SW cannot write the read-only(RO) bits of a register and write-only(WO) bits of a register return 0 when read.
Added ro_mask[] for each register that defines which bits in that register are RO. When writing to a register, the RO-bits are not updated. When reading a register, clear the WO bits and return the updated value. Tested the registers PHB_DMA_SYNC, PHB_PCIE_HOTPLUG_STATUS, PHB_PCIE_LMR, PHB_PCIE_DLP_TRWCTL, PHB_LEM_ERROR_AND_MASK and PHB_LEM_ERROR_OR_MASK by writing all 1's and reading back the value. The WO bits in these registers should read back as 0. Signed-off-by: Saif Abrar <[email protected]> Reviewed-by: Cédric Le Goater <[email protected]> --- v1 -> v2: New PnvPHB4Class to hold each register's RO mask. hw/pci-host/pnv_phb4.c | 78 ++++++++++++++++++++++++++--- include/hw/pci-host/pnv_phb4.h | 13 ++++- include/hw/pci-host/pnv_phb4_regs.h | 20 ++++++-- tests/qtest/pnv-phb4-test.c | 60 +++++++++++++++++++++- 4 files changed, 157 insertions(+), 14 deletions(-) diff --git a/hw/pci-host/pnv_phb4.c b/hw/pci-host/pnv_phb4.c index 70f5af21fa..48caba9e79 100644 --- a/hw/pci-host/pnv_phb4.c +++ b/hw/pci-host/pnv_phb4.c @@ -707,6 +707,11 @@ static void pnv_phb4_reg_write(void *opaque, hwaddr off, uint64_t val, return; } + /* Update 'val' according to the register's RO-mask */ + PnvPHB4Class *k = PNV_PHB4_GET_CLASS(phb); + val = (phb->regs[off >> 3] & k->ro_mask[off >> 3]) | + (val & ~(k->ro_mask[off >> 3])); + /* Record whether it changed */ changed = phb->regs[off >> 3] != val; @@ -781,7 +786,7 @@ static void pnv_phb4_reg_write(void *opaque, hwaddr off, uint64_t val, case PHB_TCE_TAG_ENABLE: case PHB_INT_NOTIFY_ADDR: case PHB_INT_NOTIFY_INDEX: - case PHB_DMARD_SYNC: + case PHB_DMA_SYNC: break; /* Noise on anything else */ @@ -819,7 +824,7 @@ static uint64_t pnv_phb4_reg_read(void *opaque, hwaddr off, unsigned size) case PHB_VERSION: return PNV_PHB4_PEC_GET_CLASS(phb->pec)->version; - /* Read-only */ + /* Read-only */ case PHB_PHB4_GEN_CAP: return 0xe4b8000000000000ull; case PHB_PHB4_TCE_CAP: @@ -829,18 +834,49 @@ static uint64_t pnv_phb4_reg_read(void *opaque, hwaddr off, unsigned size) case PHB_PHB4_EEH_CAP: return phb->big_phb ? 0x2000000000000000ull : 0x1000000000000000ull; + /* Write-only, read will return zeros */ + case PHB_LEM_ERROR_AND_MASK: + case PHB_LEM_ERROR_OR_MASK: + return 0; + case PHB_PCIE_DLP_TRWCTL: + val &= ~PHB_PCIE_DLP_TRWCTL_WREN; + return val; /* IODA table accesses */ case PHB_IODA_DATA0: return pnv_phb4_ioda_read(phb); + /* + * DMA sync: make it look like it's complete, + * clear write-only read/write start sync bits. + */ + case PHB_DMA_SYNC: + val = PHB_DMA_SYNC_RD_COMPLETE | + ~(PHB_DMA_SYNC_RD_START | PHB_DMA_SYNC_WR_START); + return val; + + /* + * PCI-E Stack registers + */ + case PHB_PCIE_SCR: + val |= PHB_PCIE_SCR_PLW_X16; /* RO bit */ + break; + /* Link training always appears trained */ case PHB_PCIE_DLP_TRAIN_CTL: /* TODO: Do something sensible with speed ? */ - return PHB_PCIE_DLP_INBAND_PRESENCE | PHB_PCIE_DLP_TL_LINKACT; + val |= PHB_PCIE_DLP_INBAND_PRESENCE | PHB_PCIE_DLP_TL_LINKACT; + return val; + + case PHB_PCIE_HOTPLUG_STATUS: + /* Clear write-only bit */ + val &= ~PHB_PCIE_HPSTAT_RESAMPLE; + return val; - /* DMA read sync: make it look like it's complete */ - case PHB_DMARD_SYNC: - return PHB_DMARD_SYNC_COMPLETE; + /* Link Management Register */ + case PHB_PCIE_LMR: + /* These write-only bits always read as 0 */ + val &= ~(PHB_PCIE_LMR_CHANGELW | PHB_PCIE_LMR_RETRAINLINK); + return val; /* Silent simple reads */ case PHB_LSI_SOURCE_ID: @@ -1685,6 +1721,32 @@ static PCIIOMMUOps pnv_phb4_iommu_ops = { .get_address_space = pnv_phb4_dma_iommu, }; +static void pnv_phb4_ro_mask_init(PnvPHB4 *phb) +{ + PnvPHB4Class *phb4c = PNV_PHB4_GET_CLASS(phb); + + /* + * Set register specific RO-masks + */ + + /* PBL - Error Injection Register (0x1910) */ + phb4c->ro_mask[PHB_PBL_ERR_INJECT >> 3] = + PPC_BITMASK(0, 23) | PPC_BITMASK(28, 35) | PPC_BIT(38) | PPC_BIT(46) | + PPC_BITMASK(49, 51) | PPC_BITMASK(55, 63); + + /* Reserved bits[60:63] */ + phb4c->ro_mask[PHB_TXE_ERR_LEM_ENABLE >> 3] = + phb4c->ro_mask[PHB_TXE_ERR_AIB_FENCE_ENABLE >> 3] = PPC_BITMASK(60, 63); + /* Reserved bits[36:63] */ + phb4c->ro_mask[PHB_RXE_TCE_ERR_LEM_ENABLE >> 3] = + phb4c->ro_mask[PHB_RXE_TCE_ERR_AIB_FENCE_ENABLE >> 3] = PPC_BITMASK(36, 63); + /* Reserved bits[40:63] */ + phb4c->ro_mask[PHB_ERR_LEM_ENABLE >> 3] = + phb4c->ro_mask[PHB_ERR_AIB_FENCE_ENABLE >> 3] = PPC_BITMASK(40, 63); + + /* TODO: Add more RO-masks as regs are implemented in the model */ +} + static void pnv_phb4_err_reg_reset(PnvPHB4 *phb) { STICKY_RST(PHB_ERR_STATUS, 0, PPC_BITMASK(0, 33)); @@ -1743,6 +1805,7 @@ static void pnv_phb4_reset(Object *obj, ResetType type) pnv_phb4_err_reg_reset(phb); pnv_phb4_pcie_stack_reg_reset(phb); pnv_phb4_regb_err_reg_reset(phb); + phb->regs[PHB_PCIE_CRESET >> 3] = 0xE000000000000000; } static void pnv_phb4_instance_init(Object *obj) @@ -1753,6 +1816,9 @@ static void pnv_phb4_instance_init(Object *obj) /* XIVE interrupt source object */ object_initialize_child(obj, "source", &phb->xsrc, TYPE_XIVE_SOURCE); + + /* Initialize RO-mask of registers */ + pnv_phb4_ro_mask_init(phb); } void pnv_phb4_bus_init(DeviceState *dev, PnvPHB4 *phb) diff --git a/include/hw/pci-host/pnv_phb4.h b/include/hw/pci-host/pnv_phb4.h index 47a5c3edf5..bea0684724 100644 --- a/include/hw/pci-host/pnv_phb4.h +++ b/include/hw/pci-host/pnv_phb4.h @@ -19,7 +19,7 @@ #define TYPE_PNV_PHB4 "pnv-phb4" -OBJECT_DECLARE_SIMPLE_TYPE(PnvPHB4, PNV_PHB4) +OBJECT_DECLARE_TYPE(PnvPHB4, PnvPHB4Class, PNV_PHB4) typedef struct PnvPhb4PecStack PnvPhb4PecStack; @@ -156,6 +156,17 @@ struct PnvPHB4 { QLIST_HEAD(, PnvPhb4DMASpace) dma_spaces; }; +typedef struct PnvPHB4Class { + DeviceClass parent_class; + + /* + * Read-only bitmask for registers + * Bit value: 1 => RO bit + * 0 => RW bit + */ + uint64_t ro_mask[PNV_PHB4_NUM_REGS]; +} PnvPHB4Class; + void pnv_phb4_pic_print_info(PnvPHB4 *phb, GString *buf); int pnv_phb4_pec_get_phb_id(PnvPhb4PecState *pec, int stack_index); PnvPhb4PecState *pnv_pec_add_phb(PnvChip *chip, PnvPHB *phb, Error **errp); diff --git a/include/hw/pci-host/pnv_phb4_regs.h b/include/hw/pci-host/pnv_phb4_regs.h index df5e86d29a..dfd0e01d1e 100644 --- a/include/hw/pci-host/pnv_phb4_regs.h +++ b/include/hw/pci-host/pnv_phb4_regs.h @@ -180,9 +180,11 @@ #define PHB_M64_AOMASK 0x1d0 #define PHB_M64_UPPER_BITS 0x1f0 #define PHB_NXLATE_PREFIX 0x1f8 -#define PHB_DMARD_SYNC 0x200 -#define PHB_DMARD_SYNC_START PPC_BIT(0) -#define PHB_DMARD_SYNC_COMPLETE PPC_BIT(1) +#define PHB_DMA_SYNC 0x200 +#define PHB_DMA_SYNC_RD_START PPC_BIT(0) +#define PHB_DMA_SYNC_RD_COMPLETE PPC_BIT(1) +#define PHB_DMA_SYNC_WR_START PPC_BIT(2) +#define PHB_DMA_SYNC_WR_COMPLETE PPC_BIT(3) #define PHB_RTC_INVALIDATE 0x208 #define PHB_RTC_INVALIDATE_ALL PPC_BIT(0) #define PHB_RTC_INVALIDATE_RID PPC_BITMASK(16, 31) @@ -370,6 +372,7 @@ #define P32_CAP 0x228 #define P32_CTL 0x22C #define P32_STAT 0x230 + /* PHB4 REGB registers */ /* PBL core */ @@ -395,8 +398,8 @@ #define PHB_PCIE_SCR 0x1A00 #define PHB_PCIE_SCR_SLOT_CAP PPC_BIT(15) #define PHB_PCIE_SCR_MAXLINKSPEED PPC_BITMASK(32, 35) +#define PHB_PCIE_SCR_PLW_X16 PPC_BIT(41) /* x16 */ #define PHB_PCIE_BNR 0x1A08 - #define PHB_PCIE_CRESET 0x1A10 #define PHB_PCIE_CRESET_CFG_CORE PPC_BIT(0) #define PHB_PCIE_CRESET_TLDLP PPC_BIT(1) @@ -405,7 +408,14 @@ #define PHB_PCIE_CRESET_PIPE_N PPC_BIT(4) #define PHB_PCIE_CRESET_REFCLK_N PPC_BIT(8) #define PHB_PCIE_HOTPLUG_STATUS 0x1A20 +#define PHB_PCIE_HPSTAT_SIMDIAG PPC_BIT(3) +#define PHB_PCIE_HPSTAT_RESAMPLE PPC_BIT(9) #define PHB_PCIE_HPSTAT_PRESENCE PPC_BIT(10) +#define PHB_PCIE_HPSTAT_LINKACTIVE PPC_BIT(12) +#define PHB_PCIE_LMR 0x1A30 +#define PHB_PCIE_LMR_CHANGELW PPC_BIT(0) +#define PHB_PCIE_LMR_RETRAINLINK PPC_BIT(1) +#define PHB_PCIE_LMR_LINKACTIVE PPC_BIT(8) #define PHB_PCIE_DLP_TRAIN_CTL 0x1A40 #define PHB_PCIE_DLP_LINK_WIDTH PPC_BITMASK(30, 35) @@ -433,7 +443,7 @@ #define PHB_PCIE_DLP_TRWCTL 0x1A80 #define PHB_PCIE_DLP_TRWCTL_EN PPC_BIT(0) - +#define PHB_PCIE_DLP_TRWCTL_WREN PPC_BIT(1) #define PHB_PCIE_DLP_ERRLOG1 0x1AA0 #define PHB_PCIE_DLP_ERRLOG2 0x1AA8 #define PHB_PCIE_DLP_ERR_STATUS 0x1AB0 diff --git a/tests/qtest/pnv-phb4-test.c b/tests/qtest/pnv-phb4-test.c index f186efaf0d..841306ae3f 100644 --- a/tests/qtest/pnv-phb4-test.c +++ b/tests/qtest/pnv-phb4-test.c @@ -73,7 +73,8 @@ static void phb4_sticky_rst_test(QTestState *qts) * Sticky reset test of PHB_PBL_ERR_STATUS. * * Write all 1's to reg PHB_PBL_ERR_INJECT. - * Updated value will be copied to reg PHB_PBL_ERR_STATUS. + * RO-only bits will not be written and + * updated value will be copied to reg PHB_PBL_ERR_STATUS. * * Reset PBL core by setting PHB_PCIE_CRESET_PBL in reg PHB_PCIE_CRESET. * Verify the sticky bits are still set. @@ -81,7 +82,59 @@ static void phb4_sticky_rst_test(QTestState *qts) phb4_xscom_write(PHB_PBL_ERR_INJECT, PPC_BITMASK(0, 63)); phb4_xscom_write(PHB_PCIE_CRESET, PHB_PCIE_CRESET_PBL); /*Reset*/ val = phb4_xscom_read(PHB_PBL_ERR_STATUS); - g_assert_cmpuint(val, ==, (PPC_BITMASK(0, 9) | PPC_BITMASK(12, 63))); + g_assert_cmpuint(val, ==, 0xF00DFD8E00); +} + +/* Check that write-only bits/regs return 0 when read */ +static void phb4_writeonly_read_test(QTestState *qts) +{ + uint64_t val; + + /* + * Set all bits of PHB_DMA_SYNC, + * bits 0 and 2 are write-only and should be read as 0. + */ + phb4_xscom_write(PHB_DMA_SYNC, PPC_BITMASK(0, 63)); + val = phb4_xscom_read(PHB_DMA_SYNC); + g_assert_cmpuint(val & PPC_BIT(0), ==, 0x0); + g_assert_cmpuint(val & PPC_BIT(2), ==, 0x0); + + /* + * Set all bits of PHB_PCIE_HOTPLUG_STATUS, + * bit 9 is write-only and should be read as 0. + */ + phb4_xscom_write(PHB_PCIE_HOTPLUG_STATUS, PPC_BITMASK(0, 63)); + val = phb4_xscom_read(PHB_PCIE_HOTPLUG_STATUS); + g_assert_cmpuint(val & PPC_BIT(9), ==, 0x0); + + /* + * Set all bits of PHB_PCIE_LMR, + * bits 0 and 1 are write-only and should be read as 0. + */ + phb4_xscom_write(PHB_PCIE_LMR, PPC_BITMASK(0, 63)); + val = phb4_xscom_read(PHB_PCIE_LMR); + g_assert_cmpuint(val & PPC_BIT(0), ==, 0x0); + g_assert_cmpuint(val & PPC_BIT(1), ==, 0x0); + + /* + * Set all bits of PHB_PCIE_DLP_TRWCTL, + * write-only bit-1 should be read as 0. + */ + phb4_xscom_write(PHB_PCIE_DLP_TRWCTL, PPC_BITMASK(0, 63)); + val = phb4_xscom_read(PHB_PCIE_DLP_TRWCTL); + g_assert_cmpuint(val & PPC_BIT(1), ==, 0x0); + + /* + * Set all bits of PHB_LEM_ERROR_AND_MASK, PHB_LEM_ERROR_OR_MASK, + * both regs are write-only and should be read as 0. + */ + phb4_xscom_write(PHB_LEM_ERROR_AND_MASK, PPC_BITMASK(0, 63)); + val = phb4_xscom_read(PHB_LEM_ERROR_AND_MASK); + g_assert_cmpuint(val, ==, 0x0); + + phb4_xscom_write(PHB_LEM_ERROR_OR_MASK, PPC_BITMASK(0, 63)); + val = phb4_xscom_read(PHB_LEM_ERROR_OR_MASK); + g_assert_cmpuint(val, ==, 0x0); } static void phb4_tests(void) @@ -96,6 +149,9 @@ static void phb4_tests(void) /* Check sticky reset of a register */ phb4_sticky_rst_test(qts); + /* Check write-only logic */ + phb4_writeonly_read_test(qts); + qtest_quit(qts); } -- 2.47.3
