[PATCH v5 2/3] remoteproc: stm32: add support for co-processor booted before kernel

From: Arnaud Pouliquen
Date: Tue Feb 11 2020 - 12:42:52 EST


From: Fabien Dessenne <fabien.dessenne@xxxxxx>

Add support of a remote firmware, preloaded by the boot loader.
Two backup registers are used to retrieve the state of the remote
firmware and to get the optional resource table address.

Signed-off-by: Fabien Dessenne <fabien.dessenne@xxxxxx>
Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxx>
---
drivers/remoteproc/stm32_rproc.c | 205 ++++++++++++++++++++++++++++---
1 file changed, 191 insertions(+), 14 deletions(-)

diff --git a/drivers/remoteproc/stm32_rproc.c b/drivers/remoteproc/stm32_rproc.c
index a18f88044111..3d1e0774318c 100644
--- a/drivers/remoteproc/stm32_rproc.c
+++ b/drivers/remoteproc/stm32_rproc.c
@@ -38,6 +38,15 @@
#define STM32_MBX_VQ1_ID 1
#define STM32_MBX_SHUTDOWN "shutdown"

+#define RSC_TBL_SIZE (1024)
+
+#define COPRO_STATE_OFF 0
+#define COPRO_STATE_INIT 1
+#define COPRO_STATE_CRUN 2
+#define COPRO_STATE_CSTOP 3
+#define COPRO_STATE_STANDBY 4
+#define COPRO_STATE_CRASH 5
+
struct stm32_syscon {
struct regmap *map;
u32 reg;
@@ -70,12 +79,14 @@ struct stm32_rproc {
struct reset_control *rst;
struct stm32_syscon hold_boot;
struct stm32_syscon pdds;
+ struct stm32_syscon copro_state;
int wdg_irq;
u32 nb_rmems;
struct stm32_rproc_mem *rmems;
struct stm32_mbox mb[MBOX_NB_MBX];
struct workqueue_struct *workqueue;
bool secured_soc;
+ void __iomem *rsc_va;
};

static int stm32_rproc_pa_to_da(struct rproc *rproc, phys_addr_t pa, u64 *da)
@@ -98,6 +109,28 @@ static int stm32_rproc_pa_to_da(struct rproc *rproc, phys_addr_t pa, u64 *da)
return -EINVAL;
}

+static int stm32_rproc_da_to_pa(struct rproc *rproc, u64 da, phys_addr_t *pa)
+{
+ unsigned int i;
+ struct stm32_rproc *ddata = rproc->priv;
+ struct stm32_rproc_mem *p_mem;
+
+ for (i = 0; i < ddata->nb_rmems; i++) {
+ p_mem = &ddata->rmems[i];
+
+ if (da < p_mem->dev_addr ||
+ da >= p_mem->dev_addr + p_mem->size)
+ continue;
+ *pa = da - p_mem->dev_addr + p_mem->bus_addr;
+ dev_dbg(rproc->dev.parent, "da %llx to pa %#x\n", da, *pa);
+ return 0;
+ }
+
+ dev_err(rproc->dev.parent, "can't translate da %llx\n", da);
+
+ return -EINVAL;
+}
+
static int stm32_rproc_mem_alloc(struct rproc *rproc,
struct rproc_mem_entry *mem)
{
@@ -127,6 +160,15 @@ static int stm32_rproc_mem_release(struct rproc *rproc,
return 0;
}

+static int stm32_rproc_elf_load_segments(struct rproc *rproc,
+ const struct firmware *fw)
+{
+ if (!rproc->skip_fw_load)
+ return rproc_elf_load_segments(rproc, fw);
+
+ return 0;
+}
+
static int stm32_rproc_of_memory_translations(struct rproc *rproc)
{
struct device *parent, *dev = rproc->dev.parent;
@@ -197,9 +239,34 @@ static int stm32_rproc_mbox_idx(struct rproc *rproc, const unsigned char *name)
static int stm32_rproc_elf_load_rsc_table(struct rproc *rproc,
const struct firmware *fw)
{
- if (rproc_elf_load_rsc_table(rproc, fw))
- dev_warn(&rproc->dev, "no resource table found for this firmware\n");
+ struct resource_table *table = NULL;
+ struct stm32_rproc *ddata = rproc->priv;
+
+ if (!rproc->skip_fw_load) {
+ if (rproc_elf_load_rsc_table(rproc, fw))
+ goto no_rsc_table;
+
+ return 0;
+ }
+
+ if (ddata->rsc_va) {
+ table = (struct resource_table *)ddata->rsc_va;
+ /* Assuming that the resource table fits in 1kB is fair */
+ rproc->cached_table = kmemdup(table, RSC_TBL_SIZE, GFP_KERNEL);
+ if (!rproc->cached_table)
+ return -ENOMEM;
+
+ rproc->table_ptr = rproc->cached_table;
+ rproc->table_sz = RSC_TBL_SIZE;
+ return 0;
+ }

+ rproc->cached_table = NULL;
+ rproc->table_ptr = NULL;
+ rproc->table_sz = 0;
+
+no_rsc_table:
+ dev_warn(&rproc->dev, "no resource table found for this firmware\n");
return 0;
}

@@ -259,6 +326,36 @@ static int stm32_rproc_parse_fw(struct rproc *rproc, const struct firmware *fw)
return stm32_rproc_elf_load_rsc_table(rproc, fw);
}

+static struct resource_table *
+stm32_rproc_elf_find_loaded_rsc_table(struct rproc *rproc,
+ const struct firmware *fw)
+{
+ struct stm32_rproc *ddata = rproc->priv;
+
+ if (!rproc->skip_fw_load)
+ return rproc_elf_find_loaded_rsc_table(rproc, fw);
+
+ return (struct resource_table *)ddata->rsc_va;
+}
+
+static int stm32_rproc_elf_sanity_check(struct rproc *rproc,
+ const struct firmware *fw)
+{
+ if (!rproc->skip_fw_load)
+ return rproc_elf_sanity_check(rproc, fw);
+
+ return 0;
+}
+
+static u32 stm32_rproc_elf_get_boot_addr(struct rproc *rproc,
+ const struct firmware *fw)
+{
+ if (!rproc->skip_fw_load)
+ return rproc_elf_get_boot_addr(rproc, fw);
+
+ return 0;
+}
+
static irqreturn_t stm32_rproc_wdg(int irq, void *data)
{
struct rproc *rproc = data;
@@ -420,7 +517,7 @@ static int stm32_rproc_start(struct rproc *rproc)
stm32_rproc_add_coredump_trace(rproc);

/* clear remote proc Deep Sleep */
- if (ddata->pdds.map) {
+ if (ddata->pdds.map && !rproc->skip_fw_load) {
err = regmap_update_bits(ddata->pdds.map, ddata->pdds.reg,
ddata->pdds.mask, 0);
if (err) {
@@ -429,9 +526,15 @@ static int stm32_rproc_start(struct rproc *rproc)
}
}

- err = stm32_rproc_set_hold_boot(rproc, false);
- if (err)
- return err;
+ /*
+ * If M4 previously started by bootloader, just guarantee holdboot
+ * is set to catch any crash.
+ */
+ if (!rproc->skip_fw_load) {
+ err = stm32_rproc_set_hold_boot(rproc, false);
+ if (err)
+ return err;
+ }

return stm32_rproc_set_hold_boot(rproc, true);
}
@@ -473,6 +576,21 @@ static int stm32_rproc_stop(struct rproc *rproc)
}
}

+ /* update copro state to OFF */
+ if (ddata->copro_state.map) {
+ err = regmap_update_bits(ddata->copro_state.map,
+ ddata->copro_state.reg,
+ ddata->copro_state.mask,
+ COPRO_STATE_OFF);
+ if (err) {
+ dev_err(&rproc->dev, "failed to set copro state\n");
+ return err;
+ }
+ }
+
+ /* Reset skip_fw_load state as we stop the co-processor */
+ rproc->skip_fw_load = false;
+
return 0;
}

@@ -502,11 +620,11 @@ static struct rproc_ops st_rproc_ops = {
.start = stm32_rproc_start,
.stop = stm32_rproc_stop,
.kick = stm32_rproc_kick,
- .load = rproc_elf_load_segments,
+ .load = stm32_rproc_elf_load_segments,
.parse_fw = stm32_rproc_parse_fw,
- .find_loaded_rsc_table = rproc_elf_find_loaded_rsc_table,
- .sanity_check = rproc_elf_sanity_check,
- .get_boot_addr = rproc_elf_get_boot_addr,
+ .find_loaded_rsc_table = stm32_rproc_elf_find_loaded_rsc_table,
+ .sanity_check = stm32_rproc_elf_sanity_check,
+ .get_boot_addr = stm32_rproc_elf_get_boot_addr,
};

static const struct of_device_id stm32_rproc_match[] = {
@@ -543,8 +661,10 @@ static int stm32_rproc_parse_dt(struct platform_device *pdev)
struct device_node *np = dev->of_node;
struct rproc *rproc = platform_get_drvdata(pdev);
struct stm32_rproc *ddata = rproc->priv;
- struct stm32_syscon tz;
- unsigned int tzen;
+ struct stm32_syscon tz, rsctbl;
+ phys_addr_t rsc_pa;
+ u32 rsc_da;
+ unsigned int tzen, state;
int err, irq;

irq = platform_get_irq(pdev, 0);
@@ -602,11 +722,62 @@ static int stm32_rproc_parse_dt(struct platform_device *pdev)

err = stm32_rproc_get_syscon(np, "st,syscfg-pdds", &ddata->pdds);
if (err)
- dev_warn(dev, "failed to get pdds\n");
+ dev_warn(dev, "pdds not supported\n");

rproc->auto_boot = of_property_read_bool(np, "st,auto-boot");

- return stm32_rproc_of_memory_translations(rproc);
+ err = stm32_rproc_of_memory_translations(rproc);
+ if (err)
+ return err;
+
+ /* check if the coprocessor has been started from the bootloader */
+ err = stm32_rproc_get_syscon(np, "st,syscfg-copro-state",
+ &ddata->copro_state);
+ if (err) {
+ /* no copro_state syscon (optional) */
+ dev_warn(dev, "copro_state not supported\n");
+ goto bail;
+ }
+
+ err = regmap_read(ddata->copro_state.map, ddata->copro_state.reg,
+ &state);
+ if (err) {
+ dev_err(&rproc->dev, "failed to read copro state\n");
+ return err;
+ }
+
+ if (state == COPRO_STATE_CRUN) {
+ rproc->skip_fw_load = true;
+
+ if (stm32_rproc_get_syscon(np, "st,syscfg-rsc-tbl", &rsctbl)) {
+ /* no rsc table syscon (optional) */
+ dev_warn(dev, "rsc tbl syscon not supported\n");
+ goto bail;
+ }
+
+ err = regmap_read(rsctbl.map, rsctbl.reg, &rsc_da);
+ if (err) {
+ dev_err(&rproc->dev, "failed to read rsc tbl addr\n");
+ return err;
+ }
+ if (!rsc_da)
+ /* no rsc table */
+ goto bail;
+
+ err = stm32_rproc_da_to_pa(rproc, rsc_da, &rsc_pa);
+ if (err)
+ return err;
+
+ ddata->rsc_va = devm_ioremap_wc(dev, rsc_pa, RSC_TBL_SIZE);
+ if (IS_ERR_OR_NULL(ddata->rsc_va)) {
+ dev_err(dev, "Unable to map memory region: %pa+%zx\n",
+ &rsc_pa, RSC_TBL_SIZE);
+ ddata->rsc_va = NULL;
+ return -ENOMEM;
+ }
+ }
+bail:
+ return 0;
}

static int stm32_rproc_probe(struct platform_device *pdev)
@@ -640,6 +811,12 @@ static int stm32_rproc_probe(struct platform_device *pdev)
if (ret)
goto free_wkq;

+ if (!rproc->skip_fw_load) {
+ ret = stm32_rproc_stop(rproc);
+ if (ret)
+ goto free_rproc;
+ }
+
ret = stm32_rproc_request_mbox(rproc);
if (ret)
goto free_rproc;
--
2.17.1