[PATCH AUTOSEL 5.7 134/388] firmware: qcom_scm: fix bogous abuse of dma-direct internals

Sasha Levin
2020-06-18T02:45:08Z

From: Christoph Hellwig <hch@lst.de>

[ Upstream commit 459b1f86f1cba7de813fbc335df476c111feec22 ]

As far as the device is concerned the dma address is the physical
address. There is no need to convert it to a physical address,
especially not using dma-direct internals that are not available
to drivers and which will interact badly with IOMMUs. Last but not
least the commit introducing it claimed to just fix a type issue,
but actually changed behavior.

Fixes: 6e37ccf78a532 ("firmware: qcom_scm: Use proper types for dma mappings")
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20200414123136.441454-1-hch@lst.de
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/firmware/qcom_scm.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
index 059bb0fbae9e..4701487573f7 100644
--- a/drivers/firmware/qcom_scm.c
+++ b/drivers/firmware/qcom_scm.c
@@ -6,7 +6,6 @@
#include <linux/init.h>
#include <linux/cpumask.h>
#include <linux/export.h>
-#include <linux/dma-direct.h>
#include <linux/dma-mapping.h>
#include <linux/module.h>
#include <linux/types.h>
@@ -806,8 +805,7 @@ int qcom_scm_assign_mem(phys_addr_t mem_addr, size_t mem_sz,
struct qcom_scm_mem_map_info *mem_to_map;
phys_addr_t mem_to_map_phys;
phys_addr_t dest_phys;
- phys_addr_t ptr_phys;
- dma_addr_t ptr_dma;
+ dma_addr_t ptr_phys;
size_t mem_to_map_sz;
size_t dest_sz;
size_t src_sz;
@@ -824,10 +822,9 @@ int qcom_scm_assign_mem(phys_addr_t mem_addr, size_t mem_sz,
ptr_sz = ALIGN(src_sz, SZ_64) + ALIGN(mem_to_map_sz, SZ_64) +
ALIGN(dest_sz, SZ_64);

- ptr = dma_alloc_coherent(__scm->dev, ptr_sz, &ptr_dma, GFP_KERNEL);
+ ptr = dma_alloc_coherent(__scm->dev, ptr_sz, &ptr_phys, GFP_KERNEL);
if (!ptr)
return -ENOMEM;
- ptr_phys = dma_to_phys(__scm->dev, ptr_dma);

/* Fill source vmid detail */
src = ptr;
@@ -855,7 +852,7 @@ int qcom_scm_assign_mem(phys_addr_t mem_addr, size_t mem_sz,

ret = __qcom_scm_assign_mem(__scm->dev, mem_to_map_phys, mem_to_map_sz,
ptr_phys, src_sz, dest_phys, dest_sz);
- dma_free_coherent(__scm->dev, ptr_sz, ptr, ptr_dma);
+ dma_free_coherent(__scm->dev, ptr_sz, ptr, ptr_phys);
if (ret) {
dev_err(__scm->dev,
"Assign memory protection call failed %d\n", ret);
--
2.25.1