Introduce the function pci_epc_mem_map() to facilitate controller memory
address allocation and mapping to a RC PCI address region in endpoint
function drivers.
This function first uses pci_epc_map_align() to determine the controller
memory address size (and offset into) depending on the controller
address alignment constraints. The result of this function is used to
allocate a controller physical memory region using
pci_epc_mem_alloc_addr() and map that memory to the RC PCI address
space with pci_epc_map_addr().
Since pci_epc_map_align() may indicate that the effective mapping
of a PCI address region is smaller than the user requested size,
pci_epc_mem_map() may only partially map the RC PCI address region
specified. It is the responsibility of the caller (an endpoint function
driver) to handle such smaller mapping.
The counterpart of pci_epc_mem_map() to unmap and free the controller
memory address region is pci_epc_mem_unmap().
Both functions operate using a struct pci_epc_map data structure
Endpoint function drivers can use struct pci_epc_map to access the
mapped RC PCI address region using the ->virt_addr and ->pci_size
fields.
Co-developed-by: Rick Wertenbroek <rick.wertenbroek@xxxxxxxxx>
Signed-off-by: Rick Wertenbroek <rick.wertenbroek@xxxxxxxxx>
Signed-off-by: Damien Le Moal <dlemoal@xxxxxxxxxx>
Reviewed-by: Niklas Cassel <cassel@xxxxxxxxxx>
---
drivers/pci/endpoint/pci-epc-core.c | 78 +++++++++++++++++++++++++++++
include/linux/pci-epc.h | 4 ++
2 files changed, 82 insertions(+)
diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index 1adccf07c33e..d03c753d0a53 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -532,6 +532,84 @@ int pci_epc_map_addr(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
}
EXPORT_SYMBOL_GPL(pci_epc_map_addr);
+/**
+ * pci_epc_mem_map() - allocate and map a PCI address to a CPU address
+ * @epc: the EPC device on which the CPU address is to be allocated and mapped
+ * @func_no: the physical endpoint function number in the EPC device
+ * @vfunc_no: the virtual endpoint function number in the physical function
+ * @pci_addr: PCI address to which the CPU address should be mapped
+ * @pci_size: the number of bytes to map starting from @pci_addr
+ * @map: where to return the mapping information
+ *
+ * Allocate a controller memory address region and map it to a RC PCI address
+ * region, taking into account the controller physical address mapping
+ * constraints using pci_epc_map_align().
+ * The effective size of the PCI address range mapped from @pci_addr is
+ * indicated by @map->pci_size. This size may be less than the requested
+ * @pci_size. The local virtual CPU address for the mapping is indicated by
+ * @map->virt_addr (@map->phys_addr indicates the physical address).
+ * The size and CPU address of the controller memory allocated and mapped are
+ * respectively indicated by @map->map_size and @map->virt_base (and
+ * @map->phys_base).
+ *
+ * Returns 0 on success and a negative error code in case of error.
+ */
+int pci_epc_mem_map(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
+ u64 pci_addr, size_t pci_size, struct pci_epc_map *map)
+{
+ int ret;
+
+ ret = pci_epc_map_align(epc, func_no, vfunc_no, pci_addr, pci_size, map);
+ if (ret)
+ return ret;
+
+ map->virt_base = pci_epc_mem_alloc_addr(epc, &map->phys_base,
+ map->map_size);
+ if (!map->virt_base)
+ return -ENOMEM;
+
+ map->phys_addr = map->phys_base + map->map_ofst;
+ map->virt_addr = map->virt_base + map->map_ofst;
+
+ ret = pci_epc_map_addr(epc, func_no, vfunc_no, map->phys_base,
+ map->map_pci_addr, map->map_size);
+ if (ret) {
+ pci_epc_mem_free_addr(epc, map->phys_base, map->virt_base,
+ map->map_size);
+ map->virt_base = 0;
+ return ret;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(pci_epc_mem_map);
+
+/**
+ * pci_epc_mem_unmap() - unmap and free a CPU address region
+ * @epc: the EPC device on which the CPU address is allocated and mapped
+ * @func_no: the physical endpoint function number in the EPC device
+ * @vfunc_no: the virtual endpoint function number in the physical function
+ * @map: the mapping information
+ *
+ * Unmap and free a CPU address region that was allocated and mapped with
+ * pci_epc_mem_map().
+ */
+void pci_epc_mem_unmap(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
+ struct pci_epc_map *map)
+{
+ if (!pci_epc_function_is_valid(epc, func_no, vfunc_no))
+ return;
+
+ if (!map || !map->virt_base)
+ return;
+
+ pci_epc_unmap_addr(epc, func_no, vfunc_no, map->phys_base);
+ pci_epc_mem_free_addr(epc, map->phys_base, map->virt_base,
+ map->map_size);
+ map->map_size = 0;
+}
+EXPORT_SYMBOL_GPL(pci_epc_mem_unmap);
+
/**
* pci_epc_clear_bar() - reset the BAR
* @epc: the EPC device for which the BAR has to be cleared
diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
index 9df8a83e8d10..97d2fbb740fd 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -315,6 +315,10 @@ void __iomem *pci_epc_mem_alloc_addr(struct pci_epc *epc,
phys_addr_t *phys_addr, size_t size);
void pci_epc_mem_free_addr(struct pci_epc *epc, phys_addr_t phys_addr,
void __iomem *virt_addr, size_t size);
+int pci_epc_mem_map(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
+ u64 pci_addr, size_t pci_size, struct pci_epc_map *map);
+void pci_epc_mem_unmap(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
+ struct pci_epc_map *map);
#else
static inline void pci_epc_init_notify(struct pci_epc *epc)
--
2.46.2
