Sakari,
Could you help review this patch? It's verified on ChromeOS and Linux.
This change can reduce the power usage and imporve the performance.
On 8/16/24 11:31 AM, bingbu.cao@xxxxxxxxx wrote:
> From: Bingbu Cao <bingbu.cao@xxxxxxxxx>
>
> ipu6_mmu_map() and ipu6_mmu_unmap() operated on a per-page basis,
> leading to frequent calls to spin_locks/unlocks and
> clflush_cache_range for each page. This will cause inefficiencies,
> especially when handling large dma-bufs with hundreds of pages.
>
> This change enhances ipu6_mmu_map()/ipu6_mmu_unmap() with batching
> process multiple contiguous pages. This significantly reduces calls
> for spin_lock/unlock and clflush_cache_range() and improve the
> performance.
>
> Signed-off-by: Jianhui Dai <jianhui.j.dai@xxxxxxxxx>
> Signed-off-by: Bingbu Cao <bingbu.cao@xxxxxxxxx>
> ---
> v2: fix one build warning found by kernel test robot
> ---
> drivers/media/pci/intel/ipu6/ipu6-mmu.c | 283 ++++++++++--------------
> drivers/media/pci/intel/ipu6/ipu6-mmu.h | 4 +-
> 2 files changed, 121 insertions(+), 166 deletions(-)
> ---
>
> diff --git a/drivers/media/pci/intel/ipu6/ipu6-mmu.c b/drivers/media/pci/intel/ipu6/ipu6-mmu.c
> index c3a20507d6db..2d9c6fbd5da2 100644
> --- a/drivers/media/pci/intel/ipu6/ipu6-mmu.c
> +++ b/drivers/media/pci/intel/ipu6/ipu6-mmu.c
> @@ -252,75 +252,140 @@ static u32 *alloc_l2_pt(struct ipu6_mmu_info *mmu_info)
> return pt;
> }
>
> +static void l2_unmap(struct ipu6_mmu_info *mmu_info, unsigned long iova,
> + phys_addr_t dummy, size_t size)
> +{
> + unsigned int l2_entries;
> + unsigned int l2_idx;
> + unsigned long flags;
> + u32 l1_idx;
> + u32 *l2_pt;
> +
> + spin_lock_irqsave(&mmu_info->lock, flags);
> + for (l1_idx = iova >> ISP_L1PT_SHIFT;
> + size > 0 && l1_idx < ISP_L1PT_PTES; l1_idx++) {
> + dev_dbg(mmu_info->dev,
> + "unmapping l2 pgtable (l1 index %u (iova 0x%8.8lx))\n",
> + l1_idx, iova);
> +
> + if (mmu_info->l1_pt[l1_idx] == mmu_info->dummy_l2_pteval) {
> + dev_err(mmu_info->dev,
> + "unmap not mapped iova 0x%8.8lx l1 index %u\n",
> + iova, l1_idx);
> + continue;
> + }
> + l2_pt = mmu_info->l2_pts[l1_idx];
> +
> + l2_entries = 0;
> + for (l2_idx = (iova & ISP_L2PT_MASK) >> ISP_L2PT_SHIFT;
> + size > 0 && l2_idx < ISP_L2PT_PTES; l2_idx++) {
> + dev_dbg(mmu_info->dev,
> + "unmap l2 index %u with pteval 0x%10.10llx\n",
> + l2_idx, TBL_PHYS_ADDR(l2_pt[l2_idx]));
> + l2_pt[l2_idx] = mmu_info->dummy_page_pteval;
> +
> + iova += ISP_PAGE_SIZE;
> + size -= ISP_PAGE_SIZE;
> +
> + l2_entries++;
> + }
> +
> + WARN_ON_ONCE(!l2_entries);
> + clflush_cache_range(&l2_pt[l2_idx - l2_entries],
> + sizeof(l2_pt[0]) * l2_entries);
> + }
> +
> + WARN_ON_ONCE(size);
> + spin_unlock_irqrestore(&mmu_info->lock, flags);
> +}
> +
> static int l2_map(struct ipu6_mmu_info *mmu_info, unsigned long iova,
> phys_addr_t paddr, size_t size)
> {
> - u32 l1_idx = iova >> ISP_L1PT_SHIFT;
> - u32 iova_start = iova;
> + struct device *dev = mmu_info->dev;
> + unsigned int l2_entries;
> u32 *l2_pt, *l2_virt;
> unsigned int l2_idx;
> unsigned long flags;
> + size_t mapped = 0;
> dma_addr_t dma;
> u32 l1_entry;
> -
> - dev_dbg(mmu_info->dev,
> - "mapping l2 page table for l1 index %u (iova %8.8x)\n",
> - l1_idx, (u32)iova);
> + u32 l1_idx;
> + int err = 0;
>
> spin_lock_irqsave(&mmu_info->lock, flags);
> - l1_entry = mmu_info->l1_pt[l1_idx];
> - if (l1_entry == mmu_info->dummy_l2_pteval) {
> - l2_virt = mmu_info->l2_pts[l1_idx];
> - if (likely(!l2_virt)) {
> - l2_virt = alloc_l2_pt(mmu_info);
> - if (!l2_virt) {
> - spin_unlock_irqrestore(&mmu_info->lock, flags);
> - return -ENOMEM;
> +
> + paddr = ALIGN(paddr, ISP_PAGE_SIZE);
> + for (l1_idx = iova >> ISP_L1PT_SHIFT;
> + size > 0 && l1_idx < ISP_L1PT_PTES; l1_idx++) {
> + dev_dbg(dev,
> + "mapping l2 page table for l1 index %u (iova %8.8x)\n",
> + l1_idx, (u32)iova);
> +
> + l1_entry = mmu_info->l1_pt[l1_idx];
> + if (l1_entry == mmu_info->dummy_l2_pteval) {
> + l2_virt = mmu_info->l2_pts[l1_idx];
> + if (likely(!l2_virt)) {
> + l2_virt = alloc_l2_pt(mmu_info);
> + if (!l2_virt) {
> + err = -ENOMEM;
> + goto error;
> + }
> }
> - }
>
> - dma = map_single(mmu_info, l2_virt);
> - if (!dma) {
> - dev_err(mmu_info->dev, "Failed to map l2pt page\n");
> - free_page((unsigned long)l2_virt);
> - spin_unlock_irqrestore(&mmu_info->lock, flags);
> - return -EINVAL;
> - }
> + dma = map_single(mmu_info, l2_virt);
> + if (!dma) {
> + dev_err(dev, "Failed to map l2pt page\n");
> + free_page((unsigned long)l2_virt);
> + err = -EINVAL;
> + goto error;
> + }
>
> - l1_entry = dma >> ISP_PADDR_SHIFT;
> + l1_entry = dma >> ISP_PADDR_SHIFT;
>
> - dev_dbg(mmu_info->dev, "page for l1_idx %u %p allocated\n",
> - l1_idx, l2_virt);
> - mmu_info->l1_pt[l1_idx] = l1_entry;
> - mmu_info->l2_pts[l1_idx] = l2_virt;
> - clflush_cache_range((void *)&mmu_info->l1_pt[l1_idx],
> - sizeof(mmu_info->l1_pt[l1_idx]));
> - }
> + dev_dbg(dev, "page for l1_idx %u %p allocated\n",
> + l1_idx, l2_virt);
> + mmu_info->l1_pt[l1_idx] = l1_entry;
> + mmu_info->l2_pts[l1_idx] = l2_virt;
>
> - l2_pt = mmu_info->l2_pts[l1_idx];
> + clflush_cache_range(&mmu_info->l1_pt[l1_idx],
> + sizeof(mmu_info->l1_pt[l1_idx]));
> + }
>
> - dev_dbg(mmu_info->dev, "l2_pt at %p with dma 0x%x\n", l2_pt, l1_entry);
> + l2_pt = mmu_info->l2_pts[l1_idx];
> + l2_entries = 0;
>
> - paddr = ALIGN(paddr, ISP_PAGE_SIZE);
> + for (l2_idx = (iova & ISP_L2PT_MASK) >> ISP_L2PT_SHIFT;
> + size > 0 && l2_idx < ISP_L2PT_PTES; l2_idx++) {
> + l2_pt[l2_idx] = paddr >> ISP_PADDR_SHIFT;
>
> - l2_idx = (iova_start & ISP_L2PT_MASK) >> ISP_L2PT_SHIFT;
> + dev_dbg(dev, "l2 index %u mapped as 0x%8.8x\n", l2_idx,
> + l2_pt[l2_idx]);
>
> - dev_dbg(mmu_info->dev, "l2_idx %u, phys 0x%8.8x\n", l2_idx,
> - l2_pt[l2_idx]);
> - if (l2_pt[l2_idx] != mmu_info->dummy_page_pteval) {
> - spin_unlock_irqrestore(&mmu_info->lock, flags);
> - return -EINVAL;
> - }
> + iova += ISP_PAGE_SIZE;
> + paddr += ISP_PAGE_SIZE;
> + mapped += ISP_PAGE_SIZE;
> + size -= ISP_PAGE_SIZE;
>
> - l2_pt[l2_idx] = paddr >> ISP_PADDR_SHIFT;
> + l2_entries++;
> + }
>
> - clflush_cache_range((void *)&l2_pt[l2_idx], sizeof(l2_pt[l2_idx]));
> - spin_unlock_irqrestore(&mmu_info->lock, flags);
> + WARN_ON_ONCE(!l2_entries);
> + clflush_cache_range(&l2_pt[l2_idx - l2_entries],
> + sizeof(l2_pt[0]) * l2_entries);
> + }
>
> - dev_dbg(mmu_info->dev, "l2 index %u mapped as 0x%8.8x\n", l2_idx,
> - l2_pt[l2_idx]);
> + spin_unlock_irqrestore(&mmu_info->lock, flags);
>
> return 0;
> +
> +error:
> + spin_unlock_irqrestore(&mmu_info->lock, flags);
> + /* unroll mapping in case something went wrong */
> + if (mapped)
> + l2_unmap(mmu_info, iova - mapped, paddr - mapped, mapped);
> +
> + return err;
> }
>
> static int __ipu6_mmu_map(struct ipu6_mmu_info *mmu_info, unsigned long iova,
> @@ -336,48 +401,8 @@ static int __ipu6_mmu_map(struct ipu6_mmu_info *mmu_info, unsigned long iova,
> return l2_map(mmu_info, iova_start, paddr, size);
> }
>
> -static size_t l2_unmap(struct ipu6_mmu_info *mmu_info, unsigned long iova,
> - phys_addr_t dummy, size_t size)
> -{
> - u32 l1_idx = iova >> ISP_L1PT_SHIFT;
> - u32 iova_start = iova;
> - unsigned int l2_idx;
> - size_t unmapped = 0;
> - unsigned long flags;
> - u32 *l2_pt;
> -
> - dev_dbg(mmu_info->dev, "unmapping l2 page table for l1 index %u (iova 0x%8.8lx)\n",
> - l1_idx, iova);
> -
> - spin_lock_irqsave(&mmu_info->lock, flags);
> - if (mmu_info->l1_pt[l1_idx] == mmu_info->dummy_l2_pteval) {
> - spin_unlock_irqrestore(&mmu_info->lock, flags);
> - dev_err(mmu_info->dev,
> - "unmap iova 0x%8.8lx l1 idx %u which was not mapped\n",
> - iova, l1_idx);
> - return 0;
> - }
> -
> - for (l2_idx = (iova_start & ISP_L2PT_MASK) >> ISP_L2PT_SHIFT;
> - (iova_start & ISP_L1PT_MASK) + (l2_idx << ISP_PAGE_SHIFT)
> - < iova_start + size && l2_idx < ISP_L2PT_PTES; l2_idx++) {
> - l2_pt = mmu_info->l2_pts[l1_idx];
> - dev_dbg(mmu_info->dev,
> - "unmap l2 index %u with pteval 0x%10.10llx\n",
> - l2_idx, TBL_PHYS_ADDR(l2_pt[l2_idx]));
> - l2_pt[l2_idx] = mmu_info->dummy_page_pteval;
> -
> - clflush_cache_range((void *)&l2_pt[l2_idx],
> - sizeof(l2_pt[l2_idx]));
> - unmapped++;
> - }
> - spin_unlock_irqrestore(&mmu_info->lock, flags);
> -
> - return unmapped << ISP_PAGE_SHIFT;
> -}
> -
> -static size_t __ipu6_mmu_unmap(struct ipu6_mmu_info *mmu_info,
> - unsigned long iova, size_t size)
> +static void __ipu6_mmu_unmap(struct ipu6_mmu_info *mmu_info,
> + unsigned long iova, size_t size)
> {
> return l2_unmap(mmu_info, iova, 0, size);
> }
> @@ -619,40 +644,13 @@ phys_addr_t ipu6_mmu_iova_to_phys(struct ipu6_mmu_info *mmu_info,
> return phy_addr;
> }
>
> -static size_t ipu6_mmu_pgsize(unsigned long pgsize_bitmap,
> - unsigned long addr_merge, size_t size)
> +void ipu6_mmu_unmap(struct ipu6_mmu_info *mmu_info, unsigned long iova,
> + size_t size)
> {
> - unsigned int pgsize_idx;
> - size_t pgsize;
> -
> - /* Max page size that still fits into 'size' */
> - pgsize_idx = __fls(size);
> -
> - if (likely(addr_merge)) {
> - /* Max page size allowed by address */
> - unsigned int align_pgsize_idx = __ffs(addr_merge);
> -
> - pgsize_idx = min(pgsize_idx, align_pgsize_idx);
> - }
> -
> - pgsize = (1UL << (pgsize_idx + 1)) - 1;
> - pgsize &= pgsize_bitmap;
> -
> - WARN_ON(!pgsize);
> -
> - /* pick the biggest page */
> - pgsize_idx = __fls(pgsize);
> - pgsize = 1UL << pgsize_idx;
> -
> - return pgsize;
> -}
> -
> -size_t ipu6_mmu_unmap(struct ipu6_mmu_info *mmu_info, unsigned long iova,
> - size_t size)
> -{
> - size_t unmapped_page, unmapped = 0;
> unsigned int min_pagesz;
>
> + dev_dbg(mmu_info->dev, "unmapping iova 0x%lx size 0x%zx\n", iova, size);
> +
> /* find out the minimum page size supported */
> min_pagesz = 1 << __ffs(mmu_info->pgsize_bitmap);
>
> @@ -664,38 +662,16 @@ size_t ipu6_mmu_unmap(struct ipu6_mmu_info *mmu_info, unsigned long iova,
> if (!IS_ALIGNED(iova | size, min_pagesz)) {
> dev_err(NULL, "unaligned: iova 0x%lx size 0x%zx min_pagesz 0x%x\n",
> iova, size, min_pagesz);
> - return -EINVAL;
> - }
> -
> - /*
> - * Keep iterating until we either unmap 'size' bytes (or more)
> - * or we hit an area that isn't mapped.
> - */
> - while (unmapped < size) {
> - size_t pgsize = ipu6_mmu_pgsize(mmu_info->pgsize_bitmap,
> - iova, size - unmapped);
> -
> - unmapped_page = __ipu6_mmu_unmap(mmu_info, iova, pgsize);
> - if (!unmapped_page)
> - break;
> -
> - dev_dbg(mmu_info->dev, "unmapped: iova 0x%lx size 0x%zx\n",
> - iova, unmapped_page);
> -
> - iova += unmapped_page;
> - unmapped += unmapped_page;
> + return;
> }
>
> - return unmapped;
> + return __ipu6_mmu_unmap(mmu_info, iova, size);
> }
>
> int ipu6_mmu_map(struct ipu6_mmu_info *mmu_info, unsigned long iova,
> phys_addr_t paddr, size_t size)
> {
> - unsigned long orig_iova = iova;
> unsigned int min_pagesz;
> - size_t orig_size = size;
> - int ret = 0;
>
> if (mmu_info->pgsize_bitmap == 0UL)
> return -ENODEV;
> @@ -718,28 +694,7 @@ int ipu6_mmu_map(struct ipu6_mmu_info *mmu_info, unsigned long iova,
> dev_dbg(mmu_info->dev, "map: iova 0x%lx pa %pa size 0x%zx\n",
> iova, &paddr, size);
>
> - while (size) {
> - size_t pgsize = ipu6_mmu_pgsize(mmu_info->pgsize_bitmap,
> - iova | paddr, size);
> -
> - dev_dbg(mmu_info->dev,
> - "mapping: iova 0x%lx pa %pa pgsize 0x%zx\n",
> - iova, &paddr, pgsize);
> -
> - ret = __ipu6_mmu_map(mmu_info, iova, paddr, pgsize);
> - if (ret)
> - break;
> -
> - iova += pgsize;
> - paddr += pgsize;
> - size -= pgsize;
> - }
> -
> - /* unroll mapping in case something went wrong */
> - if (ret)
> - ipu6_mmu_unmap(mmu_info, orig_iova, orig_size - size);
> -
> - return ret;
> + return __ipu6_mmu_map(mmu_info, iova, paddr, size);
> }
>
> static void ipu6_mmu_destroy(struct ipu6_mmu *mmu)
> diff --git a/drivers/media/pci/intel/ipu6/ipu6-mmu.h b/drivers/media/pci/intel/ipu6/ipu6-mmu.h
> index 21cdb0f146eb..8e40b4a66d7d 100644
> --- a/drivers/media/pci/intel/ipu6/ipu6-mmu.h
> +++ b/drivers/media/pci/intel/ipu6/ipu6-mmu.h
> @@ -66,8 +66,8 @@ int ipu6_mmu_hw_init(struct ipu6_mmu *mmu);
> void ipu6_mmu_hw_cleanup(struct ipu6_mmu *mmu);
> int ipu6_mmu_map(struct ipu6_mmu_info *mmu_info, unsigned long iova,
> phys_addr_t paddr, size_t size);
> -size_t ipu6_mmu_unmap(struct ipu6_mmu_info *mmu_info, unsigned long iova,
> - size_t size);
> +void ipu6_mmu_unmap(struct ipu6_mmu_info *mmu_info, unsigned long iova,
> + size_t size);
> phys_addr_t ipu6_mmu_iova_to_phys(struct ipu6_mmu_info *mmu_info,
> dma_addr_t iova);
> #endif
>
--
Best regards,
Bingbu Cao
