On Wed, 22 Mar 2023 16:21:26 +0000 Fan Ni <fan...@samsung.com> wrote:
> On Wed, Mar 22, 2023 at 10:33:00AM +0000, Jonathan Cameron wrote: > > The hardware clearing the commit bit is not spec compliant. > > Clearing of committed bit when commit is cleared is not specifically > > stated in the CXL spec, but is the expected (and simplest) permitted > > behaviour so use that for QEMU emulation. > > > > Signed-off-by: Jonathan Cameron <jonathan.came...@huawei.com> > > --- > > Reviewed-by: Fan Ni <fan...@samsung.com> > Tested-by: Fan Ni <fan...@samsung.com> > > > The patch passed the tests as shown in previous mailing list discussion: > https://lore.kernel.org/linux-cxl/640276695c8e8_5b27929...@dwillia2-xfh.jf.intel.com.notmuch/T/#m0afcfc21d68c84c07f2e9e3194f587c2ffa82d6d > The following two topologies are tested: > 1. one HB with one root port and a direct attached memdev. > 2. one HB with 2 root ports and a memdev is directly attached to a CXL switch > which is attached to one root port. > > One minor thing below. > > > hw/cxl/cxl-component-utils.c | 6 +++++- > > hw/mem/cxl_type3.c | 21 ++++++++++++++++++++- > > 2 files changed, 25 insertions(+), 2 deletions(-) > > > > diff --git a/hw/cxl/cxl-component-utils.c b/hw/cxl/cxl-component-utils.c > > index a3e6cf75cf..378f1082ce 100644 > > --- a/hw/cxl/cxl-component-utils.c > > +++ b/hw/cxl/cxl-component-utils.c > > @@ -38,19 +38,23 @@ static void dumb_hdm_handler(CXLComponentState > > *cxl_cstate, hwaddr offset, > > ComponentRegisters *cregs = &cxl_cstate->crb; > > uint32_t *cache_mem = cregs->cache_mem_registers; > > bool should_commit = false; > > + bool should_uncommit = false; > > > > switch (offset) { > > case A_CXL_HDM_DECODER0_CTRL: > > should_commit = FIELD_EX32(value, CXL_HDM_DECODER0_CTRL, COMMIT); > > + should_uncommit = !should_commit; > This will cause committed always reset if COMMIT is 0, not only > 1->0. No issue for now, just point out to make sure it is what we > want. True. However I think it's harmless. We will want to be a little careful if uncommitting gains other functionality in future though. Note that the same potential corner existing on the commit side of things. Trying to commit a decoder that is already committed will call the code for commit (also currently harmless) I'm not particularly keen to introduce additional complexity to separate out these cases until / if we ever need it. Jonathan > > break; > > default: > > break; > > } > > > > if (should_commit) { > > - value = FIELD_DP32(value, CXL_HDM_DECODER0_CTRL, COMMIT, 0); > > value = FIELD_DP32(value, CXL_HDM_DECODER0_CTRL, ERR, 0); > > value = FIELD_DP32(value, CXL_HDM_DECODER0_CTRL, COMMITTED, 1); > > + } else if (should_uncommit) { > > + value = FIELD_DP32(value, CXL_HDM_DECODER0_CTRL, ERR, 0); > > + value = FIELD_DP32(value, CXL_HDM_DECODER0_CTRL, COMMITTED, 0); > > } > > stl_le_p((uint8_t *)cache_mem + offset, value); > > } > > diff --git a/hw/mem/cxl_type3.c b/hw/mem/cxl_type3.c > > index 846089ccda..9598d584ac 100644 > > --- a/hw/mem/cxl_type3.c > > +++ b/hw/mem/cxl_type3.c > > @@ -320,13 +320,28 @@ static void hdm_decoder_commit(CXLType3Dev *ct3d, int > > which) > > > > ctrl = ldl_le_p(cache_mem + R_CXL_HDM_DECODER0_CTRL); > > /* TODO: Sanity checks that the decoder is possible */ > > - ctrl = FIELD_DP32(ctrl, CXL_HDM_DECODER0_CTRL, COMMIT, 0); > > ctrl = FIELD_DP32(ctrl, CXL_HDM_DECODER0_CTRL, ERR, 0); > > ctrl = FIELD_DP32(ctrl, CXL_HDM_DECODER0_CTRL, COMMITTED, 1); > > > > stl_le_p(cache_mem + R_CXL_HDM_DECODER0_CTRL, ctrl); > > } > > > > +static void hdm_decoder_uncommit(CXLType3Dev *ct3d, int which) > > +{ > > + ComponentRegisters *cregs = &ct3d->cxl_cstate.crb; > > + uint32_t *cache_mem = cregs->cache_mem_registers; > > + uint32_t ctrl; > > + > > + assert(which == 0); > > + > > + ctrl = ldl_le_p(cache_mem + R_CXL_HDM_DECODER0_CTRL); > > + > > + ctrl = FIELD_DP32(ctrl, CXL_HDM_DECODER0_CTRL, ERR, 0); > > + ctrl = FIELD_DP32(ctrl, CXL_HDM_DECODER0_CTRL, COMMITTED, 0); > > + > > + stl_le_p(cache_mem + R_CXL_HDM_DECODER0_CTRL, ctrl); > > +} > > + > > static int ct3d_qmp_uncor_err_to_cxl(CxlUncorErrorType qmp_err) > > { > > switch (qmp_err) { > > @@ -395,6 +410,7 @@ static void ct3d_reg_write(void *opaque, hwaddr offset, > > uint64_t value, > > CXLType3Dev *ct3d = container_of(cxl_cstate, CXLType3Dev, cxl_cstate); > > uint32_t *cache_mem = cregs->cache_mem_registers; > > bool should_commit = false; > > + bool should_uncommit = false; > > int which_hdm = -1; > > > > assert(size == 4); > > @@ -403,6 +419,7 @@ static void ct3d_reg_write(void *opaque, hwaddr offset, > > uint64_t value, > > switch (offset) { > > case A_CXL_HDM_DECODER0_CTRL: > > should_commit = FIELD_EX32(value, CXL_HDM_DECODER0_CTRL, COMMIT); > > + should_uncommit = !should_commit; > > which_hdm = 0; > > break; > > case A_CXL_RAS_UNC_ERR_STATUS: > > @@ -489,6 +506,8 @@ static void ct3d_reg_write(void *opaque, hwaddr offset, > > uint64_t value, > > stl_le_p((uint8_t *)cache_mem + offset, value); > > if (should_commit) { > > hdm_decoder_commit(ct3d, which_hdm); > > + } else if (should_uncommit) { > > + hdm_decoder_uncommit(ct3d, which_hdm); > > } > > } > > > > -- > > 2.37.2 > >
