[PATCH] dma-mapping: Use IOMMU DMA calls for common alloc/free page calls

From: Leon Romanovsky
Date: Thu Sep 05 2024 - 03:14:20 EST

From: Leon Romanovsky <leonro@xxxxxxxxxx>

Common alloca and free pages routines are called when IOMMU DMA is used,
and internally it calls to DMA ops structure which is not available for
default IOMMU. This patch adds necessary if checks to call IOMMU DMA.

It fixes the following crash:

Unable to handle kernel NULL pointer dereference at virtual address 0000000000000040
Mem abort info:
ESR = 0x0000000096000006
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x06: level 2 translation fault
Data abort info:
ISV = 0, ISS = 0x00000006, ISS2 = 0x00000000
CM = 0, WnR = 0, TnD = 0, TagAccess = 0
GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
user pgtable: 4k pages, 48-bit VAs, pgdp=00000000d20bb000
[0000000000000040] pgd=08000000d20c1003
, p4d=08000000d20c1003
, pud=08000000d20c2003, pmd=0000000000000000
Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP
Modules linked in: ipv6 hci_uart venus_core btqca
v4l2_mem2mem btrtl qcom_spmi_adc5 sbs_battery btbcm qcom_vadc_common
cros_ec_typec videobuf2_v4l2 leds_cros_ec cros_kbd_led_backlight
cros_ec_chardev videodev elan_i2c
videobuf2_common qcom_stats mc bluetooth coresight_stm stm_core
ecdh_generic ecc pwrseq_core panel_edp icc_bwmon ath10k_snoc ath10k_core
ath mac80211 phy_qcom_qmp_combo aux_bridge libarc4 coresight_replicator
coresight_etm4x coresight_tmc
coresight_funnel cfg80211 rfkill coresight qcom_wdt cbmem ramoops
reed_solomon pwm_bl coreboot_table backlight crct10dif_ce
CPU: 7 UID: 0 PID: 70 Comm: kworker/u32:4 Not tainted 6.11.0-rc6-next-20240903-00003-gdfc6015d0711 #660
Hardware name: Google Lazor Limozeen without Touchscreen (rev5 - rev8) (DT)
Workqueue: events_unbound deferred_probe_work_func
hub 2-1:1.0: 4 ports detected

pstate: 80400009 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : dma_common_alloc_pages+0x54/0x1b4
lr : dma_common_alloc_pages+0x4c/0x1b4
sp : ffff8000807d3730
x29: ffff8000807d3730 x28: ffff02a7d312f880 x27: 0000000000000001
x26: 000000000000c000 x25: 0000000000000000 x24: 0000000000000001
x23: ffff02a7d23b6898 x22: 0000000000006cc0 x21: 000000000000c000
x20: ffff02a7858bf410 x19: fffffe0a60006000 x18: 0000000000000001
x17: 00000000000000d5 x16: 1fffe054f0bcc261 x15: 0000000000000001
x14: ffff02a7844dc680 x13: 0000000000100180 x12: dead000000000100
x11: dead000000000122 x10: 00000000001001ff x9 : ffff02a87f7b7b00
x8 : ffff02a87f7b7b00 x7 : ffff405977d6b000 x6 : ffff8000807d3310
x5 : ffff02a87f6b6398 x4 : 0000000000000001 x3 : ffff405977d6b000
x2 : ffff02a7844dc600 x1 : 0000000100000000 x0 : fffffe0a60006000
Call trace:
dma_common_alloc_pages+0x54/0x1b4
__dma_alloc_pages+0x68/0x90
dma_alloc_pages+0x10/0x1c
snd_dma_noncoherent_alloc+0x28/0x8c
__snd_dma_alloc_pages+0x30/0x50
snd_dma_alloc_dir_pages+0x40/0x80
do_alloc_pages+0xb8/0x13c
preallocate_pcm_pages+0x6c/0xf8
preallocate_pages+0x160/0x1a4
snd_pcm_set_managed_buffer_all+0x64/0xb0
lpass_platform_pcm_new+0xc0/0xe8
snd_soc_pcm_component_new+0x3c/0xc8
soc_new_pcm+0x4fc/0x668
snd_soc_bind_card+0xabc/0xbac
snd_soc_register_card+0xf0/0x108
devm_snd_soc_register_card+0x4c/0xa4
sc7180_snd_platform_probe+0x180/0x224
platform_probe+0x68/0xc0
really_probe+0xbc/0x298
__driver_probe_device+0x78/0x12c
driver_probe_device+0x3c/0x15c
__device_attach_driver+0xb8/0x134
bus_for_each_drv+0x84/0xe0
__device_attach+0x9c/0x188
device_initial_probe+0x14/0x20
bus_probe_device+0xac/0xb0
deferred_probe_work_func+0x88/0xc0
process_one_work+0x14c/0x28c
worker_thread+0x2cc/0x3d4
kthread+0x114/0x118
ret_from_fork+0x10/0x20
Code: f9411c19 940000c9 aa0003f3 b4000460 (f9402326)
---[ end trace 0000000000000000 ]---

Fixes: b5c58b2fdc42 ("dma-mapping: direct calls for dma-iommu")
Reported-by: Nícolas F. R. A. Prado <nfraprado@xxxxxxxxxxxxx> #KernelCI
Closes: https://lore.kernel.org/all/10431dfd-ce04-4e0f-973b-c78477303c18@notapiano
Tested-by: Nícolas F. R. A. Prado <nfraprado@xxxxxxxxxxxxx>
Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxx>
---
include/linux/iommu-dma.h | 8 ++++++++
kernel/dma/mapping.c | 12 ------------
kernel/dma/ops_helpers.c | 14 +++++++++++---
3 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/include/linux/iommu-dma.h b/include/linux/iommu-dma.h
index 011e5453d56b..561d81b12d9c 100644
--- a/include/linux/iommu-dma.h
+++ b/include/linux/iommu-dma.h
@@ -10,6 +10,10 @@
#include <linux/dma-mapping.h>

#ifdef CONFIG_IOMMU_DMA
+static inline bool use_dma_iommu(struct device *dev)
+{
+ return dev->dma_iommu;
+}
dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size,
enum dma_data_direction dir, unsigned long attrs);
@@ -65,6 +69,10 @@ void iommu_dma_unlink_range(struct device *dev, dma_addr_t start, size_t size,
bool iommu_can_use_iova(struct device *dev, struct page *page, size_t size,
enum dma_data_direction dir);
#else
+static inline bool use_dma_iommu(struct device *dev)
+{
+ return false;
+}
static inline dma_addr_t iommu_dma_map_page(struct device *dev,
struct page *page,
unsigned long offset, size_t size,
diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
index 9ce34bd4d407..7ec3deb7630d 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c
@@ -117,18 +117,6 @@ void *dmam_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle,
}
EXPORT_SYMBOL(dmam_alloc_attrs);

-#ifdef CONFIG_IOMMU_DMA
-static bool use_dma_iommu(struct device *dev)
-{
- return dev->dma_iommu;
-}
-#else
-static bool use_dma_iommu(struct device *dev)
-{
- return false;
-}
-#endif
-
static bool dma_go_direct(struct device *dev, dma_addr_t mask,
const struct dma_map_ops *ops)
{
diff --git a/kernel/dma/ops_helpers.c b/kernel/dma/ops_helpers.c
index af4a6ef48ce0..9afd569eadb9 100644
--- a/kernel/dma/ops_helpers.c
+++ b/kernel/dma/ops_helpers.c
@@ -4,6 +4,7 @@
* the allocated memory contains normal pages in the direct kernel mapping.
*/
#include <linux/dma-map-ops.h>
+#include <linux/iommu-dma.h>

static struct page *dma_common_vaddr_to_page(void *cpu_addr)
{
@@ -70,8 +71,12 @@ struct page *dma_common_alloc_pages(struct device *dev, size_t size,
if (!page)
return NULL;

- *dma_handle = ops->map_page(dev, page, 0, size, dir,
- DMA_ATTR_SKIP_CPU_SYNC);
+ if (use_dma_iommu(dev))
+ *dma_handle = iommu_dma_map_page(dev, page, 0, size, dir,
+ DMA_ATTR_SKIP_CPU_SYNC);
+ else
+ *dma_handle = ops->map_page(dev, page, 0, size, dir,
+ DMA_ATTR_SKIP_CPU_SYNC);
if (*dma_handle == DMA_MAPPING_ERROR) {
dma_free_contiguous(dev, page, size);
return NULL;
@@ -86,7 +91,10 @@ void dma_common_free_pages(struct device *dev, size_t size, struct page *page,
{
const struct dma_map_ops *ops = get_dma_ops(dev);

- if (ops->unmap_page)
+ if (use_dma_iommu(dev))
+ iommu_dma_unmap_page(dev, dma_handle, size, dir,
+ DMA_ATTR_SKIP_CPU_SYNC);
+ else if (ops->unmap_page)
ops->unmap_page(dev, dma_handle, size, dir,
DMA_ATTR_SKIP_CPU_SYNC);
dma_free_contiguous(dev, page, size);
--
2.46.0