[PATCH v2 3/3] remoteproc/mediatek: read IPI buffer offset from FW

Tzung-Bi Shih
2020-11-16T09:11:42Z

Reads the IPI buffer offset from the FW binary. The information resides
in addr of .ipi_buffer section.

Moves scp_ipi_init() to scp_load() phase. The IPI buffer can be
initialized only if the offset is clear.

Signed-off-by: Tzung-Bi Shih <tzungbi@google.com>
---
drivers/remoteproc/mtk_scp.c | 73 ++++++++++++++++++++++++------------
1 file changed, 49 insertions(+), 24 deletions(-)

diff --git a/drivers/remoteproc/mtk_scp.c b/drivers/remoteproc/mtk_scp.c
index 74ed675f61a6..0ea3427cddc6 100644
--- a/drivers/remoteproc/mtk_scp.c
+++ b/drivers/remoteproc/mtk_scp.c
@@ -21,7 +21,7 @@
#include "remoteproc_internal.h"

#define MAX_CODE_SIZE 0x500000
-#define SCP_FW_END 0x7C000
+#define SECTION_NAME_IPI_BUFFER ".ipi_buffer"

/**
* scp_get() - get a reference to SCP.
@@ -119,16 +119,24 @@ static void scp_ipi_handler(struct mtk_scp *scp)
wake_up(&scp->ack_wq);
}

-static int scp_ipi_init(struct mtk_scp *scp)
+static int scp_elf_read_ipi_buf_addr(struct mtk_scp *scp,
+ const struct firmware *fw,
+ size_t *offset);
+
+static int scp_ipi_init(struct mtk_scp *scp, const struct firmware *fw)
{
- size_t send_offset = SCP_FW_END - sizeof(struct mtk_share_obj);
- size_t recv_offset = send_offset - sizeof(struct mtk_share_obj);
+ int ret;
+ size_t offset;
+
+ ret = scp_elf_read_ipi_buf_addr(scp, fw, &offset);
+ if (ret)
+ return ret;
+ dev_info(scp->dev, "IPI buf addr %#010zx\n", offset);

- /* shared buffer initialization */
- scp->recv_buf =
- (struct mtk_share_obj __iomem *)(scp->sram_base + recv_offset);
- scp->send_buf =
- (struct mtk_share_obj __iomem *)(scp->sram_base + send_offset);
+ scp->recv_buf = (struct mtk_share_obj __iomem *)
+ (scp->sram_base + offset);
+ scp->send_buf = (struct mtk_share_obj __iomem *)
+ (scp->sram_base + offset + sizeof(*scp->recv_buf));
memset_io(scp->recv_buf, 0, sizeof(*scp->recv_buf));
memset_io(scp->send_buf, 0, sizeof(*scp->send_buf));

@@ -271,6 +279,32 @@ static int scp_elf_load_segments(struct rproc *rproc, const struct firmware *fw)
return ret;
}

+static int scp_elf_read_ipi_buf_addr(struct mtk_scp *scp,
+ const struct firmware *fw,
+ size_t *offset)
+{
+ struct elf32_hdr *ehdr;
+ struct elf32_shdr *shdr, *shdr_strtab;
+ int i;
+ const u8 *elf_data = fw->data;
+ const char *strtab;
+
+ ehdr = (struct elf32_hdr *)elf_data;
+ shdr = (struct elf32_shdr *)(elf_data + ehdr->e_shoff);
+ shdr_strtab = shdr + ehdr->e_shstrndx;
+ strtab = (const char *)(elf_data + shdr_strtab->sh_offset);
+
+ for (i = 0; i < ehdr->e_shnum; i++, shdr++) {
+ if (strcmp(strtab + shdr->sh_name,
+ SECTION_NAME_IPI_BUFFER) == 0) {
+ *offset = shdr->sh_addr;
+ return 0;
+ }
+ }
+
+ return -ENOENT;
+}
+
static int mt8183_scp_before_load(struct mtk_scp *scp)
{
/* Clear SCP to host interrupt */
@@ -350,11 +384,15 @@ static int scp_load(struct rproc *rproc, const struct firmware *fw)

ret = scp->data->scp_before_load(scp);
if (ret < 0)
- return ret;
+ goto leave;

ret = scp_elf_load_segments(rproc, fw);
- clk_disable_unprepare(scp->clk);
+ if (ret)
+ goto leave;

+ ret = scp_ipi_init(scp, fw);
+leave:
+ clk_disable_unprepare(scp->clk);
return ret;
}

@@ -680,19 +718,6 @@ static int scp_probe(struct platform_device *pdev)
goto release_dev_mem;
}

- ret = clk_prepare_enable(scp->clk);
- if (ret) {
- dev_err(dev, "failed to enable clocks\n");
- goto release_dev_mem;
- }
-
- ret = scp_ipi_init(scp);
- clk_disable_unprepare(scp->clk);
- if (ret) {
- dev_err(dev, "Failed to init ipi\n");
- goto release_dev_mem;
- }
-
/* register SCP initialization IPI */
ret = scp_ipi_register(scp, SCP_IPI_INIT, scp_init_ipi_handler, scp);
if (ret) {
--
2.29.2.299.gdc1121823c-goog