[RFC PATCH 09/31] lmb: allow for resizing lmb regions
Sughosh Ganu
sughosh.ganu at linaro.org
Tue Jun 11 11:50:09 CEST 2024
On Tue, 11 Jun 2024 at 14:47, Heinrich Schuchardt <xypron.glpk at gmx.de> wrote:
>
> On 07.06.24 20:52, Sughosh Ganu wrote:
> > Allow for resizing of LMB regions if the region attributes match. The
> > current code returns a failure status on detecting an overlapping
> > address. This worked up until now since the LMB calls were not
> > persistent and global -- the LMB memory map was specific and private
> > to a given caller of the LMB API's.
> >
> > With the change in the LMB code to make the LMB reservations
> > persistent, there needs to be a check on whether the memory region can
> > be resized, and then do it if so. To distinguish between memory that
> > cannot be resized, add a new flag, LMB_NOOVERWRITE. Reserving a region
> > of memory with this attribute would indicate that the region cannot be
> > resized.
> >
> > Signed-off-by: Sughosh Ganu <sughosh.ganu at linaro.org>
> > ---
> > include/lmb.h | 1 +
> > lib/lmb.c | 120 ++++++++++++++++++++++++++++++++++++++++++++------
> > 2 files changed, 107 insertions(+), 14 deletions(-)
> >
> > diff --git a/include/lmb.h b/include/lmb.h
> > index 03bce2a50c..1d4cd255d2 100644
> > --- a/include/lmb.h
> > +++ b/include/lmb.h
> > @@ -20,6 +20,7 @@
> > enum lmb_flags {
> > LMB_NONE = 0x0,
> > LMB_NOMAP = 0x4,
> > + LMB_NOOVERWRITE = 0x8,
>
> Please, add the missing description for the new value. Using the first
> available bit (0x01) would be expected.
>
> Using the BIT macro would make it clearer that these are bits of a bitmap:
>
> enum lmb_flags {
> LMB_NONE = BIT(0),
> LMB_NOOVERWRITE = BIT(1),
> };
Noted. Will change.
-sughosh
>
> Best regards
>
> Heinrich
>
>
> > };
> >
> > /**
> > diff --git a/lib/lmb.c b/lib/lmb.c
> > index de5a2cf23b..0a4f3d5bcd 100644
> > --- a/lib/lmb.c
> > +++ b/lib/lmb.c
> > @@ -260,12 +260,88 @@ void lmb_add_memory(struct bd_info *bd)
> > }
> > }
> >
> > +static bool lmb_region_flags_match(struct lmb_region *rgn, unsigned long r1,
> > + enum lmb_flags flags)
> > +{
> > + return rgn->region[r1].flags == flags;
> > +}
> > +
> > +static long lmb_merge_overlap_regions(struct lmb_region *rgn, unsigned long i,
> > + phys_addr_t base, phys_size_t size,
> > + enum lmb_flags flags)
> > +{
> > + phys_size_t rgnsize;
> > + unsigned long rgn_cnt, idx;
> > + phys_addr_t rgnbase, rgnend;
> > + phys_addr_t mergebase, mergeend;
> > +
> > + rgn_cnt = 0;
> > + idx = i;
> > + /*
> > + * First thing to do is to identify how many regions does
> > + * the requested region overlap.
> > + * If the flags match, combine all these overlapping
> > + * regions into a single region, and remove the merged
> > + * regions.
> > + */
> > + while (idx < rgn->cnt - 1) {
> > + rgnbase = rgn->region[idx].base;
> > + rgnsize = rgn->region[idx].size;
> > +
> > + if (lmb_addrs_overlap(base, size, rgnbase,
> > + rgnsize)) {
> > + if (!lmb_region_flags_match(rgn, idx, flags))
> > + return -1;
> > + rgn_cnt++;
> > + idx++;
> > + }
> > + }
> > +
> > + /* The merged region's base and size */
> > + rgnbase = rgn->region[i].base;
> > + mergebase = min(base, rgnbase);
> > + rgnend = rgn->region[idx].base + rgn->region[idx].size;
> > + mergeend = max(rgnend, (base + size));
> > +
> > + rgn->region[i].base = mergebase;
> > + rgn->region[i].size = mergeend - mergebase;
> > +
> > + /* Now remove the merged regions */
> > + while (--rgn_cnt)
> > + lmb_remove_region(rgn, i + 1);
> > +
> > + return 0;
> > +}
> > +
> > +static long lmb_resize_regions(struct lmb_region *rgn, unsigned long i,
> > + phys_addr_t base, phys_size_t size,
> > + enum lmb_flags flags)
> > +{
> > + long ret = 0;
> > + phys_addr_t rgnend;
> > +
> > + if (i == rgn->cnt - 1 ||
> > + base + size < rgn->region[i + 1].base) {
> > + if (!lmb_region_flags_match(rgn, i, flags))
> > + return -1;
> > +
> > + rgnend = rgn->region[i].base + rgn->region[i].size;
> > + rgn->region[i].base = min(base, rgn->region[i].base);
> > + rgnend = max(base + size, rgnend);
> > + rgn->region[i].size = rgnend - rgn->region[i].base;
> > + } else {
> > + ret = lmb_merge_overlap_regions(rgn, i, base, size, flags);
> > + }
> > +
> > + return ret;
> > +}
> > +
> > /* This routine called with relocation disabled. */
> > static long lmb_add_region_flags(struct lmb_region *rgn, phys_addr_t base,
> > phys_size_t size, enum lmb_flags flags)
> > {
> > unsigned long coalesced = 0;
> > - long adjacent, i;
> > + long ret, i;
> >
> > if (rgn->cnt == 0) {
> > rgn->region[0].base = base;
> > @@ -290,23 +366,32 @@ static long lmb_add_region_flags(struct lmb_region *rgn, phys_addr_t base,
> > return -1; /* regions with new flags */
> > }
> >
> > - adjacent = lmb_addrs_adjacent(base, size, rgnbase, rgnsize);
> > - if (adjacent > 0) {
> > + ret = lmb_addrs_adjacent(base, size, rgnbase, rgnsize);
> > + if (ret > 0) {
> > if (flags != rgnflags)
> > break;
> > rgn->region[i].base -= size;
> > rgn->region[i].size += size;
> > coalesced++;
> > break;
> > - } else if (adjacent < 0) {
> > + } else if (ret < 0) {
> > if (flags != rgnflags)
> > break;
> > rgn->region[i].size += size;
> > coalesced++;
> > break;
> > } else if (lmb_addrs_overlap(base, size, rgnbase, rgnsize)) {
> > - /* regions overlap */
> > - return -1;
> > + if (flags == LMB_NONE) {
> > + ret = lmb_resize_regions(rgn, i, base, size,
> > + flags);
> > + if (ret < 0)
> > + return -1;
> > +
> > + coalesced++;
> > + break;
> > + } else {
> > + return -1;
> > + }
> > }
> > }
> >
> > @@ -448,7 +533,7 @@ static phys_addr_t lmb_align_down(phys_addr_t addr, phys_size_t size)
> > }
> >
> > static phys_addr_t __lmb_alloc_base(phys_size_t size, ulong align,
> > - phys_addr_t max_addr)
> > + phys_addr_t max_addr, enum lmb_flags flags)
> > {
> > long i, rgn;
> > phys_addr_t base = 0;
> > @@ -498,7 +583,7 @@ phys_addr_t lmb_alloc_base(phys_size_t size, ulong align, phys_addr_t max_addr)
> > {
> > phys_addr_t alloc;
> >
> > - alloc = __lmb_alloc_base(size, align, max_addr);
> > + alloc = __lmb_alloc_base(size, align, max_addr, LMB_NONE);
> >
> > if (alloc == 0)
> > printf("ERROR: Failed to allocate 0x%lx bytes below 0x%lx.\n",
> > @@ -507,11 +592,8 @@ phys_addr_t lmb_alloc_base(phys_size_t size, ulong align, phys_addr_t max_addr)
> > return alloc;
> > }
> >
> > -/*
> > - * Try to allocate a specific address range: must be in defined memory but not
> > - * reserved
> > - */
> > -phys_addr_t lmb_alloc_addr(phys_addr_t base, phys_size_t size)
> > +static phys_addr_t __lmb_alloc_addr(phys_addr_t base, phys_size_t size,
> > + enum lmb_flags flags)
> > {
> > long rgn;
> >
> > @@ -526,13 +608,23 @@ phys_addr_t lmb_alloc_addr(phys_addr_t base, phys_size_t size)
> > lmb.memory.region[rgn].size,
> > base + size - 1, 1)) {
> > /* ok, reserve the memory */
> > - if (lmb_reserve(base, size) >= 0)
> > + if (lmb_reserve_flags(base, size, flags) >= 0)
> > return base;
> > }
> > }
> > +
> > return 0;
> > }
> >
> > +/*
> > + * Try to allocate a specific address range: must be in defined memory but not
> > + * reserved
> > + */
> > +phys_addr_t lmb_alloc_addr(phys_addr_t base, phys_size_t size)
> > +{
> > + return __lmb_alloc_addr(base, size, LMB_NONE);
> > +}
> > +
> > /* Return number of bytes from a given address that are free */
> > phys_size_t lmb_get_free_size(phys_addr_t addr)
> > {
>
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