On 2019-10-02 10:19 a.m., Thomas Bogendoerfer wrote: > On Sat, Sep 28, 2019 at 11:44:36PM +0200, Sven Schnelle wrote: >> Hi List, >> >> i've spent quite some time this evening debugging why the Fire GL >> doesn't work in my C8000. As reading debug output didn't give me >> much insights, i decided to throw some Hardware at the Problem and >> connect a Logic Analyzer to the C8000. For that i switched to an old >> PCI Radeon 7000 which shows the same ring test failure. > below patch (with debug print left in) got PCI radeon working for me, when > I played with it last time. The added fdc is a real fix, while the change > in parisc_agp_mask_memory is just a hack. The big problem there is to get > virtual address where the memory is mapped to in user space... > > Thomas. > > > diff --git a/drivers/char/agp/parisc-agp.c b/drivers/char/agp/parisc-agp.c > index 15f2e7025b78..756bc4a265d9 100644 > --- a/drivers/char/agp/parisc-agp.c > +++ b/drivers/char/agp/parisc-agp.c > @@ -20,6 +20,7 @@ > #include <linux/agp_backend.h> > #include <linux/log2.h> > #include <linux/slab.h> > +#include <linux/pagemap.h> > > #include <asm/parisc-device.h> > #include <asm/ropes.h> > @@ -162,6 +163,16 @@ parisc_agp_insert_memory(struct agp_memory *mem, off_t pg_start, int type) > info->gatt[j] = > parisc_agp_mask_memory(agp_bridge, > paddr, type); > + asm volatile("fdc %%r0(%0)" : : "r" (&info->gatt[j])); > +#if 0 > +#if 0 > + printk("i %x j %lx page %p va %lx paddr %lx gatt %lx\n", > + i, j, mem->pages[i], __va(paddr), paddr, info->gatt[j]); > +#else > + printk("i %x j %lx page %p va %lx paddr %lx\n", > + i, j, mem->pages[i], __va(paddr), paddr); > +#endif > +#endif > } > } > > @@ -184,7 +195,7 @@ parisc_agp_remove_memory(struct agp_memory *mem, off_t pg_start, int type) > io_pg_start = info->io_pages_per_kpage * pg_start; > io_pg_count = info->io_pages_per_kpage * mem->page_count; > for (i = io_pg_start; i < io_pg_count + io_pg_start; i++) { > - info->gatt[i] = agp_bridge->scratch_page; > + // info->gatt[i] = agp_bridge->scratch_page; > } > > agp_bridge->driver->tlb_flush(mem); > @@ -195,7 +206,22 @@ static unsigned long > parisc_agp_mask_memory(struct agp_bridge_data *bridge, dma_addr_t addr, > int type) > { > - return SBA_PDIR_VALID_BIT | addr; > +#if 1 > + u64 pa; > + register unsigned ci; /* coherent index */ > + > + pa = addr & IOVP_MASK; > + mtsp(0,1); > + asm("lci 0(%%sr1, %1), %0" : "=r" (ci) : "r" (__va(pa))); I believe you can remove the mtsp and just use "lci 0(%1), %0" to load the coherence index. The space registers sr4 to sr7 are always 0 in kernel. > + > + pa |= (ci >> PAGE_SHIFT) & 0xff; /* move CI (8 bits) into lowest byte */ > + > + pa |= SBA_PDIR_VALID_BIT; /* set "valid" bit */ > + > + return cpu_to_le64(pa); > +#else > + return cpu_to_le64(SBA_PDIR_VALID_BIT | addr); > +#endif > } > > static void > Dave -- John David Anglin dave.anglin@xxxxxxxx