[PATCH] remoteproc: imx_dsp_rproc: add custom memory copy implementation for i.MX DSP Cores

Iuliana Prodan (OSS)
2023-01-25T11:02:50Z

From: Iuliana Prodan <iuliana.prodan@nxp.com>

The IRAM is part of the HiFi DSP.
According to hardware specification only 32-bits write are allowed
otherwise we get a Kernel panic.

Therefore add a custom memory copy function to deal with the
above restriction.

Signed-off-by: Iuliana Prodan <iuliana.prodan@nxp.com>
---
drivers/remoteproc/imx_dsp_rproc.c | 122 ++++++++++++++++++++++++++++-
1 file changed, 121 insertions(+), 1 deletion(-)

diff --git a/drivers/remoteproc/imx_dsp_rproc.c b/drivers/remoteproc/imx_dsp_rproc.c
index 95da1cbefacf..a9991d085494 100644
--- a/drivers/remoteproc/imx_dsp_rproc.c
+++ b/drivers/remoteproc/imx_dsp_rproc.c
@@ -715,6 +715,126 @@ static void imx_dsp_rproc_kick(struct rproc *rproc, int vqid)
dev_err(dev, "%s: failed (%d, err:%d)\n", __func__, vqid, err);
}

+/*
+ * Custom memory copy implementation for i.MX DSP Cores
+ *
+ * The IRAM is part of the HiFi DSP.
+ * According to hw specs only 32-bits writes are allowed.
+ */
+static int imx_dsp_rproc_memcpy(void *dest, const void *src, size_t size)
+{
+ const u8 *src_byte = src;
+ u32 affected_mask;
+ u32 tmp;
+ int q, r;
+
+ q = size / 4;
+ r = size % 4;
+
+ /* __iowrite32_copy use 32bit size values so divide by 4 */
+ __iowrite32_copy(dest, src, q);
+
+ if (r) {
+ affected_mask = (1 << (8 * r)) - 1;
+
+ /* first read the 32bit data of dest, then change affected
+ * bytes, and write back to dest.
+ * For unaffected bytes, it should not be changed
+ */
+ tmp = ioread32(dest + q * 4);
+ tmp &= ~affected_mask;
+
+ tmp |= *(u32 *)(src_byte + q * 4) & affected_mask;
+ iowrite32(tmp, dest + q * 4);
+ }
+
+ return 0;
+}
+
+/**
+ * imx_dsp_rproc_elf_load_segments() - load firmware segments to memory
+ * @rproc: remote processor which will be booted using these fw segments
+ * @fw: the ELF firmware image
+ *
+ * This function loads the firmware segments to memory, where the remote
+ * processor expects them.
+ *
+ * Return: 0 on success and an appropriate error code otherwise
+ */
+static int imx_dsp_rproc_elf_load_segments(struct rproc *rproc, const struct firmware *fw)
+{
+ struct device *dev = &rproc->dev;
+ const void *ehdr, *phdr;
+ int i, ret = 0;
+ u16 phnum;
+ const u8 *elf_data = fw->data;
+ u8 class = fw_elf_get_class(fw);
+ u32 elf_phdr_get_size = elf_size_of_phdr(class);
+
+ ehdr = elf_data;
+ phnum = elf_hdr_get_e_phnum(class, ehdr);
+ phdr = elf_data + elf_hdr_get_e_phoff(class, ehdr);
+
+ /* go through the available ELF segments */
+ for (i = 0; i < phnum; i++, phdr += elf_phdr_get_size) {
+ u64 da = elf_phdr_get_p_paddr(class, phdr);
+ u64 memsz = elf_phdr_get_p_memsz(class, phdr);
+ u64 filesz = elf_phdr_get_p_filesz(class, phdr);
+ u64 offset = elf_phdr_get_p_offset(class, phdr);
+ u32 type = elf_phdr_get_p_type(class, phdr);
+ bool is_iomem = false;
+ void *ptr;
+
+ if (type != PT_LOAD || !memsz)
+ continue;
+
+ dev_dbg(dev, "phdr: type %d da 0x%llx memsz 0x%llx filesz 0x%llx\n",
+ type, da, memsz, filesz);
+
+ if (filesz > memsz) {
+ dev_err(dev, "bad phdr filesz 0x%llx memsz 0x%llx\n",
+ filesz, memsz);
+ ret = -EINVAL;
+ break;
+ }
+
+ if (offset + filesz > fw->size) {
+ dev_err(dev, "truncated fw: need 0x%llx avail 0x%zx\n",
+ offset + filesz, fw->size);
+ ret = -EINVAL;
+ break;
+ }
+
+ if (!rproc_u64_fit_in_size_t(memsz)) {
+ dev_err(dev, "size (%llx) does not fit in size_t type\n",
+ memsz);
+ ret = -EOVERFLOW;
+ break;
+ }
+
+ /* grab the kernel address for this device address */
+ ptr = rproc_da_to_va(rproc, da, memsz, &is_iomem);
+ if (!ptr) {
+ dev_err(dev, "bad phdr da 0x%llx mem 0x%llx\n", da,
+ memsz);
+ ret = -EINVAL;
+ break;
+ }
+
+ /* put the segment where the remote processor expects it */
+ if (filesz) {
+ ret = imx_dsp_rproc_memcpy(ptr, elf_data + offset, filesz);
+ if (ret) {
+ dev_err(dev, "memory copy failed for da 0x%llx memsz 0x%llx\n",
+ da, memsz);
+ break;
+ }
+ }
+ }
+
+ return ret;
+}
+
static int imx_dsp_rproc_parse_fw(struct rproc *rproc, const struct firmware *fw)
{
if (rproc_elf_load_rsc_table(rproc, fw))
@@ -729,7 +849,7 @@ static const struct rproc_ops imx_dsp_rproc_ops = {
.start = imx_dsp_rproc_start,
.stop = imx_dsp_rproc_stop,
.kick = imx_dsp_rproc_kick,
- .load = rproc_elf_load_segments,
+ .load = imx_dsp_rproc_elf_load_segments,
.parse_fw = imx_dsp_rproc_parse_fw,
.sanity_check = rproc_elf_sanity_check,
.get_boot_addr = rproc_elf_get_boot_addr,
--
2.17.1