[PATCH v4 05/10] cxl/pci: Make more use of cxl_register_map

From: Dan Williams
Date: Sat Oct 09 2021 - 16:51:19 EST


From: Ben Widawsky <ben.widawsky@xxxxxxxxx>

The structure exists to pass around information about register mapping.
Use it for passing @barno and @block_offset, and eliminate duplicate
local variables.

The helpers that use @map do not care about @cxlm, so just pass them a
pdev instead.

Signed-off-by: Ben Widawsky <ben.widawsky@xxxxxxxxx>
Reported-by: kernel test robot <lkp@xxxxxxxxx>
[djbw: separate @base conversion]
[djbw: reorder before cxl_pci_setup_regs() refactor to improver readability]
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
Changes since v3:
- Fix a 0day report about printing a resource_size_t

drivers/cxl/pci.c | 55 ++++++++++++++++++++++-------------------------------
1 file changed, 23 insertions(+), 32 deletions(-)

diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
index 21dd10a77eb3..f1de236ccd13 100644
--- a/drivers/cxl/pci.c
+++ b/drivers/cxl/pci.c
@@ -306,12 +306,13 @@ static int cxl_pci_setup_mailbox(struct cxl_mem *cxlm)
return 0;
}

-static void __iomem *cxl_pci_map_regblock(struct cxl_mem *cxlm,
- u8 bar, u64 offset)
+static void __iomem *cxl_pci_map_regblock(struct pci_dev *pdev,
+ struct cxl_register_map *map)
{
void __iomem *addr;
- struct device *dev = cxlm->dev;
- struct pci_dev *pdev = to_pci_dev(dev);
+ int bar = map->barno;
+ struct device *dev = &pdev->dev;
+ resource_size_t offset = map->block_offset;

/* Basic sanity check that BAR is big enough */
if (pci_resource_len(pdev, bar) < offset) {
@@ -326,15 +327,15 @@ static void __iomem *cxl_pci_map_regblock(struct cxl_mem *cxlm,
return addr;
}

- dev_dbg(dev, "Mapped CXL Memory Device resource bar %u @ %#llx\n",
- bar, offset);
+ dev_dbg(dev, "Mapped CXL Memory Device resource bar %u @ %pa\n",
+ bar, &offset);

return addr;
}

-static void cxl_pci_unmap_regblock(struct cxl_mem *cxlm, void __iomem *base)
+static void cxl_pci_unmap_regblock(struct pci_dev *pdev, void __iomem *base)
{
- pci_iounmap(to_pci_dev(cxlm->dev), base);
+ pci_iounmap(pdev, base);
}

static int cxl_pci_dvsec(struct pci_dev *pdev, int dvsec)
@@ -360,12 +361,12 @@ static int cxl_pci_dvsec(struct pci_dev *pdev, int dvsec)
return 0;
}

-static int cxl_probe_regs(struct cxl_mem *cxlm, void __iomem *base,
+static int cxl_probe_regs(struct pci_dev *pdev, void __iomem *base,
struct cxl_register_map *map)
{
struct cxl_component_reg_map *comp_map;
struct cxl_device_reg_map *dev_map;
- struct device *dev = cxlm->dev;
+ struct device *dev = &pdev->dev;

switch (map->reg_type) {
case CXL_REGLOC_RBI_COMPONENT:
@@ -420,12 +421,13 @@ static int cxl_map_regs(struct cxl_mem *cxlm, struct cxl_register_map *map)
return 0;
}

-static void cxl_decode_register_block(u32 reg_lo, u32 reg_hi,
- u8 *bar, u64 *offset, u8 *reg_type)
+static void cxl_decode_regblock(u32 reg_lo, u32 reg_hi,
+ struct cxl_register_map *map)
{
- *offset = ((u64)reg_hi << 32) | (reg_lo & CXL_REGLOC_ADDR_MASK);
- *bar = FIELD_GET(CXL_REGLOC_BIR_MASK, reg_lo);
- *reg_type = FIELD_GET(CXL_REGLOC_RBI_MASK, reg_lo);
+ map->block_offset =
+ ((u64)reg_hi << 32) | (reg_lo & CXL_REGLOC_ADDR_MASK);
+ map->barno = FIELD_GET(CXL_REGLOC_BIR_MASK, reg_lo);
+ map->reg_type = FIELD_GET(CXL_REGLOC_RBI_MASK, reg_lo);
}

/**
@@ -462,34 +464,23 @@ static int cxl_pci_setup_regs(struct cxl_mem *cxlm)

for (i = 0, n_maps = 0; i < regblocks; i++, regloc += 8) {
u32 reg_lo, reg_hi;
- u8 reg_type;
- u64 offset;
- u8 bar;

pci_read_config_dword(pdev, regloc, &reg_lo);
pci_read_config_dword(pdev, regloc + 4, &reg_hi);

- cxl_decode_register_block(reg_lo, reg_hi, &bar, &offset,
- &reg_type);
+ map = &maps[n_maps];
+ cxl_decode_regblock(reg_lo, reg_hi, map);

/* Ignore unknown register block types */
- if (reg_type > CXL_REGLOC_RBI_MEMDEV)
+ if (map->reg_type > CXL_REGLOC_RBI_MEMDEV)
continue;

- base = cxl_pci_map_regblock(cxlm, bar, offset);
+ base = cxl_pci_map_regblock(pdev, map);
if (!base)
return -ENOMEM;

- map = &maps[n_maps];
- map->barno = bar;
- map->block_offset = offset;
- map->reg_type = reg_type;
-
- ret = cxl_probe_regs(cxlm, base + offset, map);
-
- /* Always unmap the regblock regardless of probe success */
- cxl_pci_unmap_regblock(cxlm, base);
-
+ ret = cxl_probe_regs(pdev, base + map->block_offset, map);
+ cxl_pci_unmap_regblock(pdev, base);
if (ret)
return ret;