[PATCH v10 03/15] firmware: qcom: scm: enable the TZ mem allocator

From: Bartosz Golaszewski
Date: Mon May 27 2024 - 08:58:15 EST


From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>

Select the TrustZone memory allocator in Kconfig and create a pool of
memory shareable with the TrustZone when probing the SCM driver.

This will allow a gradual conversion of all relevant SCM calls to using
the dedicated allocator.

The policy used for the pool is "on-demand" and the initial size is 0
as - depending on the config - it's possible that no SCM calls needing
to allocate memory will be called. The sizes of possible allocations also
vary substiantially further warranting the "on-demand" approach.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
Reviewed-by: Andrew Halaney <ahalaney@xxxxxxxxxx>
Tested-by: Andrew Halaney <ahalaney@xxxxxxxxxx> # sc8280xp-lenovo-thinkpad-x13s
Tested-by: Deepti Jaggi <quic_djaggi@xxxxxxxxxxx> #sa8775p-ride
Reviewed-by: Elliot Berman <quic_eberman@xxxxxxxxxxx>
---
drivers/firmware/qcom/Kconfig | 1 +
drivers/firmware/qcom/qcom_scm.c | 22 ++++++++++++++++++++++
2 files changed, 23 insertions(+)

diff --git a/drivers/firmware/qcom/Kconfig b/drivers/firmware/qcom/Kconfig
index 3c495f8698e1..4634f8cecc7b 100644
--- a/drivers/firmware/qcom/Kconfig
+++ b/drivers/firmware/qcom/Kconfig
@@ -7,6 +7,7 @@
menu "Qualcomm firmware drivers"

config QCOM_SCM
+ select QCOM_TZMEM
tristate

config QCOM_TZMEM
diff --git a/drivers/firmware/qcom/qcom_scm.c b/drivers/firmware/qcom/qcom_scm.c
index 68f4df7e6c3c..0e7b1813e4a7 100644
--- a/drivers/firmware/qcom/qcom_scm.c
+++ b/drivers/firmware/qcom/qcom_scm.c
@@ -10,8 +10,10 @@
#include <linux/completion.h>
#include <linux/cpumask.h>
#include <linux/dma-mapping.h>
+#include <linux/err.h>
#include <linux/export.h>
#include <linux/firmware/qcom/qcom_scm.h>
+#include <linux/firmware/qcom/qcom_tzmem.h>
#include <linux/init.h>
#include <linux/interconnect.h>
#include <linux/interrupt.h>
@@ -22,9 +24,11 @@
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/reset-controller.h>
+#include <linux/sizes.h>
#include <linux/types.h>

#include "qcom_scm.h"
+#include "qcom_tzmem.h"

static bool download_mode = IS_ENABLED(CONFIG_QCOM_SCM_DOWNLOAD_MODE_DEFAULT);
module_param(download_mode, bool, 0);
@@ -43,6 +47,8 @@ struct qcom_scm {
int scm_vote_count;

u64 dload_mode_addr;
+
+ struct qcom_tzmem_pool *mempool;
};

struct qcom_scm_current_perm_info {
@@ -1810,6 +1816,7 @@ static irqreturn_t qcom_scm_irq_handler(int irq, void *data)

static int qcom_scm_probe(struct platform_device *pdev)
{
+ struct qcom_tzmem_pool_config pool_config;
struct qcom_scm *scm;
int irq, ret;

@@ -1885,6 +1892,21 @@ static int qcom_scm_probe(struct platform_device *pdev)
if (of_property_read_bool(pdev->dev.of_node, "qcom,sdi-enabled"))
qcom_scm_disable_sdi();

+ ret = qcom_tzmem_enable(__scm->dev);
+ if (ret)
+ return dev_err_probe(__scm->dev, ret,
+ "Failed to enable the TrustZone memory allocator\n");
+
+ memset(&pool_config, 0, sizeof(pool_config));
+ pool_config.initial_size = 0;
+ pool_config.policy = QCOM_TZMEM_POLICY_ON_DEMAND;
+ pool_config.max_size = SZ_256K;
+
+ __scm->mempool = devm_qcom_tzmem_pool_new(__scm->dev, &pool_config);
+ if (IS_ERR(__scm->mempool))
+ return dev_err_probe(__scm->dev, PTR_ERR(__scm->mempool),
+ "Failed to create the SCM memory pool\n");
+
/*
* Initialize the QSEECOM interface.
*

--
2.43.0