The application processor accessing the dynamically assigned metadata
region after assigning it to the remote Q6 would lead to an XPU violation.
Fix this by un-mapping the metadata region post firmware header copy. The
metadata region is freed only after the modem Q6 is done with fw header
authentication.
Signed-off-by: Sibi Sankar <quic_sibis@xxxxxxxxxxx>
---
V2:
* Fix error when MSS is built as a module [Kernel Test Bot]
* Fixup cleanup errors
drivers/remoteproc/qcom_q6v5_mss.c | 38 ++++++++++++++++++++++++++++++++------
1 file changed, 32 insertions(+), 6 deletions(-)
diff --git a/drivers/remoteproc/qcom_q6v5_mss.c b/drivers/remoteproc/qcom_q6v5_mss.c
index af217de75e4d..4b37e11fbb03 100644
--- a/drivers/remoteproc/qcom_q6v5_mss.c
+++ b/drivers/remoteproc/qcom_q6v5_mss.c
@@ -10,6 +10,7 @@
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/devcoredump.h>
+#include <linux/dma-map-ops.h>
#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
@@ -932,27 +933,52 @@ static void q6v5proc_halt_axi_port(struct q6v5 *qproc,
static int q6v5_mpss_init_image(struct q6v5 *qproc, const struct firmware *fw,
const char *fw_name)
{
- unsigned long dma_attrs = DMA_ATTR_FORCE_CONTIGUOUS;
+ unsigned long dma_attrs = DMA_ATTR_FORCE_CONTIGUOUS | DMA_ATTR_NO_KERNEL_MAPPING;
+ unsigned long flags = VM_DMA_COHERENT | VM_FLUSH_RESET_PERMS;
+ struct page **pages;
+ struct page *page;
dma_addr_t phys;
void *metadata;
int mdata_perm;
int xferop_ret;
size_t size;
- void *ptr;
+ void *vaddr;
+ int count;
int ret;
+ int i;
metadata = qcom_mdt_read_metadata(fw, &size, fw_name, qproc->dev);
if (IS_ERR(metadata))
return PTR_ERR(metadata);
- ptr = dma_alloc_attrs(qproc->dev, size, &phys, GFP_KERNEL, dma_attrs);
- if (!ptr) {
+ page = dma_alloc_attrs(qproc->dev, size, &phys, GFP_KERNEL, dma_attrs);
+ if (!page) {
kfree(metadata);
dev_err(qproc->dev, "failed to allocate mdt buffer\n");
return -ENOMEM;
}
- memcpy(ptr, metadata, size);
+ count = PAGE_ALIGN(size) >> PAGE_SHIFT;
+ pages = kmalloc_array(count, sizeof(struct page *), GFP_KERNEL);
+ if (!pages) {
+ ret = -ENOMEM;
+ goto free_dma_attrs;
+ }
+
+ for (i = 0; i < count; i++)
+ pages[i] = nth_page(page, i);
+
+ vaddr = vmap(pages, count, flags, pgprot_dmacoherent(PAGE_KERNEL));
+ kfree(pages);
+ if (!vaddr) {
+ dev_err(qproc->dev, "unable to map memory region: %pa+%zx\n", &phys, size);
+ ret = -EBUSY;
+ goto free_dma_attrs;
+ }
+
+ memcpy(vaddr, metadata, size);
+
+ vunmap(vaddr);
/* Hypervisor mapping to access metadata by modem */
mdata_perm = BIT(QCOM_SCM_VMID_HLOS);
@@ -982,7 +1008,7 @@ static int q6v5_mpss_init_image(struct q6v5 *qproc, const struct firmware *fw,
"mdt buffer not reclaimed system may become unstable\n");
free_dma_attrs:
- dma_free_attrs(qproc->dev, size, ptr, phys, dma_attrs);
+ dma_free_attrs(qproc->dev, size, page, phys, dma_attrs);
kfree(metadata);
return ret < 0 ? ret : 0;
--
2.7.4
