From aaa675f07e781e248fcf169ce9a917b48bc2cc9b Mon Sep 17 00:00:00 2001 From: Brian Norris Date: Fri, 28 Jul 2023 12:06:23 +0200 Subject: [PATCH 3/3] firmware: qcom: scm: fix SCM cold boot address This effectively reverts upstream Linux commit 13e77747800e ("firmware: qcom: scm: Use atomic SCM for cold boot"), because Google WiFi boot firmwares don't support the atomic variant. This fixes SMP support for Google WiFi. Signed-off-by: Brian Norris --- drivers/firmware/qcom_scm-legacy.c | 62 +++++++++++++++++++++++++----- drivers/firmware/qcom_scm.c | 11 ++++++ 2 files changed, 63 insertions(+), 10 deletions(-) --- a/drivers/firmware/qcom_scm-legacy.c +++ b/drivers/firmware/qcom_scm-legacy.c @@ -13,6 +13,9 @@ #include #include +#include +#include + #include "qcom_scm.h" static DEFINE_MUTEX(qcom_scm_lock); @@ -117,6 +120,25 @@ static void __scm_legacy_do(const struct } while (res->a0 == QCOM_SCM_INTERRUPTED); } +static void qcom_scm_inv_range(unsigned long start, unsigned long end) +{ + u32 cacheline_size, ctr; + + asm volatile("mrc p15, 0, %0, c0, c0, 1" : "=r" (ctr)); + cacheline_size = 4 << ((ctr >> 16) & 0xf); + + start = round_down(start, cacheline_size); + end = round_up(end, cacheline_size); + outer_inv_range(start, end); + while (start < end) { + asm ("mcr p15, 0, %0, c7, c6, 1" : : "r" (start) + : "memory"); + start += cacheline_size; + } + dsb(); + isb(); +} + /** * scm_legacy_call() - Sends a command to the SCM and waits for the command to * finish processing. @@ -163,10 +185,16 @@ int scm_legacy_call(struct device *dev, rsp = scm_legacy_command_to_response(cmd); - cmd_phys = dma_map_single(dev, cmd, alloc_len, DMA_TO_DEVICE); - if (dma_mapping_error(dev, cmd_phys)) { - kfree(cmd); - return -ENOMEM; + if (dev) { + cmd_phys = dma_map_single(dev, cmd, alloc_len, DMA_TO_DEVICE); + if (dma_mapping_error(dev, cmd_phys)) { + kfree(cmd); + return -ENOMEM; + } + } else { + cmd_phys = virt_to_phys(cmd); + __cpuc_flush_dcache_area(cmd, alloc_len); + outer_flush_range(cmd_phys, cmd_phys + alloc_len); } smc.args[0] = 1; @@ -182,13 +210,26 @@ int scm_legacy_call(struct device *dev, goto out; do { - dma_sync_single_for_cpu(dev, cmd_phys + sizeof(*cmd) + cmd_len, - sizeof(*rsp), DMA_FROM_DEVICE); + if (dev) { + dma_sync_single_for_cpu(dev, cmd_phys + sizeof(*cmd) + + cmd_len, sizeof(*rsp), + DMA_FROM_DEVICE); + } else { + unsigned long start = (uintptr_t)cmd + sizeof(*cmd) + + cmd_len; + qcom_scm_inv_range(start, start + sizeof(*rsp)); + } } while (!rsp->is_complete); - dma_sync_single_for_cpu(dev, cmd_phys + sizeof(*cmd) + cmd_len + - le32_to_cpu(rsp->buf_offset), - resp_len, DMA_FROM_DEVICE); + if (dev) { + dma_sync_single_for_cpu(dev, cmd_phys + sizeof(*cmd) + cmd_len + + le32_to_cpu(rsp->buf_offset), + resp_len, DMA_FROM_DEVICE); + } else { + unsigned long start = (uintptr_t)cmd + sizeof(*cmd) + cmd_len + + le32_to_cpu(rsp->buf_offset); + qcom_scm_inv_range(start, start + resp_len); + } if (res) { res_buf = scm_legacy_get_response_buffer(rsp); @@ -196,7 +237,8 @@ int scm_legacy_call(struct device *dev, res->result[i] = le32_to_cpu(res_buf[i]); } out: - dma_unmap_single(dev, cmd_phys, alloc_len, DMA_TO_DEVICE); + if (dev) + dma_unmap_single(dev, cmd_phys, alloc_len, DMA_TO_DEVICE); kfree(cmd); return ret; } --- a/drivers/firmware/qcom_scm.c +++ b/drivers/firmware/qcom_scm.c @@ -312,6 +312,17 @@ static int qcom_scm_set_boot_addr(void * desc.args[0] = flags; desc.args[1] = virt_to_phys(entry); + /* + * Factory firmware doesn't support the atomic variant. Non-atomic SCMs + * require ugly DMA invalidation support that was dropped upstream a + * while ago. For more info, see: + * + * [RFC] qcom_scm: IPQ4019 firmware does not support atomic API? + * https://lore.kernel.org/linux-arm-msm/20200913201608.GA3162100@bDebian/ + */ + if (of_machine_is_compatible("google,wifi")) + return qcom_scm_call(__scm ? __scm->dev : NULL, &desc, NULL); + return qcom_scm_call_atomic(__scm ? __scm->dev : NULL, &desc, NULL); }