| Message ID | 1594938035-7327-5-git-send-email-rishabhb@codeaurora.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Extend coredump functionality | expand |
On Thu 16 Jul 15:20 PDT 2020, Rishabh Bhatnagar wrote: > The current coredump implementation uses vmalloc area to copy > all the segments. But this might put strain on low memory targets > as the firmware size sometimes is in tens of MBs. The situation > becomes worse if there are multiple remote processors undergoing > recovery at the same time. This patch adds inline coredump > functionality that avoids extra memory usage. This requires > recovery to be halted until data is read by userspace and free > function is called. > > Signed-off-by: Rishabh Bhatnagar <rishabhb@codeaurora.org> > Tested-by: Sibi Sankar <sibis@codeaurora.org> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> > --- > drivers/remoteproc/remoteproc_coredump.c | 156 +++++++++++++++++++++++++++---- > include/linux/remoteproc.h | 16 ++++ > 2 files changed, 154 insertions(+), 18 deletions(-) > > diff --git a/drivers/remoteproc/remoteproc_coredump.c b/drivers/remoteproc/remoteproc_coredump.c > index 390f563..bb15a29 100644 > --- a/drivers/remoteproc/remoteproc_coredump.c > +++ b/drivers/remoteproc/remoteproc_coredump.c > @@ -5,6 +5,7 @@ > * Copyright (c) 2020, The Linux Foundation. All rights reserved. > */ > > +#include <linux/completion.h> > #include <linux/devcoredump.h> > #include <linux/device.h> > #include <linux/kernel.h> > @@ -12,6 +13,12 @@ > #include "remoteproc_internal.h" > #include "remoteproc_elf_helpers.h" > > +struct rproc_coredump_state { > + struct rproc *rproc; > + void *header; > + struct completion dump_done; > +}; > + > /** > * rproc_coredump_cleanup() - clean up dump_segments list > * @rproc: the remote processor handle > @@ -115,12 +122,110 @@ int rproc_coredump_set_elf_info(struct rproc *rproc, u8 class, u16 machine) > } > EXPORT_SYMBOL(rproc_coredump_set_elf_info); > > +static void rproc_coredump_free(void *data) > +{ > + struct rproc_coredump_state *dump_state = data; > + > + vfree(dump_state->header); > + complete(&dump_state->dump_done); > +} > + > +static void *rproc_coredump_find_segment(loff_t user_offset, > + struct list_head *segments, > + size_t *data_left) > +{ > + struct rproc_dump_segment *segment; > + > + list_for_each_entry(segment, segments, node) { > + if (user_offset < segment->size) { > + *data_left = segment->size - user_offset; > + return segment; > + } > + user_offset -= segment->size; > + } > + > + *data_left = 0; > + return NULL; > +} > + > +static void rproc_copy_segment(struct rproc *rproc, void *dest, > + struct rproc_dump_segment *segment, > + size_t offset, size_t size) > +{ > + void *ptr; > + > + if (segment->dump) { > + segment->dump(rproc, segment, dest, offset, size); > + } else { > + ptr = rproc_da_to_va(rproc, segment->da + offset, size); > + if (!ptr) { > + dev_err(&rproc->dev, > + "invalid copy request for segment %pad with offset %zu and size %zu)\n", > + &segment->da, offset, size); > + memset(dest, 0xff, size); > + } else { > + memcpy(dest, ptr, size); > + } > + } > +} > + > +static ssize_t rproc_coredump_read(char *buffer, loff_t offset, size_t count, > + void *data, size_t header_sz) > +{ > + size_t seg_data, bytes_left = count; > + ssize_t copy_sz; > + struct rproc_dump_segment *seg; > + struct rproc_coredump_state *dump_state = data; > + struct rproc *rproc = dump_state->rproc; > + void *elfcore = dump_state->header; > + > + /* Copy the vmalloc'ed header first. */ > + if (offset < header_sz) { > + copy_sz = memory_read_from_buffer(buffer, count, &offset, > + elfcore, header_sz); > + > + return copy_sz; > + } > + > + /* > + * Find out the segment memory chunk to be copied based on offset. > + * Keep copying data until count bytes are read. > + */ > + while (bytes_left) { > + seg = rproc_coredump_find_segment(offset - header_sz, > + &rproc->dump_segments, > + &seg_data); > + /* EOF check */ > + if (!seg) { > + dev_info(&rproc->dev, "Ramdump done, %lld bytes read", > + offset); > + break; > + } > + > + copy_sz = min_t(size_t, bytes_left, seg_data); > + > + rproc_copy_segment(rproc, buffer, seg, seg->size - seg_data, > + copy_sz); > + > + offset += copy_sz; > + buffer += copy_sz; > + bytes_left -= copy_sz; > + } > + > + return count - bytes_left; > +} > + > /** > * rproc_coredump() - perform coredump > * @rproc: rproc handle > * > * This function will generate an ELF header for the registered segments > - * and create a devcoredump device associated with rproc. > + * and create a devcoredump device associated with rproc. Based on the > + * coredump configuration this function will directly copy the segments > + * from device memory to userspace or copy segments from device memory to > + * a separate buffer, which can then be read by userspace. > + * The first approach avoids using extra vmalloc memory. But it will stall > + * recovery flow until dump is read by userspace. > */ > void rproc_coredump(struct rproc *rproc) > { > @@ -130,11 +235,13 @@ void rproc_coredump(struct rproc *rproc) > size_t data_size; > size_t offset; > void *data; > - void *ptr; > u8 class = rproc->elf_class; > int phnum = 0; > + struct rproc_coredump_state dump_state; > + enum rproc_dump_mechanism dump_conf = rproc->dump_conf; > > - if (list_empty(&rproc->dump_segments)) > + if (list_empty(&rproc->dump_segments) || > + dump_conf == RPROC_COREDUMP_DISABLED) > return; > > if (class == ELFCLASSNONE) { > @@ -144,7 +251,14 @@ void rproc_coredump(struct rproc *rproc) > > data_size = elf_size_of_hdr(class); > list_for_each_entry(segment, &rproc->dump_segments, node) { > - data_size += elf_size_of_phdr(class) + segment->size; > + /* > + * For default configuration buffer includes headers & segments. > + * For inline dump buffer just includes headers as segments are > + * directly read from device memory. > + */ > + data_size += elf_size_of_phdr(class); > + if (dump_conf == RPROC_COREDUMP_DEFAULT) > + data_size += segment->size; > > phnum++; > } > @@ -183,23 +297,29 @@ void rproc_coredump(struct rproc *rproc) > elf_phdr_set_p_flags(class, phdr, PF_R | PF_W | PF_X); > elf_phdr_set_p_align(class, phdr, 0); > > - if (segment->dump) { > - segment->dump(rproc, segment, data + offset, 0, segment->size); > - } else { > - ptr = rproc_da_to_va(rproc, segment->da, segment->size); > - if (!ptr) { > - dev_err(&rproc->dev, > - "invalid coredump segment (%pad, %zu)\n", > - &segment->da, segment->size); > - memset(data + offset, 0xff, segment->size); > - } else { > - memcpy(data + offset, ptr, segment->size); > - } > - } > + if (dump_conf == RPROC_COREDUMP_DEFAULT) > + rproc_copy_segment(rproc, data + offset, segment, 0, > + segment->size); > > offset += elf_phdr_get_p_filesz(class, phdr); > phdr += elf_size_of_phdr(class); > } > + if (dump_conf == RPROC_COREDUMP_DEFAULT) { > + dev_coredumpv(&rproc->dev, data, data_size, GFP_KERNEL); > + return; > + } > + > + /* Initialize the dump state struct to be used by rproc_coredump_read */ > + dump_state.rproc = rproc; > + dump_state.header = data; > + init_completion(&dump_state.dump_done); > + > + dev_coredumpm(&rproc->dev, NULL, &dump_state, data_size, GFP_KERNEL, > + rproc_coredump_read, rproc_coredump_free); > > - dev_coredumpv(&rproc->dev, data, data_size, GFP_KERNEL); > + /* > + * Wait until the dump is read and free is called. Data is freed > + * by devcoredump framework automatically after 5 minutes. > + */ > + wait_for_completion(&dump_state.dump_done); > } > diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h > index eb08139..38d037d 100644 > --- a/include/linux/remoteproc.h > +++ b/include/linux/remoteproc.h > @@ -435,6 +435,20 @@ enum rproc_crash_type { > }; > > /** > + * enum rproc_dump_mechanism - Coredump options for core > + * @RPROC_COREDUMP_DEFAULT: Copy dump to separate buffer and carry on with > + recovery > + * @RPROC_COREDUMP_INLINE: Read segments directly from device memory. Stall > + recovery until all segments are read > + * @RPROC_COREDUMP_DISABLED: Don't perform any dump > + */ > +enum rproc_dump_mechanism { > + RPROC_COREDUMP_DEFAULT, > + RPROC_COREDUMP_INLINE, > + RPROC_COREDUMP_DISABLED, > +}; > + > +/** > * struct rproc_dump_segment - segment info from ELF header > * @node: list node related to the rproc segment list > * @da: device address of the segment > @@ -466,6 +480,7 @@ struct rproc_dump_segment { > * @dev: virtual device for refcounting and common remoteproc behavior > * @power: refcount of users who need this rproc powered up > * @state: state of the device > + * @dump_conf: Currently selected coredump configuration > * @lock: lock which protects concurrent manipulations of the rproc > * @dbg_dir: debugfs directory of this rproc device > * @traces: list of trace buffers > @@ -499,6 +514,7 @@ struct rproc { > struct device dev; > atomic_t power; > unsigned int state; > + enum rproc_dump_mechanism dump_conf; > struct mutex lock; > struct dentry *dbg_dir; > struct list_head traces; > -- > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, > a Linux Foundation Collaborative Project >
On 2020-07-17 03:50, Rishabh Bhatnagar wrote: > The current coredump implementation uses vmalloc area to copy > all the segments. But this might put strain on low memory targets > as the firmware size sometimes is in tens of MBs. The situation > becomes worse if there are multiple remote processors undergoing > recovery at the same time. This patch adds inline coredump > functionality that avoids extra memory usage. This requires > recovery to be halted until data is read by userspace and free > function is called. > > Signed-off-by: Rishabh Bhatnagar <rishabhb@codeaurora.org> Reviewed-by: Sibi Sankar <sibis@codeaurora.org> > Tested-by: Sibi Sankar <sibis@codeaurora.org> > --- > drivers/remoteproc/remoteproc_coredump.c | 156 > +++++++++++++++++++++++++++---- > include/linux/remoteproc.h | 16 ++++ > 2 files changed, 154 insertions(+), 18 deletions(-) > > diff --git a/drivers/remoteproc/remoteproc_coredump.c > b/drivers/remoteproc/remoteproc_coredump.c > index 390f563..bb15a29 100644 > --- a/drivers/remoteproc/remoteproc_coredump.c > +++ b/drivers/remoteproc/remoteproc_coredump.c > @@ -5,6 +5,7 @@ > * Copyright (c) 2020, The Linux Foundation. All rights reserved. > */ > > +#include <linux/completion.h> > #include <linux/devcoredump.h> > #include <linux/device.h> > #include <linux/kernel.h> > @@ -12,6 +13,12 @@ > #include "remoteproc_internal.h" > #include "remoteproc_elf_helpers.h" > > +struct rproc_coredump_state { > + struct rproc *rproc; > + void *header; > + struct completion dump_done; > +}; > + > /** > * rproc_coredump_cleanup() - clean up dump_segments list > * @rproc: the remote processor handle > @@ -115,12 +122,110 @@ int rproc_coredump_set_elf_info(struct rproc > *rproc, u8 class, u16 machine) > } > EXPORT_SYMBOL(rproc_coredump_set_elf_info); > > +static void rproc_coredump_free(void *data) > +{ > + struct rproc_coredump_state *dump_state = data; > + > + vfree(dump_state->header); > + complete(&dump_state->dump_done); > +} > + > +static void *rproc_coredump_find_segment(loff_t user_offset, > + struct list_head *segments, > + size_t *data_left) > +{ > + struct rproc_dump_segment *segment; > + > + list_for_each_entry(segment, segments, node) { > + if (user_offset < segment->size) { > + *data_left = segment->size - user_offset; > + return segment; > + } > + user_offset -= segment->size; > + } > + > + *data_left = 0; > + return NULL; > +} > + > +static void rproc_copy_segment(struct rproc *rproc, void *dest, > + struct rproc_dump_segment *segment, > + size_t offset, size_t size) > +{ > + void *ptr; > + > + if (segment->dump) { > + segment->dump(rproc, segment, dest, offset, size); > + } else { > + ptr = rproc_da_to_va(rproc, segment->da + offset, size); > + if (!ptr) { > + dev_err(&rproc->dev, > + "invalid copy request for segment %pad with offset %zu and size > %zu)\n", > + &segment->da, offset, size); > + memset(dest, 0xff, size); > + } else { > + memcpy(dest, ptr, size); > + } > + } > +} > + > +static ssize_t rproc_coredump_read(char *buffer, loff_t offset, size_t > count, > + void *data, size_t header_sz) > +{ > + size_t seg_data, bytes_left = count; > + ssize_t copy_sz; > + struct rproc_dump_segment *seg; > + struct rproc_coredump_state *dump_state = data; > + struct rproc *rproc = dump_state->rproc; > + void *elfcore = dump_state->header; > + > + /* Copy the vmalloc'ed header first. */ > + if (offset < header_sz) { > + copy_sz = memory_read_from_buffer(buffer, count, &offset, > + elfcore, header_sz); > + > + return copy_sz; > + } > + > + /* > + * Find out the segment memory chunk to be copied based on offset. > + * Keep copying data until count bytes are read. > + */ > + while (bytes_left) { > + seg = rproc_coredump_find_segment(offset - header_sz, > + &rproc->dump_segments, > + &seg_data); > + /* EOF check */ > + if (!seg) { > + dev_info(&rproc->dev, "Ramdump done, %lld bytes read", > + offset); > + break; > + } > + > + copy_sz = min_t(size_t, bytes_left, seg_data); > + > + rproc_copy_segment(rproc, buffer, seg, seg->size - seg_data, > + copy_sz); > + > + offset += copy_sz; > + buffer += copy_sz; > + bytes_left -= copy_sz; > + } > + > + return count - bytes_left; > +} > + > /** > * rproc_coredump() - perform coredump > * @rproc: rproc handle > * > * This function will generate an ELF header for the registered > segments > - * and create a devcoredump device associated with rproc. > + * and create a devcoredump device associated with rproc. Based on the > + * coredump configuration this function will directly copy the > segments > + * from device memory to userspace or copy segments from device memory > to > + * a separate buffer, which can then be read by userspace. > + * The first approach avoids using extra vmalloc memory. But it will > stall > + * recovery flow until dump is read by userspace. > */ > void rproc_coredump(struct rproc *rproc) > { > @@ -130,11 +235,13 @@ void rproc_coredump(struct rproc *rproc) > size_t data_size; > size_t offset; > void *data; > - void *ptr; > u8 class = rproc->elf_class; > int phnum = 0; > + struct rproc_coredump_state dump_state; > + enum rproc_dump_mechanism dump_conf = rproc->dump_conf; > > - if (list_empty(&rproc->dump_segments)) > + if (list_empty(&rproc->dump_segments) || > + dump_conf == RPROC_COREDUMP_DISABLED) > return; > > if (class == ELFCLASSNONE) { > @@ -144,7 +251,14 @@ void rproc_coredump(struct rproc *rproc) > > data_size = elf_size_of_hdr(class); > list_for_each_entry(segment, &rproc->dump_segments, node) { > - data_size += elf_size_of_phdr(class) + segment->size; > + /* > + * For default configuration buffer includes headers & segments. > + * For inline dump buffer just includes headers as segments are > + * directly read from device memory. > + */ > + data_size += elf_size_of_phdr(class); > + if (dump_conf == RPROC_COREDUMP_DEFAULT) > + data_size += segment->size; > > phnum++; > } > @@ -183,23 +297,29 @@ void rproc_coredump(struct rproc *rproc) > elf_phdr_set_p_flags(class, phdr, PF_R | PF_W | PF_X); > elf_phdr_set_p_align(class, phdr, 0); > > - if (segment->dump) { > - segment->dump(rproc, segment, data + offset, 0, segment->size); > - } else { > - ptr = rproc_da_to_va(rproc, segment->da, segment->size); > - if (!ptr) { > - dev_err(&rproc->dev, > - "invalid coredump segment (%pad, %zu)\n", > - &segment->da, segment->size); > - memset(data + offset, 0xff, segment->size); > - } else { > - memcpy(data + offset, ptr, segment->size); > - } > - } > + if (dump_conf == RPROC_COREDUMP_DEFAULT) > + rproc_copy_segment(rproc, data + offset, segment, 0, > + segment->size); > > offset += elf_phdr_get_p_filesz(class, phdr); > phdr += elf_size_of_phdr(class); > } > + if (dump_conf == RPROC_COREDUMP_DEFAULT) { > + dev_coredumpv(&rproc->dev, data, data_size, GFP_KERNEL); > + return; > + } > + > + /* Initialize the dump state struct to be used by rproc_coredump_read > */ > + dump_state.rproc = rproc; > + dump_state.header = data; > + init_completion(&dump_state.dump_done); > + > + dev_coredumpm(&rproc->dev, NULL, &dump_state, data_size, GFP_KERNEL, > + rproc_coredump_read, rproc_coredump_free); > > - dev_coredumpv(&rproc->dev, data, data_size, GFP_KERNEL); > + /* > + * Wait until the dump is read and free is called. Data is freed > + * by devcoredump framework automatically after 5 minutes. > + */ > + wait_for_completion(&dump_state.dump_done); > } > diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h > index eb08139..38d037d 100644 > --- a/include/linux/remoteproc.h > +++ b/include/linux/remoteproc.h > @@ -435,6 +435,20 @@ enum rproc_crash_type { > }; > > /** > + * enum rproc_dump_mechanism - Coredump options for core > + * @RPROC_COREDUMP_DEFAULT: Copy dump to separate buffer and carry on > with > + recovery > + * @RPROC_COREDUMP_INLINE: Read segments directly from device memory. > Stall > + recovery until all segments are read > + * @RPROC_COREDUMP_DISABLED: Don't perform any dump > + */ > +enum rproc_dump_mechanism { > + RPROC_COREDUMP_DEFAULT, > + RPROC_COREDUMP_INLINE, > + RPROC_COREDUMP_DISABLED, > +}; > + > +/** > * struct rproc_dump_segment - segment info from ELF header > * @node: list node related to the rproc segment list > * @da: device address of the segment > @@ -466,6 +480,7 @@ struct rproc_dump_segment { > * @dev: virtual device for refcounting and common remoteproc behavior > * @power: refcount of users who need this rproc powered up > * @state: state of the device > + * @dump_conf: Currently selected coredump configuration > * @lock: lock which protects concurrent manipulations of the rproc > * @dbg_dir: debugfs directory of this rproc device > * @traces: list of trace buffers > @@ -499,6 +514,7 @@ struct rproc { > struct device dev; > atomic_t power; > unsigned int state; > + enum rproc_dump_mechanism dump_conf; > struct mutex lock; > struct dentry *dbg_dir; > struct list_head traces;
On Thu, Jul 16, 2020 at 03:20:34PM -0700, Rishabh Bhatnagar wrote: > The current coredump implementation uses vmalloc area to copy > all the segments. But this might put strain on low memory targets > as the firmware size sometimes is in tens of MBs. The situation > becomes worse if there are multiple remote processors undergoing > recovery at the same time. This patch adds inline coredump > functionality that avoids extra memory usage. This requires > recovery to be halted until data is read by userspace and free > function is called. > > Signed-off-by: Rishabh Bhatnagar <rishabhb@codeaurora.org> > Tested-by: Sibi Sankar <sibis@codeaurora.org> Thanks for doing the modifications. Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> > --- > drivers/remoteproc/remoteproc_coredump.c | 156 +++++++++++++++++++++++++++---- > include/linux/remoteproc.h | 16 ++++ > 2 files changed, 154 insertions(+), 18 deletions(-) > > diff --git a/drivers/remoteproc/remoteproc_coredump.c b/drivers/remoteproc/remoteproc_coredump.c > index 390f563..bb15a29 100644 > --- a/drivers/remoteproc/remoteproc_coredump.c > +++ b/drivers/remoteproc/remoteproc_coredump.c > @@ -5,6 +5,7 @@ > * Copyright (c) 2020, The Linux Foundation. All rights reserved. > */ > > +#include <linux/completion.h> > #include <linux/devcoredump.h> > #include <linux/device.h> > #include <linux/kernel.h> > @@ -12,6 +13,12 @@ > #include "remoteproc_internal.h" > #include "remoteproc_elf_helpers.h" > > +struct rproc_coredump_state { > + struct rproc *rproc; > + void *header; > + struct completion dump_done; > +}; > + > /** > * rproc_coredump_cleanup() - clean up dump_segments list > * @rproc: the remote processor handle > @@ -115,12 +122,110 @@ int rproc_coredump_set_elf_info(struct rproc *rproc, u8 class, u16 machine) > } > EXPORT_SYMBOL(rproc_coredump_set_elf_info); > > +static void rproc_coredump_free(void *data) > +{ > + struct rproc_coredump_state *dump_state = data; > + > + vfree(dump_state->header); > + complete(&dump_state->dump_done); > +} > + > +static void *rproc_coredump_find_segment(loff_t user_offset, > + struct list_head *segments, > + size_t *data_left) > +{ > + struct rproc_dump_segment *segment; > + > + list_for_each_entry(segment, segments, node) { > + if (user_offset < segment->size) { > + *data_left = segment->size - user_offset; > + return segment; > + } > + user_offset -= segment->size; > + } > + > + *data_left = 0; > + return NULL; > +} > + > +static void rproc_copy_segment(struct rproc *rproc, void *dest, > + struct rproc_dump_segment *segment, > + size_t offset, size_t size) > +{ > + void *ptr; > + > + if (segment->dump) { > + segment->dump(rproc, segment, dest, offset, size); > + } else { > + ptr = rproc_da_to_va(rproc, segment->da + offset, size); > + if (!ptr) { > + dev_err(&rproc->dev, > + "invalid copy request for segment %pad with offset %zu and size %zu)\n", > + &segment->da, offset, size); > + memset(dest, 0xff, size); > + } else { > + memcpy(dest, ptr, size); > + } > + } > +} > + > +static ssize_t rproc_coredump_read(char *buffer, loff_t offset, size_t count, > + void *data, size_t header_sz) > +{ > + size_t seg_data, bytes_left = count; > + ssize_t copy_sz; > + struct rproc_dump_segment *seg; > + struct rproc_coredump_state *dump_state = data; > + struct rproc *rproc = dump_state->rproc; > + void *elfcore = dump_state->header; > + > + /* Copy the vmalloc'ed header first. */ > + if (offset < header_sz) { > + copy_sz = memory_read_from_buffer(buffer, count, &offset, > + elfcore, header_sz); > + > + return copy_sz; > + } > + > + /* > + * Find out the segment memory chunk to be copied based on offset. > + * Keep copying data until count bytes are read. > + */ > + while (bytes_left) { > + seg = rproc_coredump_find_segment(offset - header_sz, > + &rproc->dump_segments, > + &seg_data); > + /* EOF check */ > + if (!seg) { > + dev_info(&rproc->dev, "Ramdump done, %lld bytes read", > + offset); > + break; > + } > + > + copy_sz = min_t(size_t, bytes_left, seg_data); > + > + rproc_copy_segment(rproc, buffer, seg, seg->size - seg_data, > + copy_sz); > + > + offset += copy_sz; > + buffer += copy_sz; > + bytes_left -= copy_sz; > + } > + > + return count - bytes_left; > +} > + > /** > * rproc_coredump() - perform coredump > * @rproc: rproc handle > * > * This function will generate an ELF header for the registered segments > - * and create a devcoredump device associated with rproc. > + * and create a devcoredump device associated with rproc. Based on the > + * coredump configuration this function will directly copy the segments > + * from device memory to userspace or copy segments from device memory to > + * a separate buffer, which can then be read by userspace. > + * The first approach avoids using extra vmalloc memory. But it will stall > + * recovery flow until dump is read by userspace. > */ > void rproc_coredump(struct rproc *rproc) > { > @@ -130,11 +235,13 @@ void rproc_coredump(struct rproc *rproc) > size_t data_size; > size_t offset; > void *data; > - void *ptr; > u8 class = rproc->elf_class; > int phnum = 0; > + struct rproc_coredump_state dump_state; > + enum rproc_dump_mechanism dump_conf = rproc->dump_conf; > > - if (list_empty(&rproc->dump_segments)) > + if (list_empty(&rproc->dump_segments) || > + dump_conf == RPROC_COREDUMP_DISABLED) > return; > > if (class == ELFCLASSNONE) { > @@ -144,7 +251,14 @@ void rproc_coredump(struct rproc *rproc) > > data_size = elf_size_of_hdr(class); > list_for_each_entry(segment, &rproc->dump_segments, node) { > - data_size += elf_size_of_phdr(class) + segment->size; > + /* > + * For default configuration buffer includes headers & segments. > + * For inline dump buffer just includes headers as segments are > + * directly read from device memory. > + */ > + data_size += elf_size_of_phdr(class); > + if (dump_conf == RPROC_COREDUMP_DEFAULT) > + data_size += segment->size; > > phnum++; > } > @@ -183,23 +297,29 @@ void rproc_coredump(struct rproc *rproc) > elf_phdr_set_p_flags(class, phdr, PF_R | PF_W | PF_X); > elf_phdr_set_p_align(class, phdr, 0); > > - if (segment->dump) { > - segment->dump(rproc, segment, data + offset, 0, segment->size); > - } else { > - ptr = rproc_da_to_va(rproc, segment->da, segment->size); > - if (!ptr) { > - dev_err(&rproc->dev, > - "invalid coredump segment (%pad, %zu)\n", > - &segment->da, segment->size); > - memset(data + offset, 0xff, segment->size); > - } else { > - memcpy(data + offset, ptr, segment->size); > - } > - } > + if (dump_conf == RPROC_COREDUMP_DEFAULT) > + rproc_copy_segment(rproc, data + offset, segment, 0, > + segment->size); > > offset += elf_phdr_get_p_filesz(class, phdr); > phdr += elf_size_of_phdr(class); > } > + if (dump_conf == RPROC_COREDUMP_DEFAULT) { > + dev_coredumpv(&rproc->dev, data, data_size, GFP_KERNEL); > + return; > + } > + > + /* Initialize the dump state struct to be used by rproc_coredump_read */ > + dump_state.rproc = rproc; > + dump_state.header = data; > + init_completion(&dump_state.dump_done); > + > + dev_coredumpm(&rproc->dev, NULL, &dump_state, data_size, GFP_KERNEL, > + rproc_coredump_read, rproc_coredump_free); > > - dev_coredumpv(&rproc->dev, data, data_size, GFP_KERNEL); > + /* > + * Wait until the dump is read and free is called. Data is freed > + * by devcoredump framework automatically after 5 minutes. > + */ > + wait_for_completion(&dump_state.dump_done); > } > diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h > index eb08139..38d037d 100644 > --- a/include/linux/remoteproc.h > +++ b/include/linux/remoteproc.h > @@ -435,6 +435,20 @@ enum rproc_crash_type { > }; > > /** > + * enum rproc_dump_mechanism - Coredump options for core > + * @RPROC_COREDUMP_DEFAULT: Copy dump to separate buffer and carry on with > + recovery > + * @RPROC_COREDUMP_INLINE: Read segments directly from device memory. Stall > + recovery until all segments are read > + * @RPROC_COREDUMP_DISABLED: Don't perform any dump > + */ > +enum rproc_dump_mechanism { > + RPROC_COREDUMP_DEFAULT, > + RPROC_COREDUMP_INLINE, > + RPROC_COREDUMP_DISABLED, > +}; > + > +/** > * struct rproc_dump_segment - segment info from ELF header > * @node: list node related to the rproc segment list > * @da: device address of the segment > @@ -466,6 +480,7 @@ struct rproc_dump_segment { > * @dev: virtual device for refcounting and common remoteproc behavior > * @power: refcount of users who need this rproc powered up > * @state: state of the device > + * @dump_conf: Currently selected coredump configuration > * @lock: lock which protects concurrent manipulations of the rproc > * @dbg_dir: debugfs directory of this rproc device > * @traces: list of trace buffers > @@ -499,6 +514,7 @@ struct rproc { > struct device dev; > atomic_t power; > unsigned int state; > + enum rproc_dump_mechanism dump_conf; > struct mutex lock; > struct dentry *dbg_dir; > struct list_head traces; > -- > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, > a Linux Foundation Collaborative Project >
diff --git a/drivers/remoteproc/remoteproc_coredump.c b/drivers/remoteproc/remoteproc_coredump.c index 390f563..bb15a29 100644 --- a/drivers/remoteproc/remoteproc_coredump.c +++ b/drivers/remoteproc/remoteproc_coredump.c @@ -5,6 +5,7 @@ * Copyright (c) 2020, The Linux Foundation. All rights reserved. */ +#include <linux/completion.h> #include <linux/devcoredump.h> #include <linux/device.h> #include <linux/kernel.h> @@ -12,6 +13,12 @@ #include "remoteproc_internal.h" #include "remoteproc_elf_helpers.h" +struct rproc_coredump_state { + struct rproc *rproc; + void *header; + struct completion dump_done; +}; + /** * rproc_coredump_cleanup() - clean up dump_segments list * @rproc: the remote processor handle @@ -115,12 +122,110 @@ int rproc_coredump_set_elf_info(struct rproc *rproc, u8 class, u16 machine) } EXPORT_SYMBOL(rproc_coredump_set_elf_info); +static void rproc_coredump_free(void *data) +{ + struct rproc_coredump_state *dump_state = data; + + vfree(dump_state->header); + complete(&dump_state->dump_done); +} + +static void *rproc_coredump_find_segment(loff_t user_offset, + struct list_head *segments, + size_t *data_left) +{ + struct rproc_dump_segment *segment; + + list_for_each_entry(segment, segments, node) { + if (user_offset < segment->size) { + *data_left = segment->size - user_offset; + return segment; + } + user_offset -= segment->size; + } + + *data_left = 0; + return NULL; +} + +static void rproc_copy_segment(struct rproc *rproc, void *dest, + struct rproc_dump_segment *segment, + size_t offset, size_t size) +{ + void *ptr; + + if (segment->dump) { + segment->dump(rproc, segment, dest, offset, size); + } else { + ptr = rproc_da_to_va(rproc, segment->da + offset, size); + if (!ptr) { + dev_err(&rproc->dev, + "invalid copy request for segment %pad with offset %zu and size %zu)\n", + &segment->da, offset, size); + memset(dest, 0xff, size); + } else { + memcpy(dest, ptr, size); + } + } +} + +static ssize_t rproc_coredump_read(char *buffer, loff_t offset, size_t count, + void *data, size_t header_sz) +{ + size_t seg_data, bytes_left = count; + ssize_t copy_sz; + struct rproc_dump_segment *seg; + struct rproc_coredump_state *dump_state = data; + struct rproc *rproc = dump_state->rproc; + void *elfcore = dump_state->header; + + /* Copy the vmalloc'ed header first. */ + if (offset < header_sz) { + copy_sz = memory_read_from_buffer(buffer, count, &offset, + elfcore, header_sz); + + return copy_sz; + } + + /* + * Find out the segment memory chunk to be copied based on offset. + * Keep copying data until count bytes are read. + */ + while (bytes_left) { + seg = rproc_coredump_find_segment(offset - header_sz, + &rproc->dump_segments, + &seg_data); + /* EOF check */ + if (!seg) { + dev_info(&rproc->dev, "Ramdump done, %lld bytes read", + offset); + break; + } + + copy_sz = min_t(size_t, bytes_left, seg_data); + + rproc_copy_segment(rproc, buffer, seg, seg->size - seg_data, + copy_sz); + + offset += copy_sz; + buffer += copy_sz; + bytes_left -= copy_sz; + } + + return count - bytes_left; +} + /** * rproc_coredump() - perform coredump * @rproc: rproc handle * * This function will generate an ELF header for the registered segments - * and create a devcoredump device associated with rproc. + * and create a devcoredump device associated with rproc. Based on the + * coredump configuration this function will directly copy the segments + * from device memory to userspace or copy segments from device memory to + * a separate buffer, which can then be read by userspace. + * The first approach avoids using extra vmalloc memory. But it will stall + * recovery flow until dump is read by userspace. */ void rproc_coredump(struct rproc *rproc) { @@ -130,11 +235,13 @@ void rproc_coredump(struct rproc *rproc) size_t data_size; size_t offset; void *data; - void *ptr; u8 class = rproc->elf_class; int phnum = 0; + struct rproc_coredump_state dump_state; + enum rproc_dump_mechanism dump_conf = rproc->dump_conf; - if (list_empty(&rproc->dump_segments)) + if (list_empty(&rproc->dump_segments) || + dump_conf == RPROC_COREDUMP_DISABLED) return; if (class == ELFCLASSNONE) { @@ -144,7 +251,14 @@ void rproc_coredump(struct rproc *rproc) data_size = elf_size_of_hdr(class); list_for_each_entry(segment, &rproc->dump_segments, node) { - data_size += elf_size_of_phdr(class) + segment->size; + /* + * For default configuration buffer includes headers & segments. + * For inline dump buffer just includes headers as segments are + * directly read from device memory. + */ + data_size += elf_size_of_phdr(class); + if (dump_conf == RPROC_COREDUMP_DEFAULT) + data_size += segment->size; phnum++; } @@ -183,23 +297,29 @@ void rproc_coredump(struct rproc *rproc) elf_phdr_set_p_flags(class, phdr, PF_R | PF_W | PF_X); elf_phdr_set_p_align(class, phdr, 0); - if (segment->dump) { - segment->dump(rproc, segment, data + offset, 0, segment->size); - } else { - ptr = rproc_da_to_va(rproc, segment->da, segment->size); - if (!ptr) { - dev_err(&rproc->dev, - "invalid coredump segment (%pad, %zu)\n", - &segment->da, segment->size); - memset(data + offset, 0xff, segment->size); - } else { - memcpy(data + offset, ptr, segment->size); - } - } + if (dump_conf == RPROC_COREDUMP_DEFAULT) + rproc_copy_segment(rproc, data + offset, segment, 0, + segment->size); offset += elf_phdr_get_p_filesz(class, phdr); phdr += elf_size_of_phdr(class); } + if (dump_conf == RPROC_COREDUMP_DEFAULT) { + dev_coredumpv(&rproc->dev, data, data_size, GFP_KERNEL); + return; + } + + /* Initialize the dump state struct to be used by rproc_coredump_read */ + dump_state.rproc = rproc; + dump_state.header = data; + init_completion(&dump_state.dump_done); + + dev_coredumpm(&rproc->dev, NULL, &dump_state, data_size, GFP_KERNEL, + rproc_coredump_read, rproc_coredump_free); - dev_coredumpv(&rproc->dev, data, data_size, GFP_KERNEL); + /* + * Wait until the dump is read and free is called. Data is freed + * by devcoredump framework automatically after 5 minutes. + */ + wait_for_completion(&dump_state.dump_done); } diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h index eb08139..38d037d 100644 --- a/include/linux/remoteproc.h +++ b/include/linux/remoteproc.h @@ -435,6 +435,20 @@ enum rproc_crash_type { }; /** + * enum rproc_dump_mechanism - Coredump options for core + * @RPROC_COREDUMP_DEFAULT: Copy dump to separate buffer and carry on with + recovery + * @RPROC_COREDUMP_INLINE: Read segments directly from device memory. Stall + recovery until all segments are read + * @RPROC_COREDUMP_DISABLED: Don't perform any dump + */ +enum rproc_dump_mechanism { + RPROC_COREDUMP_DEFAULT, + RPROC_COREDUMP_INLINE, + RPROC_COREDUMP_DISABLED, +}; + +/** * struct rproc_dump_segment - segment info from ELF header * @node: list node related to the rproc segment list * @da: device address of the segment @@ -466,6 +480,7 @@ struct rproc_dump_segment { * @dev: virtual device for refcounting and common remoteproc behavior * @power: refcount of users who need this rproc powered up * @state: state of the device + * @dump_conf: Currently selected coredump configuration * @lock: lock which protects concurrent manipulations of the rproc * @dbg_dir: debugfs directory of this rproc device * @traces: list of trace buffers @@ -499,6 +514,7 @@ struct rproc { struct device dev; atomic_t power; unsigned int state; + enum rproc_dump_mechanism dump_conf; struct mutex lock; struct dentry *dbg_dir; struct list_head traces;