lkml.org 
[lkml]   [2018]   [Oct]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH v4 08/17] remoteproc: add alloc ops in rproc_mem_entry struct
From
Date
Hi Loic,

On 7/27/18 8:14 AM, Loic Pallardy wrote:
> Memory entry could be allocated in different ways (ioremap,
> dma_alloc_coherent, internal RAM allocator...).
> This patch introduces an alloc ops in rproc_mem_entry structure
> to associate dedicated allocation mechanism to each memory entry
> descriptor in order to do remote core agnostic from memory allocators.
>
> The introduction of this ops allows to perform allocation of all registered
> carveout at the same time, just before calling rproc_start().
> It simplifies and makes uniform carveout management whatever origin.

This patch is causing a kernel crash with trace entries. Please see
further below for the cause.

>
> Signed-off-by: Loic Pallardy <loic.pallardy@st.com>
> ---
> drivers/remoteproc/remoteproc_core.c | 261 ++++++++++++++++++++++-------------
> include/linux/remoteproc.h | 7 +
> 2 files changed, 175 insertions(+), 93 deletions(-)
>
> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> index 77b39ba..2c51549 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -642,74 +642,31 @@ static int rproc_handle_devmem(struct rproc *rproc, struct fw_rsc_devmem *rsc,
> }
>
> /**
> - * rproc_release_carveout() - release acquired carveout
> + * rproc_alloc_carveout() - allocated specified carveout
> * @rproc: rproc handle
> - * @mem: the memory entry to release
> - *
> - * This function releases specified memory entry @mem allocated via
> - * dma_alloc_coherent() function by @rproc.
> - */
> -static int rproc_release_carveout(struct rproc *rproc,
> - struct rproc_mem_entry *mem)
> -{
> - struct device *dev = &rproc->dev;
> -
> - /* clean up carveout allocations */
> - dma_free_coherent(dev->parent, mem->len, mem->va, mem->dma);
> - return 0;
> -}
> -
> -/**
> - * rproc_handle_carveout() - handle phys contig memory allocation requests
> - * @rproc: rproc handle
> - * @rsc: the resource entry
> - * @avail: size of available data (for image validation)
> - *
> - * This function will handle firmware requests for allocation of physically
> - * contiguous memory regions.
> - *
> - * These request entries should come first in the firmware's resource table,
> - * as other firmware entries might request placing other data objects inside
> - * these memory regions (e.g. data/code segments, trace resource entries, ...).
> + * @mem: the memory entry to allocate
> *
> - * Allocating memory this way helps utilizing the reserved physical memory
> - * (e.g. CMA) more efficiently, and also minimizes the number of TLB entries
> - * needed to map it (in case @rproc is using an IOMMU). Reducing the TLB
> - * pressure is important; it may have a substantial impact on performance.
> + * This function allocate specified memory entry @mem using
> + * dma_alloc_coherent() as default allocator
> */
> -static int rproc_handle_carveout(struct rproc *rproc,
> - struct fw_rsc_carveout *rsc,
> - int offset, int avail)
> +static int rproc_alloc_carveout(struct rproc *rproc,
> + struct rproc_mem_entry *mem)
> {
> - struct rproc_mem_entry *carveout, *mapping = NULL;
> + struct rproc_mem_entry *mapping = NULL;
> struct device *dev = &rproc->dev;
> dma_addr_t dma;
> void *va;
> int ret;
>
> - if (sizeof(*rsc) > avail) {
> - dev_err(dev, "carveout rsc is truncated\n");
> - return -EINVAL;
> - }
> -
> - /* make sure reserved bytes are zeroes */
> - if (rsc->reserved) {
> - dev_err(dev, "carveout rsc has non zero reserved bytes\n");
> - return -EINVAL;
> - }
> -
> - dev_dbg(dev, "carveout rsc: name: %s, da 0x%x, pa 0x%x, len 0x%x, flags 0x%x\n",
> - rsc->name, rsc->da, rsc->pa, rsc->len, rsc->flags);
> -
> - va = dma_alloc_coherent(dev->parent, rsc->len, &dma, GFP_KERNEL);
> + va = dma_alloc_coherent(dev->parent, mem->len, &dma, GFP_KERNEL);
> if (!va) {
> dev_err(dev->parent,
> - "failed to allocate dma memory: len 0x%x\n", rsc->len);
> + "failed to allocate dma memory: len 0x%x\n", mem->len);
> return -ENOMEM;
> }
>
> dev_dbg(dev, "carveout va %pK, dma %pad, len 0x%x\n",
> - va, &dma, rsc->len);
> + va, &dma, mem->len);
>
> /*
> * Ok, this is non-standard.
> @@ -729,22 +686,22 @@ static int rproc_handle_carveout(struct rproc *rproc,
> * physical address in this case.
> */
>
> - if (rsc->da != FW_RSC_ADDR_ANY && !rproc->domain) {
> - dev_err(dev->parent,
> - "Bad carveout rsc configuration\n");
> - ret = -ENOMEM;
> - goto dma_free;
> - }
> + if (mem->da != FW_RSC_ADDR_ANY) {
> + if (!rproc->domain) {
> + dev_err(dev->parent,
> + "Bad carveout rsc configuration\n");
> + ret = -ENOMEM;
> + goto dma_free;
> + }

Same comment from Patch 1.

>
> - if (rsc->da != FW_RSC_ADDR_ANY && rproc->domain) {
> mapping = kzalloc(sizeof(*mapping), GFP_KERNEL);
> if (!mapping) {
> ret = -ENOMEM;
> goto dma_free;
> }
>
> - ret = iommu_map(rproc->domain, rsc->da, dma, rsc->len,
> - rsc->flags);
> + ret = iommu_map(rproc->domain, mem->da, dma, mem->len,
> + mem->flags);
> if (ret) {
> dev_err(dev, "iommu_map failed: %d\n", ret);
> goto free_mapping;
> @@ -757,52 +714,102 @@ static int rproc_handle_carveout(struct rproc *rproc,
> * We can't trust the remote processor not to change the
> * resource table, so we must maintain this info independently.
> */
> - mapping->da = rsc->da;
> - mapping->len = rsc->len;
> + mapping->da = mem->da;
> + mapping->len = mem->len;
> list_add_tail(&mapping->node, &rproc->mappings);
>
> dev_dbg(dev, "carveout mapped 0x%x to %pad\n",
> - rsc->da, &dma);
> + mem->da, &dma);
> + } else {
> + mem->da = (u32)dma;

Hmm, what was the purpose of this? So, this appears to be handling the
missing implementation for the comment in the fw_rsc_carveout about
FW_RSC_ADDR_ANY.

> }
>
> - /*
> - * Some remote processors might need to know the pa
> - * even though they are behind an IOMMU. E.g., OMAP4's
> - * remote M3 processor needs this so it can control
> - * on-chip hardware accelerators that are not behind
> - * the IOMMU, and therefor must know the pa.
> - *
> - * Generally we don't want to expose physical addresses
> - * if we don't have to (remote processors are generally
> - * _not_ trusted), so we might want to do this only for
> - * remote processor that _must_ have this (e.g. OMAP4's
> - * dual M3 subsystem).
> - *
> - * Non-IOMMU processors might also want to have this info.
> - * In this case, the device address and the physical address
> - * are the same.
> - */
> - rsc->pa = (u32)rproc_va_to_pa(va);
> -
> - carveout = rproc_mem_entry_init(dev, va, dma, rsc->len, rsc->da,
> - rproc_release_carveout, rsc->name);
> - if (!carveout)
> - goto free_carv;
> -
> - rproc_add_carveout(rproc, carveout);
> + mem->dma = (u32)dma;

We don't need the typecast, mem->dma is already of type dma_addr_t. Same
comment above on the else part as well.

> + mem->va = va;
>
> return 0;
>
> -free_carv:
> - kfree(carveout);
> free_mapping:
> kfree(mapping);
> dma_free:
> - dma_free_coherent(dev->parent, rsc->len, va, dma);
> + dma_free_coherent(dev->parent, mem->len, va, dma);
> return ret;
> }
>
> /**
> + * rproc_release_carveout() - release acquired carveout
> + * @rproc: rproc handle
> + * @mem: the memory entry to release
> + *
> + * This function releases specified memory entry @mem allocated via
> + * rproc_alloc_carveout() function by @rproc.
> + */
> +static int rproc_release_carveout(struct rproc *rproc,
> + struct rproc_mem_entry *mem)
> +{
> + struct device *dev = &rproc->dev;
> +
> + /* clean up carveout allocations */
> + dma_free_coherent(dev->parent, mem->len, mem->va, mem->dma);
> + return 0;
> +}
> +
> +/**
> + * rproc_handle_carveout() - handle phys contig memory allocation requests
> + * @rproc: rproc handle
> + * @rsc: the resource entry
> + * @avail: size of available data (for image validation)
> + *
> + * This function will handle firmware requests for allocation of physically
> + * contiguous memory regions.
> + *
> + * These request entries should come first in the firmware's resource table,
> + * as other firmware entries might request placing other data objects inside
> + * these memory regions (e.g. data/code segments, trace resource entries, ...).
> + *
> + * Allocating memory this way helps utilizing the reserved physical memory
> + * (e.g. CMA) more efficiently, and also minimizes the number of TLB entries
> + * needed to map it (in case @rproc is using an IOMMU). Reducing the TLB
> + * pressure is important; it may have a substantial impact on performance.
> + */
> +static int rproc_handle_carveout(struct rproc *rproc,
> + struct fw_rsc_carveout *rsc,
> + int offset, int avail)
> +{
> + struct rproc_mem_entry *carveout;
> + struct device *dev = &rproc->dev;
> +
> + if (sizeof(*rsc) > avail) {
> + dev_err(dev, "carveout rsc is truncated\n");
> + return -EINVAL;
> + }
> +
> + /* make sure reserved bytes are zeroes */
> + if (rsc->reserved) {
> + dev_err(dev, "carveout rsc has non zero reserved bytes\n");
> + return -EINVAL;
> + }
> +
> + dev_dbg(dev, "carveout rsc: name: %s, da 0x%x, pa 0x%x, len 0x%x, flags 0x%x\n",
> + rsc->name, rsc->da, rsc->pa, rsc->len, rsc->flags);
> +
> + /* Register carveout in in list */
> + carveout = rproc_mem_entry_init(dev, 0, 0, rsc->len, rsc->da,
> + rproc_alloc_carveout,
> + rproc_release_carveout, rsc->name);
> + if (!carveout) {
> + dev_err(dev, "Can't allocate memory entry structure\n");
> + return -ENOMEM;
> + }
> +
> + carveout->flags = rsc->flags;
> + carveout->rsc_offset = offset;
> + rproc_add_carveout(rproc, carveout);

Once we get rid of rproc_add_carveout, the list addition will mostly be
handled in rproc_mem_entry_init itself.

> +
> + return 0;
> +}
> +
> +/**
> * rproc_add_carveout() - register an allocated carveout region
> * @rproc: rproc handle
> * @mem: memory entry to register
> @@ -832,6 +839,7 @@ void rproc_add_carveout(struct rproc *rproc, struct rproc_mem_entry *mem)
> struct rproc_mem_entry *
> rproc_mem_entry_init(struct device *dev,
> void *va, dma_addr_t dma, int len, u32 da,
> + int (*alloc)(struct rproc *, struct rproc_mem_entry *),
> int (*release)(struct rproc *, struct rproc_mem_entry *),
> const char *name, ...)
> {
> @@ -846,7 +854,9 @@ struct rproc_mem_entry *
> mem->dma = dma;
> mem->da = da;
> mem->len = len;
> + mem->alloc = alloc;
> mem->release = release;
> + mem->rsc_offset = FW_RSC_ADDR_ANY;
>
> va_start(args, name);
> vsnprintf(mem->name, sizeof(mem->name), name, args);
> @@ -978,6 +988,63 @@ static void rproc_unprepare_subdevices(struct rproc *rproc)
> }
>
> /**
> + * rproc_alloc_registered_carveouts() - allocate all carveouts registered
> + * in the list
> + * @rproc: the remote processor handle
> + *
> + * This function parses registered carveout list, performs allocation
> + * if alloc() ops registered and updates resource table information
> + * if rsc_offset set.
> + *
> + * Return: 0 on success
> + */
> +static int rproc_alloc_registered_carveouts(struct rproc *rproc)
> +{
> + struct rproc_mem_entry *entry, *tmp;
> + struct fw_rsc_carveout *rsc;
> + struct device *dev = &rproc->dev;
> + int ret;
> +
> + list_for_each_entry_safe(entry, tmp, &rproc->carveouts, node) {
> + if (entry->alloc) {
> + ret = entry->alloc(rproc, entry);
> + if (ret) {
> + dev_err(dev, "Unable to allocate carveout %s: %d\n",
> + entry->name, ret);
> + return -ENOMEM;
> + }
> + }
> +
> + if (entry->rsc_offset != FW_RSC_ADDR_ANY) {
> + /* update resource table */
> + rsc = (void *)rproc->table_ptr + entry->rsc_offset;
> +
> + /*
> + * Some remote processors might need to know the pa
> + * even though they are behind an IOMMU. E.g., OMAP4's
> + * remote M3 processor needs this so it can control
> + * on-chip hardware accelerators that are not behind
> + * the IOMMU, and therefor must know the pa.
> + *
> + * Generally we don't want to expose physical addresses
> + * if we don't have to (remote processors are generally
> + * _not_ trusted), so we might want to do this only for
> + * remote processor that _must_ have this (e.g. OMAP4's
> + * dual M3 subsystem).
> + *
> + * Non-IOMMU processors might also want to have this info.
> + * In this case, the device address and the physical address
> + * are the same.
> + */
> + if (entry->va)
> + rsc->pa = (u32)rproc_va_to_pa(entry->va);
> + }
> + }
> +
> + return 0;
> +}
> +
> +/**
> * rproc_coredump_cleanup() - clean up dump_segments list
> * @rproc: the remote processor handle
> */
> @@ -1148,6 +1215,14 @@ static int rproc_fw_boot(struct rproc *rproc, const struct firmware *fw)
> goto clean_up_resources;
> }
>
> + /* Allocate carveout resources associated to rproc */
> + ret = rproc_alloc_registered_carveouts(rproc);
> + if (ret) {
> + dev_err(dev, "Failed to allocate associated carveouts: %d\n",
> + ret);
> + goto clean_up_resources;
> + }

This is causing an issue with RSC_TRACE on where the trace region on the
remote processor is actually backed by a DDR carveout address. The
allocations are now being done after processing the resources from the
rproc_loading_handlers, which causes the RSC_TRACE to be configured with
an incorrect kernel va, and accessing it through debugfs then results in
a kernel crash.

regards
Suman

> +
> ret = rproc_start(rproc, fw);
> if (ret)
> goto clean_up_resources;
> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
> index 55f30fc..ea95b04 100644
> --- a/include/linux/remoteproc.h
> +++ b/include/linux/remoteproc.h
> @@ -317,6 +317,9 @@ struct fw_rsc_vdev {
> * @priv: associated data
> * @name: associated memory region name (optional)
> * @node: list node
> + * @rsc_offset: offset in resource table
> + * @flags: iommu protection flags
> + * @alloc: specific memory allocator function
> */
> struct rproc_mem_entry {
> void *va;
> @@ -326,6 +329,9 @@ struct rproc_mem_entry {
> void *priv;
> char name[32];
> struct list_head node;
> + u32 rsc_offset;
> + u32 flags;
> + int (*alloc)(struct rproc *rproc, struct rproc_mem_entry *mem);
> int (*release)(struct rproc *rproc, struct rproc_mem_entry *mem);
> };
>
> @@ -563,6 +569,7 @@ struct rproc *rproc_alloc(struct device *dev, const char *name,
> struct rproc_mem_entry *
> rproc_mem_entry_init(struct device *dev,
> void *va, dma_addr_t dma, int len, u32 da,
> + int (*alloc)(struct rproc *, struct rproc_mem_entry *),
> int (*release)(struct rproc *, struct rproc_mem_entry *),
> const char *name, ...);
>
>

\
 
 \ /
  Last update: 2018-10-23 23:21    [W:0.397 / U:2.296 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site