@@ -79,6 +79,7 @@ int __pci_epc_mem_init(struct pci_epc *epc, phys_addr_t phys_base, size_t size,
mem->page_size = page_size;
mem->pages = pages;
mem->size = size;
+ mutex_init(&mem->lock);
epc->mem = mem;
@@ -122,7 +123,7 @@ void __iomem *pci_epc_mem_alloc_addr(struct pci_epc *epc,
phys_addr_t *phys_addr, size_t size)
{
int pageno;
- void __iomem *virt_addr;
+ void __iomem *virt_addr = NULL;
struct pci_epc_mem *mem = epc->mem;
unsigned int page_shift = ilog2(mem->page_size);
int order;
@@ -130,15 +131,18 @@ void __iomem *pci_epc_mem_alloc_addr(struct pci_epc *epc,
size = ALIGN(size, mem->page_size);
order = pci_epc_mem_get_order(mem, size);
+ mutex_lock(&mem->lock);
pageno = bitmap_find_free_region(mem->bitmap, mem->pages, order);
if (pageno < 0)
- return NULL;
+ goto ret;
*phys_addr = mem->phys_base + ((phys_addr_t)pageno << page_shift);
virt_addr = ioremap(*phys_addr, size);
if (!virt_addr)
bitmap_release_region(mem->bitmap, pageno, order);
+ret:
+ mutex_unlock(&mem->lock);
return virt_addr;
}
EXPORT_SYMBOL_GPL(pci_epc_mem_alloc_addr);
@@ -164,7 +168,9 @@ void pci_epc_mem_free_addr(struct pci_epc *epc, phys_addr_t phys_addr,
pageno = (phys_addr - mem->phys_base) >> page_shift;
size = ALIGN(size, mem->page_size);
order = pci_epc_mem_get_order(mem, size);
+ mutex_lock(&mem->lock);
bitmap_release_region(mem->bitmap, pageno, order);
+ mutex_unlock(&mem->lock);
}
EXPORT_SYMBOL_GPL(pci_epc_mem_free_addr);
@@ -71,6 +71,7 @@ struct pci_epc_ops {
* @bitmap: bitmap to manage the PCI address space
* @pages: number of bits representing the address region
* @page_size: size of each page
+ * @lock: mutex to protect bitmap
*/
struct pci_epc_mem {
phys_addr_t phys_base;
@@ -78,6 +79,8 @@ struct pci_epc_mem {
unsigned long *bitmap;
size_t page_size;
int pages;
+ /* mutex to protect against concurrent access for memory allocation*/
+ struct mutex lock;
};
/**
pci-epc-mem uses bitmap to manage the Endpoint outbound (OB) address region. This address region will be shared by multiple endpoint functions (in the case of multi function endpoint) and it has to be protected from concurrent access to avoid updating inconsistent state. Use mutex to protect while updating bitmap without which the memory allocation API will return incorrect address. Cc: stable@vger.kernel.org # v4.14+ Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> --- drivers/pci/endpoint/pci-epc-mem.c | 10 ++++++++-- include/linux/pci-epc.h | 3 +++ 2 files changed, 11 insertions(+), 2 deletions(-)