct grub_nvme_cqe
+nvme_wait (struct grub_nvme_sq *sq)
+{
+  const grub_uint64_t limit_ms = grub_get_time_ms () + 5000;
+
+  while (!nvme_poll_cq (sq->cq))
+    {
+      if (limit_ms < grub_get_time_ms ())
+       {
+         grub_dprintf ("nvme", "NVME SQ wait timeout\n");
+         return nvme_error_cqe ();
+       }
+    }
+
+  return nvme_consume_cqe (sq);
+}
+
+/* Returns the next submission queue entry (or NULL if the queue is full). It
+   also fills out Command Dword 0 and clears the rest. */
+static struct grub_nvme_sqe *
+nvme_get_next_sqe (struct grub_nvme_sq *sq, grub_uint8_t opc, void *metadata,
+                  void *data, void *data2)
+{
+  if (((sq->head + 1) & sq->common.mask) == sq->tail)
+    {
+      grub_dprintf ("nvme", "submission queue is full\n");
+      return NULL;
+    }
+
+  struct grub_nvme_sqe *sqe = &sq->sqe[sq->tail];
+  grub_dprintf ("nvme", "sq %p next_sqe %u\n", sq, sq->tail);
+
+  grub_memset (sqe, 0, sizeof (*sqe));
+  sqe->cdw0 = opc | (sq->tail << 16 /* CID */ );
+  sqe->mptr = (grub_uint32_t) metadata;
+  sqe->dptr_prp1 = (grub_uint32_t) data;
+  sqe->dptr_prp2 = (grub_uint32_t) data2;
+
+  return sqe;
+}
+
+/* Call this after you've filled out an sqe that you've got from 
nvme_get_next_sqe. */
+static void
+nvme_commit_sqe (struct grub_nvme_sq *sq)
+{
+  grub_dprintf ("nvme", "sq %p commit_sqe %u\n", sq, sq->tail);
+  sq->tail = (sq->tail + 1) & sq->common.mask;
+  *(volatile grub_uint32_t *) sq->common.dbl = sq->tail;
+}
+
+/* Perform an identify command on the admin queue and return the resulting
+   buffer. This may be a NULL pointer, if something failed. This function
+   cannot be used after initialization, because it uses buffers in tmp zone. */
+static union nvme_identify *
+nvme_admin_identify (struct grub_nvme_ctrl *ctrl, grub_uint8_t cns,
+                    grub_uint32_t nsid)
+{
+  union nvme_identify *identify_buf = zalloc_page_aligned (4096);
+  if (!identify_buf)
+    return NULL;
+
+  struct grub_nvme_sqe *cmd_identify;
+  cmd_identify = nvme_get_next_sqe (&ctrl->admin_sq,
+                                   GRUB_NVME_SQE_OPC_ADMIN_IDENTIFY, NULL,
+                                   identify_buf, NULL);
+  if (!cmd_identify)
+    goto error;
+
+  cmd_identify->nsid = nsid;
+  cmd_identify->dword[10] = cns;
+
+  nvme_commit_sqe (&ctrl->admin_sq);
+
+  struct grub_nvme_cqe cqe = nvme_wait (&ctrl->admin_sq);
+
+  if (!nvme_is_cqe_success (&cqe))
+    {
+      goto error;
+    }
+
+  return identify_buf;
+error:
+  grub_free (identify_buf);
+  return NULL;
+}
+
+static struct grub_nvme_identify_ctrl *
+nvme_admin_identify_ctrl (struct grub_nvme_ctrl *ctrl)
+{
+  return &nvme_admin_identify (ctrl, GRUB_NVME_ADMIN_IDENTIFY_CNS_ID_CTRL,
+                              0)->ctrl;
+}
+
+static struct grub_nvme_identify_ns *
+nvme_admin_identify_ns (struct grub_nvme_ctrl *ctrl, grub_uint32_t ns_id)
+{
+  return &nvme_admin_identify (ctrl, GRUB_NVME_ADMIN_IDENTIFY_CNS_ID_NS,
+                              ns_id)->ns;
+}
+
+static void
+nvme_probe_ns (struct grub_nvme_ctrl *ctrl, grub_uint32_t ns_idx,
+              grub_uint8_t mdts)
+{
+  grub_uint32_t ns_id = ns_idx + 1;
+
+  struct grub_nvme_identify_ns *id = nvme_admin_identify_ns (ctrl, ns_id);
+  if (!id)
+    {
+      grub_dprintf ("nvme", "NVMe couldn't identify namespace %u.\n", ns_id);
+      goto free_buffer;
+    }
+
+  grub_uint8_t current_lba_format = id->flbas & 0xF;
+  if (current_lba_format > id->nlbaf)
+    {
+      grub_dprintf ("nvme",
+                   "NVMe NS %u: current LBA format %u is beyond what the "
+                   " namespace supports (%u)?\n", ns_id, current_lba_format,
+                   id->nlbaf + 1);
+      goto free_buffer;
+    }
+
+  if (!id->nsze)
+    {
+      grub_dprintf ("nvme", "NVMe NS %u is inactive.\n", ns_id);
+      goto free_buffer;
+    }
+
+  if (!nvme_dma_buffer)
+    {
+      nvme_dma_buffer = zalloc_page_aligned (GRUB_NVME_PAGE_SIZE);
+      if (!nvme_dma_buffer)
+       {
+         goto free_buffer;
+       }
+    }
+
+  struct grub_nvme_namespace *ns = grub_malloc (sizeof (*ns));
+  if (!ns)
+    {
+      goto free_buffer;
+    }
+  grub_memset (ns, 0, sizeof (*ns));
+  ns->ctrl = ctrl;
+  ns->ns_id = ns_id;
+  ns->lba_count = id->nsze;
+
+  struct grub_nvme_lba_format *fmt = &id->lbaf[current_lba_format];
+
+  ns->block_size = 1U << fmt->lbads;
+  ns->metadata_size = fmt->ms;
+
+  if (ns->block_size > GRUB_NVME_PAGE_SIZE)
+    {
+      /* If we see devices that trigger this path, we need to increase our
+         buffer size. */
+      grub_free (ns);
+      goto free_buffer;
+    }
+
+  if (mdts)
+    {
+      ns->max_req_size =
+       ((1U << mdts) * GRUB_NVME_PAGE_SIZE) / ns->block_size;
+      grub_dprintf ("nvme", "NVME NS %u max request size: %d sectors\n",
+                   ns_id, ns->max_req_size);
+    }
+  else
+    {
+      ns->max_req_size = -1U;
+    }
+
+  ns->devname = grub_xasprintf ("nvme%un%u", ctrl->ctrlnum, ns_id);
+  ns->nsnum = grub_nvme_nscnt++;
+
+  grub_list_push (GRUB_AS_LIST_P (&grub_nvme_namespaces), GRUB_AS_LIST (ns));
+
+free_buffer:
+  grub_free (id);
+}
+
+
+/* Release memory allocated for a completion queue */
+static void
+nvme_destroy_cq (struct grub_nvme_cq *cq)
+{
+  grub_free (cq->cqe);
+  cq->cqe = NULL;
+}
+
+/* Release memory allocated for a submission queue */
+static void
+nvme_destroy_sq (struct grub_nvme_sq *sq)
+{
+  grub_free (sq->sqe);
+  sq->sqe = NULL;
+}
+
+/* Returns 0 on success. */
+static int
+nvme_create_io_cq (struct grub_nvme_ctrl *ctrl, struct grub_nvme_cq *cq,
+                  grub_uint16_t q_idx)
+{
+  int rc;
+  struct grub_nvme_sqe *cmd_create_cq;
+  grub_uint32_t length = 1 + (ctrl->reg->cap & 0xffff);
+  if (length > GRUB_NVME_PAGE_SIZE / sizeof (struct grub_nvme_cqe))
+    length = GRUB_NVME_PAGE_SIZE / sizeof (struct grub_nvme_cqe);
+
+  rc = nvme_init_cq (ctrl, cq, q_idx, length);
+  if (rc)
+    {
+      goto err;
+    }
+
+  cmd_create_cq = nvme_get_next_sqe (&ctrl->admin_sq,
+                                    GRUB_NVME_SQE_OPC_ADMIN_CREATE_IO_CQ,
+                                    NULL, cq->cqe, NULL);
+  if (!cmd_create_cq)
+    {
+      goto err_destroy_cq;
+    }
+
+  cmd_create_cq->dword[10] = (cq->common.mask << 16) | (q_idx >> 1);
+  cmd_create_cq->dword[11] = 1 /* physically contiguous */ ;
+
+  nvme_commit_sqe (&ctrl->admin_sq);
+
+  struct grub_nvme_cqe cqe = nvme_wait (&ctrl->admin_sq);
+
+  if (!nvme_is_cqe_success (&cqe))
+    {
+      grub_dprintf ("nvme", "create io cq failed: %08x %08x %08x %08x\n",
+                   cqe.dword[0], cqe.dword[1], cqe.dword[2], cqe.dword[3]);
+
+      goto err_destroy_cq;
+    }
+
+  return 0;
+
+err_destroy_cq:
+  nvme_destroy_cq (cq);
+err:
+  return -1;
+}
+
+/* Returns 0 on success. */
+static int
+nvme_create_io_sq (struct grub_nvme_ctrl *ctrl, struct grub_nvme_sq *sq,
+                  grub_uint16_t q_idx, struct grub_nvme_cq *cq)
+{
+  int rc;
+  struct grub_nvme_sqe *cmd_create_sq;
+  grub_uint32_t length = 1 + (ctrl->reg->cap & 0xffff);
+  if (length > GRUB_NVME_PAGE_SIZE / sizeof (struct grub_nvme_cqe))
+    length = GRUB_NVME_PAGE_SIZE / sizeof (struct grub_nvme_cqe);
+
+  rc = nvme_init_sq (ctrl, sq, q_idx, length, cq);
+  if (rc)
+    {
+      goto err;
+    }
+
+  cmd_create_sq = nvme_get_next_sqe (&ctrl->admin_sq,
+                                    GRUB_NVME_SQE_OPC_ADMIN_CREATE_IO_SQ,
+                                    NULL, sq->sqe, NULL);
+  if (!cmd_create_sq)
+    {
+      goto err_destroy_sq;
+    }
+
+  cmd_create_sq->dword[10] = (sq->common.mask << 16) | (q_idx >> 1);
+  cmd_create_sq->dword[11] = (q_idx >> 1) << 16 | 1 /* contiguous */ ;
+  grub_dprintf ("nvme", "sq %p create dword10 %08x dword11 %08x\n", sq,
+               cmd_create_sq->dword[10], cmd_create_sq->dword[11]);
+
+  nvme_commit_sqe (&ctrl->admin_sq);
+
+  struct grub_nvme_cqe cqe = nvme_wait (&ctrl->admin_sq);
+
+  if (!nvme_is_cqe_success (&cqe))
+    {
+      grub_dprintf ("nvme", "create io sq failed: %08x %08x %08x %08x\n",
+                   cqe.dword[0], cqe.dword[1], cqe.dword[2], cqe.dword[3]);
+      goto err_destroy_sq;
+    }
+
+  return 0;
+
+err_destroy_sq:
+  nvme_destroy_sq (sq);
+err:
+  return -1;
+}
+
+/* Reads count sectors into buf. The buffer cannot cross page boundaries. */
+static int
+nvme_io_xfer (struct grub_nvme_namespace *ns, grub_uint64_t lba, void *prp1,
+             void *prp2, grub_uint16_t count, int write)
+{
+  if (((grub_uint32_t) prp1 & 0x3) || ((grub_uint32_t) prp2 & 0x3))
+    {
+      /* Buffer is misaligned */
+      return -1;
+    }
+
+  struct grub_nvme_sqe *io_read = nvme_get_next_sqe (&ns->ctrl->io_sq,
+                                                    write ?
+                                                    GRUB_NVME_SQE_OPC_IO_WRITE
+                                                    :
+                                                    GRUB_NVME_SQE_OPC_IO_READ,
+                                                    NULL, prp1, prp2);
+  io_read->nsid = ns->ns_id;
+  io_read->dword[10] = (grub_uint32_t) lba;
+  io_read->dword[11] = (grub_uint32_t) (lba >> 32);
+  io_read->dword[12] = (1U << 31 /* limited retry */ ) | (count - 1);
+
+  nvme_commit_sqe (&ns->ctrl->io_sq);
+
+  struct grub_nvme_cqe cqe = nvme_wait (&ns->ctrl->io_sq);
+
+  if (!nvme_is_cqe_success (&cqe))
+    {
+      grub_dprintf ("nvme", "read io: %08x %08x %08x %08x\n",
+                   cqe.dword[0], cqe.dword[1], cqe.dword[2], cqe.dword[3]);
+
+      return -1;
+    }
+
+  grub_dprintf ("nvme", "ns %u %s lba %llu+%u\n", ns->ns_id,
+               write ? "write" : "read", lba, count);
+  return count;
+}
+
+/* Transfer up to one page of data using the internal dma bounce buffer */
+static int
+nvme_bounce_xfer (struct grub_nvme_namespace *ns, grub_uint64_t lba,
+                 void *buf, grub_uint16_t count, int write)
+{
+  grub_uint16_t const max_blocks = GRUB_NVME_PAGE_SIZE / ns->block_size;
+  grub_uint16_t blocks = count < max_blocks ? count : max_blocks;
+
+  if (write)
+    grub_memcpy (nvme_dma_buffer, buf, blocks * ns->block_size);
+
+  int res = nvme_io_xfer (ns, lba, nvme_dma_buffer, NULL, blocks, write);
+
+  if (!write && res >= 0)
+    grub_memcpy (buf, nvme_dma_buffer, res * ns->block_size);
+
+  return res;
+}
+
+#define GRUB_NVME_MAX_PRPL_ENTRIES 15  /* Allows requests up to 64kb */
+
+/* Transfer data using page list (if applicable) */
+static int
+nvme_prpl_xfer (struct grub_nvme_namespace *ns, grub_uint64_t lba, void *buf,
+               grub_uint16_t count, int write)
+{
+  grub_uint32_t base = (long) buf;
+  grub_int32_t size;
+
+  if (count > ns->max_req_size)
+    count = ns->max_req_size;
+
+  size = count * ns->block_size;
+  /* Special case for transfers that fit into PRP1, but are unaligned */
+  if (((size + (base & ~GRUB_NVME_PAGE_MASK)) <= GRUB_NVME_PAGE_SIZE))
+    goto single;
+
+  /* Every request has to be page aligned */
+  if (base & ~GRUB_NVME_PAGE_MASK)
+    goto bounce;
+
+  /* Make sure a full block fits into the last chunk */
+  if (size & (ns->block_size - 1ULL))
+    goto bounce;
+
+  /* Build PRP list if we need to describe more than 2 pages */
+  if ((ns->block_size * count) > (GRUB_NVME_PAGE_SIZE * 2))
+    {
+      grub_uint32_t prpl_len = 0;
+      grub_uint64_t *prpl = nvme_dma_buffer;
+      int first_page = 1;
+      for (; size > 0;
+          base += GRUB_NVME_PAGE_SIZE, size -= GRUB_NVME_PAGE_SIZE)
+       {
+         if (first_page)
+           {
+             /* First page is special */
+             first_page = 0;
+             continue;
+           }
+         if (prpl_len >= GRUB_NVME_MAX_PRPL_ENTRIES)
+           goto bounce;
+         prpl[prpl_len++] = base;
+       }
+      return nvme_io_xfer (ns, lba, buf, prpl, count, write);
+    }
+
+  /* Directly embed the 2nd page if we only need 2 pages */
+  if ((ns->block_size * count) > GRUB_NVME_PAGE_SIZE)
+    return nvme_io_xfer (ns, lba, buf, (char *) buf + GRUB_NVME_PAGE_SIZE,
+                        count, write);
+
+single:
+  /* One page is enough, don't expose anything else */
+  return nvme_io_xfer (ns, lba, buf, NULL, count, write);
+
+bounce:
+  /* Use bounce buffer to make transfer */
+  return nvme_bounce_xfer (ns, lba, buf, count, write);
+}
+
+static int
+nvme_create_io_queues (struct grub_nvme_ctrl *ctrl)
+{
+  if (nvme_create_io_cq (ctrl, &ctrl->io_cq, 3))
+    goto err;
+
+  if (nvme_create_io_sq (ctrl, &ctrl->io_sq, 2, &ctrl->io_cq))
+    goto err_free_cq;
+
+  return 0;
+
+err_free_cq:
+  nvme_destroy_cq (&ctrl->io_cq);
+err:
+  return -1;
+}
+
+/* Waits for CSTS.RDY to match rdy. Returns 0 on success. */
+static int
+nvme_wait_csts_rdy (struct grub_nvme_ctrl *ctrl, unsigned rdy)
+{
+  const grub_uint64_t limit_ms =
+    grub_get_time_ms () + 500 /* ms */  * ((ctrl->reg->cap >> 24) & 0xFFU);
+  grub_uint32_t csts;
+
+  while (rdy != ((csts = ctrl->reg->csts) & GRUB_NVME_CSTS_RDY))
+    {
+      if (csts & GRUB_NVME_CSTS_FATAL)
+       {
+         grub_dprintf ("nvme",
+                       "NVMe fatal error during controller shutdown\n");
+         return -1;
+       }
+
+      if (limit_ms < grub_get_time_ms ())
+       {
+         grub_dprintf ("nvme", "NVMe timeout waiting for CSTS.RDY\n");
+         return -1;
+       }
+    }
+
+  return 0;
+}
+
+static int
+grub_nvme_controller_enable (struct grub_nvme_ctrl *ctrl)
+{
+  grub_pci_address_t addr;
+  int rc;
+
+  addr = grub_pci_make_address (ctrl->pci, GRUB_PCI_REG_COMMAND);
+  grub_pci_write_word (addr,
+                      grub_pci_read_word (addr) |
+                      GRUB_PCI_COMMAND_BUS_MASTER);
+
+  /* Turn the controller off. */
+  ctrl->reg->cc = 0;
+  if (nvme_wait_csts_rdy (ctrl, 0))
+    {
+      grub_dprintf ("nvme", "NVMe fatal error during controller shutdown\n");
+      return -1;
+    }
+
+  ctrl->doorbell_stride = 4U << ((ctrl->reg->cap >> 32) & 0xF);
+
+  rc = nvme_init_cq (ctrl, &ctrl->admin_cq, 1,
+                    GRUB_NVME_PAGE_SIZE / sizeof (struct grub_nvme_cqe));
+  if (rc)
+    {
+      return -1;
+    }
+
+  rc = nvme_init_sq (ctrl, &ctrl->admin_sq, 0,
+                    GRUB_NVME_PAGE_SIZE / sizeof (struct grub_nvme_sqe),
+                    &ctrl->admin_cq);
+  if (rc)
+    {
+      goto err_destroy_admin_cq;
+    }
+
+  ctrl->reg->aqa = ctrl->admin_cq.common.mask << 16
+    | ctrl->admin_sq.common.mask;
+
+  ctrl->reg->asq = (grub_uint32_t) ctrl->admin_sq.sqe;
+  ctrl->reg->acq = (grub_uint32_t) ctrl->admin_cq.cqe;
+
+  grub_dprintf ("nvme", "  admin submission queue: %p\n", ctrl->admin_sq.sqe);
+  grub_dprintf ("nvme", "  admin completion queue: %p\n", ctrl->admin_cq.cqe);
+
+  ctrl->reg->cc = GRUB_NVME_CC_EN | (GRUB_NVME_CQE_SIZE_LOG << 20)
+    | (GRUB_NVME_SQE_SIZE_LOG << 16 /* IOSQES */ );
+
+  if (nvme_wait_csts_rdy (ctrl, 1))
+    {
+      grub_dprintf ("nvme", "NVMe fatal error while enabling controller\n");
+      goto err_destroy_admin_sq;
+    }
+
+  /* The admin queue is set up and the controller is ready. Let's figure out
+     what namespaces we have. */
+
+  struct grub_nvme_identify_ctrl *identify = nvme_admin_identify_ctrl (ctrl);
+
+  if (!identify)
+    {
+      grub_dprintf ("nvme", "NVMe couldn't identify controller.\n");
+      goto err_destroy_admin_sq;
+    }
+
+  grub_dprintf ("nvme", "NVMe has %u namespace%s.\n",
+               identify->nn, (identify->nn == 1) ? "" : "s");
+
+  ctrl->ns_count = identify->nn;
+  grub_uint8_t mdts = identify->mdts;
+  grub_free (identify);
+
+  if ((ctrl->ns_count == 0) || nvme_create_io_queues (ctrl))
+    {
+      /* No point to continue, if the controller says it doesn't have
+         namespaces or we couldn't create I/O queues. */
+      goto err_destroy_admin_sq;
+    }
+
+  /* Give the controller a global number */
+  ctrl->ctrlnum = grub_nvme_ctrlcnt++;
+
+  /* Populate namespace IDs */
+  for (grub_uint32_t ns_idx = 0; ns_idx < ctrl->ns_count; ns_idx++)
+    {
+      nvme_probe_ns (ctrl, ns_idx, mdts);
+    }
+
+  grub_dprintf ("nvme", "NVMe initialization complete!\n");
+  return 0;
+
+err_destroy_admin_sq:
+  nvme_destroy_sq (&ctrl->admin_sq);
+err_destroy_admin_cq:
+  nvme_destroy_cq (&ctrl->admin_cq);
+  return -1;
+}
+
+static int
+grub_nvme_pci_probe (grub_pci_device_t dev, grub_pci_id_t pciid
+                    __attribute__((unused)), void *data
+                    __attribute__((unused)))
+{
+  grub_pci_address_t addr;
+  grub_uint32_t class, bar, version;
+  struct grub_nvme_reg volatile *reg;
+
+  class = grub_pci_read (grub_pci_make_address (dev, GRUB_PCI_REG_CLASS));
+  if (class >> 16 != 0x0108)
+    return 0;
+  if ((class >> 8 & 0xff) != 2)
+    {                          /* as of NVM 1.0e */
+      grub_dprintf ("nvme", "Found incompatble NVMe: prog-if=%02x\n",
+                   class >> 8 & 0xff);
+      return 0;
+    }
+
+  bar =
+    grub_pci_read (grub_pci_make_address (dev, GRUB_PCI_REG_ADDRESS_REG0));
+  reg =
+    grub_pci_device_map_range (dev, bar & GRUB_PCI_ADDR_MEM_MASK,
+                              sizeof (*reg));
+
+  addr = grub_pci_make_address (dev, GRUB_PCI_REG_COMMAND);
+  grub_pci_write_word (addr,
+                      grub_pci_read_word (addr) |
+                      GRUB_PCI_COMMAND_MEM_ENABLED);
+
+  version = reg->vs;
+  grub_dprintf ("nvme", "Found NVMe controller with version %u.%u.%u.\n",
+               version >> 16, (version >> 8) & 0xFF, version & 0xFF);
+  grub_dprintf ("nvme", "  Capabilities %016llx\n", reg->cap);
+
+  if (~reg->cap & GRUB_NVME_CAP_CSS_NVME)
+    {
+      grub_dprintf ("nvme",
+                   "Controller doesn't speak NVMe command set. Skipping.\n");
+      goto err;
+    }
+
+  struct grub_nvme_ctrl *ctrl = grub_malloc (sizeof (*ctrl));
+  if (!ctrl)
+    goto err;
+
+  grub_memset (ctrl, 0, sizeof (*ctrl));
+
+  ctrl->reg = reg;
+  ctrl->pci = dev;
+
+  if (grub_nvme_controller_enable (ctrl))
+    goto err_free_ctrl;
+
+  return 0;
+
+err_free_ctrl:
+  grub_free (ctrl);
+err:
+  grub_dprintf ("nvme", "Failed to enable NVMe controller.\n");
+  return 0;
+}
+
+static int
+grub_nvme_iterate (grub_disk_dev_iterate_hook_t hook, void *hook_data,
+                  grub_disk_pull_t pull)
+{
+  struct grub_nvme_namespace *ns;
+
+  if (pull != GRUB_DISK_PULL_NONE)
+    return 0;
+
+  FOR_LIST_ELEMENTS (ns, grub_nvme_namespaces)
+    if (hook (ns->devname, hook_data))
+    return 1;
+
+  return 0;
+}
+
+static grub_err_t
+grub_nvme_open (const char *name __attribute ((unused)),
+               grub_disk_t disk __attribute ((unused)))
+{
+  struct grub_nvme_namespace *ns;
+
+  FOR_LIST_ELEMENTS (ns, grub_nvme_namespaces)
+    if (grub_strcmp (ns->devname, name) == 0)
+    break;
+
+  if (!ns)
+    return grub_error (GRUB_ERR_UNKNOWN_DEVICE, "can't open device");
+
+  disk->total_sectors = ns->lba_count;
+  disk->max_agglomerate = ns->max_req_size;
+
+  disk->id = ns->nsnum;                /* global id of the namespace */
+
+  disk->data = ns;
+
+  return 0;
+}
+
+static grub_err_t
+nvme_readwrite (struct grub_nvme_namespace *ns, grub_disk_addr_t sector,
+               grub_size_t num_sectors, char *buf, int write)
+{
+  for (grub_size_t i = 0; i < num_sectors;)
+    {
+      grub_uint16_t blocks_remaining = num_sectors - i;
+      char *op_buf = buf + i * ns->block_size;
+      int blocks =
+       nvme_prpl_xfer (ns, sector + i, op_buf, blocks_remaining, write);
+      if (blocks < 0)
+       return GRUB_ERR_IO;
+      i += blocks;
+    }
+  return GRUB_ERR_NONE;
+}
+
+static grub_err_t
+grub_nvme_read (grub_disk_t disk, grub_disk_addr_t sector,
+               grub_size_t num_sectors, char *buf)
+{
+  return nvme_readwrite ((struct grub_nvme_namespace *) disk->data, sector,
+                        num_sectors, buf, 0);
+}
+
+static grub_err_t
+grub_nvme_write (grub_disk_t disk, grub_disk_addr_t sector,
+                grub_size_t num_sectors, const char *buf)
+{
+  return nvme_readwrite ((struct grub_nvme_namespace *) disk->data, sector,
+                        num_sectors, (char *) buf, 1);
+}
+
+static struct grub_disk_dev grub_nvme_dev = {
+  .name = "nvme",
+  .id = GRUB_DISK_DEVICE_NVME_ID,
+  .disk_iterate = grub_nvme_iterate,
+  .disk_open = grub_nvme_open,
+  .disk_read = grub_nvme_read,
+  .disk_write = grub_nvme_write,
+  .next = 0
+};
+
+GRUB_MOD_INIT (nvme)
+{
+  grub_stop_disk_firmware ();
+  grub_pci_iterate (grub_nvme_pci_probe, NULL);
+  grub_disk_dev_register (&grub_nvme_dev);
+}
+
+GRUB_MOD_FINI (nvme)
+{
+  grub_disk_dev_unregister (&grub_nvme_dev);
+}
diff --git a/include/grub/disk.h b/include/grub/disk.h
index fbf23df7f..186e76f0b 100644
--- a/include/grub/disk.h
+++ b/include/grub/disk.h
@@ -52,6 +52,7 @@ enum grub_disk_dev_id
     GRUB_DISK_DEVICE_UBOOTDISK_ID,
     GRUB_DISK_DEVICE_XEN,
     GRUB_DISK_DEVICE_OBDISK_ID,
+    GRUB_DISK_DEVICE_NVME_ID
   };
 
 struct grub_disk;
diff --git a/include/grub/nvme.h b/include/grub/nvme.h
new file mode 100644
index 000000000..5f66aa232
--- /dev/null
+++ b/include/grub/nvme.h
@@ -0,0 +1,225 @@
+/* nvme.h - NVMe datastructures and constants */
+/*
+ * Copyright 2017 Amazon.com, Inc. or its affiliates.
+ *
+ * This file may be distributed under the terms of the GNU LGPLv3 license.
+ */
+
+#ifndef GRUB_NVME_HEADER
+#define GRUB_NVME_HEADER  1
+
+#include <grub/pci.h>
+#include <grub/types.h>
+
+/* The register file of a NVMe host controller. This struct follows the naming
+   scheme in the NVMe specification. */
+struct grub_nvme_reg
+{
+  grub_uint64_t cap;           /* controller capabilities */
+  grub_uint32_t vs;            /* version */
+  grub_uint32_t intms;         /* interrupt mask set */
+  grub_uint32_t intmc;         /* interrupt mask clear */
+  grub_uint32_t cc;            /* controller configuration */
+  grub_uint32_t _res0;
+  grub_uint32_t csts;          /* controller status */
+  grub_uint32_t _res1;
+  grub_uint32_t aqa;           /* admin queue attributes */
+  grub_uint64_t asq;           /* admin submission queue base address */
+  grub_uint64_t acq;           /* admin completion queue base address */
+};
+
+/* Submission queue entry */
+struct grub_nvme_sqe
+{
+  union
+  {
+    grub_uint32_t dword[16];
+    struct
+    {
+      grub_uint32_t cdw0;      /* Command DWORD 0 */
+      grub_uint32_t nsid;      /* Namespace ID */
+      grub_uint64_t _res0;
+      grub_uint64_t mptr;      /* metadata ptr */
+
+      grub_uint64_t dptr_prp1;
+      grub_uint64_t dptr_prp2;
+    };
+  };
+};
+
+/* Completion queue entry */
+struct grub_nvme_cqe
+{
+  union
+  {
+    grub_uint32_t dword[4];
+    struct
+    {
+      grub_uint32_t cdw0;
+      grub_uint32_t _res0;
+      grub_uint16_t sq_head;
+      grub_uint16_t sq_id;
+      grub_uint16_t cid;
+      grub_uint16_t status;
+    };
+  };
+};
+
+/* The common part of every submission or completion queue. */
+struct grub_nvme_queue
+{
+  grub_uint32_t *dbl;          /* doorbell */
+  grub_uint16_t mask;          /* length - 1 */
+};
+
+struct grub_nvme_cq
+{
+  struct grub_nvme_queue common;
+  struct grub_nvme_cqe *cqe;
+
+  /* We have read upto (but not including) this entry in the queue. */
+  grub_uint16_t head;
+
+  /* The current phase bit the controller uses to indicate that it has written
+     a new entry. This is inverted after each wrap. */
+  unsigned phase:1;
+};
+
+struct grub_nvme_sq
+{
+  struct grub_nvme_queue common;
+  struct grub_nvme_sqe *sqe;
+
+  /* Corresponding completion queue. We only support a single SQ per CQ. */
+  struct grub_nvme_cq *cq;
+
+  /* The last entry the controller has fetched. */
+  grub_uint16_t head;
+
+  /* The last value we have written to the tail doorbell. */
+  grub_uint16_t tail;
+};
+
+struct grub_nvme_ctrl
+{
+  grub_pci_device_t pci;
+  struct grub_nvme_reg volatile *reg;
+
+  grub_uint32_t ctrlnum;
+
+  grub_uint32_t doorbell_stride;       /* in bytes */
+
+  struct grub_nvme_sq admin_sq;
+  struct grub_nvme_cq admin_cq;
+
+  grub_uint32_t ns_count;
+
+  struct grub_nvme_sq io_sq;
+  struct grub_nvme_cq io_cq;
+};
+
+struct grub_nvme_namespace
+{
+  struct grub_nvme_namespace *next;
+  struct grub_nvme_namespace **prev;
+
+  char *devname;
+
+  grub_uint32_t nsnum;
+
+  struct grub_nvme_ctrl *ctrl;
+
+  grub_uint32_t ns_id;
+
+  grub_uint64_t lba_count;     /* The total amount of sectors. */
+
+  grub_uint32_t block_size;
+  grub_uint32_t metadata_size;
+  grub_uint32_t max_req_size;
+};
+
+/* Data structures for NVMe admin identify commands */
+
+struct grub_nvme_identify_ctrl
+{
+  grub_uint16_t vid;
+  grub_uint16_t ssvid;
+  char sn[20];
+  char mn[40];
+  char fr[8];
+
+  grub_uint8_t rab;
+  grub_uint8_t ieee[3];
+  grub_uint8_t cmic;
+  grub_uint8_t mdts;
+
+  char _boring[516 - 78];
+
+  grub_uint32_t nn;            /* number of namespaces */
+};
+
+struct grub_nvme_identify_ns_list
+{
+  grub_uint32_t ns_id[1024];
+};
+
+struct grub_nvme_lba_format
+{
+  grub_uint16_t ms;
+  grub_uint8_t lbads;
+  grub_uint8_t rp;
+};
+
+struct grub_nvme_identify_ns
+{
+  grub_uint64_t nsze;
+  grub_uint64_t ncap;
+  grub_uint64_t nuse;
+  grub_uint8_t nsfeat;
+  grub_uint8_t nlbaf;
+  grub_uint8_t flbas;
+
+  char _boring[128 - 27];
+
+  struct grub_nvme_lba_format lbaf[16];
+};
+
+union nvme_identify
+{
+  struct grub_nvme_identify_ns ns;
+  struct grub_nvme_identify_ctrl ctrl;
+  struct grub_nvme_identify_ns_list ns_list;
+};
+
+/* NVMe constants */
+
+#define GRUB_NVME_CAP_CSS_NVME (1ULL << 37)
+
+#define GRUB_NVME_CSTS_FATAL   (1U <<  1)
+#define GRUB_NVME_CSTS_RDY     (1U <<  0)
+
+#define GRUB_NVME_CC_EN        (1U <<  0)
+
+#define GRUB_NVME_SQE_OPC_ADMIN_CREATE_IO_SQ 1U
+#define GRUB_NVME_SQE_OPC_ADMIN_CREATE_IO_CQ 5U
+#define GRUB_NVME_SQE_OPC_ADMIN_IDENTIFY     6U
+
+#define GRUB_NVME_SQE_OPC_IO_WRITE 1U
+#define GRUB_NVME_SQE_OPC_IO_READ  2U
+
+#define GRUB_NVME_ADMIN_IDENTIFY_CNS_ID_NS       0U
+#define GRUB_NVME_ADMIN_IDENTIFY_CNS_ID_CTRL     1U
+#define GRUB_NVME_ADMIN_IDENTIFY_CNS_GET_NS_LIST 2U
+
+#define GRUB_NVME_CQE_DW3_P (1U << 16)
+
+#define GRUB_NVME_PAGE_SIZE 4096
+#define GRUB_NVME_PAGE_MASK ~(GRUB_NVME_PAGE_SIZE - 1)
+
+/* Length for the queue entries. */
+#define GRUB_NVME_SQE_SIZE_LOG 6
+#define GRUB_NVME_CQE_SIZE_LOG 4
+
+#endif
+
+/* EOF */
-- 
2.39.2


_______________________________________________
Grub-devel mailing list
Grub-devel@gnu.org
https://lists.gnu.org/mailman/listinfo/grub-devel

Reply via email to