> On 15 Nov 2024, at 00:58, Mark Kettenis <mark.kettenis@xs4all.nl> wrote:
> 
>> Date: Thu, 14 Nov 2024 14:46:21 +0000
>> From: David Hill <dhill@mindcry.org>
>> 
>> Hello -
>> 
>> uvm_km_kmemalloc_pla has 3 users: bce(4), envy(4), and malloc.
>> 
>> I have attempted a conversion to km_alloc for bce(4), but I lack the 
>> hardware to test.  If anyone has bce(4), could you please test?
> 
> This should really use bus_dmamem_alloc_range(9).  I don't think we
> had that interface back when the driver was changed to use
> uvm_km_kmemalloc_pla().

to muddy the waters further, bce could make it's own mbuf pool with pool_set_constraints(). perhaps.

> 
>> Index: dev/pci/if_bce.c
>> ===================================================================
>> RCS file: /cvs/src/sys/dev/pci/if_bce.c,v
>> diff -u -p -r1.57 if_bce.c
>> --- dev/pci/if_bce.c 31 Aug 2024 16:23:09 -0000 1.57
>> +++ dev/pci/if_bce.c 8 Nov 2024 18:17:48 -0000
>> @@ -172,6 +172,21 @@ const struct pci_matchid bce_devices[] =
>>   { PCI_VENDOR_BROADCOM, PCI_PRODUCT_BROADCOM_BCM4401B1 }
>>  };
>> 
>> +struct uvm_constraint_range bce_constraint = {
>> + 0,
>> + (paddr_t)(0x40000000 - 1),
>> +};
>> +
>> +const struct kmem_pa_mode bce_mode = {
>> + .kp_constraint = &bce_constraint,
>> + .kp_maxseg = 1,
>> +};
>> +
>> +const struct kmem_va_mode bce_area = {
>> + .kv_map = &kernel_map,
>> + .kv_align = 0,
>> +};
>> +
>>  int
>>  bce_probe(struct device *parent, void *match, void *aux)
>>  {
>> @@ -249,9 +264,8 @@ bce_attach(struct device *parent, struct
>>   bce_reset(sc);
>> 
>>   /* Create the data DMA region and maps. */
>> - if ((sc->bce_data = (caddr_t)uvm_km_kmemalloc_pla(kernel_map,
>> -    uvm.kernel_object, (BCE_NTXDESC + BCE_NRXDESC) * MCLBYTES, 0,
>> -    UVM_KMF_NOWAIT, 0, (paddr_t)(0x40000000 - 1), 0, 0, 1)) == NULL) {
>> + if ((sc->bce_data = km_alloc((BCE_NTXDESC + BCE_NRXDESC) * MCLBYTES,
>> +    &bce_area, &bce_mode, &kd_nowait)) == NULL) {
>>   printf(": unable to alloc space for ring");
>>   return;
>>   }
>> @@ -261,8 +275,8 @@ bce_attach(struct device *parent, struct
>>      1, BCE_NRXDESC * MCLBYTES, 0, BUS_DMA_NOWAIT | BUS_DMA_ALLOCNOW,
>>      &sc->bce_rxdata_map))) {
>>   printf(": unable to create ring DMA map, error = %d\n", error);
>> - uvm_km_free(kernel_map, (vaddr_t)sc->bce_data,
>> -    (BCE_NTXDESC + BCE_NRXDESC) * MCLBYTES);
>> + km_free(sc->bce_data, (BCE_NTXDESC + BCE_NRXDESC) * MCLBYTES,
>> +    &bce_area, &bce_mode);
>>   return;
>>   }
>> 
>> @@ -270,8 +284,8 @@ bce_attach(struct device *parent, struct
>>   if (bus_dmamap_load(sc->bce_dmatag, sc->bce_rxdata_map, sc->bce_data,
>>      BCE_NRXDESC * MCLBYTES, NULL, BUS_DMA_READ | BUS_DMA_NOWAIT)) {
>>   printf(": unable to load rx ring DMA map\n");
>> - uvm_km_free(kernel_map, (vaddr_t)sc->bce_data,
>> -    (BCE_NTXDESC + BCE_NRXDESC) * MCLBYTES);
>> + km_free(sc->bce_data, (BCE_NTXDESC + BCE_NRXDESC) * MCLBYTES,
>> +    &bce_area, &bce_mode);
>>   bus_dmamap_destroy(sc->bce_dmatag, sc->bce_rxdata_map);
>>   return;
>>   }
>> @@ -281,8 +295,8 @@ bce_attach(struct device *parent, struct
>>      1, BCE_NTXDESC * MCLBYTES, 0, BUS_DMA_NOWAIT | BUS_DMA_ALLOCNOW,
>>      &sc->bce_txdata_map))) {
>>   printf(": unable to create ring DMA map, error = %d\n", error);
>> - uvm_km_free(kernel_map, (vaddr_t)sc->bce_data,
>> -    (BCE_NTXDESC + BCE_NRXDESC) * MCLBYTES);
>> + km_free(sc->bce_data, (BCE_NTXDESC + BCE_NRXDESC) * MCLBYTES,
>> +    &bce_area, &bce_mode);
>>   bus_dmamap_destroy(sc->bce_dmatag, sc->bce_rxdata_map);
>>   return;
>>   }
>> @@ -292,8 +306,8 @@ bce_attach(struct device *parent, struct
>>      sc->bce_data + BCE_NRXDESC * MCLBYTES,
>>      BCE_NTXDESC * MCLBYTES, NULL, BUS_DMA_WRITE | BUS_DMA_NOWAIT)) {
>>   printf(": unable to load tx ring DMA map\n");
>> - uvm_km_free(kernel_map, (vaddr_t)sc->bce_data,
>> -    (BCE_NTXDESC + BCE_NRXDESC) * MCLBYTES);
>> + km_free(sc->bce_data, (BCE_NTXDESC + BCE_NRXDESC) * MCLBYTES,
>> +    &bce_area, &bce_mode);
>>   bus_dmamap_destroy(sc->bce_dmatag, sc->bce_rxdata_map);
>>   bus_dmamap_destroy(sc->bce_dmatag, sc->bce_txdata_map);
>>   return;
>> @@ -314,8 +328,8 @@ bce_attach(struct device *parent, struct
>>      (bus_addr_t)0, (bus_addr_t)0x3fffffff))) {
>>   printf(": unable to alloc space for ring descriptors, "
>>      "error = %d\n", error);
>> - uvm_km_free(kernel_map, (vaddr_t)sc->bce_data,
>> -    (BCE_NTXDESC + BCE_NRXDESC) * MCLBYTES);
>> + km_free(sc->bce_data, (BCE_NTXDESC + BCE_NRXDESC) * MCLBYTES,
>> +    &bce_area, &bce_mode);
>>   bus_dmamap_destroy(sc->bce_dmatag, sc->bce_rxdata_map);
>>   bus_dmamap_destroy(sc->bce_dmatag, sc->bce_txdata_map);
>>   return;
>> @@ -325,8 +339,8 @@ bce_attach(struct device *parent, struct
>>   if ((error = bus_dmamem_map(sc->bce_dmatag, &seg, rseg,
>>      2 * PAGE_SIZE, &kva, BUS_DMA_NOWAIT))) {
>>   printf(": unable to map DMA buffers, error = %d\n", error);
>> - uvm_km_free(kernel_map, (vaddr_t)sc->bce_data,
>> -    (BCE_NTXDESC + BCE_NRXDESC) * MCLBYTES);
>> + km_free(sc->bce_data, (BCE_NTXDESC + BCE_NRXDESC) * MCLBYTES,
>> +    &bce_area, &bce_mode);
>>   bus_dmamap_destroy(sc->bce_dmatag, sc->bce_rxdata_map);
>>   bus_dmamap_destroy(sc->bce_dmatag, sc->bce_txdata_map);
>>   bus_dmamem_free(sc->bce_dmatag, &seg, rseg);
>> @@ -337,8 +351,8 @@ bce_attach(struct device *parent, struct
>>   if ((error = bus_dmamap_create(sc->bce_dmatag, 2 * PAGE_SIZE, 1,
>>      2 * PAGE_SIZE, 0, BUS_DMA_NOWAIT, &sc->bce_ring_map))) {
>>   printf(": unable to create ring DMA map, error = %d\n", error);
>> - uvm_km_free(kernel_map, (vaddr_t)sc->bce_data,
>> -    (BCE_NTXDESC + BCE_NRXDESC) * MCLBYTES);
>> + km_free(sc->bce_data, (BCE_NTXDESC + BCE_NRXDESC) * MCLBYTES,
>> +    &bce_area, &bce_mode);
>>   bus_dmamap_destroy(sc->bce_dmatag, sc->bce_rxdata_map);
>>   bus_dmamap_destroy(sc->bce_dmatag, sc->bce_txdata_map);
>>   bus_dmamem_free(sc->bce_dmatag, &seg, rseg);
>> @@ -349,8 +363,8 @@ bce_attach(struct device *parent, struct
>>   if (bus_dmamap_load(sc->bce_dmatag, sc->bce_ring_map, kva,
>>      2 * PAGE_SIZE, NULL, BUS_DMA_NOWAIT)) {
>>   printf(": unable to load ring DMA map\n");
>> - uvm_km_free(kernel_map, (vaddr_t)sc->bce_data,
>> -    (BCE_NTXDESC + BCE_NRXDESC) * MCLBYTES);
>> + km_free(sc->bce_data, (BCE_NTXDESC + BCE_NRXDESC) * MCLBYTES,
>> +    &bce_area, &bce_mode);
>>   bus_dmamap_destroy(sc->bce_dmatag, sc->bce_rxdata_map);
>>   bus_dmamap_destroy(sc->bce_dmatag, sc->bce_txdata_map);
>>   bus_dmamap_destroy(sc->bce_dmatag, sc->bce_ring_map);
>> 
>> 
>