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memremap: validate the pagemap type passed to devm_memremap_pages 

Most pgmap types are only supported when certain config options are
enabled.  Check for a type that is valid for the current configuration
before setting up the pagemap.  For this the usage of the 0 type for
device dax gets replaced with an explicit MEMORY_DEVICE_DEVDAX type.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
This commit is contained in:
Christoph Hellwig 2019-06-26 14:27:07 +02:00 committed by Jason Gunthorpe
parent 0092908d16
commit 3ed2dcdf54
3 changed files with 31 additions and 0 deletions
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1
drivers/dax/device.c
View File

@ -468,6 +468,7 @@ int dev_dax_probe(struct device *dev)
dev_dax->pgmap.ref = &dev_dax->ref;
dev_dax->pgmap.kill = dev_dax_percpu_kill;
dev_dax->pgmap.cleanup = dev_dax_percpu_exit;
dev_dax->pgmap.type = MEMORY_DEVICE_DEVDAX;
addr = devm_memremap_pages(dev, &dev_dax->pgmap);
if (IS_ERR(addr))
return PTR_ERR(addr);

8
include/linux/memremap.h
View File

@ -45,13 +45,21 @@ struct vmem_altmap {
* wakeup is used to coordinate physical address space management (ex:
* fs truncate/hole punch) vs pinned pages (ex: device dma).
*
* MEMORY_DEVICE_DEVDAX:
* Host memory that has similar access semantics as System RAM i.e. DMA
* coherent and supports page pinning. In contrast to
* MEMORY_DEVICE_FS_DAX, this memory is access via a device-dax
* character device.
*
* MEMORY_DEVICE_PCI_P2PDMA:
* Device memory residing in a PCI BAR intended for use with Peer-to-Peer
* transactions.
*/
enum memory_type {
/* 0 is reserved to catch uninitialized type fields */
MEMORY_DEVICE_PRIVATE = 1,
MEMORY_DEVICE_FS_DAX,
MEMORY_DEVICE_DEVDAX,
MEMORY_DEVICE_PCI_P2PDMA,
};

22
kernel/memremap.c
View File

@ -157,6 +157,28 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
pgprot_t pgprot = PAGE_KERNEL;
int error, nid, is_ram;
switch (pgmap->type) {
case MEMORY_DEVICE_PRIVATE:
if (!IS_ENABLED(CONFIG_DEVICE_PRIVATE)) {
WARN(1, "Device private memory not supported\n");
return ERR_PTR(-EINVAL);
}
break;
case MEMORY_DEVICE_FS_DAX:
if (!IS_ENABLED(CONFIG_ZONE_DEVICE) ||
IS_ENABLED(CONFIG_FS_DAX_LIMITED)) {
WARN(1, "File system DAX not supported\n");
return ERR_PTR(-EINVAL);
}
break;
case MEMORY_DEVICE_DEVDAX:
case MEMORY_DEVICE_PCI_P2PDMA:
break;
default:
WARN(1, "Invalid pgmap type %d\n", pgmap->type);
break;
}
if (!pgmap->ref || !pgmap->kill || !pgmap->cleanup) {
WARN(1, "Missing reference count teardown definition\n");
return ERR_PTR(-EINVAL);