From 9c57cde0dcbd0f76f649d152b83a2b9316277b22 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Thu, 21 Jul 2022 17:19:12 -0700 Subject: cxl/hdm: Enumerate allocated DPA In preparation for provisioning CXL regions, add accounting for the DPA space consumed by existing regions / decoders. Recall, a CXL region is a memory range comprised from one or more endpoint devices contributing a mapping of their DPA into HPA space through a decoder. Record the DPA ranges covered by committed decoders at initial probe of endpoint ports relative to a per-device resource tree of the DPA type (pmem or volatile-ram). The cxl_dpa_rwsem semaphore is introduced to globally synchronize DPA state across all endpoints and their decoders at once. The vast majority of DPA operations are reads as region creation is expected to be as rare as disk partitioning and volume creation. The device_lock() for this synchronization is specifically avoided for concern of entangling with sysfs attribute removal. Co-developed-by: Ben Widawsky Signed-off-by: Ben Widawsky Reviewed-by: Jonathan Cameron Link: https://lore.kernel.org/r/165784327682.1758207.7914919426043855876.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams --- drivers/cxl/core/hdm.c | 145 +++++++++++++++++++++++++++++++++++++++++++++---- drivers/cxl/cxl.h | 2 + drivers/cxl/cxlmem.h | 13 +++++ 3 files changed, 149 insertions(+), 11 deletions(-) (limited to 'drivers/cxl') diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c index 650363d5272f..47e3af440b3d 100644 --- a/drivers/cxl/core/hdm.c +++ b/drivers/cxl/core/hdm.c @@ -153,10 +153,107 @@ void cxl_dpa_debug(struct seq_file *file, struct cxl_dev_state *cxlds) } EXPORT_SYMBOL_NS_GPL(cxl_dpa_debug, CXL); +/* + * Must be called in a context that synchronizes against this decoder's + * port ->remove() callback (like an endpoint decoder sysfs attribute) + */ +static void __cxl_dpa_release(struct cxl_endpoint_decoder *cxled) +{ + struct cxl_memdev *cxlmd = cxled_to_memdev(cxled); + struct cxl_dev_state *cxlds = cxlmd->cxlds; + struct resource *res = cxled->dpa_res; + resource_size_t skip_start; + + lockdep_assert_held_write(&cxl_dpa_rwsem); + + /* save @skip_start, before @res is released */ + skip_start = res->start - cxled->skip; + __release_region(&cxlds->dpa_res, res->start, resource_size(res)); + if (cxled->skip) + __release_region(&cxlds->dpa_res, skip_start, cxled->skip); + cxled->skip = 0; + cxled->dpa_res = NULL; +} + +static void cxl_dpa_release(void *cxled) +{ + down_write(&cxl_dpa_rwsem); + __cxl_dpa_release(cxled); + up_write(&cxl_dpa_rwsem); +} + +static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled, + resource_size_t base, resource_size_t len, + resource_size_t skipped) +{ + struct cxl_memdev *cxlmd = cxled_to_memdev(cxled); + struct cxl_port *port = cxled_to_port(cxled); + struct cxl_dev_state *cxlds = cxlmd->cxlds; + struct device *dev = &port->dev; + struct resource *res; + + lockdep_assert_held_write(&cxl_dpa_rwsem); + + if (!len) + return 0; + + if (cxled->dpa_res) { + dev_dbg(dev, "decoder%d.%d: existing allocation %pr assigned\n", + port->id, cxled->cxld.id, cxled->dpa_res); + return -EBUSY; + } + + if (skipped) { + res = __request_region(&cxlds->dpa_res, base - skipped, skipped, + dev_name(&cxled->cxld.dev), 0); + if (!res) { + dev_dbg(dev, + "decoder%d.%d: failed to reserve skipped space\n", + port->id, cxled->cxld.id); + return -EBUSY; + } + } + res = __request_region(&cxlds->dpa_res, base, len, + dev_name(&cxled->cxld.dev), 0); + if (!res) { + dev_dbg(dev, "decoder%d.%d: failed to reserve allocation\n", + port->id, cxled->cxld.id); + if (skipped) + __release_region(&cxlds->dpa_res, base - skipped, + skipped); + return -EBUSY; + } + cxled->dpa_res = res; + cxled->skip = skipped; + + return 0; +} + +static int devm_cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled, + resource_size_t base, resource_size_t len, + resource_size_t skipped) +{ + struct cxl_port *port = cxled_to_port(cxled); + int rc; + + down_write(&cxl_dpa_rwsem); + rc = __cxl_dpa_reserve(cxled, base, len, skipped); + up_write(&cxl_dpa_rwsem); + + if (rc) + return rc; + + return devm_add_action_or_reset(&port->dev, cxl_dpa_release, cxled); +} + static int init_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld, - int *target_map, void __iomem *hdm, int which) + int *target_map, void __iomem *hdm, int which, + u64 *dpa_base) { - u64 size, base; + struct cxl_endpoint_decoder *cxled = NULL; + u64 size, base, skip, dpa_size; + bool committed; + u32 remainder; int i, rc; u32 ctrl; union { @@ -164,11 +261,15 @@ static int init_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld, unsigned char target_id[8]; } target_list; + if (is_endpoint_decoder(&cxld->dev)) + cxled = to_cxl_endpoint_decoder(&cxld->dev); + ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(which)); base = ioread64_hi_lo(hdm + CXL_HDM_DECODER0_BASE_LOW_OFFSET(which)); size = ioread64_hi_lo(hdm + CXL_HDM_DECODER0_SIZE_LOW_OFFSET(which)); + committed = !!(ctrl & CXL_HDM_DECODER0_CTRL_COMMITTED); - if (!(ctrl & CXL_HDM_DECODER0_CTRL_COMMITTED)) + if (!committed) size = 0; if (base == U64_MAX || size == U64_MAX) { dev_warn(&port->dev, "decoder%d.%d: Invalid resource range\n", @@ -181,8 +282,8 @@ static int init_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld, .end = base + size - 1, }; - /* switch decoders are always enabled if committed */ - if (ctrl & CXL_HDM_DECODER0_CTRL_COMMITTED) { + /* decoders are enabled if committed */ + if (committed) { cxld->flags |= CXL_DECODER_F_ENABLE; if (ctrl & CXL_HDM_DECODER0_CTRL_LOCK) cxld->flags |= CXL_DECODER_F_LOCK; @@ -211,14 +312,35 @@ static int init_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld, if (rc) return rc; - if (is_endpoint_decoder(&cxld->dev)) + if (!cxled) { + target_list.value = + ioread64_hi_lo(hdm + CXL_HDM_DECODER0_TL_LOW(which)); + for (i = 0; i < cxld->interleave_ways; i++) + target_map[i] = target_list.target_id[i]; + return 0; + } - target_list.value = - ioread64_hi_lo(hdm + CXL_HDM_DECODER0_TL_LOW(which)); - for (i = 0; i < cxld->interleave_ways; i++) - target_map[i] = target_list.target_id[i]; + if (!committed) + return 0; + dpa_size = div_u64_rem(size, cxld->interleave_ways, &remainder); + if (remainder) { + dev_err(&port->dev, + "decoder%d.%d: invalid committed configuration size: %#llx ways: %d\n", + port->id, cxld->id, size, cxld->interleave_ways); + return -ENXIO; + } + skip = ioread64_hi_lo(hdm + CXL_HDM_DECODER0_SKIP_LOW(which)); + rc = devm_cxl_dpa_reserve(cxled, *dpa_base + skip, dpa_size, skip); + if (rc) { + dev_err(&port->dev, + "decoder%d.%d: Failed to reserve DPA range %#llx - %#llx\n (%d)", + port->id, cxld->id, *dpa_base, + *dpa_base + dpa_size + skip - 1, rc); + return rc; + } + *dpa_base += dpa_size + skip; return 0; } @@ -231,6 +353,7 @@ int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm) void __iomem *hdm = cxlhdm->regs.hdm_decoder; struct cxl_port *port = cxlhdm->port; int i, committed; + u64 dpa_base = 0; u32 ctrl; /* @@ -277,7 +400,7 @@ int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm) cxld = &cxlsd->cxld; } - rc = init_hdm_decoder(port, cxld, target_map, hdm, i); + rc = init_hdm_decoder(port, cxld, target_map, hdm, i, &dpa_base); if (rc) { put_device(&cxld->dev); return rc; diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index e0b1e2e4dfee..5fe8b59a0b18 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -56,6 +56,8 @@ #define CXL_HDM_DECODER0_CTRL_TYPE BIT(12) #define CXL_HDM_DECODER0_TL_LOW(i) (0x20 * (i) + 0x24) #define CXL_HDM_DECODER0_TL_HIGH(i) (0x20 * (i) + 0x28) +#define CXL_HDM_DECODER0_SKIP_LOW(i) CXL_HDM_DECODER0_TL_LOW(i) +#define CXL_HDM_DECODER0_SKIP_HIGH(i) CXL_HDM_DECODER0_TL_HIGH(i) static inline int cxl_hdm_decoder_count(u32 cap_hdr) { diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h index bfa2eaf649a9..ed731124fa10 100644 --- a/drivers/cxl/cxlmem.h +++ b/drivers/cxl/cxlmem.h @@ -50,6 +50,19 @@ static inline struct cxl_memdev *to_cxl_memdev(struct device *dev) return container_of(dev, struct cxl_memdev, dev); } +static inline struct cxl_port *cxled_to_port(struct cxl_endpoint_decoder *cxled) +{ + return to_cxl_port(cxled->cxld.dev.parent); +} + +static inline struct cxl_memdev * +cxled_to_memdev(struct cxl_endpoint_decoder *cxled) +{ + struct cxl_port *port = to_cxl_port(cxled->cxld.dev.parent); + + return to_cxl_memdev(port->uport); +} + bool is_cxl_memdev(struct device *dev); static inline bool is_cxl_endpoint(struct cxl_port *port) { -- cgit v1.2.3