From: Kishon Vijay Abraham I <kishon@ti.com>
To: Kishon Vijay Abraham I <kishon@ti.com>,
Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>, <linux-pci@vger.kernel.org>,
<linux-kernel@vger.kernel.org>
Subject: [PATCH v3 3/5] PCI: endpoint: Fix for concurrent memory allocation in OB address region
Date: Mon, 24 Feb 2020 15:23:36 +0530 [thread overview]
Message-ID: <20200224095338.3758-4-kishon@ti.com> (raw)
In-Reply-To: <20200224095338.3758-1-kishon@ti.com>
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(-)
diff --git a/drivers/pci/endpoint/pci-epc-mem.c b/drivers/pci/endpoint/pci-epc-mem.c
index d2b174ce15de..abfac1109a13 100644
--- a/drivers/pci/endpoint/pci-epc-mem.c
+++ b/drivers/pci/endpoint/pci-epc-mem.c
@@ -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);
diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
index 9dd60f2e9705..4e3e527c49d1 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -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;
};
/**
--
2.17.1
next prev parent reply other threads:[~2020-02-24 9:50 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-24 9:53 [PATCH v3 0/5] PCI: Endpoint: Miscellaneous improvements Kishon Vijay Abraham I
2020-02-24 9:53 ` [PATCH v3 1/5] PCI: endpoint: Use notification chain mechanism to notify EPC events to EPF Kishon Vijay Abraham I
2020-02-24 9:59 ` Kishon Vijay Abraham I
2020-02-24 9:53 ` [PATCH v3 2/5] PCI: endpoint: Replace spinlock with mutex Kishon Vijay Abraham I
2020-02-24 9:53 ` Kishon Vijay Abraham I [this message]
2020-02-24 9:53 ` [PATCH v3 4/5] PCI: endpoint: Protect concurrent access to pci_epf_ops " Kishon Vijay Abraham I
2020-02-24 9:53 ` [PATCH v3 5/5] PCI: endpoint: Assign function number for each PF in EPC core Kishon Vijay Abraham I
2020-02-24 10:34 ` [PATCH v3 0/5] PCI: Endpoint: Miscellaneous improvements Lorenzo Pieralisi
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