[PATCH 3/5] firmware: tegra: Prepare for supporting in-band debugfs

From: Jon Hunter
Date: Sun Jul 12 2020 - 06:01:59 EST


Currently, BPMP debug information is accessible via the Linux debugfs
file-system using a shared-memory scheme. More recent BPMP firmware now
supports accessing the debug information by in-band messaging which does
not require shared-memory. To prepare for adding in-band debugfs support
for the BPMP, move the shared-memory specific initialisation from the
tegra_bpmp_init_debugfs() into a sub-function.

Signed-off-by: Jon Hunter <jonathanh@xxxxxxxxxx>
---
drivers/firmware/tegra/bpmp-debugfs.c | 53 ++++++++++++---------------
1 file changed, 23 insertions(+), 30 deletions(-)

diff --git a/drivers/firmware/tegra/bpmp-debugfs.c b/drivers/firmware/tegra/bpmp-debugfs.c
index f7bf19248d15..a1a1a3b9e667 100644
--- a/drivers/firmware/tegra/bpmp-debugfs.c
+++ b/drivers/firmware/tegra/bpmp-debugfs.c
@@ -354,32 +354,43 @@ static int bpmp_populate_dir(struct tegra_bpmp *bpmp, struct seqbuf *seqbuf,
return 0;
}

-static int create_debugfs_mirror(struct tegra_bpmp *bpmp, void *buf,
- size_t bufsize, struct dentry *root)
+static int bpmp_populate_debugfs_shmem(struct tegra_bpmp *bpmp,
+ struct dentry *root)
{
struct seqbuf seqbuf;
+ const size_t sz = SZ_512K;
+ dma_addr_t phys;
+ size_t nbytes;
+ void *virt;
int err;

bpmp->debugfs_mirror = debugfs_create_dir("debug", root);
if (!bpmp->debugfs_mirror)
return -ENOMEM;

- seqbuf_init(&seqbuf, buf, bufsize);
- err = bpmp_populate_dir(bpmp, &seqbuf, bpmp->debugfs_mirror, 0);
+ virt = dma_alloc_coherent(bpmp->dev, sz, &phys,
+ GFP_KERNEL | GFP_DMA32);
+ if (!virt)
+ return -ENOMEM;
+
+ err = mrq_debugfs_dumpdir(bpmp, phys, sz, &nbytes);
if (err < 0) {
- debugfs_remove_recursive(bpmp->debugfs_mirror);
- bpmp->debugfs_mirror = NULL;
+ goto free;
+ } else if (nbytes > sz) {
+ err = -EINVAL;
+ goto free;
}

+ seqbuf_init(&seqbuf, virt, nbytes);
+ err = bpmp_populate_dir(bpmp, &seqbuf, bpmp->debugfs_mirror, 0);
+free:
+ dma_free_coherent(bpmp->dev, sz, virt, phys);
+
return err;
}

int tegra_bpmp_init_debugfs(struct tegra_bpmp *bpmp)
{
- dma_addr_t phys;
- void *virt;
- const size_t sz = SZ_512K;
- size_t nbytes;
struct dentry *root;
int err;

@@ -390,27 +401,9 @@ int tegra_bpmp_init_debugfs(struct tegra_bpmp *bpmp)
if (!root)
return -ENOMEM;

- virt = dma_alloc_coherent(bpmp->dev, sz, &phys,
- GFP_KERNEL | GFP_DMA32);
- if (!virt) {
- err = -ENOMEM;
- goto out;
- }
-
- err = mrq_debugfs_dumpdir(bpmp, phys, sz, &nbytes);
- if (err < 0) {
- goto free;
- } else if (nbytes > sz) {
- err = -EINVAL;
- goto free;
- }
-
- err = create_debugfs_mirror(bpmp, virt, nbytes, root);
-free:
- dma_free_coherent(bpmp->dev, sz, virt, phys);
-out:
+ err = bpmp_populate_debugfs_shmem(bpmp, root);
if (err < 0)
- debugfs_remove(root);
+ debugfs_remove_recursive(root);

return err;
}
--
2.17.1