Linaro-mm-sig

linaro-mm-sig@lists.linaro.org

46 participants
6001 discussions

Re: [PATCH v2 4/6] dma-buf: heaps: Add Coherent heap to dmabuf heaps

by Albert Esteve

On Thu, Mar 5, 2026 at 1:30 PM Maxime Ripard <mripard(a)redhat.com> wrote: > > On Tue, Mar 03, 2026 at 03:47:14PM +0100, Albert Esteve wrote: > > On Tue, Mar 3, 2026 at 2:20 PM Maxime Ripard <mripard(a)redhat.com> wrote: > > > On Tue, Mar 03, 2026 at 01:33:47PM +0100, Albert Esteve wrote: > > > > Add a dma-buf heap for DT coherent reserved-memory > > > > (i.e., 'shared-dma-pool' without 'reusable' property), > > > > exposing one heap per region for userspace buffers. > > > > > > > > The heap binds the heap device to each memory region so > > > > coherent allocations use the correct dev->dma_mem, and > > > > it defers registration until module_init when normal > > > > allocators are available. > > > > > > > > Signed-off-by: Albert Esteve <aesteve(a)redhat.com> > > > > --- > > > > drivers/dma-buf/dma-heap.c | 4 +- > > > > drivers/dma-buf/heaps/Kconfig | 9 + > > > > drivers/dma-buf/heaps/Makefile | 1 + > > > > drivers/dma-buf/heaps/coherent_heap.c | 426 ++++++++++++++++++++++++++++++++++ > > > > include/linux/dma-heap.h | 11 + > > > > include/linux/dma-map-ops.h | 7 + > > > > 6 files changed, 456 insertions(+), 2 deletions(-) > > > > > > > > diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c > > > > index 88189d4e48561..ba87e5ac16ae2 100644 > > > > --- a/drivers/dma-buf/dma-heap.c > > > > +++ b/drivers/dma-buf/dma-heap.c > > > > @@ -390,8 +390,8 @@ struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info) > > > > > > > > heap = dma_heap_create(exp_info); > > > > if (IS_ERR(heap)) { > > > > - pr_err("dma_heap: failed to create heap (%d)\n", PTR_ERR(heap)); > > > > - return PTR_ERR(heap); > > > > + pr_err("dma_heap: failed to create heap (%ld)\n", PTR_ERR(heap)); > > > > + return ERR_CAST(heap); > > > > > > This looks unrelated and should possibly be squashed into the previous > > > patch that introduces dma_heap_create()? > > > > > > > +static int coherent_heap_init_dma_mask(struct device *dev) > > > > +{ > > > > + int ret; > > > > + > > > > + ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(64)); > > > > + if (!ret) > > > > + return 0; > > > > + > > > > + /* Fallback to 32-bit DMA mask */ > > > > + return dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32)); > > > > +} > > > > > > Why do you need to mess with the DMA mask? I'd expect that device to be > > > able to access everything. > > > > When I tested I was getting: "reserved memory is beyond device's set > > DMA address range", so I tested if it was fixed with > > dma_coerce_mask_and_coherent() and/or dma_set_mask_coherent(). I did > > not debug the value of coherent_dma_mask, but given the error I assume > > it was not set properly? Ultimately, using the 64 bit mask fixed it, > > and I added a 32-bit fallback to ensure support for 32-bit systems. > > So you don't need to handle the fallback because > dma_coerce_mask_and_coherent will truncate the generated mask to > dma_addr_t, which is 64bits on 64 bits platforms, and 32 bits on 32 bits > platforms. > > https://elixir.bootlin.com/linux/v6.19.3/source/kernel/dma/mapping.c#L908 Good! I didn't realise that. I will remove it for the next revision. > > But I think my point was more than there's nothing specific to the > coherent heap itself: the device allocated for the heap should have the > right mask for any heap, so it's something I'd rather put in > dma_heap_add. That was my first take too. But when I checked, I did not see dma_heap_add() doing anything to dev->coherent_dma_mask. So I assumed the problem relates to the rmem being bound, which triggers the check to ensure the memory pool is within boundaries. That's a specific issue with the coherent heap, so it sounds like it would be better handled here in the heap-specific code rather than in `dma_heap_add()`, which would affect all the dmabuf heaps. That being said, setting the mask is probably(?) harmless for the other heaps anyway, so I would be fine with moving it -- to dma_heap_create() to be more specific. BR, Albert. > > > > > +static int __coherent_heap_register(struct reserved_mem *rmem) > > > > +{ > > > > + struct dma_heap_export_info exp_info; > > > > + struct coherent_heap *coh_heap; > > > > + struct device *heap_dev; > > > > + int ret; > > > > + > > > > + if (!rmem || !rmem->name) > > > > + return -EINVAL; > > > > + > > > > + coh_heap = kzalloc_obj(*coh_heap); > > > > + if (!coh_heap) > > > > + return -ENOMEM; > > > > + > > > > + coh_heap->rmem = rmem; > > > > + coh_heap->name = kstrdup(rmem->name, GFP_KERNEL); > > > > + if (!coh_heap->name) { > > > > + ret = -ENOMEM; > > > > + goto free_coherent_heap; > > > > + } > > > > + > > > > + exp_info.name = coh_heap->name; > > > > + exp_info.ops = &coherent_heap_ops; > > > > + exp_info.priv = coh_heap; > > > > + > > > > + coh_heap->heap = dma_heap_create(&exp_info); > > > > + if (IS_ERR(coh_heap->heap)) { > > > > + ret = PTR_ERR(coh_heap->heap); > > > > + goto free_name; > > > > + } > > > > + > > > > + heap_dev = dma_heap_get_dev(coh_heap->heap); > > > > + ret = coherent_heap_init_dma_mask(heap_dev); > > > > + if (ret) { > > > > + pr_err("coherent_heap: failed to set DMA mask (%d)\n", ret); > > > > + goto destroy_heap; > > > > + } > > > > + > > > > + ret = of_reserved_mem_device_init_with_mem(heap_dev, rmem); > > > > + if (ret) { > > > > + pr_err("coherent_heap: failed to initialize memory (%d)\n", ret); > > > > + goto destroy_heap; > > > > + } > > > > + > > > > + ret = dma_heap_register(coh_heap->heap); > > > > + if (ret) { > > > > + pr_err("coherent_heap: failed to register heap (%d)\n", ret); > > > > + goto destroy_heap; > > > > + } > > > > > > I guess it's more of a comment about your previous patch, but it's not > > > clear to me why you needed to split dma_heap_add into dma_heap_create / > > > _register. Can you expand a bit? > > > > So first I tried to just use dma_heap_add() and then use the heap_dev > > afterward to call of_reserved_mem_device_init_with_mem(), but if that > > call failed, the error path required some kind dma_heap_remove() > > function as the heap was already registered by then. > > > > In the CMA heap for example, dma_heap_add() is invoked at the end of > > the `init` function. Therefore, you do not have this issue, if it > > failed it means the heap was not added and you just need to clean > > everything else. > > > > However, performing a remove() does not sound like something that can > > be done safely. I've spent some time thinking on alternatives, but > > splitting felt the best pattern. > > > > This way I can: > > 1. Create the device > > 2. Call of_reserved_mem_device_init_with_mem > > 3. Register the heap > > > > This places registration at the end, making every error path and > > cleanup easy to handle. > > > > Also, the `dma_heap_add()` code already seemed to handle these two > > parts/phases implicitly with device_create(), so splitting felt > > architecturally sound. > > That makes sense, thanks! > > Maxime

5 days, 8 hours

#### royboint@gmail.com | Telegram @buyhighs Buy Weed, Cocaine, Heroin and Shrooms in France, Germany, Poland Serbia, Romania, Ukraine

by spaceyrolince＠gmail.com

### royboint(a)gmail.com | Telegram @buyhighs Buy weed in Dubai, Buy weed in Abu Dhabi, Buy weed in Sharjah, Buy weed in Ras Al Khaimah, Buy weed in UAE, #### royboint(a)gmail.com | Telegram @buyhighs Buy Weed, Cocaine, Heroin and Shrooms in France, Germany, Poland Serbia, Romania, Ukraine ##### royboint(a)gmail.com | Telegram @buyhighs Buy Weed, ketamine, Cocaine, Heroin and Shrooms in Dubai UAE Malaysia Oman Kuwait Bahrain Saudi Arabia Qatar CONTACT US!!! Contact; royboint(a)gmail.com or on Telegram @buyhighs. WhatsApp+447438 969225 Buy Weed, Cocaine, Heroin and Shrooms in Qatar Dubai UAE Malaysia Oman Kuwait Bahrain Saudi Arabia #Singapore #Jordan #Ireland, #Belgium, #United Kingdom, #Iceland, #*Portugal, Spain, China, Japan, Turkey, Canada United States, Morocco, France, Germany, Poland Serbia, Romania, Ukraine, and all countries United Arab Emirates. Our team has successfully delivered in 26 different countries. All marijuana and cocaine is double vacuum packed before shipping, making it completely odorless to ensure that it arrives safely at your door. Our distribution crew is expert at making packages that blend in with the rest of the mail. We have also put into place many other security measures to ensure the security of our customers. buy weed Dubai #Buy Weed Qatar #Buy Weed Kuwait #Buy Weed Bahrain #Buy #Weed #Oman #Buy Weed UAE #Buy Weed Abu Dhabi @Buy Weed Doha Qatar #@Buy Weed Ajman #@Buy Weed Online #@Buy Weed UK #@Buy Weed Iceland #*@Buy Weed All Countries Below are the various strains of kush available; buy hash and Weed in dubai,abu dhabi,sharjah where to buy weed in doha,where can i find weed in jeddah,Can I get weed delivered to Riyadh?,Buy weed Online Jeddah Saudi Arabia,Buy Weed and THC Cannabis Oil online ,QATAR , DOHA buy kush in DOHA , buy kush in DOHAWeed in QATAR # DOHA Buy Weed and THC Cannabis Oil online who delivers at your own location in Qatar Doha ,Kuwait ,Dubai including cannabis / weed,Where can I find weed in Dubai as a tourist?,Is marijuana allowed in Dubai? How much is medical marijuana in Dubai? Is weed legal in Dubai? How to get marijuana in Saudi Arabia Do people in Saudi Arabia smoke weed? Is Hash legal in Saudi Arabia? Where is marijuana the most illegal? Can you get weed in Baku? Dubai, United Arab Emirates Cannabis smokers - Dubai, Buy Marijuana Products Online in UAE Desertcart ships the Marijuana products in Dubai, Abu Dhabi, Sharjah, Al Ain, Ajman and more cities in UAE. Get unlimited free shipping in 164+ countriesBuy Weed Products Online in Saudi Arabia Order thc Weed in Saudi Arabia Order thc Weed in Saudi Arabia Order thc Weed in Saudi Arabia Order thc Weed in Saudi Arabia Buy Marijuana Saudi Arabia weed in jeddahis cbd legal in saudi arabia cali tins smoke in saudi arabia drug use saudi arabia Buy weed marijuana. White Widow OG #Kush Sensi Star x ak 47 Afghan Kush Northern Lights Hawaii-Skunk Hindu Kush Super Silver Haze Super Skunk Green crack Sour Diesel Grand Daddy Purple AK 47 White rhino Sativa Orange kush Purple kush And much more……….. Where can I find weed in Doha, Qatar? Where can I find weed in Dubai? How can a tourist get weed in Dubai/UAE? Where can I have weed in Dubai? I am going to Abu Dhabi. How hard is it to find weed Is marijuana allowed in Dubai? Now I'm in Dubai. Can I find high quality cannabis here? How much is medical marijuana in Dubai? where can i find weed, cocaine, hash, mdma in dubai as a tourist? weed, cocaine, hash, cystal, mdma for sell in uae, dubai, saudi arabia, qatar, oman, kuwait where to get good quality weed, cocaine, hash, crystal mdma online in dubai, uae, ajman, abu dhabi Buy THC and CBD Vape in Dubai UAE Buy THC vape carts in riyadh Saudi Arabia Buy weed in Dubai, Buy weed in Abu Dhabi, Buy weed in Sharjah, Buy weed in Ras Al Khaimah, Buy weed in UAE, Buy weed in Al Ain, Buy weed in Umm al-Qaiwain, Buy weed in Fujairah, Buy weed in Ajman, Buy weed in qatar buy weed in jeddah buy weed in saudi arabia buy weed in riyadh buy weed in Jordan buy THC and CBD vape in dubai buy THC and CBD vape in abu dhabi buy THC and CBD vape in saudi arabia buy THC and CBD vape in sharjah buy THC and CBD vape in kuwait buy THC and CBD vape in bahrain buy THC and CBD vape in Jordan buy THC and CBD vape in fujairah buy THC and CBD vape in ajman buy THC and CBD vape in oman Buy THC and CBD vape in qatar where can i buy weed, cocaine, hash, xanax, cbd oil, mdma in dubai, uae, abu dhabi where can i find hashish in Dubai UAE Buy Afghan hash in Abu Dhabi in How can you buy hash in saudi arabia https://buyauthenticnembutalonline.club https://buyauthenticnembutalonline.club/elements/blog/ https://buyauthenticnembutalonline.club/buy-original-nembutal-online-in-aus… https://buyauthenticnembutalonline.club/acheter-du-nembutal-en-france-nembu… https://buyauthenticnembutalonline.club/nembutal-zum-verkauf-in-deutschland/ https://buyauthenticnembutalonline.club/where-to-buy-nembutal-in-usa/ https://buyauthenticnembutalonline.club/buy-nembutal-in-uk-from-us/ https://buyauthenticnembutalonline.club/ https://buyauthenticnembutalonline.club/shop-2/ https://buyauthenticnembutalonline.club/nembutal-oral-solution-powder-dosag… https://buycockonline.club/blog/ https://buycockonline.club/post-2/ https://buycockonline.club/post-3/ https://buycockonline.club/post-1/ https://buycockonline.club/buying-cheap-used-transmissions-isnt-as-risky-as… https://buycockonline.club/does-toyota-really-make-the-most-reliable-engine… https://buycockonline.club/signs-your-car-needs-a-new-ac-compressor/ https://buycockonline.club/sul-getreng-seligt-askanka-niliga-kol-reatt-deci… https://buycockonline.club/shop-2/ https://buycockonline.club/product/order-semaglutide-online/ https://buycockonline.club/product/order-phentermine-online/ https://buycockonline.club/product/order-uncut-cocaine-online/ https://buycockonline.club/product/order-97-8-crack-cocaine-online/ https://buycockonline.club/product/order-crystal-meth-tina-online/ https://buycockonline.club/product/order-mdma-ecstasy-online/ https://buycockonline.club/product/order-molly-mdma-capsule-online/ https://buycockonline.club/product/order-mdma-crystal-online/ https://buycockonline.club/product/order-mdma-blue-punisher-300mg-online/ https://buycockonline.club/product/order-nembutal-pentobarbital-online/ https://buycockonline.club/product/order-ketamine-ketalar-online/ https://buycockonline.club/product/order-native-dmt-online-your/ https://buy4mmconline.club/ https://buy4mmconline.club/blog/ https://buy4mmconline.club/order-pure-mephedrone-4mmc-within-australia/ https://buy4mmconline.club/buying-mephedrone-4mmc-in-canada/ https://buy4mmconline.club/buy-pure-quality-4mmc-within-usa-obtain-4mmc-eff… https://buy4mmconline.club/ou-acheter-de-la-mephedrone-4mmc-en-france-mephe… https://buy4mmconline.club/mephedron-4mmc-online-in-deutschland-kaufen-4mmc… https://buy4mmconline.club/buy-98-9-pure-4mmc-crystal-online-within-uk/ https://buy4mmconline.club/product-tag/4mmc-london/ https://buy4mmconline.club/product-tag/mephedrone-london/ https://buy4mmconline.club/product-tag/buy-mephedrone-uk/ https://buy4mmconline.club/product-tag/4mmc-risks/ https://buy4mmconline.club/product-tag/mephedrone-effects/ Don’t miss out on the best deals for your favorite drugs!

5 days, 9 hours