[RFC PATCH 09/31] lmb: allow for resizing lmb regions
Heinrich Schuchardt
xypron.glpk at gmx.de
Tue Jun 11 11:17:08 CEST 2024
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),
};
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)
> {
More information about the U-Boot
mailing list