Re: [PATCH 2/7] cxl/mem: Split creation from mapping in probe

Jonathan Cameron
2021-04-08T17:28:18Z

On Wed, 7 Apr 2021 15:26:20 -0700
Ben Widawsky <ben.widawsky@intel.com> wrote:

> Add a new function specifically for mapping the register blocks and
> offsets within. The new function can be used more generically for other
> register block identifiers.
>
> No functional change is meant to be introduced in this patch with the
> exception of a dev_err printed when the device register block isn't
> found.
>
> Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Agreed, this seems to be a noop refactor to me.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

> ---
> drivers/cxl/mem.c | 64 +++++++++++++++++++++++++++++------------------
> 1 file changed, 40 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
> index 99534260034e..520edaf233d4 100644
> --- a/drivers/cxl/mem.c
> +++ b/drivers/cxl/mem.c
> @@ -925,22 +925,40 @@ static int cxl_mem_setup_mailbox(struct cxl_mem *cxlm)
> return 0;
> }
>
> -static struct cxl_mem *cxl_mem_create(struct pci_dev *pdev, u32 reg_lo,
> - u32 reg_hi)
> +static struct cxl_mem *cxl_mem_create(struct pci_dev *pdev)
> {
> struct device *dev = &pdev->dev;
> struct cxl_mem *cxlm;
> - void __iomem *regs;
> - u64 offset;
> - u8 bar;
> - int rc;
>
> cxlm = devm_kzalloc(dev, sizeof(*cxlm), GFP_KERNEL);
> if (!cxlm) {
> dev_err(dev, "No memory available\n");
> - return NULL;
> + return ERR_PTR(-ENOMEM);
> + }
> +
> + mutex_init(&cxlm->mbox_mutex);
> + cxlm->pdev = pdev;
> + cxlm->enabled_cmds =
> + devm_kmalloc_array(dev, BITS_TO_LONGS(cxl_cmd_count),
> + sizeof(unsigned long),
> + GFP_KERNEL | __GFP_ZERO);
> + if (!cxlm->enabled_cmds) {
> + dev_err(dev, "No memory available for bitmap\n");
> + return ERR_PTR(-ENOMEM);
> }
>
> + return cxlm;
> +}
> +
> +static int cxl_mem_map_regblock(struct cxl_mem *cxlm, u32 reg_lo, u32 reg_hi)
> +{
> + struct pci_dev *pdev = cxlm->pdev;
> + struct device *dev = &pdev->dev;
> + void __iomem *regs;
> + u64 offset;
> + u8 bar;
> + int rc;
> +
> offset = ((u64)reg_hi << 32) | FIELD_GET(CXL_REGLOC_ADDR_MASK, reg_lo);
> bar = FIELD_GET(CXL_REGLOC_BIR_MASK, reg_lo);
>
> @@ -948,30 +966,20 @@ static struct cxl_mem *cxl_mem_create(struct pci_dev *pdev, u32 reg_lo,
> if (pci_resource_len(pdev, bar) < offset) {
> dev_err(dev, "BAR%d: %pr: too small (offset: %#llx)\n", bar,
> &pdev->resource[bar], (unsigned long long)offset);
> - return NULL;
> + return -ENXIO;
> }
>
> rc = pcim_iomap_regions(pdev, BIT(bar), pci_name(pdev));
> if (rc) {
> dev_err(dev, "failed to map registers\n");
> - return NULL;
> + return rc;
> }
> regs = pcim_iomap_table(pdev)[bar];
>
> - mutex_init(&cxlm->mbox_mutex);
> - cxlm->pdev = pdev;
> cxlm->base = regs + offset;
> - cxlm->enabled_cmds =
> - devm_kmalloc_array(dev, BITS_TO_LONGS(cxl_cmd_count),
> - sizeof(unsigned long),
> - GFP_KERNEL | __GFP_ZERO);
> - if (!cxlm->enabled_cmds) {
> - dev_err(dev, "No memory available for bitmap\n");
> - return NULL;
> - }
>
> dev_dbg(dev, "Mapped CXL Memory Device resource\n");
> - return cxlm;
> + return 0;
> }
>
> static int cxl_mem_dvsec(struct pci_dev *pdev, int dvsec)
> @@ -1403,14 +1411,18 @@ static int cxl_mem_identify(struct cxl_mem *cxlm)
> static int cxl_mem_probe(struct pci_dev *pdev, const struct pci_device_id *id)
> {
> struct device *dev = &pdev->dev;
> - struct cxl_mem *cxlm = NULL;
> u32 regloc_size, regblocks;
> + struct cxl_mem *cxlm;
> int rc, regloc, i;
>
> rc = pcim_enable_device(pdev);
> if (rc)
> return rc;
>
> + cxlm = cxl_mem_create(pdev);
> + if (IS_ERR(cxlm))
> + return PTR_ERR(cxlm);
> +
> regloc = cxl_mem_dvsec(pdev, PCI_DVSEC_ID_CXL_REGLOC_OFFSET);
> if (!regloc) {
> dev_err(dev, "register location dvsec not found\n");
> @@ -1435,13 +1447,17 @@ static int cxl_mem_probe(struct pci_dev *pdev, const struct pci_device_id *id)
> reg_type = FIELD_GET(CXL_REGLOC_RBI_MASK, reg_lo);
>
> if (reg_type == CXL_REGLOC_RBI_MEMDEV) {
> - cxlm = cxl_mem_create(pdev, reg_lo, reg_hi);
> + rc = cxl_mem_map_regblock(cxlm, reg_lo, reg_hi);
> + if (rc)
> + return rc;
> break;
> }
> }
>
> - if (!cxlm)
> - return -ENODEV;
> + if (i == regblocks) {
> + dev_err(dev, "Missing register locator for device registers\n");
> + return -ENXIO;
> + }
>
> rc = cxl_mem_setup_regs(cxlm);
> if (rc)