Re: [RFC PATCH 4/4] nvme: translate virtual addresses into the bus's address space

On 2021-09-24 01:20, Stefan Agner wrote:

So far we've been content with passing physical/CPU addresses when configuring memory addresses into NVMe controllers, but not all platforms have buses with transparent mappings. Specifically the Raspberry Pi 4 might introduce an offset to memory accesses incoming from its PCIe port.

Introduce nvme_virt_to_bus() and nvme_bus_to_virt() to cater with these limitations, and make sure we don't break non DM users. For devices where PCIe's view of host memory doesn't match the memory as seen by the CPU.

A similar change has been introduced for XHCI controller with commit 1a474559d90a ("xhci: translate virtual addresses into the bus's address space").

Signed-off-by: Stefan Agner stefan@agner.ch

drivers/nvme/nvme.c | 32 ++++++++++++++++++-------------- drivers/nvme/nvme.h | 15 +++++++++++++++ 2 files changed, 33 insertions(+), 14 deletions(-)

diff --git a/drivers/nvme/nvme.c b/drivers/nvme/nvme.c index 4c4dc7cc4d..0b7082d71b 100644 --- a/drivers/nvme/nvme.c +++ b/drivers/nvme/nvme.c @@ -95,7 +95,7 @@ static int nvme_setup_prps(struct nvme_dev *dev, u64 *prp2, buffer += (page_size - offset);

if (length <= page_size) {

• *prp2 = (u64)buffer;
  

• *prp2 = nvme_virt_to_bus(dev, buffer);
  

  return 0; }

@@ -120,16 +120,16 @@ static int nvme_setup_prps(struct nvme_dev *dev, u64 *prp2, i = 0; while (nprps) { if (i == prps_per_page) {

• 	u64 next_prp_list = (u64)prp_pool + page_size;
  

• 	*(prp_pool + i) = cpu_to_le64(next_prp_list);
  

• 	u64 next = nvme_virt_to_bus(dev, prp_pool + page_size);
  

• 	*(prp_pool + i) = cpu_to_le64(next);
  i = 0;
  prp_pool += page_size;
  

  }

• *(prp_pool + i++) = cpu_to_le64((u64)buffer);
  

• *(prp_pool + i++) = cpu_to_le64(nvme_virt_to_bus(dev, buffer));
  

  buffer += page_size; nprps--; }

• *prp2 = (u64)dev->prp_pool;

• *prp2 = nvme_virt_to_bus(dev, dev->prp_pool);

  flush_dcache_range((ulong)dev->prp_pool, (ulong)dev->prp_pool + dev->prp_entry_num * sizeof(u64));

@@ -356,6 +356,7 @@ static int nvme_configure_admin_queue(struct nvme_dev *dev) int result; u32 aqa; u64 cap = dev->cap;

• u64 dma_addr; struct nvme_queue *nvmeq; /* most architectures use 4KB as the page size */ unsigned page_shift = 12;

@@ -396,8 +397,10 @@ static int nvme_configure_admin_queue(struct nvme_dev *dev) dev->ctrl_config |= NVME_CC_IOSQES | NVME_CC_IOCQES;

writel(aqa, &dev->bar->aqa);

• nvme_writeq((ulong)nvmeq->sq_cmds, &dev->bar->asq);
• nvme_writeq((ulong)nvmeq->cqes, &dev->bar->acq);

• dma_addr = nvme_virt_to_bus(dev, nvmeq->sq_cmds);

• nvme_writeq(dma_addr, &dev->bar->asq);

• dma_addr = nvme_virt_to_bus(dev, nvmeq->cqes);

• nvme_writeq(dma_addr, &dev->bar->acq);

  result = nvme_enable_ctrl(dev); if (result)

@@ -423,7 +426,7 @@ static int nvme_alloc_cq(struct nvme_dev *dev, u16 qid,

memset(&c, 0, sizeof(c)); c.create_cq.opcode = nvme_admin_create_cq;

• c.create_cq.prp1 = cpu_to_le64((ulong)nvmeq->cqes);

• c.create_cq.prp1 = cpu_to_le64(nvme_virt_to_bus(dev, nvmeq->cqes)); c.create_cq.cqid = cpu_to_le16(qid); c.create_cq.qsize = cpu_to_le16(nvmeq->q_depth - 1); c.create_cq.cq_flags = cpu_to_le16(flags);

@@ -440,7 +443,7 @@ static int nvme_alloc_sq(struct nvme_dev *dev, u16 qid,

memset(&c, 0, sizeof(c)); c.create_sq.opcode = nvme_admin_create_sq;

• c.create_sq.prp1 = cpu_to_le64((ulong)nvmeq->sq_cmds);

• c.create_sq.prp1 = cpu_to_le64(nvme_virt_to_bus(dev, nvmeq->sq_cmds)); c.create_sq.sqid = cpu_to_le16(qid); c.create_sq.qsize = cpu_to_le16(nvmeq->q_depth - 1); c.create_sq.sq_flags = cpu_to_le16(flags);

@@ -461,14 +464,14 @@ int nvme_identify(struct nvme_dev *dev, unsigned nsid, memset(&c, 0, sizeof(c)); c.identify.opcode = nvme_admin_identify; c.identify.nsid = cpu_to_le32(nsid);

• c.identify.prp1 = cpu_to_le64((u64)buffer);

• c.identify.prp1 = cpu_to_le64(nvme_virt_to_bus(dev, buffer));

  length -= (page_size - offset); if (length <= 0) { c.identify.prp2 = 0; } else { buffer += (page_size - offset);

• c.identify.prp2 = cpu_to_le64((u64)buffer);
  

• c.identify.prp2 = cpu_to_le64(nvme_virt_to_bus(dev, buffer));
  

  }

  c.identify.cns = cpu_to_le32(cns);

@@ -493,7 +496,7 @@ int nvme_get_features(struct nvme_dev *dev, unsigned fid, unsigned nsid, memset(&c, 0, sizeof(c)); c.features.opcode = nvme_admin_get_features; c.features.nsid = cpu_to_le32(nsid);

• c.features.prp1 = cpu_to_le64((u64)buffer);

• c.features.prp1 = cpu_to_le64(nvme_virt_to_bus(dev, buffer)); c.features.fid = cpu_to_le32(fid);

  ret = nvme_submit_admin_cmd(dev, &c, result);

@@ -519,7 +522,7 @@ int nvme_set_features(struct nvme_dev *dev, unsigned fid, unsigned dword11,

memset(&c, 0, sizeof(c)); c.features.opcode = nvme_admin_set_features;

• c.features.prp1 = cpu_to_le64((u64)buffer);

• c.features.prp1 = cpu_to_le64(nvme_virt_to_bus(dev, buffer)); c.features.fid = cpu_to_le32(fid); c.features.dword11 = cpu_to_le32(dword11);

@@ -775,7 +778,7 @@ static ulong nvme_blk_rw(struct udevice *udev, lbaint_t blknr, c.rw.slba = cpu_to_le64(slba); slba += lbas; c.rw.length = cpu_to_le16(lbas - 1);

• c.rw.prp1 = cpu_to_le64((ulong)buffer);
  

• c.rw.prp1 = cpu_to_le64(nvme_virt_to_bus(dev, buffer));
  

  c.rw.prp2 = cpu_to_le64(prp2); status = nvme_submit_sync_cmd(dev->queues[NVME_IO_Q], &c, NULL, IO_TIMEOUT);

@@ -834,6 +837,7 @@ static int nvme_probe(struct udevice *udev) struct nvme_id_ns *id;

ndev->instance = trailing_strtol(udev->name);

• ndev->dev = udev->parent;

It only translates addresses correctly once I chose the parent device. I am pretty sure that this is not the right way to fix it. Shouldn't the child automatically assume that the same translation is required?

-- Stefan

INIT_LIST_HEAD(&ndev->namespaces); ndev->bar = dm_pci_map_bar(udev, PCI_BASE_ADDRESS_0, diff --git a/drivers/nvme/nvme.h b/drivers/nvme/nvme.h index c6aae4da5d..31e6899bca 100644 --- a/drivers/nvme/nvme.h +++ b/drivers/nvme/nvme.h @@ -7,8 +7,15 @@ #ifndef __DRIVER_NVME_H__ #define __DRIVER_NVME_H__

+#include <phys2bus.h> #include <asm/io.h>

+#if CONFIG_IS_ENABLED(DM_USB) +#define nvme_to_dev(_dev) _dev->dev +#else +#define nvme_to_dev(_dev) NULL +#endif

struct nvme_id_power_state { __le16 max_power; /* centiwatts */ __u8 rsvd2; @@ -596,6 +603,9 @@ enum {

/* Represents an NVM Express device. Each nvme_dev is a PCI function. */ struct nvme_dev { +#if CONFIG_IS_ENABLED(DM_USB)

• struct udevice *dev;

+#endif struct list_head node; struct nvme_queue **queues; u32 __iomem *dbs; @@ -635,4 +645,9 @@ struct nvme_ns { u8 flbas; };

+static inline dma_addr_t nvme_virt_to_bus(struct nvme_dev *dev, void *addr) +{

• return dev_phys_to_bus(nvme_to_dev(dev), virt_to_phys(addr));

+}

#endif /* __DRIVER_NVME_H__ */